Changes in in vitro anti-adipogenic activity and aroma-related volatile compound profiles of bioconverted goji berry extract

Goji berry ( Lycium barbarum L.) contains diverse bioactive compounds with reported anti-obesity potential. Microbial bioconverted by lactic acid bacteria (LAB) can enhance the functional properties of plant extracts through enzymatic modification. However, studies investigating the improvement of goji berry extract (GBE) via LAB-mediated bioconversion remain limited. This study evaluated the in vitro anti-adipogenic effects and aroma-related volatile profile changes of GBE following bioconversion using Pediococcus acidilactici HW01 and Leuconostoc citreum HW02. Bioconverted GBE significantly inhibited 3T3-L1 adipocyte differentiation, reducing lipid accumulation by 43% (HW02) and 35% (HW01), compared with 16% in non-bioconverted GBE. RT-qPCR and western blot analyses showed time- and marker-dependent changes in adipogenic transcription factors, with PPAR-γ showing the clearest protein-level reduction at the later differentiation stage. Lipid metabolism-related markers (FABP4 and LPL) and adipokines (resistin and leptin) were also significantly reduced. Volatile profiling identified 28 compounds, with total volatiles increasing by 20.62% (HW01) and 8.84% (HW02). Alcohols, terpenes, and esters increased, whereas aldehydes decreased after fermentation. LAB-mediated bioconversion of GBE was associated with reduced lipid accumulation and altered expression of selected adipogenesis-related markers in differentiated 3T3-L1 cells. It also modified the aroma-related volatile profile of GBE, but further studies are needed to clarify the underlying mechanisms and biological relevance of individual volatile compounds.