Ashok K. Pathera

PRODUCTION OF TANNASE UNDER SOLID-STATE FERMENTATION AND ITS APPLICATION IN DETANNIFICATION OF GUAVA JUICE

Guava juice is known to be rich in antioxidant activity due a high level of vitamins A and C. However, tannins present in the guava juice form tannin–protein complexes that affect the utilization of vitamins and minerals and inhibit digestive enzymes. Beside this, bitterness and cloudiness are the other major problems of juice industries. The present study aimed to utilize a low-cost substrate (tea residue) for the production of tannase and its application in detannification of guava juice. Solid-state fermentation (SSF) was evaluated to produce tannase from Aspergillus niger. Maximum tannase (1.86 U/g dry substrate) production was observed at 30°C after 96 hr of the incubation period. The optimum pH of the moistening agent was found to be 5.0. Partially purified enzyme using ammonium sulfate precipitation was subjected to guava juice treatment at a level of 0.5, 1.0, and 2.0% for 30 and 60 min. Decrease in tannic acid content of guava juice was found to be 17.60, 29.04, and 44.38% after 30 min and 40.59, 53.69, and 59.23% after 60 min, respectively.

Effect of Dietary Fiber Enrichment and Different Cooking Methods on Quality of Chicken Nuggets

The effect of dietary fiber enrichment (wheat bran) and cooking methods (oven, steam and microwave) on functional and physico-chemical properties of raw nuggets formulation as well as nutritional, color and textural properties of chicken nuggets were analyzed in this study. Among different cooking methods used for nuggets preparation, steam cooked nuggets had significantly (p<0.05) higher water holding capacity (56.65%), cooking yield (97.16%) and total dietary fiber content (4.32%) in comparison to oven and microwave cooked nuggets. The effect of cooking methods and wheat bran incorporation was also noticed on textural properties of the nuggets. Hardness, firmness and toughness values of oven and steam cooked nuggets were significantly (p<0.05) higher than microwave cooked nuggets. Among nuggets prepared by different cooking methods, cohesiveness of microwave cooked nuggets was found to be significantly (p<0.05) highest, whereas, oven cooked nuggets had significantly (p<0.05) highest gumminess and chewiness values. Steam cooked nuggets were found to be better among all nuggets due to their higher cooking yield and dietary fiber content.

Effect of cooking methods on lipid oxidation, microbiological and sensory quality of chicken nuggets under refrigerated storage

Abstract This study was conducted to evaluate the effect of oven, steam and microwave cooking methods on lipid oxidation, microbiological and sensory quality of chicken nuggets. Nuggets were prepared and analyzed at a regular interval of 5 days from day of production to spoilage of products under refrigerated storage. Cooking methods significantly affected the lipid oxidation of nuggets under refrigerated storage. Highest lipid oxidation was reported in microwave cooked nuggets, however cooking methods did not affect the microbiological quality of nuggets during storage. Products were safe for consumption up to 15 days at refrigerated storage as the microbial count had not exceeded the permissible limit. Steam cooked nuggets had better sensory scores in comparison to microwave and oven. Overall acceptability scores for all the products were more than 6.0 at the end of storage period, reflecting more than moderate acceptance till the products were microbiologically safe.