Types of Functional Foods
Different types of functional foods have been launched in different categories e.g. bakery, confectionery, dairy, probiotics, meat, baby foods etc. [19].
1.4.1 Dairy Based Functional Foods
Milk is a nearly complete food with good amount of proteins, fat, minerals. Dairy products contain various biologically active compounds like bioactive peptides, antioxidants, vitamins, lactoferrin, immunoglobulins, oligosaccharides, conjugated linoleic acid, organic acids, melatonin etc. These bioactive compounds have been associated with lots of bioactivities e.g. haemodynamics, modulating digestive and gastrointestinal functions, favoring and maintenance of intestinal microflora etc. [20]. Different examples of functional foods commercially available are ‘Calpis’ sour milk with functional ingredients for lowering the blood pressure developed by Calpis Co. (Japan); ‘BioZate’ hydrolysed whey protein isolate containing β-lactoglobulin fragments for regulating blood pressure and ‘BioPure-GMP’ whey protein isolate containing glycomacropeptide as functional ingredient for regulating blood pressure, dental issues, viral and bacterial infections were developed by Davisco (USA); protein hydrolysates named ‘C12’ and ‘Cysteine peptide’ with functionality of lowering the blood pressure and maintaining high energy level respectively developed by DMV International (The Netherlands); ‘Clarinol’ yoghurt formulation with conjugated linolenic acid to reduce body weight (Lipid Nutrition, USA). Dairy products like drinks, yoghurts and spreads are suitable carrier for functional food formulation. Major section of functional foods is occupied by dairy products and is expected to increase at compound annual growth rate (CAGR) of about 8% in coming years [21].
1.4.2 Cereal Based Functional Foods
Cereal grains are grown all over world due to their adaptations to wide range of environmental conditions and are the staple food across the globe [22, 23]. Different cereals consumed are wheat, rice, maize, sorghum, barley, millets possess numerous macro, micronutrients and bioactive compounds accounting for numerous health benefits [24]. Different bioactive compounds present in cereals viz., tannins, phytates, phenolics, flavonoids, carotenoids, anthocyanins, phytosterols and fibers etc. have been associated with lowering cholesterol level, oxidative stress, prevent cardiovascular disease, diabetes, obesity and cancer etc. This clearly indicates about their potential for usage as functional food ingredient [25]. The fibers like β- glucan, arabinoxylans and oligosaccharides like galacto- and fructo- oligosaccharides and resistant starch stimulates and maintains the growth of intestinal microflora and also act as prebiot-ics [13]. The immature kernels of grains contain higher amount of lysine, fructans, and simple sugars and thus appropriate to be used in functional foods [26]. The extraction and purification of such biologically active ingredients can be attained by knowledge of their distribution pattern in grain and concentration at different maturity levels and advanced processing technologies. β-glucan is a valuable dietary fiber present in barley and oats, accounting for reducing the cholesterol level and glycemic index. Extracted β-glucan have been incorporated in various products like breakfast cereals, baked products, pasta, chews, nutrition bars, yoghurt, ice-cream, beverages and dietary supplements. The different industries like Cargill, Kerry Group, Angel Yeast Co. Ltd., Agroingredients Technology, Super beta glucan, Immuno medic, DSM, Ohly, Tate & Lyle PLC, Frutarom, Sigma Aldrich Corporation, Alltech Life Sciences, Parrheim Inc., Lesaffre International, Biorigin, Nutraceuticals Inc., Speciality Biotech, Ceapro Inc., and GlycaNova are the leading key player industries for beta glucan.
Resistant starch is defined as starch which is resistant to digestion in small intestine and passes to the large intestine and is fermented by intestinal colon microflora. Resistant starch fermentation produces short chain fatty acids, acetates, propionates and butyrates [27]. Resistant starch can be incorporated in wide range of food due to their water solubility and indigestibility without any impact on sensory profile of food. This will provide bulk to food sample without contributing calories. The prolonged consumption of resistant starch may decline the fasting cholesterol and triglycerides and increases the absorption of micronutrients [28]. Lopez et al., [29] reported the improved absorption of minerals (calcium, magnesium, iron, zinc and copper) in intestines of rats when fed on a resistant starch rich diet.
Oilseeds are a rich source of proteins, fiber, fat, minerals, vitamins and bioactive compounds such as flavonoids, tocopherols, phenolics, lignans, tocotrienols, peptides and thus considered as suitable functional ingredient [30–32]. This rich phytochemical profile accounts for high antioxidant activity and also accounts for reducing the oxidative stress and cancer also. Oilseed fat is rich in n-3 and n-6 fatty acids polyunsaturated fats (PUFA) with higher concentration of linoleic acid and decline the risk of inflammation, cardiovascular disease, blood pressure, rheumatoid arthritis, sclerosis and cancer etc. [33]. The hydrolysis of sesame hydrolysate with pepsin, papain and alcalse produced the peptides with enhanced digestibility, antihypertensive characteristics and antioxidant profile [34].
1.4.3 Fruits and Vegetables Based Functional Foods
Fruits and vegetables contain abundant amount of various nutrients like vitamins, minerals, dietary fibers and health promoting phytoconstituents such as polyphenols, tannins, flavonoids, carotenoids [35]. Reservatol is important phytoconstituent in various fruits like berries, mulberry, pines, Indian blackberry, grapes and jackfruit etc. [36, 37]. This compound reported as anticancer, antioxidant, anti-inflammatory, antiallergic, platelet anti-aggregation, cardioprotective and modulator for lipid metabolism [38–40]. The postharvest treatment using ultra-violet radiation has been reported to develop grape berries with higher stilbenes [41] and functional table grapes [42] and grape juice with higher resveratrol concentration [43]. Various clinical, epidemiological and in-vitro studies suggested the health-beneficial characteristics of red wine in prevention of cardiovascular diseases and cancerous cells [44]. Resveratrol has been reported to act as antioxidant, antimutagen, anti-inflammatory, antipromotion activity, and anti-initiation, and antiprogression activity [45, 46].
Lycopene is a natural carotenoid pigment with antioxidant potential and provides red and pink color to fruits and vegetables like tomatoes, pink grapefruit, watermelons etc. The antioxidant potential has been demonstrated to possess protective effects against oxidative stress, atherosclerosis, hypertension, sunburn, infertility, liver damage, metabolic syndrome and diabetes [47, 48]. Lycopene has been extensively used as functional ingredient in different food formulations such as energy drinks, syrups, nectars, soft drinks, bakery, dairy, and meat products [49].
The consumer interest is more in dried fruits and vegetables as snacks to reduce the consumption of high energy desserts and consider these as a more healthy option [50]. The waste pomace from fruit and vegetable industry is also source of pectin, hemicelluloses, lignin and cellulose and can be used as functional ingredient in different food formulations [51, 52].
Herbs are small annual/perennial plants with aromatic quality and have juicy stems. These provide unique flavour and aroma to the food as well as possess health promoting benefits. Herbs are the valuable source of various types of the functional ingredients e.g. curcumin, menthol, gingerol, black pepper, capsaicin and coumarin in turmeric, peppermint, ginger, black pepper, chilli and coriander respectively [53]. Curcumin, characteristics component of turmeric, exhibited huge therapeutic potential and are effective in treatment of Parkinson’s disease, Alzheimer, sclerosis, cerebral injury, cardiovascular disease, cancer, diabetes, allergy, asthma, obesity, depression and bronchitis etc. [54, 55]. GRAS approval of curcumin has favoured its incorporation in wide range of foods like probiotics, beverages, soups, snacks, candy, baked products etc. and integral component of active packaging material [56–58].
1.4.4 Seafood, Meat and Poultry Based Functional Foods
Fish is an important component of staple diet of large population groups and provides high quality protein, lipids, vitamins and minerals. Fish is richest source of omega-3- polyunsaturated
