KINETIC STUDIES OF AN AMYLASE USED COMMERCIALLY FOR THE CLARIFICATION OF APPLE JUICE

• Published in: Journal of food processing and preservation Vol. 26; no. 2; pp. 153 - 163
• Main Authors: CARRIN, MARIA E., CECI, LILIANA, LOZANO, JORGE
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2002; Blackwell Publishing
• Subjects: Biological and medical sciences; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Use and upgrading of agricultural and food by-products. Biotechnology; Enzymatic treatment; Clarifying; Apple; Fruit; Enzymatic activity; Amylase; Enzyme; pH; Fruit product; Kinetics; Calcium Chlorides; Fruit juice
• ISSN: 0145-8892; 1745-4549
• DOI: 10.1111/j.1745-4549.2002.tb00859.x

ABSTRACT The effect of substrate and enzyme concentrations on the degradation of soluble corn starch with a commercial amylase (Rohalase HT) recommended for apple juice clarification was studied. The reaction was conducted at 50C at different pH values (3.6–5.6). Starch solutions containing from 2.48 to 14.85 mg/mL were used as substrate in the experiments. Influence of Ca2+ on amylase activity was also determined. Obtained results showed that amylase exhibits an optimal activity pH value of 4.6, following a Michaelis‐Menten type kinetics (Km= 8.11 mg/mL and vmax= 2.19 U/mg enzyme). The activity of amylase decreased significantly when CaCl2 was added to the amylase solution (final amylase concentration in reaction mixture: 5–10 mM). An empirical equation relating the rate of product of hydrolysis formation (dCm/dt) with starch (Cst) and amylase (Ce) concentrations was obtained: