Utilization of seeds from tomato processing wastes as raw material for oil production

Abstract

The increase of waste quantities from tomato processing industry is an important ecological and also financial problem. Seeds are the major component of this waste and one valuable alternative of transforming them into raw materials is oil extraction. The isolated oil can be used for nutritive or industrial purposes. In this research, the influence of some extraction parameters (time, solvent and granularity of tomato milled seeds) on the fatty acid (FA) composition, water content and water reaction rate has been evaluated. The FA composition of tomato seed oil, determined by gas chromatography–mass spectrometry, has shown a high content of linoleic acid (20.8–39.9 mg/mL), followed by palmitic acid (6.3–19.3 mg/mL), oleic acid (2.5–14.2 mg/mL), linolenic acid (0.7–4.9 mg/mL), stearic acid (0.1–0.8 mg/mL), palmitoleic acid (0.03–0.5 mg/mL), arachidic acid (0.08–0.4 mg/mL), myristic acid (0.05–0.2 mg/mL) and margaric acid (0.02–0.11 mg/mL). The oil content of tomato seeds was registered in the range of 13.3–19.3 %. For evaluation of water content, a method using Karl Fischer titration (KFT) has been established. Comparing with the physical methods that do not distinguish the water content from volatile matter, KFT is an important technique, very accurate, that determines water content by a chemical reaction.