Introduction to Food
Analysis
1.1 Introduction
- McGorrin stated in a review of food
analysis history that “the growth and
infrastructure of the model food
distribution system heavily relies on
food analysis as a tool for new
product development, quality
control, regulatory enforcement, and
problem solving,”
- In food analysis, it is usually the
nature of the sample along with the
intended use of information (data
obtained from analysis) that dictated
what food analytical methods should
be used. This along with speed,
precision, accuracy, robustness,
specificity, and sensitivity are key
factors in making this decision.
- Validation of the analytical method is
a must to ensure that the data
obtained is reliable.
1.2
Reasons for Analyzing
Foods and Types of
Samples Analyzed
- 1.2.2 Consumers demand has
become one of the most significant
factors in products making claims
which led to product development.
- 1.2.3 In order for food companies to
be able to compete locally and
internationally, and present their
products in every marketplace, they
must satisfy first the government
regulations and international
standard along with the guidelines
and policies set to each product.
- 1.2.4.1 When competing in the
international market, not only do the
products manufactured satisfy the
regulations and standards, it also
must comply to the demands of the
consumers. For this reason,
analytical methods used in quality
control is applied in every step of the
manufacturing process, especially in
the examination of the raw
ingredients.
- Sometimes, the price of a certain
good can be linked directly to the
composition as determined by
analytical tests.
- The nature of the sample, and the
way in which the information is
intended to be used may dictate the
analytical method that should be
employed.
- 1.2.4.2 Chemical and physical
analysis of food is an important part
of a quality management system.
The following are the types of
samples analyzed:
1. Raw Materials
- Do they meet your specifications?
- Do they meet required legal
specifications?
- Are they safe and authentic?
- Will a processing parameter have to
be modified because of any change
in the composition of raw material?
- Are the quality and composition the
same as for previous deliveries?
- How does the material from a
potential new supplier compare to
that from the current supplier?
2. Process Samples Control
- Did a specific processing step result
in a product of acceptable
composition or characteristics?
- Does a further processing step need
to be modified to obtain a final
product of acceptable quality?
3. Finished Product
- Does it meet the legal requirements?
- What is the nutritional value, so that
label information can be developed?
Or is the nutritive value as specified
on an existing label?
- Does it meet the product claim
requirements?
- Will it be acceptable to the
consumer?
- Will it have the appropriate shelf
life?
- If unacceptable and cannot be
salvaged, how do you handle it?
4. Competitor’s Sample
- What are its composition and
characteristics?
- How can we use this information to
develop new products?
5. Complaint Sample
- How do the composition and
characteristics of a complaint sample
submitted by a customer differ from
a sample with no problems?
- 1.2.4.3 In order to reduce the
production costs and time when
analyzing the raw ingredients,
companies downsize and rely on
select suppliers that can supply them
with quality ingredients. They
depend on this suppliers to satisfy
not only the standards but also the
specifications needed. These
specifications along with the
associated tests needed comes in
various forms within the food
industry. The following are the three
commonly used forms:
1. Technical/Product Data Sheet
2. Specifications – Internal company
documents that is also based on the
product data sheet.
3. Certificate of Analysis – presents the
actual values and is useful when
shipping the ingredient.
1.3 Steps in Analysis
1. Select and Prepare Sample
2. Perform Assay – Assay is unique for
each component or characteristic to
be analyzed and may be unique to a
specific type of food product.
3. Calculate and Interpret the Results –
in order to make decisions and take
action based on the results obtained
from performing the assay that
determined the composition or
characteristics of a food product,
one must make the appropriate
calculations to interpret the data
correctly, this process is usually
referred to as “data handling”.
1.4 Method Selection
- 1.4.1 The selection of the analytical
method as discussed earlier is based
on the nature of material and its
intended use or the objective of the
assay. If for example, the objective of
the assay is for quality control, then
secondary analytical methods that
can be used for rapid online
processing measurements can be
used, however, if the purpose of
conducting the experiment if for
nutritional labeling, then official
methods, can also be called as
primary methods, should be used.
Primary methods may take longer
than secondary but their validity and
reliability are second to none. Hence
the reason why secondary methods
are always calibrated and
standardized against primary.
- 1.4.3.1 To ensure the validity of the
analytical method, the equipment
should be standardized and
appropriately used, and the
performance limitations of the
equipment be recognized.
- 1.4.3.2 When proving whether the
method is valid, control sample
called as Standard Reference
Materials or Check Samples are
used. Sources of SRM’s can be the
following:
1. NIST – National Institute of
Standards and Technology
2. US Pharmacopeia
3. IRMM – Institute for Reference
Material and Measurements
4. AACC International – American
Association of Cereal Chemistry
5. AOCS – American Oil Chemists’
Society
- SRM’s are great however, such
materials need not necessarily come
from outside organizations, it can be
from the laboratory itself. This time
SRM’s will be called as Internal
Reference Materials.
- 1.4.3.3 To help ensure the validity of
results generated by methods of
analysis, commercial, private, and
government laboratories are
increasingly using ISO certification
(International Organization for
Standardization).
- 1.4.4 Proximate analysis of foods
refers to determining the major
components of moisture, ash, lipids,
and carbohydrates. Remember that
the performance of analytical
methods is affected by the nature of
the food or the food matrix.
- AOAC International (Association of
Official Analytical Chemists)
suggested a “triangle scheme” for
dividing foods into matrix categories.
The apexes of the triangle contain
food groups that were either 100%
fat, 100% protein, and 100%
carbohydrates. Creating nine
possible combinations of high, low,
and medium levels of fat, protein,
and carbohydrates.
- The three nutrients expected to have
an effect on the applied analytical
method are: fats, proteins, and
carbohydrates.
1.5 Official Methods
- 1.3.1 AOAC International which dates
back to 1884, is well-known for its
program to provide official methods
of analysis that fit their intended
purpose. The official methods
developed are intended for use by
regulated industries, regulatory
agencies, contract research
organizations, and testing
laboratories, and academic
institutions.
Study Questions
1. Identify six specific reasons you
might need to determine certain
chemical characteristics of a food
product (or ingredient) as part of a
quality management program.
2. You are considering the use of a new
method to measure compound X in
your food product. List six factors
you will consider before adopting
this new method in your quality
assurance laboratory.
3. In your work at a food company, you
mentioned to a coworker something
about the Official Methods of
Analysis published by AOAC
International. The coworker asks you
what AOAC International does and
what the Official Methods of Analysis
is. Answer your coworker’s
questions.
4. For each type of product listed
below, identify a publication in which
you can find standard methods of
analysis appropriate for the product:
(a) Ice cream
(b) Enriched flour
(c) Wastewater (from food
processing plant)
(d) Margarine
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Lecture notes
- What is the importance of food
analysis? Why do we need to conduct
it? Conducting food analysis through
the use of various analytical tools
allows us to modify the food and
check its quality. Putting it simple,
food analysis is a vital part of a
quality management system. Widely
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utilized in the field of research and
development.
Quality Management System, does
not only refer to the checking of the
quality of the final or finished
product but the analysis of food
quality in every part of the food
manufacturing process.
Note: As food engineers working in
the food industry, we must conform
to the consumer’s demands.
Consumers demands are really the
most important factor in food
product development.
Authenticity, one of the reasons why
food analysis is important; refers to
checking whether the claims of a
certain product is correct (for
instance, determining whether the
hotdog which claims that it is
composed of 100% meat is true).
Consumer driven demands caused
many companies to make claims
which would lead to an increase
need in food analysis.
Food Industry Management of
Product Quality.
Ingredient (Raw Materials) –
Specification, Certificate of Analysis,
In-House Testing
Processing – Process control samples
Final Product – Consistent quality,
Nutrition Labeling, Legal
Requirements.
Where to get the process control
samples? In a food manufacturing
process, knowing where to get the
process control samples is very
important in ensuring that the
quality of the product is consistent.
Get the process control samples at
the initial, middle, and final points of
the manufacturing process.
- Food analysis is applied throughout
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the whole manufacturing process.
In the various types of samples being
analyzed, in process samples control
we check about the quality or
capability of the equipment or the
process itself.
In terms of requirements, at least
two of the three (Product Data
Sheet, Specifications, and Certificate
of Analysis).
Retain Samples. These are the
finished products from the previous
batch that is compared to the
products of a latter batch to answer
the question of whether or not the
quality of the product is consistent.
AOAC-OMA (AOAC – Official Methods
of Analysis) – widely used
compilation of methods adopted
over the years. Details of the method
validation program are given online
and in the front matter of that book.
Standard Methods for the
Examination of Dairy Products,
Standard Methods for the
Examination of Water and
Wastewater, Food Chemical Codes
(for food additives), and Chemistry
Laboratory Guidebook are other
endorsed references.