Brighton and Sussex Universities Food Network
Functional Food and
Food Functionalisation
Dr Dipak K Sarker
Biomaterials Research Group
School of Pharmacy and Biomolecular Sciences
University of Brighton
d.k.sarker@brighton.ac.uk
Overview
Biological assembly of molecules in a complicated “soup”
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Use of foods as therapeutics
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Engineering of chemicals within “new” foods
Functional Food
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The term Functional Foods was first introduced in Japan in the mid-1980s
and refers to processed foods containing ingredients that aid specific bodily
functions
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Functional foods are foods that have a potentially positive effect on health
beyond basic nutrition. Oatmeal for example, is a functional food because it
contains natural soluble fibre that can help lower blood cholesterol
•
Some foods are modified to have health benefits. Some functional foods are
generated around a particular functional ingredient, for example foods
containing pro-vitamins, probiotics, prebiotics, or plant stanols and sterols
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Functional foods are part of the list of products that people consume to
increase their health status or contribute to reducing their disease burden
Functional foods. Position statement of the American Dietetic Association. Journal of the American Dietetic Association. 2009;109:735
Functional Food
Example
Functional agent
Benefit
Green tea
Epigallocatechin-3gallate, polyphenol
Free radical destroyer: use in anti-cancer
and heart disease
Yogurt
Metchnikoff’s “probiotic
bacillus” – e.g.
Lactobacillus rhamnosus
Lactobacillus acidophilus
Use in: colon microflora equilibrium, antidiarrhoeal, reduction of peptic ulcer,
ulcerative colitis, IBS; production of
acidolin, vitamin K/B12/B9 - folate
Honey
Quercetin, flavonoid
pigment
Free radical destroyer: use in arterial and
circulatory health, diabetes prophylaxis
Beer and
wine
Resveratrol, polyphenol
Free radical destroyer: use in anti-aging,
anti-heart disease, anti-blood clot agent,
anti-inflammatory, anti-cancer
Oats
b-glucan, lipid binding
polysaccharide
Use in: reduction in serum cholesterol/LDL
(>10%) and vessel plaques
Soya
Stanol ester
EMEA approved. Use in: cholesterol uptake
blocking, reduction in blood e.g. Benecol®
spread
Functional Food
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Nature teaches us a thing or two!
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Foods provide us with water, carbohydrate and glucose, protein, fats,
minerals, vitamins/factors and water
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Foods are made of molecules (chemicals), water being one of them!
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A food chemical
Vitamin C
(ascorbic acid)
Found in coloured fruit
and vegetables used for
tissue growth/repair and
neutralising free radicals
Functional Food
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Functional foods promote well-being in themselves. Soya, a mix of protein,
oil and intrinsic ingredients from the bean contains phyto-oestrogens
(stanols) that reduce blood cholesterol/LDL and free fats, thereby reducing
obesity, hyperlipidemia and athosclerosis
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Oats have after heating, a particular smearing texture; this is because they
contain soluble and insoluble lubricating mucilages (glycoproteins) and
polysaccharides (gums)
•
•
They can: 1) bind water,
reducing diverticulitis and
excess lipids and fats (and
and thus aid a low calorie
diet
increase stool volume and thus, aid bolus transit,
bowel congestion and torsion but also 2) sequester
heavy metals) allowing excretion without absorption
diet and a lowering of risk with a fat-laden Western
Broccoli, kale and beets - so-called "super foods" contain bright coloured
pigments – betanin (reds), chlorophyll (greens), carotenoids (oranges),
xanthophylls (yellows) and flavonoids and flavonols (pinks and violets). These
compounds not only appear as pretty colours but also prevent free radicals
that destroy tissue and cause cancer and fatty build-ups
Food Functionalisation
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We answer back to basic raw food (raw materials) with food
improvements for our busy modern life!
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Food functionalisation, we copy functional foods and improve on
them
Another chemical
Oil dispersible Vitamin C
(ascorbyl palmitate)
Added to fatty foods,
such as biscuits and margarine to
prevent them going rancid
on storage
Food Functionalisation
The secret is we build up in stages
1. Make something very tiny - assemblies of molecules
2. Add the assemblies to make a superstructure
3. Add the superstructures to give something that can be prodded,
chewed, spread and poured with a texture that can be appreciated e.g. jams and
confectionary
Jam: an assembly of water, pectin, seeds,
fruit pieces, fruit acids and natural sugars
Without food technology we're “reduced to monotony”, with a perfunctory and a
risky and poorly hygienic, parasite and germ-laden diet, which is incompatible
with our busy lives, love of food and life-expectancy. The answer lies in
harnessing natures secrets and adapting and reusing the materials that evolved
over hundreds of millennia.
Food Functionalisation
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How do cranberries, citrus fruits and dry-cured salamis stay fresh? Because of
the acids they contain (in order: sorbic, citric/ascorbic, propionic/lactic,
respectively). We now use these acids to prolong shelf life in other
commercial foods by retarding the growth of spoilage microbes and
pathogens.
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How do you ensure you cover your salad leaves with simple oil and vinegar
vinaigrette dressing? Add an emulsifier... ground mustard seeds, ground
peppercorns or egg yolk. This means small oil droplets are evenly dispersed in
the vinegar or lemon juice
Food Functionalisation
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How do you make foods such as, 1) soufflés, 2) mousses or 3) pannacotta,
which are unique and contrived but ever so lovely? You need functionalising
materials (polymers) such as:
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1) egg white (ovalbumin) entwined with wheat and flour proteins (gliadins)
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2) sugar-dehydrated ovalbumin and a-lactalbumin and b-lactoglobulin proteins
from milk and
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3) collagen derived gelatin (gelatine) or seaweed derived alginate for
vegetarians, together with egg yolk lecithin to emulsify the fat globules in full
fat cream.
An assembly
of polymers
and proteins
gives a “jelly”
(gel) that traps
air, water or fat
Food Functionalisation
Ever had a “tannin furry tongue” on consumption of
claret, grape skin or chewing a pip or green tea? That’s
the polyphenols reacting with the protein of your tongue
to cement and glue it up. A temporary situation. Food
technologists now use tannin rich varieties of food,
foods rich in natural tannins or refined natural tannins to
improve foods.
Beer and champagne with long lasting froth (foam;
head)... enhanced with hop acids and other polyphenols
that glue together natural proteins in the product - give
the bubble a mechanical resilience to soap in the glass
rinse water or the lipid (natural soap) from your lips and
lipstick
Let’s take a look at “simple” beer foam …
Beer foam
Basic beer foam ingredients from malted and fermented barley and hops
Primary ingredient
Functionalising agent
Hydrophobin proteins
Iso-a-acids (hop acids)
Lipid transfer proteins (LTPs)
Polyphenols e.g. catechin
Insoluble - hordein proteins
Lipid fats
Hydrolysed hordein proteins
Arabinoxylan gums
Elastic - protein Z
b-glucan gum (beer viscosifier)
Lipid binding proteins (LBPs)
Metals
Shokribousjein et al. (2011)
Beer foam stability
Gas in bubble
bubble
Super-structured multiple
layers
Hydrophobins
Albumin protein Z
Globular LTP
Hordeins
LBP
Beer
liquid
Trapped CO2
Hop acid-metal
complex
Polyphenol
Arabinoxylans
b-glucans
Interfering lipid
Hydrophobins are the surface attachment proteins produced by the fungus (yeast)
Saccharomyces cerevisiae in brewing, they also trap carbon dioxide bubbles preserving
drink “fizz.” Very important in lagers and beer froth. Beer is an excellent source of B
vitamins (B2, B3, B5, B6, B9 and B12) produced as part of brewing (microbial synthesis)
Shokribousjein et al. (2011); Hughes et al. (1999); Cooper et al. (2002); Linder (2009) - model of
beer bubble surface and interstitial liquid
Sarker et al. (1995b)
Sarker et al. (1998)
“Disruption of
bubble surface”
“Joining of protein
molecules on the
bubble surface”
“Rigidification of
bubble surface”
Fracture
Concentration of
lipid (fat) in bubble
surface
Unification
Concentration of
polyphenol (catechin)
in bubble surface
Surface elasticity, E
Sarker et al. (1995a)
Molecular mobility, D
Molecular mobility, D
Foam stability models
Cementing
action
Concentration of
arabinoxylan in
bubble surface
Conclusions
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Natural and modified natural ingredients can be used to shape, modify
and preserve foods
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The same ingredients can be added in other combination to create new
foods and create foods of superior quality, texture and taste
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Terms such as “nanotechnology”, the notion of molecular constructions,
that in modern times alarm people have always been the building-blocks
of all foods
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What we do is only a question of imagination - what the consumer wants
and what the technologist is able to create
Acknowledgements
Instrumental in the work presented here:
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Dr David Clark, Bovina Mountain Consulting – New York
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Drs Yves Popineau and Monique Axelos, Institut National de la Recherche
Agronomique – Nantes, France
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Dr Peter Wilde, Institute of Food Research – Norwich
References
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Cooper, D.J. et al. (2002) Journal and Agricultural and Food Chemistry,
50: 7645-7650
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Hughes, P.S. et al. (1999) In: European Brewing Convention Symposium
on Beer Foam Quality, 27: 129-138
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Linder, M.B. (2009) Current Opinion in Colloid and Interface Science, 14:
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Sarker, D.K. et al. (1995a) Colloids and Surfaces B: Biointerfaces, 3: 349356
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Sarker, D.K. et al. (1995b) Journal and Agricultural and Food Chemistry,
43: 295-300
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Sarker, D.K. et al. (1998) Cereal Chemistry, 75: 493-499
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Shokribousjein, Z. et al. (2011) Cerevisia, 35: 85-101