Wu Dan, Xia Qile, Cheng Huan, Zhang Qichun, Wang Yanbin, Ye Xingqian
College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China.
Food Science Institute, Zhejiang Academy of Agricultural Sciences, Key Laboratory of Post-Harvest Handling of Fruits, Hangzhou 310021, China.
Foods. 2022 Nov 1;11(21):3471. doi: 10.3390/foods11213471.
Sea buckthorn is rich in polyphenolic compounds with antioxidant activities. However, it is very sour, and its odor is slightly unpleasant, so it requires flavor improvement. Fermentation is one potential method. Sea buckthorn juice was fermented at 37 °C for 72 h and then post-fermented at 4 °C for 10 days. The flavor-related properties of the sea buckthorn juice were evaluated during fermentation, including the pH, total soluble solids (TSS), color, sensory evaluation, and volatile flavors. The sea buckthorn fermented juice had a low pH. The total soluble solids decreased from 10.60 ± 0.10% to 5.60 ± 0.12%. The total color change was not more than 20%. Fermentation increased the sweet odor of the sea buckthorn juice, but the fruity flavor decreased and the bitter flavor increased. A total of 33 volatile flavors were identified by headspace gas chromatography-ion mobility spectrometry (GC-IMS), including 24 esters, 4 alcohols, 4 terpenes, and 1 ketone. Their total relative contents were 79.63-81.67%, 10.04-11.76%, 1.56-1.22%, and 0.25-0.55%, respectively. The differences in the characteristic volatile molecular species of the sea buckthorn juice at different fermentation stages could be visually discerned using fingerprint maps. Through principal component analysis (PCA), the total flavor difference of the sea buckthorn juice at different fermentation stages could be effectively distinguished into three groups: the samples fermented for 0 h and 12 h were in one group, the samples fermented for 36 h, 48 h, 60 h, and 72 h were in another group, and the samples fermented for 24 h were in another group. It is suggested that sea buckthorn juice be fermented for 36 h to improve its flavor. GC-IMS and PCA are effective methods of identifying and distinguishing the flavor characteristics of sea buckthorn juice. The above results can provide a theoretical basis for studying the changes in sea buckthorn's characteristics as a result of fermentation, particularly with regard to its flavor.
沙棘富含具有抗氧化活性的多酚类化合物。然而，它非常酸，气味也稍有不悦，因此需要改善风味。发酵是一种潜在的方法。沙棘汁在37℃下发酵72小时，然后在4℃下后发酵10天。在发酵过程中对沙棘汁的风味相关特性进行了评估，包括pH值、总可溶性固形物（TSS）、颜色、感官评价和挥发性风味。沙棘发酵汁的pH值较低。总可溶性固形物从10.60±0.10%降至5.60±0.12%。总颜色变化不超过20%。发酵增加了沙棘汁的甜味，但果味减少，苦味增加。通过顶空气相色谱-离子迁移谱（GC-IMS）共鉴定出33种挥发性风味物质，包括24种酯类、4种醇类、4种萜类和1种酮类。它们的总相对含量分别为79.63-81.67%、10.04-11.76%、1.56-1.22%和0.25-0.55%。利用指纹图谱可以直观地辨别不同发酵阶段沙棘汁特征挥发性分子种类的差异。通过主成分分析（PCA），不同发酵阶段沙棘汁的总风味差异可有效分为三组：发酵0小时和12小时的样品为一组，发酵36小时、48小时、60小时和72小时的样品为另一组，发酵24小时的样品为另一组。建议将沙棘汁发酵36小时以改善其风味。GC-IMS和PCA是识别和区分沙棘汁风味特征的有效方法。上述结果可为研究沙棘发酵后特性的变化，特别是风味变化提供理论依据。
