Kinetic model and optimization for enzyme‐assisted hydrodistillation of d‐limonene‐rich essential oil from orange peel

Abstract

AbstractThe present research has been planned to evaluate the effect of enzymatic maceration on the recovery of essential oil during hydrodistillation of orange (Citrus sinensis L.) peel. In the execution phase, the orange peel was hydrolysed under different conditions regarding enzyme concentration, liquid‐to‐solid ratio, temperature and incubation time, which established that hydrolysis of orange peel with 3.9% (mL/100 g) Viscozyme L® at liquid/solid ratio of 4.0 (mL/g) and 55°C for 3.8 hours can produce essential oil fourfold higher as compared to untreated orange peel. The kinetic modelling of the data further established that the incorporation of enzymatic pretreatment can reduce the extraction time up to 4 hours without any loss of aroma compounds. The GC‐MS analysis of orange peel essential oil obtained under optimum conditions of enzyme‐assisted hydrodistillation (EAHD) revealed the presence of D‐limonene as a major constituent (66%) followed by β‐caryophyllene (23%) and isopropyl myristate (11%). Moreover, the orange peel essential oil expressed via EAHD showed a good tendency to neutralize free radicals and protect linoleic acid under ambient conditions. Henceforth, it might be brought forward that enzyme‐assisted hydrodistillation worked more efficiently and economically than the conventional counterpart.