单菌/混菌发酵对豆腐黄浆水风味、成分及抗氧化性的影响

Effects of Single and Mixed Fermentation on Flavor, Composition, and Antioxidant Activity of Soybean Whey

摘要:

【目的】探究单菌与混菌发酵对豆腐黄浆水风味、成分与抗氧化性的影响。【方法】采用气相色谱-离子迁移谱（GC-IMS）联合电子鼻以及高效液相色谱（HPLC）技术对单菌和混菌发酵后的豆腐黄浆水风味与功能进行测定。【结果】相较于发酵乳杆菌HJS-1（Limosilactobacillus fermentum HJS-1）、马克斯克鲁维酵母HJS-2（Kluyveromyces marxianus HJS-2）单菌发酵，发酵乳杆菌HJS-1与马克斯克鲁维酵母HJS-2混菌发酵可以有效提升豆腐黄浆水中功能性物质水平及其抗氧化性。相较于未发酵豆腐黄浆水，混菌发酵豆腐黄浆水中大豆异黄酮苷元和有机酸质量浓度分别增加了65.53%和182.39%，甜味氨基酸和芳香味氨基酸占比分别增加了49%和9%，鲜味/酸味氨基酸和苦味氨基酸占比分别减少了16%、42%。此外，在混菌发酵36 h后，豆腐黄浆水的ABTS⁺自由基、羟自由基、DPPH自由基清除率分别为（20.95±0.07）%、（9.08±0.07）%和（37.62±0.21）%。GC-IMS分析结果表明，发酵豆腐黄浆水中共鉴定出53种挥发性风味物质，主要为酯类、醛类、醇类和酸类物质。混菌发酵豆腐黄浆水中存在乙酸异丁酯、乙酸乙酯等大量酯类物质，可有效去除豆腐黄浆水的豆腥味。【结论】混菌发酵可有效提升豆腐黄浆水的风味品质及抗氧化性。

Abstract:

[Objective] This study aims to explore the impacts of single strain fermentation and mixed fermentation on the flavor,composition, and antioxidant activity of soybean whey.[Method] Gas chromatography-ion mobility spectrometry (GC-IMS) was coupled with E-nose and high-performance liquid chromatography (HPLC) to analyze the flavor and function of soybean whey fermented by the single and mixed strains.[Result] Compared with single-strain fermentation by Limosilactobacillus fermentum HJS-1 or Kluyveromyces marxianus HJS-2, mixed fermentation (Limosilactobacillus fermentum HJS-1 + Kluyveromyces marxianus HJS-2) effectively improved the levels of functional substances and antioxidant activity of soybean whey. Compared with non-fermented soybean whey, mixed fermentation increased the mass concentrations of soy isoflavones and organic acids in soybean whey by 65.53% and 182.39%, respectively. Moreover, mixed fermentation increased the proportions of sweet-taste amino acids and aromatic amino acids by 49% and 9%, while reducing the proportions of umami/sour-taste amino acids and bitter-taste amino acids by 16% and 42%, respectively. The ABTS⁺, hydroxyl, and DPPH free radical clearance rates of the soybean whey after 36 h of mixed fermentation reached (20.95±0.07)%, (9.08±0.07)%, and (37.62±0.21)%, respectively. A total of 53 volatile flavor compounds in the fermented soybean whey were identified by GC-IMS, mainly including esters, aldehydes, alcohols, and acids. Large amounts of esters such as isobutyl acetate and ethyl acetate existed in the soybean whey after mixed fermentation, which removed the beany flavor of soybean whey.[Conclusion] Mixed fermentation can effectively improve the flavor quality and antioxidant activity of soybean whey.