Abstract:
This study took pomegranate juice as the experimental subject and conducted single-factor and orthogonal experiments using chitosan, xanthan gum, guar gum, locust bean gum, and sodium alginate, with the aim of determining the optimal clarification process for pomegranate juice. Meanwhile, Gas Chromatography-Mass Spectrometry (GC-MS) technology was employed to analyze the volatile compounds in naturally clarified pomegranate juice and pomegranate juice treated with composite clarifying agents. In terms of evaluating clarification effects, the transmittance of pomegranate juice was used as an indicator to compare the clarification effects of the five clarifying agents. Through orthogonal optimization experiments, the optimal clarification process conditions for pomegranate juice were ultimately determined: A compound ratio of 0.1 g/L chitosan to 0.1 g/L sodium alginate at 1:1.5, a flocculation temperature of 30 ℃, and a calcium chloride addition amount of 0.05 g/L, achieving a transmittance of 83.239%. Additionally, the GC-MS results revealed that after treatment with the composite clarifying agent group, the relative content of ethyl acetate significantly increased, enhancing the fruity aroma. The relative content of 4-terpineol increased by 61.49%, adding woody, citrus, and floral notes. The relative content of 2-ethylhexanol increased by 34.79%, contributing sweet and fruity aromas. The relative content of nonanal rose by 54.75%. Nonanal possesses a fresh citrus peel aroma, which helps retain a mild aldehyde flavor and stabilizes the overall flavor profile. Moreover, the composite clarifying agent group reduced the relative contents of ethanol, (+)-
α-terpineol, n-hexanal, trans,trans-2,4-nonadienal, and other substances that might produce undesirable flavors, thereby decreasing the pungent odor and rancid oil smell in pomegranate juice and further improving its overall flavor. This study systematically explores the impact of processing techniques on the quality of pomegranate juice, and its research findings can provide a theoretical basis for improving the sensory and nutritional quality of pomegranate juice products.