EFFECT OF INFRARED THERMAL PRE-TREATMENT OF SESAME SEEDS (SESAMUM INDICUM L.) ON OIL YIELD AND QUALITY

The aim of the study was to determine the effect of thermal infrared treatment of Indian sesame seeds (Sesamum indicum L.) on the yield and quality of extracted oil. The infrared radiation treatment of the seeds was applied for 30s, 60s, 90s, 120s, and 150s at a temperature of 180oC. The mean moisture and fat content in the seeds was 7,46 and 45,61%, respectively. The extracted oil was assessed in terms of the hydrolysis degree (AV), primary oxidation degree (PV), oxidative stability in the Rancimat test, and content of carotenoid and chlorophyll pigments. Additionally, the composition and percent content of fatty acids in the oil pressed from the seeds were evaluated prior to the thermal treatment. The study has shown that the infrared thermal treatment of sesame seeds contributed to an increase in the oil extraction efficiency, compared to the control sample. The highest increase in the oil yield was found in the case of seeds heated for 120s. Simultaneously, there was a reduction of the quality of these oils accompanied by increased oxidative stability. The induction time in oils extracted from infrared-treated seeds increased gradually together with the increase in the length of the heating process. The longest induction time (9,53 h) was noted in sesame oil obtained from seeds heated for 150s.