BIOLOGICAL VALUE OF BY-PRODUCTS OF TOMATO PROCESSING

The article analyses the biological value of secondary products of tomato processing, namely tomato seeds, which are seldom considered in the food industry as an object of processing. Tomato seeds, a secondary raw material formed during manufacture of tomato products, are suggested as a source of bioactive substances to be further used in food technologies. The paper presents the results of theoretical and experimental studies of the physicochemical composition of tomato seeds. It has been confirmed that tomato seeds, due to their high content of proteins, lipids, and carbohydrates, have high nutritional and biological value that conforms to modem recommendations for creating healthy diets. Tomato seeds contain 27-30% of fat, 25-35% of nitrogenous extractives, 11-18% of nitrogen-free extractives, 2.5-5.8% of minerals, and 12-25% of cellulose. They are also rich in polyunsaturated fatty acids, phospholipids, macronutrients and trace elements, vitamin E. However, their nutritional value is significantly reduced by natural bioactive antialimentary substances that inhibit proteinases. The experiments have allowed establishing the activity of trypsin inhibitors - anti-nutrients contained in tomato seeds. Their activity was 0.30mg trypsin/g protein for technically mature seeds, and 0.52mg trypsin/g protein for biologically mature seeds. To reduce the activity of trypsin inhibitors, it has been suggested to use hydrothermal treatment and micronisation of tomato seeds. Hydrothermal treatment for 40min, with the temperature of the water 90-100 degrees C, reduced the trypsin inhibitory activity by 1-3%, as compared with the initial values. Micronisation, too, allowed significantly reducing the activity of inhibitors of tomato seed trypsin: keeping the samples for 60s in a microniser reduced the activity of trypsin inhibitors in the technically ripe tomato seeds by about 34%, and that in the biologically ripe ones by 28.8%. This research is important and topical, because it extends the range of possible applications of secondary raw materials obtained from tomato processing, namely tomato seeds, in the technology of canned products with high biological value.