Properties of sweetened Indian yogurt (mishti dohi) as affected by added tryptic whey protein hydrolysate.

Utilization of Indian sweetened yogurt (colloquially termed as Mishti Dohi), as vehicle for ACE inhibition and antioxidant activity, by added tryptic whey protein hydrolysate (TWPH) (@ 1, 2, 3 % v/milk), was attempted. Yogurt with 3 % TWPH exhibited non-significant (p > 0.05) difference for sensory attributes; but for body & texture; and maximum biofunctional properties, electing it for storage study (5 ± 1 °C). Flavor and body & texture scores registered significant (p < 0.05) decline under 14 days storage. ACE inhibition and antioxidant activity of control increased by 47.95 and 13.18 % and of experimental 24.58 and 13.43 %, correspondingly. Acidity rose to 1.18 % LA. Control samples conveyed 18.07 % and experimental of 20.77 % escalation for wheying-off. Tyrosine value was 27.04 µg.mL(-1). Among rheological attributes, firmness, quantified by texture analyzer TA-XT2i, dropped (p < 0.05), due to decrease of gel rigidity whereas work of adhesion revealed non-significant difference (p > 0.05), throughout.

Effect of microGARD on keeping quality of direct acidified Cottage cheese.

Direct acidified Cottage cheese could be kept well for only 10 to 12 days under refrigeration on account of its high moisture (~74 %) content and relatively high pH (~5.0). The study was, therefore, undertaken to improve the keeping quality of direct acidified Cottage cheese using MicroGARD. The effects of three different levels of MicroGARD 400 viz. 0.20, 0.35 and 0.50 % on the physico-chemical, microbiological and organoleptic properties were studied at four-day interval during storage under refrigeration (4-5 °C). Promising results were found using 0.50 % MicroGARD 400 for inhibiting psychrotrophs, yeasts and molds as well as retard the acidity development and proteolysis in Cottage cheese, thus extending its keeping quality. It was observed that addition of MicroGARD 400 at the level of 0.50 % considerably improved the flavour as well as the aesthetic quality of the product during storage and extended the shelf life of Cottage cheese from 12 to 26 days.

Discordance between in silico & in vitro analyses of ACE inhibitory & antioxidative peptides from mixed milk tryptic whey protein hydrolysate.

ACE inhibitory and antioxidative peptides identified by LCMS/MS, from mixed milk (Bubalus bubalis and Bos taurus) tryptic whey protein hydrolysate, were compared with the in silico predictions. α la and ß lg sequences, both from Bubalus bubalis and Bos taurus, were used for in silico study. SWISS-PROT and BIOPEP protein libraries were accessed for prediction of peptide generation. Study observed gaps in the prediction versus actual results, which remain unaddressed in the literature. Many peptides obtained in vitro, were not reflected in in silico predictions. Differences in identified peptides in separate libraries were observed too. In in silico prediction, peptides with known biological activities were also not reflected. Predictions, towards generation of bioactive peptides, based upon in silico release of proteins and amino acid sequences from different sources and thereupon validation in relation to actual results has often been reported in research literature. Given that computer aided simulation for prediction purposes is an effective research direction, regular updating of protein libraries and an effectual integration, for more precise results, is critical. The gaps addressed between these two techniques of research, have not found any address in literature. Inclusion of more flexibility with the variables, within the tools being used for prediction, and a hierarchy based database with search options for various peptides, will further enhance the scope and strength of research.

Effect of rate of addition of starter culture on textural characteristics of buffalo milk Feta type cheese during ripening.

The effect of rate of addition of starter culture on textural characteristics of buffalo milk Feta type cheese was investigated during ripening period up to two months. The textural characteristics of buffalo milk Feta type cheese in terms of hardness, cohesiveness, springiness, gumminess and chewiness were analyzed by using textural profile analyzer. The maximum hardness was found with cheese made using 1% culture, while the minimum was found with 2% culture. The cohesiveness and springiness decreased as the level of addition of starter culture increased. The chewiness of cheese also decreased, as the rate of addition of starter culture increased for cheese making. In addition to this, yield, moisture, fat, FDM, protein, salt and S/M of fresh buffalo milk Feta type cheese increased with the increase in rate of addition of starter culture; however, TS of experimental cheeses decreased.