HO CHI MINH CITY UNIVERSITY OF
TECHNOLOGY AND EDUCATION
FACULTY OF CHEMICAL AND FOOD TECHNOLOGY
SUBJECT: TEA, COFFEE AND CHOCOLATE PRODUCTION
HOMEWORK 1-10
Instructor: Assoc. Prof. Le Hong Phu
Student: VU THI THAO TRANG
ID: 20116002
HO CHI MINH CITY, NOVEMBER 2021
Acknowledgments
The thing I want to say is thank you, Mr. Phú and Ms. Nhi. Thank you for your
willingness to teach and help me during this time. There are more and more things that I can
learn and have to learn in the future. I hope that I can see you in the near future. Wish all best
for you!
Contents
HOMEWORK 1 .......................................................................................................................... 4
HOMEWORK 2 .........................................................................................................................12
HOMEWORK 3 .........................................................................................................................17
HOMEWORK 4 .........................................................................................................................20
HOMEWORK 5 .........................................................................................................................23
HOMEWORK 6 .........................................................................................................................27
HOMEWORK 7 .........................................................................................................................32
HOMEWORK 8 .........................................................................................................................36
HOMEWORK 9 .........................................................................................................................40
HOMEWORK 10 .......................................................................................................................48
HOMEWORK 1
Question: What did you like most in the last lesson?
Pick up a lot of stuff in my tiny box, but in the end, I never open the box
again to view and look at it, this was one of the teacher's remarks that impressed
me in class on September 10. A student who excels academically frequently
commits the grave error of knowing too much and, as a result, is unable to be
competent or professional at anything. I get a lot of new knowledge every day,
and the amount of homework, exams, and projects I have to do make my head
spin.
Like other young people, I strive to study as much as I can as a member of
the active Gen Z. I am now a third-year student as a result of that method of
learning, but I still have gaps in my professional knowledge and am unable to
connect them. After reading your remarks, I understand that I am putting in
virtual efforts, keeping myself occupied but not fully assimilating the selflearned knowledge.
But now I believe that instead of trying to design a beautiful scoreboard
with little thought, I should concentrate on a subject that I love and am
enthusiastic about. Perhaps among the majors that I am studying, I should find
the subject that I am interested in and then start to learn more deeply. Then,
when you graduate, you can bring with your in-depth knowledge and skills to
meet the needs of employers.
Everyone is only 24 hours a day, and can't keep focusing on useless things.
From now on, I will learn to filter the items I see fit into my inventory and take
time during the week to seriously look at each item I have put in the box before
it gets old and damaged.
Question: Find out my three favorite types of coffee in the last lesson
Three favorite types of coffee are Weasel Bascd Coffee, Italian coffee and
French coffee.
1. Weasel Coffee Weasel coffee is a unique coffee with an odd flavor that
combines mustiness, syrup, and chocolate. Despite having a limited
manufacturing volume, coffee is quite costly.
a. History: Weasel coffee originates in Indonesia. When the Dutch first
began farming on the islands of Java and Sumatra in the early 18th century, they
came upon a unique species known as the Asian Palm Civet that could consume
both plants and animals. They were then cultivating coffee plants in sizable
farms to send back to their nation for usage and commerce.
Of course, the owners of the coffee trees do not permit the local farmers
who look after them to eat haphazardly. Then one day, they discovered that the
ferrets also eat the coffee fruit, but the coffee beans are still in their shape.
The farmers were allowed to collect the beans and they decided to clean
them and roast them to make their coffee drinks. The taste of that coffee was
delicious and quickly became known to the owners of Dutch plantations. Since
then weasel coffee began to be known and widely developed and due to the
specific nature of the production process, the price was extremely expensive and
was dubbed the most expensive coffee in the world.
b. Production process
Stage 1: Coffee beans are digested in the weasel's stomach. After the weasel
eats the coffee cherries, the coffee beans are affected by many enzyme-induced
processes that transform and create a new flavor. Next, the coffee beans will
follow the weasel droppings out and people will harvest them.
Stage 2: Cleaning. This is the stage to remove the coffee beans from the
ferret manure, ensuring that the beans are free of any stains or odors from the
manure.
Stage 3: Sun exposure Coffee beans, after removing weasel manure, will be
spread evenly and exposed to the sun, helping to reduce the moisture of the
beans to avoid microbial growth.
Stage 4: Separating the husks The husk will not be digested, helping the
coffee beans avoid infection when excreted. Therefore, this stage will remove
the husk and classify and evaluate the coffee beans according to different
standards before roasting.
Stage 5: Roasting coffee beans This is the stage that determines the taste
and quality of weasel coffee.
c. Market price
Weasel coffee in Trung Nguyen (updated September 14, 2022) is priced on
their website as: 250 grams- 17 million VND.
d. The reason why weasel coffee prices are high
- In the world, weasel species are only distributed in certain areas and the
amount of coffee that weasels can produce is also very little because weasels are
carnivores, so coffee is not their regular food.
- The habitat of ferrets is decreasing sharply, causing the number of mink to
decrease sharply. Meanwhile, ferrets raised for production cannot produce good
quality coffee like wild ferrets.
2. Italian Coffee
In Italy, coffee is a need for daily living and is almost considered a religion.
From Espresso to Caffé Shakerato, the menu offers a wide variety of Italian
coffees. There are also two, three, or four various ways they may be prepared. I t
must be said that Italian coffee is among the most flavorful and diverse types of
coffee.
a. Types of Italian Coffee
1. Caffè
2. Caffè Doppio (Double Espresso)
3. Cappuccino
4. Caffè Macchiato
5. Caffè Con Panna (Espresso With Whipped Cream)
6. Latte Macchiato
7. Caffè Latte
8. Caffè Ristretto
9. Caffè Shakerato 10. Caffè Ginseng
11. Caffè D’Orzo
12. Marocchino
13. Caffè Lungo (Long Espresso)
14. Caffè Americano
15. Caffè Corretto
16. Caffè Anisette (Le Marche)
17. Caffè D’un Parrinu (Sicily)
18. Bicerin (Piedmont)
19. Patavina (Veneto)
20. Moretta Di Fano (Le Marche)
21. Caffe ‘Allo Zabione (Bologna)
b. History
When the Paduan Prospero Alpino brought few bags from the East to
Venice in 1570, the history of coffee in Italy officially began. The beverage was
initially marketed at pharmacies, but due to its expensive price, it quickly gained
popularity, especially among the more affluent classes. This, however, was
insufficient justification for the failure of coffee, since the number of "coffee
shops" quickly expanded, reaching 218 in Venice in 1763.
At this point, coffee started to take on the role of beverage that most
strongly evokes the sense of community and familial bonds that are among the
fundamental principles of the Italian character.
c. Information about some of the classics of Italian coffee
- Espresso: Was invented by the Italians in 1884. In Italian, Espresso means
"express", meaning coffee can be served to customers immediately. This coffee
is brewed at very high pressure. The most standard is brewing with a machine
invented by the Italians. On the surface of the coffee, there must be a layer of
brown foam called crema, which is the standard to judge whether a cup of
Espresso is good or not.
- Cappuccino: Originates from Espresso but is somewhat more famous and
popular in many countries around the world. A cup of Cappuccino consists of
three equal parts: Espresso coffee mixed with double the amount of water
(espresso lungo), hot milk, and foamed milk. The thick milk froth on a
Cappuccino is created by stirring and frothing in a jug of fresh milk. The surface
of the foam layer is sprinkled with a little cocoa powder or cinnamon powder to
increase the aroma.
- Latte Macchiato: Is a hot drink consisting of Espresso coffee and milk,
basically like milk coffee but with more milk. The amount of caffeine in Latte
Macchiato is exceptionally low. A standard cup of coffee must consist of three
distinct layers, poured one after another without mixing. Milk is the first layer,
then milk foam - is the highest layer. Finally, the espresso is poured into the
glass through the milk foam.
3. Instant coffee
Our favorite beverage, instant coffee, is a dehydrated form that is easily
accessible and has the same fantastic flavor. Not to mention, making it is quick
and simple. Other names for instant coffee include: Granulated coffee,
Powdered coffee, and Soluble coffee.
a. History David Strang of Invercargill, New Zealand, created and patented
instant or soluble coffee in 1890. It was marketed under the trade name Strang's
Coffee.
b. Production process
Step 1. Extraction. To produce instant coffee, the soluble and volatile
contents of the beans, which provide the coffee aroma and flavor, have to be
extracted. This is done using water.
Step 2. Freeze drying. The coffee extract is frozen and cut into small
fragments, which are then dried at a low temperature under vacuum conditions.
Step 3. Spray drying. Coffee extract is sprayed into hot air, which quickly
dries the droplets and turns them into fine powder or small pieces.
Step 4. Decaffeination. In commercial processes, the decaffeination of
instant coffee almost always happens before the critical roasting process which
will determine the coffee's flavour and aroma processes.
Step 5. Byproducts. The main byproduct of the instant coffee production
process is spent coffee grounds. These grounds can be used as biomass, for
example to produce heat used in the manufacturing process.
c. Good or Bad
Instant coffee may be made without a coffee machine and is quick and
simple. It is also less expensive and has a far longer shelf life than normal
coffee. As a result, it might come in handy when you're traveling or otherwise
on the go. Compared to regular coffee, instant coffee has a little bit less caffeine
and a little bit more acrylamide, but it also has a lot of the same antioxidants. In
general, instant coffee is a wholesome, low-calorie beverage that has the same
positive effects on health as other varieties of coffee.
Question: Additives used in coffee.
1. Color improvers: These preparations have the INS designation 150a. 150c,
150d.
2. Odor enhancers: The smell of coffee is very specific and very attractive,
so perfecting the aroma of coffee is of great interest to manufacturers. People can
use ethyl alcohol (C2H5OH). Alcohol added to coffee near the end of the
roasting process will react with some organic acids available in coffee to create
esters with a pleasant aroma.
3. Substances that improve the taste of coffee: To create a strong taste for
coffee, an appropriate amount of table salt (NaCl) is added. To create a pleasant
"bitter and sweet" taste for coffee, some synthetic sweeteners can be used such as
Acesulfame potassium (INS 950), Aspartame (INS 951), Sucralose (INS 955),
and Sacarin (INS 954).
4. Coffee Thickness Enhancers: Coffee thickeners are produced using several
thickening additives such as Sodium Carboxymethyl Cellulose (INS 466),
Carrageenan (INS) 407), Aga Aga (INS 406), Gua Gum (INS 412)
HOMEWORK 2
Question 1: What are methods to demucilage?
The Amorphous Gel of mucilage around the bean consists of hemicelluloses,
pestic substances and sugars and is soluble in water. It can therefore be removed
by use of chemicals or mechanics
a. Chemicals: Fermentation involves the beans being placed in plastic
buckets or tanks and left until the mucilage has been broken down. Natural
enzymes in the mucilage and feasts bacteria in the environment work together to
break down the mucilage. The beans should be stirred occasionally and a few
beans tested by washing them in water. The beans are ready when the mucilage
can be washed off and the beans feel gritty.
b. Mechanics: Based on mechanical rubbing, this process mainly makes the
peel, flesh, and mucilage separate, and the coffee beans are cleaned. Because the
pulp and mucilage of the fruit is separated from the bean by mechanical means, it
is often left around the coffee bean and will have an adverse effect on the quality
of the coffee.
Question 2. Research pectin/cellulose, pectinase/cellulase. Clarify
Question 3: What is the coffee fermentation for?
The edogenous mucilage enzymes initiate the fermentation process, which
includes the elimination of the mucilagegenous layer clinging to the parchment.
Bacterial, fungus, and yeast fermentation then follow. Coffee tastes better after
being fermented.
Question 4. List out 3 interesting things that you have learnt in class.
I was interested in 3 things in the previous lesson including:
− Demucilage.
− Thomas Edison's quote: I have not failed. I’ve just found 10,000 ways that
won’t work.
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− Dry method.
a.
Demucilage
Demucilage means removal mucilage from coffee beans. The three main
categories of elements that make up the mucilage that surrounds coffee beans are
pectin, cellulose, and starch. It is this "mucis" that increases the time it takes to
dry the beans and, in certain situations, to dry also encourages the growth of
mold, lowering the quality of the product.
Therefore, we constantly work to encourage fermentation, which is made
possible by natural enzymes found in coffee cherries and environmental
microbes. The production of several enzymes by microorganisms (yeast,
bacteria) during fermentation plays a significant part in the reduction of mucus.
b. Thomas Edison's quote: I have not failed.
I’ve just found 10,000 ways that won’t work. Science is about doing
experiments to find the solution. You can get some direction from a theory, but it
may not always be confirmed by your findings.
Facts, not emotions, are the foundation of science. Without extensive study
and scientific advancement, we would not have the same level of information and
comprehension of our world as we do now.
Be confident and proud of your findings whether they support or refute your
idea. Making a finding through experimenting, not getting it "perfect," is the
most crucial aspect of science. Just be careful to explain how and why you
believe your hypothesis was rejected in the conclusion.
c. Dry method.
To get rid of any bruised, immature, or otherwise faulty cherries, sorting is
necessary first. The extra trash, such as soil and twigs, is often removed by hand
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using a seive because the cherries are not cleaned in the same manner as they are
in the wet process. However, cherries may be floated in a washing channel and
the surplus can be taken out in this manner if one is provided.
In the dry process, the fruit is still obscuring the beans. Only by frequently
stirring the coffee can even drying be ensured. It may take up to four weeks,
depending on the weather, for the coffee to achieve the desired moisture content
of less than 12.5% because the beans are still covered by their protective coating
of cherry. In order to make the process more efficient overall, larger farms and
plantations may think about machine drying the coffee after it has slept in the sun
for a few days.
Large coffee silos hold the cherries until they are ready to be transferred to a
mill once they have completely dried. The coffee will be hulled, sorted, and
graded in the mill; this procedure will also get rid of the fruit
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HOMEWORK 3
I liked 3 things that I learned in the last class. Includes "Every day we should
ask ourselves 3 questions", a story about dancing goats and definition of Solid State
Fermentation.
The first is about asking yourself 3 questions.
Up until now, my life has always gone by in a hurry. So I've never stopped for a
minute in my life to think if I'm stopping learning and becoming a mindless learning
machine.
Through your words, I have been practicing for myself the habit of asking
myself 3 questions early in the morning before going to school. Maybe it's a
knowledge question just received yesterday or simple questions like are you happy
today?
Honestly, when I started asking the question I was a bit funny and had a hard
time thinking about what I had to ask myself today. But 3 days later, it became
easier and I also learned a few new things and felt more energized.
I realized that by asking questions, sometimes it's just questions that sound
stupid, but it makes my thinking better and trains the critical thinking skills that I've
always been weak with.
Your statement that "There are no stupid questions" is what made me realize
that I have always been too self-conscious in voicing my opinions and thoughts.
Because only asking questions is the essence of learning, making us absorb
knowledge faster as well as remember it longer than usual.
The second is a story about dancing goats. The story is attached to the history of
coffee.
A goat herder boy named Kaldi is on a mission to herd the goats for his father.
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However, one afternoon, he did not see a trace of the return. After searching for
a while, he finally heard a beep in the distance. Kaldi ran behind the bend of the
narrow road, and immediately saw the goats.
Under the thick canopy of the rainforest, light barely penetrates, the goats are
running around, fighting with each other, legs jumping, and happily bleating. You
think they've been enchanted. But as he watched the goats, he saw one after another
munching on the smooth green leaves and red fruits of a tree he had never seen
before.
After a while the goats refused to come home with him, but none of them died.
The next day, they ran right behind the cave and ate again like yesterday. So he tried
them because he knew they wouldn't be poisonous. Legend has it that immediately
Kaldi jumped up with the goats. He sings and dances around. Poetry and music
flowed freely. Kaldi told his father about this magical plant.
Thanks to Kaldi's discovery, the strange fruit trees spread very quickly to other
regions, especially in the Middle East. The coffee cherries were shipped from
Ethiopia to the Arab regions and grown in the territory of present-day Yemen. Then,
when it spread to Turkey, they began to peel, roast and grind the coffee beans,
creating the coffee we use today. So, the history of coffee began to take shape and
expand as it is today.
The final thing is Definition of Solid-State Fermentation.
a. Definition of Solid-State Fermentation.
Solid State Fermentation (SSF) is a fermentation method used by several
industries like the pharmaceuticals, food, textile etc., to produce metabolites of
microorganisms using solid support in place of the liquid medium. It is defined as
the growth of microbes without free-flowing aqueous phase.
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The primary SSF-related feature is the resistance of microorganisms (bacterial
and fungal cells) to catabolic repression (inhibition of enzyme production) in the
presence of plentiful substrates, such as glycerol, glucose, or other carbon sources.
Because of such characteristics, this process has some advantages and
disadvantages of its own.
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HOMEWORK 4
Since I missed school last week due to illness and didn't attend the class, I
borrowed the presentation of my friends to read and draw out three things that I
liked the most out of the two presentations.
The first is the pectin layer, why to remove it and how to remove it by emzym.
The principal components of the 0.4 mm thick coating of mucus, also known as
pulp or pulpa in Spanish, which covers the coffee bean include water,
polysaccharides, sugar, proteins, lipids, minerals, and acids. The coffee bean must
be separated from this framework during the fermentation phase of wet processing,
despite the fact that it makes up 15% to 22% of the weight of the mature fruit.
It is this “slime” that will prolong the time it takes to dry the coffee beans and,
in some cases, also lead to the growth of mold, reducing the quality of the product.
So, we need remove it from coffee. There are several enzymes responsible for this.
Enzyme pectinase can Break down complex polysaccharides of plant tissues into
simpler molecules like galacturonic acids.
And hydrolyzing the α-1,4-glycoside linkage in pectin. Or enzyme cellulase can
degradation of cell wall and hydrolyze the β-1,4-glycosidic linkages of cellulose.
The second thing is how to adjust the amount of enzyme is just enough.
If you add too little enzyme and the fermentation time is not long enough, it
will not enough to hydrolyze cellulose and pectin.
But giving too much enzyme and fermentation time too long will happen
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hydrolyze both pectin, cellulose and soluble solid. We need to have actively selected
spontaneous fermentation or added commercial yeast strains to the processing to
guide the positive changes in taste. Based on experiments to determine the dose and
duration of fermentation to be able to control this process effectively.
The last one is caffeine.
Caffeine (1,3,7-trimethylxanthine) is the main alkaloid component in coffee
fruits and the source for bitter taste of coffee. Caffeine is widely found in tea, cocoa
and coffee, and is one of the widely used psychotropic drugs.
Although caffeine as pure chemical has a clearly bitter taste (it can be used as a
‘‘bitter’’ standard in basic sensory tests), it plays only a minor role in giving a bitter
tinge to the coffee beverage.
Caffeine biosynthesis takes place in the leaves and in the pericarp, the outer part
of the fruit. In aged leaves the caffeine content is lower. In the pericarp tissues, light
strongly stimulates the methylation step of caffeine synthesis. When the seed inside
the fruit starts growing, caffeine is translocated through the membranes and
accumulates in the endosperm.
The caffeine content of the coffee beans depends on species and variety, from
0.6% in Laurina up to 4% in some extreme Robustas; averages are given in Table 3.
The caffeine content in dry matter base is not affected by postharvest
processing, neither by the roasting. Although the roasting process occurs well above
sublimation temperature, during it only a small percentage of caffeine vanishes.
Caffeine content of coffee can be reduced by decaffeination. The process starts with
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a steam treatment of the green coffee to soften the tissues, followed by solvent
extraction.
Legal requirements on the caffeine content apply to decaffeinated coffee for the
final product for consumption, that is, roast and soluble coffees. The European
legislation sets a maximum residual caffeine content of 0.3% for soluble coffee; 0,1
% for roast coffee.
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HOMEWORK 5
I liked these 3 the most in last week's lesson.
First is caffeine.
Caffeine (1,3,7-trimethylxanthine) is the main alkaloid component in coffee
fruits and the source for bitter taste of coffee. Caffeine is widely found in tea, cocoa
and coffee, and is one of the widely used psychotropic drugs. Although caffeine as
pure chemical has a clearly bitter taste, it plays only a minor role in giving a bitter
tinge to the coffee beverage.
Caffeine concentrations decrease as leaves and fruits mature, but substantial
quantities of caffeine remain in mature leaves and fruits, even in aged tissues.
This is a very weak base forming unstable salts. It is relatively stable in dilute
acids and alkalis but can form a series of complexes with other coffee components,
for example chlorogenic acids or polynuclear aromatics. In fact, this property is also
used in the selective extraction of polynuclear aromatics from other foods.
The caffeine content of the coffee beans depends on species and variety, from
0.6% in Laurina up to 4% in some extreme Robustas; averages aregiven in Table 3.
The caffeine content in dry matter base is not affected by postharvest
processing, neither by the roasting. Although the roasting process occurs well above
sublimation temperature, during it only a small percentage of caffeine vanishes. The
reasons for this modest loss of caffeine are complex, but the two major contributing
factors are probably an increase in the sublimation point of caffeine as a result of
pressure build-up within the bean and a poor rate of diffusion of vapour through its
outer layers.
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Second is decaffeination.
The legal requirements for caffeine content that apply to coffee are very strict.
The European legislation sets a maximum residual caffeine content of 0.3% for
soluble coffee; 0,1 % for roast coffee.
The question is, what can we do to reduce the caffeine content?
Caffeine content of coffee can be reduced by decaffeination. Since I don't have
much time, I'll just introduce some techniques of decaffeination. The process starts
with a steam treatment of the green coffee to soften the tissues, followed by solvent
extraction.
We have four main methods.
1. Di-Chloride methane (DCM)
2. Ethyl Acetate (E.A.) – also called sugar cane technique
3. Swiss water
4. Liquid CO2
Details of the 2 simplest methods:
1. Swiss Water is starts by adding green coffee to a vat of warm water. All of
the water will twirl the beans and pass through a carbon filter, then back to the
coffee and so on. The carbon filter only takes out the caffeine but leaves all other
compounds in the liquid. After all the soluble compounds are in the water, the green
beans are taken out. The remaining soup is the liquid Swiss water.
The soaked green beans that need to be decaffeinated are immersed in the liquid
and continue the same circulation as the previous coffee. The only difference is that
the water has already taken compounds from the previous coffee. Soluble
compounds only move from one cell to another when they find a place of lower
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saturation within a liquid. When there is an equilibrium, soluble compounds do not
move and stay in the cell. The water is saturated with green coffee so the liquid
doesn’t extract the soluble compounds out of the green bean. Meanwhile, the
caffeine does get extracted into the soup and taken out by the carbon filter. The
whole process takes up to 8 hours until the caffeine level is below 0,8% of its
weight.
2. The Carbon Dioxide (CO2) Method is the most recent method.
Coffee beans that have been steeped in water are put in an extraction vessel
made of stainless steel to undergo CO2 decaffeination. Caffeine is then extracted
from the coffee by sealing the extractor and applying pressures of 1,000 pounds per
square inch to liquid CO2.
The larger-molecule taste components are left behind while the CO2 serves as a
solvent to dissolve and pull the caffeine from the coffee beans. The caffeine-filled
CO2 is then transported to the absorption chamber, another container. Here, the
pressure is released, the caffeine is left behind, and the CO2 returns to its gaseous
condition. Pumped back into a pressurized container for reuse, the caffeine-free
CO2 gas.
Because of its cost, this process is primarily used to decaffeinate large
quantities of commercial-grade, less-exotic coffee found in grocery stores.
Third is benefits of trigonelline.
Trigonelline is an essential component for triggering a uniform endogenous
antioxidant defense system. But it has received great attention because its thermal
degradation products are important from both a sensory and nutritional point of
view.
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The overall scent of roasted coffee and other drinks is influenced by trigonelline
derivatives. The breakdown product of trigonellin, niacin (nicotinic acid), one of the
eight B vitamins, and it’s also called vitamin B3. The key role of niacin inyour body
is to synthesize the coenzymes nicotinamide adenine dinucleotide (NAD) and
nicotinamide adenine dinucleotide phosphate
(NADP), which are involved in over 400 biochemical reactions in your body —
mainly related to obtaining energy from the food you eat. Niacin is water-soluble, so
your body does not store it. This also means that your body can excrete excess
amounts of the vitamin through urine if they are not needed.
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HOMEWORK 6
Question 1: What are the enzymes involved in tea production?
In tea leaves, polyphenol oxidase and peroxidase are the most significant
enzymes. When the cell walls of the leaves are damaged and the polyphenols are
exposed to oxygen, a process known as oxidation, they are to blame for the
enzymatic browning of tea leaves. The browning of apples, potatoes, avocados, and
bananas is caused by the same enzymes. Heat can be used to denature or inactivate
polyphenol oxidase and peroxidase, preventing browning.
The reason why completed green tea leaves stay green is because this is one of
the earliest processes in the creation of greentea (and why cooked apples or potatoes
remain white). Around 150 degrees Fahrenheit deactivates polyphenol oxidase and
peroxidase, rendering them inactive.
Polyphenol oxidase (PPO), an enzyme involved in fruit browning, is a tetramer
that contains four atoms of copper per molecule. PPO may accept monophenols
and/or o-diphenols as substrates.
The enzyme works by catalyzing the o-hydroxylation of monophenol molecules
in which the benzene ring contains a single hydroxyl substituent to o-diphenols
(phenol molecules containing two hydroxyl substituents at the 1, 2 positions, with
no carbon between). It can also further catalyse the oxidation of o-diphenols to
produce o-quinones. PPO catalyses the rapid polymerization of o-quinones to
produce black, brown or red pigments (polyphenols) that cause fruit browning.
Peroxidase are enzymes that catalyze oxidation-reduction reaction by
mechanism of free radical that transform several compounds into oxidized or
polymerized products. Peroxidase can be produced by bacteria and fungi.
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POD was observed to oxidize theaflavins in the presence of H(2)O(2), leading
to the formation of thearubigin, another black tea pigment
Question 2: Clarifying fermentation in tea technology
One method of classifying teas is based on the degree of fermentation:
1. Non and light-fermented
These teas have a good deal of their original flavor left over. These include all
types of green tea. Most green teas, including Dragon Well, stop the fermentation
process by pan-frying, while a few also do so by steaming. White teas experience a
very mild fermentation process known as withering. These lightly fermented, nonfermented teas are occasionally given a jasmine scent by being perfumed with
jasmine petals.
2. Semi-fermented
Semi-fermented teas broadly refer to teas that have been permitted to
experience 10% to 80% fermentation. Semifermented tea has a faint yellow brown
tint and a gentle, delicate fragrance when brewed. Based on the degree of
fermentation, these teas can be further divided into three groups:
 Light (10% - 20%): Jasmine Tea (Pouchong scented with Jasmine petals),
Pouchong Tea.
 Medium (20% - 50%): Oolong, Tung-Ting Oolong
 Heavy (50% - 80%): Champagne Oolong.
3. Fully-fermented
Black teas are fully fermented. Tea from Black tea leaves have a dark red hue
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and a sweet aroma of malt sugar
4. Post-fermented
Post-fermented teas are those that have been first allowed to ferment, had the
process stopped, and then allowed to ferment once again.
Question 3: List 3 interesting things you have learned
The first thing is yin-yang in food.
A fundamental idea in Chinese medicine is the concept of yin and yang, which
is applied to all facets of life and health, including nutrition.
The dynamic equilibrium of opposing forces is symbolized by the term yin
(which tends to be more feminine) and yang (which tends to be more masculine).
And it's crucial to obtain nutrients from diet without upsetting this balance.
Yang foods are associated with fire and produce heat: Alcohol, Apricot, Beef,
Caffeine, Cayenne pepper, Chicken.
Yin foods are associated with water and are more cooling:Apples, Bananas,
Beans, Bean sprouts, Bok choy, Broccoli.
Neutral foods fall somewhere in the middle: Carrots, Dates, Duck, Peaches,
Peas, Pork.
In order to establish a balance of flavor (sweet, sour, spicy, bitter, and salty),
texture, and cooking methods, the various ingredients work together. It's important
to have a balance of starch (rice or noodles), meat, and vegetables. Congee or soup
should be served alongside dry dishes like a fiery stir-fry. A Chinese chef will even
take into account the meal's color harmony. For instance, vegetables with
contrasting colors, like ell peppers or scallions, should be served with diced meat.
The second thing is Black Tea.
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As with all “true teas,” black tea is derived from the Camellia sinensis plant.
Leaves of the plant are crushed, curled, rolled, or torn and then left to oxidize before
they’re dried and sold.
The fact that the leaves are fully oxidized accounts for black tea’s strong, dark
flavor profile. The oxidation process also decreases black tea’s flavonoid content a
bit, but this brew is still loaded with beneficial properties.
Black tea is often sold in some kind of blend, which will determine its flavor
profile. The season and place where a tea plant was grown will also impact its
flavor. As a general rule, black tea is produced in China, India, Sri Lanka, or Nepal.
As we mentioned above, black tea is the most common type of tea (at least in
the US) and comes in many varieties.
Benefits of Black Tea is help support the body’s protection against oxidative
stress (which happens when damaging free radicals are left unchecked in the body).
Process black tea.
1) Withering
Here, the thick and still immalleable leaf is rid of approximately 30% of its
humidity. There are two methods:
a) The natural withering where the leaves are spread out on laths which are
covered with jute, wire or nylon nets. The withering time takes, depeding on the
weather and humidity content of the leaves, between 14-18 hours.
b) The modern withering in large troughs of a length of 25-30 metres which are
covered with wire grids and are ventilated with large ventilators. These can also be
used to warm the leaves, should it be necessary, to reduce the withering time to 8-12
hours.
2) Rolling
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3) Fermentation
This oxidation and fermentation process already starts with the rolling. The
correct fermentation is very important for the final quality of the tea.
4) Drying
5) Sieving/Sorting
The third thing is withering process in tea. When a tea leaf is taken from the tea
plant, it starts to wither naturally, which is what we refer to as wilting. However, the
tea producer has control over this process once the tea leaves arrive at the
processing plant. By lowering the moisture level of the leaves, a controlled wither is
used to get them ready for processing.
In order to control the withering process, it is important to continuously monitor
the air's temperature, humidity, and flow. Tea leaves can be let to gently wither
outside on bamboo mats or tarps, or indoors in troughs with forced air. If necessary,
the process might be sped up by heating the air. The moisture content of the leaf
decreases during withering, making it flaccid and malleable. The leaf is now ready
for shape and rolling, among other processing steps. On a chemical level, the leaf's
chlorophyll starts to deteriorate, caffeine levels gradually rise, flavor and scent
volatiles form in the leaves, and grassy odors fade.
The leaves are deprived of their energy source, so they start to convert their
stored carbohydrates into energy. The breakdown of the cell walls brought on by
moisture loss also starts the oxidizing process known as polyphenol oxidase and
peroxidase activity. The development of new flavor and aroma chemicals in the
leaves increases with the duration of the wither.
But when the leaves are withered over a long time, polyphenol and peroxidase
activity will stop due to dehydration
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HOMEWORK 7
Question 1: Cocoa fermentation, anaerobic and aerobic
Cacao fermentation is a two-step – anaerobic and aerobic fermentation.
In anaerobic fermentation, the cacao is protected from air to allow
microorganisms like yeast to grow. Anaerobic conditions are simply environments
that lack oxygen. In cacao, the pulp surrounding snugly packed beans creates a juicy
barrier that blocks air from entering the system.
The pulp is composed of water, high levels of sugars (sucrose, glucose,
fructose), and various acids. These sugars and the high acidity in the pulp create
ideal conditions for microorganisms. The main players during this phase are yeasts,
lactic-acid-producing bacteria, and pulp enzymes.
Using anaerobic respiration, yeasts quickly consume simple sugars and produce
carbon dioxide, ethanol, and low amounts of energy. Lactic acid producing bacteria
convert citric acid, glucose, and other carbohydrates in the pulp into lactic acid.
Microbes are working around the clock to produce ethanol and lactic acid. You can
see tiny bubbles of carbon dioxide gurgle up to the surface of the cacao in this stage.
Enzymes also help to break down the pulp, transforming it into a liquid that runs off
and is known as sweatings.
As the mass is broken down, there is more space for air to enter the process.
Citric acid is also broken down and runs off with the sweatings, helping to increase
the overall pH of the fermentation. The combination of rising pH and increased
airflow marks the beginning of the aerobic phase of fermentation.
Anaerobic fermentation also creates heat, which destroys the germ of the seed,
which is particularly bitter.
In the second state, air is introduced to promote aerobic fermentation. Aerobic
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conditions are environments that contain oxygen. In cacao processing, producers
mix and move the beans, a process known as “turning”, to incorporate oxygen.
The influence of this oxygen varies based on fermentation style, vessel,
insulation, and the size of the ferment. But turning the beans will always make the
fermentation process more uniform across the batch.
The aerobic stage is bursting with heat. During this step, acetic-acidproducing
bacteria dominates and oxidizes ethanol and acids (citric, malic, lactic) to produce
acetic acid. This acetic acid is further broken down into carbon dioxide and water by
the oxygen.
Breaking down ethanol generates energy, which is expressed as heat. These
exothermic reactions increase the overall temperature of the cacao. As the beans are
turned, heat escapes and the overall temperature drops, but it then builds again
through the introduction of more oxygen.
The combination of intense heat and the diffusion of ethanol and acetic acid
into the cacao beans breaks down the cell walls. They will no longer germinate and
the damaged internal structure becomes a venue for chemical activities that develop
the flavor precursors associated with chocolate.
Question 2: Fermentation in HEAP
A common technique used by smallholder farmers in Ghana and many other
African nations that produce cocoa is heap fermentation. A lesser degree of it is also
practiced in Brazil's Amazon region.
According to the characteristics of Ghanaian cocoa's final quality, fermenting in
heaps might result in high-grade goods. From 25 to 1,000 kg of cocoa beans are
piled up in the field on plantain leaves and covered with the same substance. To
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guarantee equal fermentation and reduce the risk of mold formation, the beans are
periodically combined (turned).
By creating another heap, this is frequently done every day or every other day.
It takes a lot of work to mix, and little heaps might not even be turned. Fermentation
takes 4 to 7 days to complete.
Question 3: List out 3 interesting things that you have learnt in class.
First is what is cocoa.
Cacao is a "pure" form of chocolate, meaning it's raw and less processed than
cocoa powder and the chocolate bars we're used to seeing. Cocoa is believed to be
the highest source of antioxidants and magnesium of all foods. Cocoa has been used
for a long time for health purposes and is also a high value commercial commodity.
Cocoa tree, also known as Theobroma Cacao. The cocoa pods are harvested and the
pods cracked to get the cocoa beans inside. From there, cocoa beans are processed
in different ways.
Cocoa butter is the fattest part of the cocoa fruit, located inside the skin and
covering each cocoa bean. It has a white color, a buttery texture and a taste similar
to white chocolate. Cocoa butter is separated from the beans during the
manufacturing process. The remainder of the cocoa pod is used to produce raw
cocoa powder.
Cocoa chips are cocoa beans that are chopped into edible pieces, similar to
chocolate chips but without added sugar or fat. Cocoa chips include fiber, fat, and
many of the same natural nutrients as cocoa beans.
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Second is a person's appearance are benevolent, from the good and evil heart of
each person I will say this part in Vietnamese.
Quan điểm phật giáo cho rằng tâm sinh tướng chính là biểu hiện của việc tâm
hồn có bao dung hay hèn kém sẽ thể hiện qua từng ngũ quan trên cơ thể gương mặt
cũng như hình hài lẫn dáng đi đứng nằm ngồi. Người hiền từ, tâm tốt và luôn biết
nghĩ cho người khác, sống một cuộc đời không vướng bận và suy nghĩ đố kị sẽ luôn
có gương mặt phúc hậu, gây hảo cảm cho người đối diện dù chỉ là một cái chạm
mắt.
Họ thu hút những người tốt xung quanh đến với họ, năng lượng tích cực khiến
mắt họ sáng, gương mặt luôn rạng rỡ và khóe môi mềm mại để nợ nụ cười xinh đẹp.
Trong khi đó, những người có tâm toan tính, lúc nào cũng có vẻ chột dạ và không
đáng tin tưởng. Họ khiến người khác dè chừng và cảm thấy nên tránh xa, không khí
quanh họ u ám.
Và tất nhiên, cuộc sống của họ sẽ gặp những khó khăn nhất định, dù họ có được
lợi ngay trước mắt thì ngay sau đó cũng tiêu tán nhanh chóng.
Final is the fermentation in cocoa.
It was mentioned above, so I would like to shorten it to a few issues. Cacao
fermentation is a two-step – anaerobic and aerobic fermentation.
Understand the difference between these two methods to determine for your
product as well as take advantage of the advantages and disadvantages of each
method to achieve the best effect.
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HOMEWORK 8
Question 1: List out 3 interesting things that you have learnt in class.
First is free and total fatty acid in coffee
For the most part, the fatty acids are to be found in the combined state. Most are
esterified with glycerol in the triacylglycerols. Approximate 20 % are esterified with
diterpenes. There are small proportion is to be found in the sterol esters.
In coffees roasted at different temperatures, there were scarcely any changes
in the amount and distribution of the individual fatty acids. Only the linoleic acid
content decreased slightly as the roasting temperature increased. Using a roasting
series of a Madagascar coffee, the differences between the FFA contents
determined directly by chromotography and those determined indirectly via the
acid value could be demonstrated (Fig. 1.14). While the difference is only about
360 mg for green coffee, it becomes steadily greater as the roasting temperature
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increases; at the last roasting stage the difference is 1300 mg. This can be
explained by the fact that more and more acid compounds are released as the
temperature rises. These are primarily phenolic degradation products of the
chlorogenic acids that considerably distort the results for the free fatty acids
Sencond, is diterpenes in the lipid fraction of robusta and arabica coffees.
The main diterpenes in coffee are pentacyclic diterpene alcohols based on
the kauran skeleton. The research worked for several years to identify the
structure of two of the coffee diterpenes, namely kahweol and cafestol. Both are
sensitive against acids, heat and light, and kahweol in particular is unstable in the
purified form.
Another important group of diterpene derivatives found in coffee is the
atractylosides, which are mainly present as glycosides. Arabica coffees contain
cafestol and kahweol, robusta coffees cafestol, small amounts of kahweol and,
additionally, 16-O-methylcafestol (16-OMC), which was found only in robusta
coffee beans.
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Finally, is about coffee wax.
The surface of green coffee beans is covered by a thin waxy layer. Coffee
wax is generally defined as the material obtained by extracting it from coffee
beans using chlorinated organic solvents. The amount of the surface wax is about
0.2 - 0.3 % of the total bean weight.
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The amount of the surface wax is about 0.2 - 0.3 % of the total bean weight.
The main constituents of the petroleum ether insoluble part of the coffee wax are
called carboxylic acid-5-hydroxytryptamides.
Even though the C-5HTs are the main constituents of the coffee wax, it is
unlikely that they are solely responsible for the undesirable effects of untreated
coffee. The antioxidant effects of the C-5HT have led to a great interest in coffee
wax as a natural antioxidizing agent to be used in food
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HOMEWORK 9
Question 1: List out 3 interesting things that you have learnt in class.
First is History of Cocoa.
Cocoa (Theobroma cacao L.) is a local species of tropical humid forests at
the decrease japanese equatorial slopes of the Andes in South America. Allen
(1987) pronounced the centre of genetic variety of T. cacao to be the Amazon
The phrase cacao is derived from the Olmec and the following Mayan languages
(Kakaw) and the chocolate-associated time period cacahuatl is Nahuatl (Aztec
language) derived from Olmec/Mayan etymology.
Based on archaeological information, Purdy and Schmidt pronounced that the
Mayans cultivated cocoa 2,000–4,000 years earlier than Spanish contact. It is
recorded that cocoa changed into domesticated and ate up for the primary time via
way of means of the Maya and Aztecs.
The Maya, Olmec, Toltec and Aztecs used the beans of cocoa as each foreign
money and because the base for a bitter drink. The call cocoa is a corruption of
the phrase cacao, which originated from the Amazons in South America.
Its cultivation and price unfold in historic instances at some stage in central
and japanese Amazonia and northwards to Central America (Afoakwa 2010).
Cocoa changed into first cultivated via way of means of the Aztecs in Mexico,
South America, and unfold at some stage in the Caribbean islands.
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The principal varieties of the cocoa tree Theobroma cacao are:
1. Forastero from the Amazonas region, and grown mainly in West Africa as
bulk cocoa
2. Criollo, rarely grown because of disease susceptibility
3. Trinitario, a hybrid of Forastero and Criollo
4. Nacional with fine flavour, grown in Ecuador
Second is Process of Chocolate
Once the cocoa beans have reached the machinery of chocolate factories, they
are ready to be refined into chocolate. Generally, manufacturing processes differ
slightly due to the different species of cocoa trees, but most factories use similar
machines to break down the cocoa beans into cocoa butter and chocolate
(International Cocoa Organization, 1998).
Firstly, fermented and dried cocoa beans will be refined to a roasted nib by
winnowing and roasting. Then, they will be heated and will melt into chocolate
liquor. Lastly, manufacturers blend chocolate liquor with sugar and milk to add
flavour. After the blending process, the liquid chocolate will be stored or delivered
to the molding factory in tanks and will be poured into moulds for sale. Finally,
wrapping and packaging machines will pack the chocolates and then they will be
ready to transport.
A diagram showing the manufacturing process:
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Some important step:
Step #1: Roasting and Winnowing the Cocoa
The first thing that chocolate manufacturers do with cocoa beans is roast them.
This develops the colour and flavour of the beans into what our modern palates
expect from fine chocolate. The outer shell of the beans is removed, and the inner
cocoa bean meat is broken into small pieces called "cocoa nibs."
The roasting process makes the shells of the cocoa brittle, and cocoa nibs pass
through a series of sieves, which strain and sort the nibs according to size in a
process called "winnowing".
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Step #2: Grinding the Cocoa Nibs
Grinding is the process by which cocoa nibs are ground into " cocoa liquor",
which is also known as unsweetened chocolate or cocoa mass. The grinding process
generates heat and the dry granular consistency of the cocoa nib is then turned into a
liquid as the high amount of fat contained in the nib melts. The cocoa liquor is
mixed with cocoa butter and sugar. In the case of milk chocolate, fresh, sweetened
condensed or roller-dry low-heat powdered whole milk is added, depending on the
individual manufacturer's formula and manufacturing methods.
Step #3: Blending Cocoa liquor and molding Chocolate
After the mixing process, the blend is further refined to bring the particle size of
the added milk and sugar down to the desired fineness. The Cocoa powder or 'mass'
is blended back with the butter and liquor in varying quantities to make different
types of chocolate or couverture
Step #4: Tempering.
Melting the chocolate while controlling how its temperature rises and falls
This technique lets you use the chocolate the way you want to and get the
perfect result for all your creations
Cocoa butter has fatty acids that undergo polymorphous crystallization,
meaning they can form six different types of crystal structures at any one time
However only form bV—the second most stable crystal form—is desired in the
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final product
Tempering will control this propensity in order to obtain chocolate candy of the
highest standard: lustrous, smooth, hard, crisp, and rich
Finally, is Spoilage Problems with Chocolate.
Chocolate Blooming is the term we use when we see that the chocolate has
dusting or streaking across the surface. There are two types of blooms – fat bloom
and sugar bloom.
Fat bloom can be identified by greyish or whitish streaks on the surface of the
chocolate that typically feels slick. This blooming happens when the chocolate has
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been exposed to warm temperatures. Once the chocolate is warm, the cocoa butter in
the chocolate softens and separates from other ingredients in the chocolate. Once it
rises to the surface and re-solidifies, it creates the bloom. Fat bloom is the most
common type of chocolate blooming.
It is caused by:
1. Bad tempering of the chocolate in that stage of the process.
2. Incorrect cooling methods, including covering cold centers.
3. The presence of soft fat in the centers of chocolate-covered units.
4. Warm storage conditions.
5. The addition to chocolate of fats incompatible with cocoa butter.
6. Abrasion and finger marking, particularly under warm
conditions.
Sugar bloom can be characterized as a dry, hard white surface film on
chocolate. Sugar bloom is caused by moisture in the chocolate coating. The sugar
absorbs the moisture, dissolves, and evaporates. The sugar then forms larger crystals
on the surface of the chocolate, which causes this dusty layer.
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It is caused by:
1. Storage of chocolates in damp conditions or against damp walls.
2. Deposit of "dew" during manufacture from damp cooler air or
allowing chocolates to enter a packing room at a temperature
below the dew point of that room.
3. Use of hygroscopic ingredients (e.g., low-grade or brown sugars).
4. Removal of chocolate from cold storage without adequate wrapping
protection.
5. Use of damp packing materials.
6. High-temperature storage conditions of chocolate covered confectionery
where centers have a high equilibrium relative
humidity (e.g., fondants) and the water vapor given off is
trapped in impervious wrappings.
Can Chocolate Blooming Be Avoided?
Generally, yes. Fat bloom results from inadequate tempering or temperature abuse
of well-tempered chocolate, therefore you can prevent fat bloom by storing your
chocolate at a constant, cool temperature and avoiding warm temperatures. Sugar
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bloom occurs when the sugar crystals are affected by moisture. This happens when
the chocolate is stored in damp conditions (ex: humidity in the air or condensation
from refrigeration), which causes the sugar to dissolve and come to the surface. You
can prevent sugar bloom by preventing temperature shocks.
Can You Still Use Chocolate That’s Been Bloomed?
While fat bloom and sugar bloom have a negative effect on appearance, the product
remains perfectly safe to eat and can be remelted to remove discoloration.
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HOMEWORK 10
Question 1: List out 3 interesting things that you have learnt in class.
First, is Benefits of tea.
People all over the world have been drinking tea for thousands of centuries, and
for good reason. Tea is an aromatic beverage prepared by pouring hot or boiling
water over cured or fresh leaves of Camellia sinensis, an evergreen shrub native to
East Asia which probably originated in the borderlands of southwestern China and
northern Myanmar. Tea is also rarely made from the leaves of Camellia taliensis.
After plain water, tea is the most widely consumed drink in the world.
There are many different types of tea; some have a cooling, slightly bitter, and
astringent flavour, while others have vastly different profiles that include sweet,
nutty, floral, or grassy notes. And this has different benefits.
White Tea Benefits
White tea is made from the Camellia sinensis plant, which is indigenous to
China and India and is known for having a delicate flavor. The least processed tea
kind is this one.
Due to its strong antioxidant content, research suggests it may be the best tea
for preventing many types of cancer. Since white tea has a high concentration of
fluoride, catechins, and tannins that strengthen teeth, fight plaque, and increase their
resistance to acid and sugar, it may also be beneficial for your oral health.
This variety also has the lowest caffeine content, making it a wise choice for tea
drinkers who want to avoid or consume little to no caffeine.
Herbal Tea Benefits
Herbal teas, sometimes called tisanes, are very similar to white teas, but they
contain a blend of herbs, spices, fruits or other plants in addition to tea leaves.
Herbal teas don’t contain caffeine, which is why they’re known for their calming
properties.
There are numerous types of herbal teas, all with their unique benefits. Some of
the most popular herbal teas include:
 Chamomile tea – Helps to reduce menstrual pain and muscle spasms, improves
sleep and relaxation, and reduces stress
 Rooibos – Improves blood pressure and circulation, boosts good cholesterol while
lowering bad cholesterol, keeps hair strong and skin healthy, and provides relief
from allergies
 Peppermint – Contains menthol, which can soothe an upset stomach and serve as a
cure for constipation, irritable bowel syndrome and motion sickness. This tea
variety also offers pain relief from tension headaches and migraines.
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Ginger – Helps to fight against morning sickness, can be used to treat chronic
indigestion and helps to relieve joint pain caused by osteoarthritis
 Hibiscus – Lowers blood pressure and fat levels, improves overall liver health, can
starve off cravings for unhealthy sweets, and may prevent the formation of kidney
stones
Green Tea Benefits
Green tea comes from China, where the leaves are heated up and processed
through roasting or pan-firing, and Japan, where the leaves are more frequently
steamed.
Green tea has a particularly high concentration of flavonoids, which can
improve heart health by lowering harmful cholesterol and blood clotting. According
to studies, this kind of tea can also decrease triglycerides, cholesterol, and blood
pressure.
Green tea may have an effect on cancers of the liver, breast, prostate, and
colorectal, according to additional research. This particular tea variety has also
demonstrated anti-inflammatory properties, which support healthy, clear skin.
Matcha, a type of green tea, has gained popularity recently, is a very fine, highquality green tea powder made from the entire leaves of tea bushes grown in the
shade. Since it is the only form of tea in which the leaves are ingested, matcha
contains even more antioxidants that regular green tea. In fact, some have suggested
that one cup of matcha is the equivalent to 10 cups of regular green tea.
Black Tea Benefits
The same plant that is used to produce green tea, Camellia sinensis, also
produces black tea. Black tea, on the other hand, has a darker color and fuller flavor
since the leaves are dried and fermented.
Black tea contains caffeine, unlike many other types, therefore it's vital to limit
your consumption. If you do make yourself a cup of black tea, you gain the
advantages of flavonoids that reduce inflammation and promote a strong immune
system.
However, in order to take advantage of black tea's health benefits, you don't just
have to drink it. To relieve pain and lessen swelling, it can be steamed, cooled, and
then applied to small cuts, scrapes, and bruises.
Oolong Tea Benefits
Oolong tea is a traditional Chinese tea variety that’s made from the same plant
used to make green and black teas. The difference is how the tea is processed: Green
tea is not allowed to oxidize much, but black tea is allowed to oxidize until it turns
black. Oolong tea is somewhere in between the two, so it is partially oxidized. This

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partial oxidation is responsible for oolong tea's color and characteristic taste.
Oolong tea is notable for containing l-theanine, an amino acid that reduces
anxiety and increases alertness and attention. Scientists have found that l-theanine
can help prevent cognitive diseases such as Parkinson’s and Alzheimer’s diseases.
Oolong tea is also high in polyphenols, which are linked to lowering
inflammation, preventing the growth of cancers and decreasing type 2 diabetes risk.
Second, is why does traditional tea become popular?
Surely everyone has known about tea, but to say when tea will be widely
known, not everyone knows. According to some research documents, tea appeared
more than 5000 years ago in China, but at that time, tea was like a food, often used
to prepare with some other foods or eat like vegetables.
After tea began to flourish in China, in the 9th century under the Tang Dynasty,
a Japanese monk brought the first tea tree to Japan, also from here the emergence of
the culture of "Tea" Tao" is famous all over the world. Around the seventeenth
century, when the exchange of goods between Europe and China flourished, tea was
also followed by shipments and developed to this day.
In 2017, Mansci Professional Services, an organization specializing in market
research, researched and found that tea is the second most popular beverage in the
world after bottled water. Besides, up to 80% of households in the US use tea at
home.
Finally, is turning waste tea to wealth.
 Extraction of useful compounds: Black Tea Polyphenols (Catechins):
excellent health promoting activities, reduce blood pressure and prevent
the growth of cancer cells. Tea Polysaccharides (leaves & buds): used as
natural antioxidants & potential candidates for application in the feed
industry.
 Formation of different materials: A promising source of several valueadded materials: activated carbon, nanoparticles, biochar and other
cellulosic derivatives. The application in textile industry wastewater,
environmental, biomedical and pharmaceutical sector and also in polymer
composite industry
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