Determination of Physico-Chemical and Functional Properties of Plum Seed Cakes for Estimation of Their Further Industrial Applications

The extraction of bioactive compounds from the waste material in the food industry is an important approach because, in that way, the plant raw material can be utilized before its landfill disposal or combustion. The interest of scientists is great for the development of innovative procedures for the further application of these materials. Plum kernels obtained after plum processing can be used for the isolation of oil enriched with unsaturated fatty acids and cakes remaining after oil isolation from plant material. This study aimed to consider the possibilities of the further utilization of cakes obtained after oil isolation from plum seeds using organic solvents in the Soxhlet extractor. The physical-chemical and functional properties of the obtained cakes were determined. The results indicated that the plum seed cakes are rich in proteins (36.95-61.90%) and crude fiber (6.36-9.85%). The HPLC analysis showed that the highest content of phenolic compounds had coumaric acid in the concentration range of 11.31-12.98 mg/100 g of dry weight. The amygdalin content (0.005-0.139 mg/g of dry weight) was in the allowed concentration range so that the cakes can be considered safe for human use. The antioxidant potential of the cakes (IC50 0.40-0.65 mg/mL) indicated that antioxidants are also present in this waste material so that the cakes can be used as a raw material for the development of sustainable products in the food, pharmaceutical, and cosmetic industries.