Solid-state fermentation of avocado seed by aspergillus oryzae and aspergillus awamori: Effects on nutritional composition, antioxidant activity, and volatile compounds
Juliana Villasante, Arnau Vilas-Franquesa, Vincenzo Fogliano
Abstract
The evolution of phenolic contents and antioxidant activities during solid-state fermentation of avocado seed by Aspergillus oryzae and Aspergillus awamori was investigated. The effect of fermentation time on fat and protein content, and volatile compounds in the avocado seed was also studied. Results showed that total phenolic amounts increased by over 12 % after 72 h of solid-state fermentation with A. awamori. The flavonoid content also increased during fermentation while the opposite occurred with the tannin content. The radical scavenging activity and the concentration of 3,4-dihydroxybenzoic acid were significantly enhanced after fermentation compared to the control. The results demonstrated that solid-state fermentation increased the total fat content of avocado seeds, specifically of the alpha-linolenic acid content. A total of 42 volatile compounds were found in all the samples, some of which increased after fermentation. These findings provide valuable insights for the future development of novel avocado seed products with enhanced functionality.