Among various fermented dairy products, yogurt has been a significant ingredient of the human diet for thousands of years. Consumption of fermented dairy products maintains the balance of intestinal microflora and improves the host metabolism. Yoghurt is most accepted dairy product as it is easily digested because during fermentation, milk protein, fat and lactose components undergo partial hydrolysis. Yogurt is categorized as a food of high nutritional value due to its relatively low fat content in combination with its high protein content, as well as vitamins of the B complex, phosphorus, magnesium and potassium. However, nutritional value of different yogurts may significantly vary depending on the type of milk and straining process. Yogurt has been shown to have various beneficial effects on many aspects of human health, like blood pressure, cholesterol reduction, muscle building and prevention of various metabolic diseases1 As far as gastrointestinal health is concerned, yogurt contains cultures of lactic acid bacteria that improve digestive system function through their positive impact on gut microflora, bowel transit and gastrointestinal immune responses2.
Yogurt is alive
Since yogurt is a culture of living healthy bacteria. There are millions of bacteria of various species persisting in yogurt. Streptococcus thermophilus and Lactobacillus bulgaricus are the species found in yogurt. These are the main/starter cultures in yogurt. The function of the starter cultures is to ferment lactose (milk sugar) to produce lactic acid. Further lactic acts on milk protein and give a universal texture to yogurt as well as an acidic flavor. Few other species are also found in yogurt like Lactobacillus acidophilus and Bifidobacterium bifidus.
Enrichment enhances quality of yogurt
Additionally, the low viability of probiotics causes the short shelf life of fermented dairy products. Thus, to maintain the health- benefiting properties of yogurt its viability should be prolonged. Antioxidants are known to increase the shelf life of food products, when added. In this context, plant extracts, a good source of antioxidants and exhibiting significant antioxidant activity4 may also enhance the viability of enriched yogurt. According to a study done by Mosiyani et al, basil and savory plant extract have enhanced the viability of probiotic bacteria and probiotic yogurt5. The beneficial effect of different extracts of Aloe barbadensis and Aloe arborescens in fermented milk and yogurt has also been reported7. Further yogurt was fortified with natural and synthetic preservative, showed higher antioxidant activity which is a crucial factor of yogurt quality. In another study when two plants namely Diospyros kaki and Nelumbo nucifera (origin from Korea) and Cudrania tricuspidata leaf extract when added to yogurt, enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt.
Consuming enriched yogurt improves human health as proved by various studies. Recently, the olive fruit extract enriched yogurt has been tested for human blood redox status as well as various physiochemical and metabolic parameters have been tested and it was found that consumption of the polyphenol-enriched yogurt helps to reduce body weight, blood pressure, LDL cholesterol levels and lipid peroxidation, whereas promote growth of beneficial lactic acid bacteria3. Another research study also reveals that the incorporation of the cryoconcentrated strawberry pulp in the yogurt resulted in a product with 3-fold more anthocyanins content and antioxidant activity6 . The better immune response was observed when a polysaccharide (extracted from a Korean citrus fruit) enriched yogurt is consumed. Further When yogurt were enriched with strawberry and peach fruits, their bioactive components, polyphenols and carotenoids respectively have been reported to be absorbed into the intestine to promote health benefits. Since vitamins and minerals are the important constituents of nutrition thus fortification of food with minerals and vitamins is trending nowadays. Thus moreover their addition does not alter any property of yogurt like pH, total titrable acidity, consistency, viscosity etc. Iron is fortified in the form of NaFeEDTA [ferrochel]. Vitamin D is fortified in the form of D3 encapsulated in casein micelles. Enriched yogurt showed enhanced bioavailability of vitamin D as well as improved sensory properties of yogurt.
Yogurt is rich in vital nutrients such as calcium, magnesium as well as potassium which defend from heart disorders and neural birth defects. Further it builds up immunity, strengthen bones and improves digestion. Since non fortified yogurt itself is highly beneficial for our health. Thus the enriched yogurt would definitely be a super food with additional properties which make possible a healthy way of life However, it may not be a suitable food supplement for all. A person having lactose intolerance or avoiding high sugar food would not prefer yogurt. Still yogurt is universally demanding food supplement. Concluding that the enriched yogurt could be served as a cheap and better food supplement of future.
- Kalliopi Georgakouli, Anastasios Mpesios, Demetrios Kouretas, Konstantinos Petrotos, Chrysanthi Mitsagga,Ioannis Giavasis, and Athanasios Z. Jamurtas.The Effects of an Olive Fruit Polyphenol-Enriched Yogurt on Body Composition, Blood Redox Status, Physiological and Metabolic Parameters and Yogurt Microflora. Nutrients. 2016, 8(6): 344
- Mosiyani ZG, Pourahmad R, Eshaghi MR. Investigating the effect of aqueous extracts of basil and savory on antioxidant activity, microbial and sensory properties of probiotic yogurt. Acta Sci Pol Technol Aliment. 2017, 16(3):311-320.
- Jaster H, Arend GD, Rezzadori K, Chaves VC, Reginatto FH, Petrus JCC. Enhancement of antioxidant activity and physicochemical properties of yogurt enriched with concentrated strawberry pulp obtained by block freeze concentration. Food Res Int. 2018,104:119-125.
- Chiodelli G, Pellizzoni M, Ruzickova G, Lucini L. Effect of Different Aloe Fractions on the Growth of Lactic Acid Bacteria. J Food Sci. 2017, 82(1):219-224.
- Joung JY, Lee JY, Ha YS, Shin YK, Kim Y, Kim SH, Oh NS. Enhanced Microbial, Functional and Sensory Properties of Herbal Yogurt Fermented with Korean Traditional Plant Extracts. Korean J Food Sci Anim Resour. 2016;36(1):90-9.
- Oh NS, Lee JY, Joung JY, Kim KS, Shin YK, Lee KW, Kim SH, Oh S, Kim Y Microbiological characterization and functionality of set-type yogurtfermented with potential prebiotic substrates Cudrania tricuspidata and Morus alba L. leaf extracts. J Dairy Sci. 2016 (8):6014-6025
- Lee MH, Kim M, Kim M, Kwak JH, Chang DH, Yu WK, Lee SH, Lee JH. Consumption of dairy yogurt with the polysaccharide rhamnogalacturonan from the peel of the Korean citrus hallabong enhances immune function and attenuates the inflammatory response. Food Funct. 2016 , 15;7(6):2833-9