Characterization of the key odorants in goji wines in three levels of sweetness by applications of sensomics approach

The correlations and differences of the key odorants were systematically conducted among three sweetness of goji wines by the sensomics approach. After aroma (extract) dilution analysis, 67, 67, and 66 odorants were screened in sweet goji wine, semi-dry goji wine, and dry goji wine, in which, 63 odorants were identified in all goji wines. Determination of 53 odorants revealed a total of 30 odorants with the concentrations surpassing their olfactory thresholds. Overall, the odor activity values (OAVs) of ketones decreased, while esters, alcohols, phenols, and aldehydes increased with the decrease in sweetness in goji wine samples. Nevertheless, (E)-β-damascenone, trans- and cis-whisky lactones, and 3-methyl-2,4-nonanedione, evoked cooked apple-like, coconut-like, and hay-like odor impressions in goji wines and showed the highest OAVs. A reliable evaluation of the aroma contributions was executed as aroma recombinations and suggested a successful evaluation of key odorants in goji wines.

Characterization of the flavor in traditional Pixian Doubanjiang by polyphasic quantitative detection technology

In the present research, four different samples were investigated by multiple analyzing technology to reveal the common unique flavor and taste of traditional Pixian Doubanjiang (PXDBJ). These samples were manufactured by inheritor according to the intangible skills and ripened for two years in different enterprises. Citric acid, malic acid, Glu and Asp were the dominant non-volatiles, the proportion of both organic acids ranged from 54.78% to 65.61%, while that of both free amino acids ranged from 22.49% to 29.39%. Ethyl palmitate, ethyl laurate, γ-cis-himachalane, (+)-valencene and β-ionone were identified as typical volatile constituents by three kinds of GC techniques combined with three pretreatment approaches. These results suggested that these five volatiles and the proportion of four non-volatiles could be used as indicators of flavor and taste to discriminate with other types of traditional fermented soy pastes (miso, dajiang, gochujiang, etc), and were also proofed by sensory evaluation. It laid a vital foundation for revealing the contribution of the traditional skill to unique quality of PXDBJ and the correlation between microbial community diversity and their metabolic regulation.

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

Refinement to remove fermented mash residue is essential for obtaining clarified, stable and high-quality soy sauce. In this study, raw soy sauce microfiltration was investigated. Four widely-used microfiltration membranes were employed: ceramic, polyethersulfone (PES), polyvinylidene fluoride (PVDF) and mixed cellulose ester (MCE). Membrane fouling mechanisms were identified based on the blocking filtration model, indicating that the dominant fouling mechanism during soy sauce microfiltration was cake formation on the membrane surface. Microfiltration delivered highly dispersed soy sauce having superior clarity and a light color, with satisfactory sterilization quality, and preserved well the NaCl, reducing sugar, total acid and amino nitrogen content, leading to a product having a longer shelf life as compared to pasteurization. The loss of volatile compounds after refinement (microfiltration and pasteurization) was not neglected, particularly the ester groups (total loss of 76.3% to 96.4%), which affected the aroma profile of the soy sauce; all the samples from microfiltration seemed to lack the floral aroma. Ceramic membrane filtration and pasteurization exhibited relatively good preservation of the aroma of soy sauce, which then obtained the best scores in sensory analysis.