Effect of roasting and sonication-assisted extraction conditions on phenolic compounds, physical properties and other constituents of EU PDO Malatya apricot (Prunus armeniaca L.) kernel skins

The objective of the study was to investigate the effect of the roasting process and different extraction methods (mechanical homogenization and sonication, using water (W), ethanol (EtOH), methanol (MetOH), and equal mixtures of ethanol/water and methanol/water) on the compositional, morphological, colour, dietary fibre, antioxidant capacity, polyphenolic content, and fatty acid profile of the Hacıhaliloğlu EU PDO variety of apricot ( Prunus armeniaca L.) kernel skin. The roasting process was found to have no significant effect on the chemical composition and color values ( P > 0.05); however, other minor constituents, antioxidant activity and phenolic contents did. Minerals were mainly found at high concentrations in apricot skin, including Mn, Fe, K, Cu and Mg. Both the roasting process and the use of EtOH/W and MeOH/W solvents with ultrasound-assisting improved the extraction of phenolic compounds. The highest α-tocopherol content was observed in the oil extracted from unroasted apricot kernel skin, with 992.8 ± 22.8 µg/mL, while it was determined as 512.5 ± 5.5 µg/mL in roasted apricot kernel oil ( P < 0.05). Interestingly, the dietary fiber content of apricot kernel skin was determined to be between 65.88–67.29 %. In conclusion, due to its fibrous nature, it can improve the structural integrity of biodegradable packaging materials. Moreover, the presence of phenolic compounds provides antioxidant and antimicrobial properties, making it a promising eco-friendly material for use as a functional additive in active packaging applications.