Effects of β-glucosidase on the aroma characteristics of flat peach juice as assessed by descriptive sensory analysis and gas chromatography and compared by partial least squares regression

Abstract To investigate the effects of β-glucosidase on the aroma of flat peach juice, five flat peach juice samples (FPSs), including 1 fresh, 1 pasteurized and 3 enzyme-treated FPS samples, were analyzed by gas chromatography-mass spectrometry (GC-MS) and descriptive sensory analysis (DSA). Fruity, floral, peach-like, cooked, and unnatural were chosen as sensory attributes to evaluate FPS flavors. DSA results indicated a significant difference among the control samples (FPS0 and FPS1) and enzyme-treated samples (FPS2-4) for almost all sensory attributes. Compared to pasteurized sample FPS1, enzyme-treated samples with moderate temperature (FPS2 and FPS3) showed strong floral, fruity, and peach-like attributes, but weaker cooked and unnatural notes. A total of 71 volatiles were identified for comparison and evaluation of the aroma characteristics of FPSs. Partial least squares regression models (PLS1 and PLS2) were performed to analyze the correlation among 71 volatile compounds and DSA data. PLS1 results indicated that fourteen compounds, 2-hexanal, nonanal, (E,E)-2,4-heptadienal, decanal, amyl acetate, ethyl caproate, (Z)-3-hexenyl acetate, γ-caprolactone, δ-octanolactone, dihydro-β-ionone, (Z)-3-hexen-1-ol, (E)-6,10-dimethylundeca-5,9-dien-2-one, linalool, and geraniol, showed significant positive contribution to flat peach attribute, and PLS2 further confirmed that using β-glucosidase under suitable temperatures would be useful for improving the sensory characteristics of FPS.