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Dairy as nutraceutical
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Nidhi Shukla
March 01 , 2015
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Introduction
Foods providing health benefits beyond energy and nutrients have gained exponential market growth in recent years. This growth is supported by technological innovations, development of new products, and the increasing number of health-conscious consumers interested in products that improve life quality.
“Protein intake plays a role in satiety, or feeling of fullness,” said Matt Pikosky, director, research transfer, Dairy Management Inc., Rosemont, IL. “Research shows that protein is more filling than carbohydrates or fats and that higher protein diets lead to satiety. Consuming more foods with added whey protein is a simple way for consumers to increase their intake of protein and help achieve a higher protein diet and satiety benefits.”
In the early 1980s, the Japanese were the first to recognise dairy components as having significant contributions to “physiologically functional foods.” The term functional food was defined initially in Japan during the 1980s as foods for specific health use (FOSHU). They have been associated with health benefits containing bioactive peptides, probiotic bacteria, antioxidants, vitamins, specific proteins, oligosaccharides, organic acids, highly absorbable calcium, conjugated linoleic acid and other biologically active components with an array of bioactivities: modulating digestive and gastrointestinal functions, controlling probiotic microbial growth and immune-regulation. These dairy products contain many functional ingredients that support in reducing the absorption of cholesterol, help in significant reduction of blood pressure, play role in the regulation of satiety, food intake and obesity-related metabolic disorders and may simultaneously exert antimicrobial effects.
Milk nutrients and their major benefits
The health benefits of milk and dairy products are known to humanity since medieval times. Lactoferrin is an example of a minor milk protein that has been studied in great detail. The importance for the nonspecific defence against bacteria, fungi and viruses is becoming clearer. Oligosaccharides, glycolipids and glycoproteins containing sialic acid residues may have a role as antimicrobials. Also, immunoglobulins from vaccinated cows may be considered as natural antimicrobials with certain advantages over synthetic antibiotics.
Milk is a complex mixture of specific bioactive proteins, lipids and saccharides and contains numerous biologically active substances such as immunoglobulin, enzymes, antimicrobial peptides, oligosaccharides, hormones, cytokines and growth factors. Fresh milk contains a mixture of antimicrobial agents that exhibit bacteriostatic and even bactericidal activities. Mammalian milk contains more than 60 different enzymes including digestive enzymes (proteinases, lipases, amylases and phosphatases) and enzymes with antioxidant and antimicrobial characteristics (like lysozyme, catalase, superoxide dismutase, lactoperoxidase, myeloperoxidase, xanthine oxidoreductase, ribonuclease, etc.) that are important in terms of milk stability and in terms of protection of mammals against pathogenic agents. Whey proteins possess antimicrobial, anti-carcinogenic, immune-stimulatory, health promoting activities.
Lactose and other oligosaccharides comprise the third most abundant constituent of milk. Lactose is fermented to lactic acid that reduces the pH and influences the physical properties of casein and thus promotes digestibility, improves utilisation of calcium and other minerals and inhibits the growth of harmful bacteria. The individuals that are intolerant to lactose have insufficient activity of ß-galactosidase that causes intolerance to milk sugars. However due to its lower lactose content, fermented milk can be tolerated by people with reduced ability to digest lactose.
Almost all milk components contribute potential health benefits including proteins, peptides, lipids, minor carbohydrates, minerals, and vitamins. Some dairy product which people consume regularly in their daily life is: yogurt and other fermented dairy foods, milk, colostrum, cheese, whey protein concentrates / isolates, milk protein concentrates and more.
The function of fermented dairy products is either directly through the consumed microorganisms or indirectly as a result of action of microbial metabolites like vitamins, proteins, peptides, oligosaccharides and organic acids generated during fermentation process.
Mixtures of probiotics and prebiotics, that favourably modify the gut flora and its metabolism by increasing the survival of health promoting bacteria, are described as synbiotics. The major applications for probiotics are in dairy foods while prebiotics are added to dairy products, table spreads, baked goods and breads, breakfast cereals and bars, salad dressings, meat products and some confectionery items.
Milk proteins include caseins, ß-lactoglobulin, a-lactalbumin, immunoglobulins, lactoferrin and serum albumin that exert their biological activities either directly, or after degradations to different peptides that, through their action, affect not just the immune system, but also cardiovascular and nervous systems.
Milk proteins are currently the main source of a range of biologically active peptides such as casomorph immunopeptides, lactoferrin, lactoferricin and phosphopeptides. Fermented milks are also a rich source of whey as a-lactalbumin, 3- lactoglobulin, lactoferrin, lactoperoxidase, immunoglobulins growth factors. These proteins have demonstrated a number of biological effect anti-carcinogenic activities to different effects on the digestive function. Hydrolysis of a-lactalbumin produces peptide Oly-Leu-Phe with immunomodulatory effects which stimulates phagocytosis through specific receptors as well as respiratory burst of neutrophiles. Lactoferrin, a multifunctional glycoprotein, is present in milk in smaller concentration and has many physiological roles which include regulation of iron homeostasis, host defence range of microbial infections, anti-inflammatory activity and anti-cancer. Kitts and Weiler (2003) defines bioactive peptides as specific protein fragment that insert a positive impact on body functions or conditions and may ultimately influence health are considered the most important source of bioactive peptides that are beneficial risk of obesity and development of type two diabetes. Bioactive peptides, generated during milk ferment starter cultures, have been found in a number of dairy products, such as yoghurt and sour milk, various cheese varieties and fermented milks. Many biologically active peptides are formed during cheese ripening like calcium phosphopeptides (CPPs) have been identified in cheddar and comte cheese.
Lactulose is a disaccharide that forms during heat processing of milk and has beneficial health effects mainly by selective stimulation of growth and/or activity of probiotic bacteria including bifidobacteria and lactobacilli. The sour milk also contains some polysaccharides in addition to natural oligosaccharides produced by probiotic bacteria as well as their hydrolysed products like kefiran, basic bioactive component of kefir, that contribute their stability and organoleptic properties. Kefir is used for its beneficial effects in a variety of conditions including metabolic disorders, atherosclerosis, tuberculosis, allergic reactions and gastrointestinal disorders.
Milk also contains fat. Milk fat is known for its high content of saturated fatty acids and has been associated with atherogenic blood profile and increased risk of coronary heart diseases. However only three (lauric, myristic, palmitic) of different saturated fatty acids in milk have the property of raising blood cholesterol levels, and at least one-third of the fatty acids and unsaturated with the properties of lowering the blood cholesterol levels.
Almost all components of milk have a physiological function beyond nutrition. Milk components are multifunctional and dairy foods possess a natural “cluster” of nutrients that protect health and enhance the immune system. Hence incorporating more and more variety of milks and milk products in the upcoming and exponentially progressing nutraceutical industry would be an excellent opportunity for growth and progress of the market.
Bibliography
- Z.F.Bhat and Hina Bhat; Milk and dairy products as functional foods:A review; international journal of dairy science 6 (1),1-12: 2011.
- Sudhanshu K Bharti, Neeraj Kumar Sharma et al;Functional aspects of dairy foods in human health: An overview; critical review in pharmaceutical science.
- Daniel Granato, Gabriel F. Branco et al; Probiotic dairy products as functional foods; comprehensive reviews in food science and food safety.
(The author is junior research fellow, Kasturba Health Society Medical Research Centre, Mumbai. She can be contacted at nidhishukla67@yahoo.in)
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TOPICS
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