Tan Qibo, Wu Yongjun, Li Cen, Jin Jing, Zhang Lincheng, Tong Shuoqiu, Chen Zhaofeng, Ran Li, Huang Lu, Zuo Zeyan
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang 550025, China.
Guizhou Institute of Products Quality Inspection & Testing, Guiyang 550016, China.
Foods. 2024 Aug 28;13(17):2731. doi: 10.3390/foods13172731.
Fermented soybeans are popular among many for their rich soy sauce-like aroma. However, the precise composition of this aroma remains elusive, with key aroma compounds unidentified. In this study, we screened the candidate genes and in BJ3-2 based on previous multi-omics data, and we constructed three mutant strains, BJ3-2-, BJ3-2-, and BJ3-2-, using homologous recombination to fermented soybeans with varying intensities of soy sauce-like aroma. Our objective was to analyze samples that exhibited different aroma intensities resulting from the fermented soybeans of BJ3-2 and its mutant strains, thereby exploring the key flavor compounds influencing soy sauce-like aroma as well analyzing the effects of and on soy sauce-like aroma. We employed quantitative descriptive sensory analysis (QDA), gas chromatography-olfactometry-mass spectrometry (GC-O-MS), relative odor activity value analysis (rOAV), principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and partial least squares regression analysis (PLSR). QDA revealed the predominant soy sauce-like aroma profile of roasted and smoky aromas. GC-MS detected 99 volatile components, predominantly pyrazines and ketones, across the four samples, each showing varying concentrations. Based on rOAV (>1) and GC-O, 12 compounds emerged as primary contributors to soy sauce-like aroma. PCA and OPLS-DA were instrumental in discerning aroma differences among the samples, identifying five compounds with VIP > 1 as key marker compounds influencing soy sauce-like aroma intensity levels. Differential analyses of key aroma compounds indicated that the mutant strains of and affected soy sauce-like aroma mainly by affecting pyrazines. PLSR analysis indicated that roasted and smoky aromas were the two most important sensory attributes of soy sauce-like aroma, with pyrazines associated with roasted aroma and guaiacol associated with smoky aroma. In addition, substances positively correlated with the intensity of soy sauce-like aroma were verified by additional experiments. This study enhances our understanding of the characteristic flavor compounds in soy sauce-like aroma ferments, provides new perspectives for analyzing the molecular mechanisms of soy sauce-like aroma formation, and provides a theoretical framework for the targeted enhancement of soy sauce-like aroma in various foods.
发酵大豆因其浓郁的酱油般香气而受到许多人的喜爱。然而，这种香气的确切成分仍然难以捉摸，关键的香气化合物尚未确定。在本研究中，我们基于先前的多组学数据筛选了BJ3-2中的候选基因，并用同源重组构建了三株突变菌株BJ3-2-、BJ3-2-和BJ3-2-，用于发酵具有不同酱油样香气强度的大豆。我们的目标是分析由BJ3-2及其突变菌株发酵大豆产生的具有不同香气强度的样品，从而探索影响酱油样香气的关键风味化合物，并分析和对酱油样香气的影响。我们采用了定量描述性感官分析（QDA）、气相色谱-嗅觉-质谱联用（GC-O-MS）、相对气味活度值分析（rOAV）、主成分分析（PCA）、正交偏最小二乘判别分析（OPLS-DA）和偏最小二乘回归分析（PLSR）。QDA揭示了烤香和烟熏香为主导的酱油样香气特征。GC-MS在四个样品中检测到99种挥发性成分，主要是吡嗪类和酮类，每个样品中的浓度各不相同。基于rOAV（>1）和GC-O，有12种化合物成为酱油样香气的主要贡献者。PCA和OPLS-DA有助于辨别样品之间的香气差异，确定VIP>1的五种化合物为影响酱油样香气强度水平的关键标记化合物。关键香气化合物的差异分析表明，和的突变菌株主要通过影响吡嗪类来影响酱油样香气。PLSR分析表明，烤香和烟熏香是酱油样香气的两个最重要的感官属性，吡嗪类与烤香相关，愈创木酚与烟熏香相关。此外，通过额外实验验证了与酱油样香气强度呈正相关的物质。本研究增进了我们对酱油样香气发酵中特征风味化合物的理解，为分析酱油样香气形成的分子机制提供了新的视角，并为有针对性地增强各种食品中的酱油样香气提供了理论框架。
