Enzyme hydrolyzed bael fruit liquefaction and its kinetic study

Abstract

The study aims to explore the mechanism and optimize the process of enzyme hydrolyzed bael fruit (Aegle marmelos) liquefaction using two different enzymes: pectinase and macerozyme r-10 (enzyme mixture). A full factorial design was applied for the factors with 0.05–1.5% (w/w) enzyme concentration (EC), 30–60 °C temperature, and incubation time of 30–240 min for pectinase and 60–360 min for macerozyme. Quadratic polynomial models were developed, showing R2 ≥ 0.94. Multi-objective numeric optimization was followed to maximize the increase in yield, total reducing sugar (TRS), clarity, and minimizing EC, temperature and time. Enzyme-treated juice extracts were acceptable on the sensory scale with overall acceptability >5. Maximum pomace reduction of 58.8% and 78.9% along with rise in mono and disaccharides were observed after treating with pectinase (t = 240 min) and macerozyme (t = 360 min), respectively at identical 0.775% EC and 45 °C temperature. With the pectinase enzyme, an optimum Δyield of 32.4% was obtained at 0.82% EC, 43 °C temperature in 169.4 min. Subsequently, with the macerozyme, an optimum Δyield of 39.6% was attained at 0.96% EC, 45.6 °C temperature in 245.9 min. Substrate degradation in bael fruit by enzymatic hydrolysis with pectinase (EC = 0.01–1.50%, time = 2.5–240 min) and macerozyme (EC: 0.01–1.50%, time: 5–360 min) was studied at their respective optimum temperatures. The modified Michaelis-Menten showed a good fit (R2 > 0.98) with the non-linear curve fitting method. Macerozyme treatment showed slower enzyme activity with higher substrate degradation but lower nutrient content compared to the pectinase treatment.