Katekan Dajanta

Comparison of physical and chemical properties of high pressure- and heat-treated Lychee (Litchi chinensis Sonn.) in syrup

Lychee usually has white flesh, but its flesh is very sensitive to thermal and enzymatic impairment and ultimately changes in color. This investigation was intended to study the magnitude of color change in lychee by high pressure and thermal processing. The lychee was packed in syrup prior to being processed. Pressurized lychee was performed at 600 MPa at 30°C or 50°C for 20 min, while the pasteurized sample was heated at 90°C for 3 min. It was found that pressurization induced lower color L*, a* and b* values, including low anthocyanin content. For enzymatic activities, high pressure could reduce the activity of polyphenoloxidase by 33–51%, whereas pasteurization markedly reduced that activity by 90%.

Antioxidant Properties and Total Phenolics of Thua Nao (a Thai Fermented Soybean)as Affected by Bacillus-fermentation

The present investigation was aimed to observe the correlation of morphology of various isolates of Aspergillus niger on the production of Polygalacturonase (PG) and Pectin Methyl Esterase (PME) with the concept to develop a screening procedure for high enzyme producing strains of Aspergillus niger grown on agri waste . The strains were isolated from orange peel, tamarind seed powder, groundnut, carrot, pomegranate peel and apple baggasse, soil, waste water and bread. The maximum enzyme activity (PG: 2.20 ± 0 . 05μmoles/ml/min & PME: 0 . 73±0.08μmoles/ ml/min) was observed with the smallest spore size of Aspergillus niger obtained from orange peel (5.49±2.56μm). However, no correlation of conidiophore size, height of conidial stalk on pectinase production was noted. There is no report found on the level of pectinases in strain of Aspergillus niger grown on tamarind seed powder which showed considerable amount of pectinases in present study.