The effects of fermentation by cholesterol-lowering fungi on the functional components and bioactive properties of kiwifruit pomace

Kiwifruit pomace, a processing byproduct with lipid metabolism-regulating potential, is often discarded because of its low bioavailability. In this study, fungal fermentation, which is an efficient bioprocessing strategy, was applied to increase the contents of its active components and its bioavailability. Seven cholesterol-lowering fungal strains isolated from fermented foods— Talaromyces sp. FR, Aspergillus sp. C1YC, Fusarium solani A4YC, Alternaria alstroemeriae C2SLB, Monascus purpureus HQM, Penicillium rubens C3SLB, and Penicillium chrysogenum C2YC—were used for pomace fermentation. The contents of flavonoids, total phenolics, and soluble dietary fibre significantly increased ( P < 0.05), with the greatest increases (1.94-, 1.42-, and 1.31-fold, respectively) observed in the HQM group. All the strains and fermented pomace extracts exhibited considerable cholesterol-degrading ability, reaching 74.79 % with the HQM suspension. Extracts of C1YC and C3SLB showed prominent antioxidant capacity, whereas the HQM extract strongly bound bile salts. α-Glucosidase activity and α-amylase activity were inhibited by the C2YC and HQM suspensions (84.84 % and 83.01 %, respectively). Compared with the control, the FR-fermented pomace adsorbed 6.01 times more fat. This study is the first to report direct cholesterol degradation by Talaromyces sp., Fusarium solani , and Alternaria alstroemeriae , confirming that fungal fermentation increases the value of kiwifruit pomace. • Seven cholesterol-lowering fungal strains were isolated and identified from traditional fermented foods. • In vitro cholesterol-lowering activity first reported for Talaromyces sp., Fusarium solani, and Alternaria alstroemeriae. • Fermentation of kiwifruit pomace with cholesterol-lowering fungi boosted functional components and enhanced in vitro bioactivities.