Mechanisms of Phenolic Compounds Release and Functional Property Enhancement Through Autochthonous Probiotic Fermentation of Qingjinju Puree

This study examined the fermentation of whole qingjinju puree using the autochthonous probiotic Pichia terricola QJJY1. The results indicated that Pichia terricola QJJY1 could dynamically regulate the ratio of organic acids to sugars in fermented whole qingjinju puree (FWQP) at various fermentation stages, leading to a reduction of 26.59% and 53.65%, respectively. Additionally, fermentation significantly enhanced the release of free and bound phenolics in FWQP, with total phenolic content and total flavonoid content increasing by 50.51% and 106.59%, respectively, compared to the unfermented samples. This positive correlation resulted in a 15.20%, 56.94%, and 148.19% increase in DPPH, ABTS free radical scavenging abilities, and CUPRAC, respectively, while the ability to inhibit α-amylase, α-glucosidase, and pancreatic lipase activities were increased by 38.60%, 27.34%, and 18.14%, respectively. The increase in the activities of five enzymes produced by Pichia terricola QJJY1 and its metabolites altered the microstructure of FWQP, manifesting as increased porosity and structural loosening. This subsequently facilitated the release and conversion of phenolic compounds, and ultimately influenced the composition and content of these compounds. This study effectively enhanced the release of phenolic compounds and functional activity in whole qingjinju puree, offering a valuable bioprocessing strategy and reference for qingjinju.