Functional dairy products as a source of bioactive peptides and probiotics: current trends and future prospectives

Abstract

Milk is an incredibly healthy food world-wide. However, the 'lactase deficient' individuals cannot digest milk's carbohydrate lactose. A large part of the world population is depriving of highly beneficial milk proteins like casein, lactoalbumin, lactoglobulin, etc. due to lactose intolerance. Production of functional foods and bioactive peptides from milk with natural antioxidants and the addition of probiotics could be the best alternative to extend the use of milk functionalities. Among different probiotics, the lactic acid bacteria (LAB) like Lactobacillus delbrueckii sub sp. bulgaricus, Streptococcus thermophilus and some species of Bifidobacteria and their metabolites (paraprobiotics and postbiotics) have been given more preference to add in milk-derived functional foods. These species are generally considered as heat-tolerant, highly proteolytic, and peptidolytic towards milk proteins and they liberate smaller molecules of bioactive peptides during fermentation and other processes that stimulate the enzyme lactase to help people in digestion of milk carbohydrate lactose. Moreover, the incorporation of natural antioxidants in yoghurt and other dairy products prevents the rancidity of milk fat. The level of bioactive peptides produced in milk-derived functional foods can be determined by capillary zone electrophoresis, mass spectrometry, fractionation, and other modern assessment techniques. Commercial production of functional probiotic products with bioactive peptides could significantly contribute to reduce milk spoilage, enhance health benefits as well as the growth of the agro-processing industry.

Keywords: Bioactive peptides; Fermented dairy products; Lactic acid bacteria; Milk; Natural antioxidants; Probiotics.

Fig. 1

Functional and probiotic foods: health benefits of a functional foods (Levy 2019) and b probiotics (Tripathi and Giri 2014); and c natural sources of probiotic (Kerry et al. 2018a, b)

Fig. 2

Chemical structures of major antioxidants naturally occurring in plants and herbs

Fig. 3

a bioactivities of peptides (Mora et al. 2018) and b formation of bioactive compound from major milk proteins (Korhonen and Pihlanto 2007)

Fig. 4

Approaches towards the discovering of bioactive peptides. Adapted from Daliri et al. (2018)