Milk from different species has been exploited for the isolation of various functional ingredients for decades. Irrespective of the source, milk is considered as a complete food, as it provides essential nutrients required by the human body. Proteins and their fractions are valuable sources of bioactive peptides that might exert a health beneficial role in the human body such as immune-modulation, antioxidant activity, ACE-inhibitory activity, anti-neoplastic, anti-microbial, etc. In milk, bioactive peptides may either be present in their natural form or released from their parental proteins due to enzymatic action. The increasing interest in bioactive peptides among researchers has lately augmented the exploration of minor dairy species such as sheep, goat, camel, mithun, mare, and donkey. Alternative to cow, milk from minor dairy species have also been proven to be healthier from infancy to older age owing to their higher digestibility and other nutritive components. Therefore, realizing the significance of milk from such species and incentivized interest towards the derivatization of bioactive peptides, the present review highlights the significant research achievements on bioactive peptides from milk and milk products of minor dairy species. Graphical abstract

Antioxidant peptide enriched casein hydrolysate (AO-CH) are receiving increasing attention due to their potential as functional ingredient. Encapsulation of AO-CH using maltodextrin-gum arabic (MD/GA) as wall material could represent an attractive approach to overcome the problems related to their direct application. Encapsulation parameter were optimized using different ratio of core to coat and proportion of coating material (10:0, 8:2, 6:4) under varying pH (2-8) for encapsulation efficiency (EE).The preparation P3 resulted in maximum EE (87%) using core to coat ratio 1:20, at pH 6.0 with 8:2 MD/GA ratio. The encapsulated preparation showed reduced bitterness ( < 0.05) compared to the casein hydrolysate together with maximum retention of antioxidant activity (93%). Further, the narrow range of particle size, indicates their better stability and represents a promising food additive for incorporation in food.

No abstract

Skim milk served as the base for the production of low‐calorie synbiotic yoghurt (LCSY) and four randomly selected indigenous LAB probiotic strains namely, Lactobacillus acidophilus (NCDC 13), Lactobacillus paracasei ssp. paracasei (NCDC 627), Lactobacillus rhamnosus (NCDC 610), and Lactobacillus plantarum (NCDC 344) were evaluated for their growth characteristics in skim milk. Lactobacillus rhamnosus with S. thermophilus 74 (LR_74) exhibited desirable pH (4.60 ± 0.01), acidity, significantly highest acidification rate (4.23 ± 0.03 × 10−3 pH units min‐), probiotic count (9.10 ± 0.10 log cfu/ml), and specific growth rate (0.47 ± 0.08 hr−1). Also, Power law model fitted best for skim milk inoculated with LR_74. Further, evaluation of prebiotics namely, inulin and oligofructose at different levels revealed that the combination of inulin and oligofructose at 2% significantly improved the viscosity (13.75 ± 0.33 Pa s), sensory, textural properties, and probiotic count (9.67 ± 0.02 log cfu/ml) of LCSY. Practical applications The results of our study reveal a suitable and compatible combination of yoghurt culture and probiotic culture which could further be exploited for the development of inulin/oligofructose or combination thereof, based synbiotic beverages and other fermented dairy products.

Sialic acid, being a biologically active compound, is recognised as an important component of milk and milk products. Almost all the sialic acid estimation protocols in milk require prior hydrolysis step to release the bound sialic acid followed by its estimation. The objective of this work was to estimate sialic acid in milk and milk products by fluorimetric assay which does not require a prior hydrolysis step thus decreasing the estimation time. The recovery of added sialic acid in milk was 91·6 to 95·8%. Sialic acid in milk was found to be dependent on cattle breed and was in the range of 1·68-3·93 g/kg (dry matter basis). The assay was further extended to detect adulteration of milk with sweet whey which is based on the detection of glycomacropeptide (GMP) bound sialic acid in adulterated milk. GMP is the C-terminal part of κ-casein which is released into the whey during cheese making. For detection of adulteration, selective precipitation of GMP was done using trichloroacetic acid (TCA). TCA concentration in milk was first raised to 5% to precipitate milk proteins, especially κ-casein, followed by raising the TCA concentration to 14% to precipitate out GMP. In the precipitates GMP bound sialic acid was estimated using fluorimetric method and the fluorescence intensity was found to be directly proportional to the level of sweet whey in adulterated milk samples. The method was found to detect the presence of 5% sweet whey in milk.