Evaluation of bioactive compounds and antioxidant activity of ten seeds' residues from oil processing

Recent studies have highlighted that waste from the food industries is often rich in bioactive compounds that can be recovered and used again in a different market, therefore always contributing to the food economy [1]. This study aimed to investigate the bioactive compounds and radical scavenging effect of extracts from exhausted matrices of oil extraction from Cannabis sativa, Juglans regia, Prunus dulcis, Coriandrum sativum, Triticum aestivum, Nigella sativa, Avena sativa, Glycine max, Pimpinella anisum, and Pinus pinea. For this purpose, exhausted matrices were extracted using n-hexane and ethanol as solvents. The extracts were analysed by GC-MS analysis, while TPC was analyzed using the Folin–Ciocalteau method [2]. The radical scavenging activity was assessed using the DPPH and ABTS tests [2]. Additionally, samples were investigated for their ability for protection from lipid peroxidation [2]. Walnut’s n-hexane extract exhibited the highest linoleic acid content (87.13%) . Anise extract by-products resulted in the richest TPC (35.8 mg GAE/ g extract). With regard to antioxidant activity, the almond by-product ethanolic extract exhibited the highest ABTS+· radical scavenging activity (IC50 of 2.6 ug/mL) whereas anise showed the highest DPPH radical scavenging potential (IC50 of 27.2 ug/mL) as well as the most promising protection from lipid peroxidation (IC50 of 14.1 ug/mL). Our results confirm that these by-products are still rich in active biological compounds. Therefore, these residues may be of interest to the food, nutraceutical and pharmaceutical industries in the continuous search for innovative products for healthy and nutritional applications for the extension of the shelf life of food products.

[1] da Silva, A.; Neuza, J Bioactive compounds of the lipid fractions of agro-industrial waste. Food Res. Int., 2014, 66, 493-50. https://doi.org/10.1016/j.foodres.2014.10.025. [2] Loizzo MR, Pugliese A, Bonesi M, Tenuta MC, Menichini F, Xiao J, Tundis R. Edible Flowers: A Rich Source of Phytochemicals with Antioxidant and Hypoglycemic Properties. J Agric Food Chem. 2016, 64. 2467-74. https://doi.org/10.1021/acs.jafc.5b03092.