Every industry, including food industry has the goal of obtaining the most quality product with the best possible use of raw materials, with the minimum amount of waste, where waste does not necessarily have to be "waste" but may represent a by-product or raw material in some future process. Nowadays, a tendency for reducing food industry waste is becoming more prominent due to a growing interest for utilization of food industry by-products for various purposes. These by-products contain many potentially useful substances and they could become significant raw materials in the production/development of new products. In this research, extracts of various food industry by-products of the plant origin have been produced: walnut partitions, cocoa bean shells, coffee parchment, Teran and Merlot grape seeds, grape skin, cherry seeds, watermelon seeds, apricot kernels, and their antioxidative and antibacterial activity is determined. Antioxidant activity of extracts was determined by DPPH method. Antibacterial activity was conducted against four test bacteria strains: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in terms of minimum inhibitory concentrations by a modified broth microdilution method. The highest antioxidant activity was determined in the extract of the walnut partitions (18.80 mg/mL), and the extracts of walnut partitions and coffee parchment (0.0156 mg/mL - E. coli, 0.0156 mg/mL - P. aeruginosa, 0.0078 mg/mL - B. subtilis, 0.0625 mg/mL - S. aureus) showed the highest antibacterial activity. Furthermore, the effect of the extraction method (cold pressing and supercritical \(CO_{2}\) extraction) on the isolation of apricot and grape seed oil was tested. In apricot seeds, emphasis is given to the content of amygdalin, and in grape seeds on polyphenols that are determined by the high performance liquid chromatography (HPLC). The fatty acid composition in the obtained oils was determined by the gas chromatographic method with the flame detector GC/FID. This paper offers a potential solution against generation of large amounts of organic waste, which represents a huge ecological and financial burden in almost all branches of food industry.