Optimization of Lycopene Extraction from Tomato Processing Waste Skin Using Harmony Search Algorithm

Abstract

The skin of a tomato (Lycopersicon esculentum) is a rich source of lycopene, an important component of waste from tomato paste manufacturing plants. The lycopene content in the skin of a tomato pomace is about five times higher than in the pulp. According to the World Processing Tomato Council, 1,200,000 tons of tomato processing waste is produced worldwide annually. In this study, lycopene extraction from tomato skins is formulated as an optimization problem with respect to five independent variables, namely solvent/meal ratio, temperature, number of extractions, extraction time and particle size. The music-inspired harmony search (HS) metaheuristic algorithm is used to optimize the lycopene production, and the maximum lycopene (4.8 mg/100 g) was predicted when the solvent/meal ratio, temperature, number of extractions, extraction time and particle size is 20:1 v/w, 60 C, 5, 4 min and 0.43 mm, respectively. Response surface analysis (RSM) has been used in (Kaur et al, Food Chem 2008 [1]) to optimize the lycopene yield with respect to these variables, and the maximum yield predicted was 1.99 mg/100 g. Thus, the methodology applied in the present work for optimizing the extraction of lycopene is far better than response surface analysis. Further comparison with particle swarm optimization reveals that HS is more reliable optimization technique to solve the problem at hand.