Analysis of volatile flavor compounds influencing Chinese-type soy sauces using GC–MS combined with HS-SPME and discrimination with electronic nose

Abstract

Soy sauce contains a variety of volatiles that are highly valuable to its quality with regard to sensory characteristics. This paper describes the analysis of volatile compounds influencing the flavor quality of Chinese-type soy sauces. Gas chromatography-mass spectrometry (GC-MS) combined with headspace-solid phase microextraction and electronic nose (E-nose) were applied for identifying the volatile flavor compounds as well as determining their volatile profiles of 12 soy sauces manufactured by different fermentation process. Forty one key volatile components of these 12 soy sauce products, a pure soy sauce and an acidhydrolyzed vegetable protein sample, were compared in semi-quantitative form, and their volatile flavor profiles were analyzed by E-nose. The substantially similar results between hierarchical cluster analysis based on GC-MS data and E-nose analysis suggested that both techniques may be useful in evaluating the flavor quality of soy sauces and differentiating soy sauce products. The study also showed that there were less volatile flavor compounds in soy sauces produced through low-salt solid-state fermentation process, a traditional manufacturing technology and a widely adopted technology in Chinese soy sauce industries. In addition, the investigation suggested that the flavor quality of soy sauce varied widely in Chinese domestic market, and that the present Chinese national standards of soy sauce should be further perfected by the addition of flavor grades of soy sauce in the physical and chemical index. Meanwhile, this research provided valuable information to manufacturers and government regulators, which have practical significance to improve quality of soy sauces.

Effect of raw material and starters on the metabolite constituents and microbial community diversity of fermented soy sauce

“…The differences in soy sauce flavor profiles among the different processes were investigated by odor activity values and omission tests . Similar research had been carried out using gas chromatography–mass spectrometry (GC–MS) combined with electronic nose approaches . The quality of soy sauce could be enhanced by optimizing the process parameters .…”

“…2 Similar research had been carried out using gas chromatography-mass spectrometry (GC-MS) combined with electronic nose approaches. 7 The quality of soy sauce could be enhanced by optimizing the process parameters. 8 Pure-cultured halotolerant bacteria (such as Tetragenococcus halophilus) and yeasts (including Zygosaccharomyces rouxii, and Candida versatilis) were used as starters to improve the quality of fermented soy sauce and to reduce the costs for the large-scale production of soy sauce.…”

Microfiltration of raw soy sauce: membrane fouling mechanisms and characterization of physicochemical, aroma and shelf-life properties

“…where J is the permeate ux (L m À2 s À1 ), DP is the transmembrane pressure (Pa), m is the viscosity of the permeate (Pa s), and R t is the total resistance to the ltration process (m À1 ), shown in eqn (2). ), R f is the fouling layer resistance formed during micro-ltration (m À1 ).…”

“…1 Soy sauce is typically produced from soybean and wheat by complex fermentation processes involving enzymatic catalysis by various microorganisms. 2 As time goes by, the soy sauce is endowed with a unique avor, formed mainly by volatile components with aromas that could be described as smoky, fruity, owery, mellow, malt-like and mushroom-like. 3 In addition to volatiles, the contents of saccharides, amino acid nitrogen, organic acids and other constituents are all related to the taste and quality of soy sauce.…”

“…11,12 Feng et al 13 have shown that avor is a key index for soy sauce, which determines consumer acceptance; they optimized the extraction method for the volatile components in soy sauce via coupling direct GC-olfactometry and gas chromatography-mass spectrometry. Gao et al 2 believe that soy sauce contains a variety of volatiles that are highly valuable to its quality with regard to sensory characteristics and they described the analysis of volatile compounds inuencing the avor quality of Chinese-type soy sauce. Therefore, the changes in the volatile compounds in the rened soy sauce can provide important information for both the science and production of soy sauce.…”