Veerappa H. Mulimani

Reduction of flatus‐inducing factors in soymilk by immobilized α‐galactosidase

α‐Galactosidase from Aspergillus oryzae was immobilized on chitosan beads using glutaraldehyde as a cross‐linking agent. The general properties of free and immobilized enzymes were determined. The optimum pH for the free and immobilized enzymes was 4.8 and 4.6 respectively. The optimum temperature for the free enzyme was 50 °C, whereas that of immobilized enzyme was increased to 56 °C. Kinetic parameters were determined with synthetic substrate (p‐nitrophenyl α‐D‐galactopyranoside) and raffinose. Immobilized enzyme showed a higher Km and a lower Vmax than the free enzyme. The immobilized enzymes were used in batch, repeated and continuous mode. A level of 92% hydrolysis was observed at a flow rate of 60 ml/h. The immobilized enzyme was used repeatedly ten times without any change in the performance of the immobilized enzyme in fluidized‐bed reactor. The results obtained are of considerable interest for industrial purposes.

Production of α-Galactosidase by Aspergillus oryzae through solid-state fermentation and its application in soymilk Galactooligosaccharide hydrolysis

α-Galactosidase was produced by Aspergillus oryzae on red gram plant waste-wheat bran based media in solid-state fermentation (SSF). Optimum temperature for α-galactosidase production was 35 0C and upto 4 cm of bed height of substrate had no inhibitory effect on enzyme production. Hydrolysis of galactooligosaccharides in soymilk was carried out by α-galactosidase. Optimum temperature and pH for the hydrolysis of raffinose and stachyose of soymilk were 550C and 5.2-6.2, respectively. The enzymatic treatment for 3 h completely removed the raffinose oligosaccharides in soymilk. Crude extract also showed considerable amount of invertase activity.

Detection of legume protease inhibitors by the Gel-X-ray film contact print technique

Redgram (Cajanus cajan L.) extracts have been analyzed for the protease inhibitors using a new, sensitive, simple, and rapid method for detection of electrophoretically separated protease inhibitors. The detection involves equilibrating the gel successively in the protease assay buffer and protease solution, rinsing the gel in assay buffer, and later exposing it to an unprocessed x‐ray film. Gelatin on the film in places corresponding to the inhibitor bands remains unhydrolyzed. A simple and inexpensive laboratory experiment to detect protease inhibitors of legume seeds by the gel‐x‐r ay film contact print technique is described.

Investigating plant galactomannans

This paper presents a review of biological importance and occurrence of galactomannan in plants. Its chemical composition and structure are reviewed, and a short laboratory practical exercise on the isolation and determination of D‐mannose/D‐galactose ratio of plant galactomannan is presented.

Electrophoretic transfer technique to detect and identify amylases in polyacrylamide gels

A simple experiment to detect amylases of human saliva by electrophoretic transfer technique is described.