International Journal of Dairy Technology最新文献

Casein (CN) is the major family of proteins in milk and can cause allergic reactions in some infants and children. This study investigated the regulatory mechanisms of three animal-derived proteases on allergenic epitopes. The results showed that all three proteases effectively reduced the antigenicity of CN. After hydrolysis, the secondary structure of CN underwent a conformational transition from α-helix to β-turn. Based on peptidomics analysis, the allergenic epitopes of αs1-CN at positions 91–110, 131–151, 166–180 and 188–201 were effectively cleaved by pepsin, and the allergenic epitopes of β-CN at positions 60–69, 139–158 and 182–194 were effectively cleaved by pancreatic elastase.

Upon spray drying of dairy powders, the distribution of components within the droplets can become nonuniform. In this study, the influence of the composition on the drying behaviour, morphological development and surface composition were studied using single droplet drying. The addition of fat was found to result in an earlier locking point (1.1 instead of 1.8 s). The fat content did not influence the morphological development, but the protein and lactose ratios did influence whether the dried particle was smooth or wrinkled. Confocal Raman microscopy revealed that the initial fat, lactose and protein contents influenced the dry surface composition. For example, fat was found on the surface of emulsions that were either rich in fat or in whey protein.

β-Galactosidases are crucial enzymes that hydrolyse oligosaccharides and polysaccharides with terminal β-1,4-glycosidic bonds. Though the traditional application of β-Galactosidases has been to catalyse the breakdown of lactose in dairy products, its application extends beyond the production of lactose-free products since variants capable of facilitating lactose condensation and exhibiting galactosyl transferase activity are extensively utilised for the synthesis of prebiotic galacto-oligosaccharides. This review analyses β-Galactosidase in multiple aspects, including sources, classification, characterisation, immobilisation, genetic engineering and applications in terms of whey treatment, biofuel production, production of lactose-free dietary product, synthesis of galacto-oligosaccharides and the early detection of cellular senescence and tumours.

To obtain functional fermented dairy products with strong probiotic proliferation and high antioxidant ability, the proliferation ability of oligosaccharides on probiotics and their DPPH radical scavenging ability were studied. Key functional oligosaccharides (galactooligosaccharide and galactomannan oligosaccharide) and probiotics (Bifidobacterium bifidum and Lactobacillus acidophilus) were selected. The orthogonal experimental design of L9(3⁴) was employed to study the optimal process, which was adding 5 g/L galactomannan oligosaccharide and 5 g/L galactooligosaccharide in reconstituted milk, inoculating 1% Streptococcus thermophilus, 1% Lactobacillus bulgaricus and 1% probiotics (B. bifidum and L. acidophilus = 2:1) and fermenting for 6 h. This work is important for preparing functional fermented dairy products with a high content of probiotics and strong antioxidant capacity.

The feasibility of incorporating different concentrations (0; 1% – ‘Y1’; 7% – ‘Y7’) of coenzyme Q10 (CoQ10)-loaded nanoemulsions (Ynano Q10) in yogurts was evaluated, as well as the bioactive's stability during static in vitro digestion. Yogurts were characterised regarding CoQ10 concentrations, physicochemical/rheological properties and sensory acceptability. Ynano Q10 incorporation has not negatively affected yogurts properties, stability and overall acceptance on sensory tests. Bioactive's stability during in vitro digestion was higher in Ynano Q10 than in fortified yogurts; however, CoQ10 concentrations in yogurts after the intestinal phase (0.008% for Y1 and 0.175% for Y7) were sufficiently high, considering CoQ10 recommended daily intake.