Optimization of olive pomace enzymatic hydrolysis for fermentable sugar production

Abstract

Purpose

The purpose of this paper was to find out the appropriate enzymatic hydrolysis conditions of alkali pretreated olive pomace (OP) which enable maximum yield of reducing sugar.

Design/methodology/approach

The commercial enzymatic preparation (Viscozyme^® L) was used for the hydrolysis of OP. The effects of pretreatment, time, temperature, pH, enzyme quantity and substrate loading on the hydrolysis yield were investigated.

Findings

This study showed that enzymatic hydrolysis of OP using Viscozyme^® L can be successfully performed at 50°C. Alkaline pretreatment step of OP prior the enzymatic hydrolysis was indispensable. The hydrolysis yield of alkaline pretreated OP was 2.6 times higher than the hydrolysis yield of untreated OP. Highest hydrolysis yield (33.5 ± 1.5 per cent) was achieved after 24 h using 1 per cent (w/v) OP load in the presence of 100 μl Viscozyme^® L at 50°C and pH 5.5 with mixing rate of 100 rpm (p = 0.05).

Originality/value

Reaction time, temperature, pH value and enzyme quantity were found to have a significant effect on enzymatic hydrolysis yield of alkali pretreated of OP. Although high-solid loadings of OP lowered the hydrolysis yield, it produced higher concentration of reducing sugars, which may render the OP conversion process more economically feasible.

Citation

Abo Chameh, G., Kheder, F. and Karabet, F. (2016), "Optimization of olive pomace enzymatic hydrolysis for fermentable sugar production", Nutrition & Food Science, Vol. 46 No. 6, pp. 778-790. https://doi.org/10.1108/NFS-03-2016-0038