Characterization of Flavor Profile of "Nanx Wudl" Sour Meat Fermented from Goose and Pork Using Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) Combined with Electronic Nose and Tongue

Insights into the Flavor Profile of Yak Jerky from Different Muscles Based on Electronic Nose, Electronic Tongue, Gas Chromatography-Mass Spectrometry and Gas Chromatography-Ion Mobility Spectrometry

It is well known that different muscles of yak exhibit distinctive characteristics, such as muscle fibers and metabolomic profiles. We hypothesized that different muscles could alter the flavor profile of yak jerky. Therefore, the objective of this study was to investigate the differences in flavor profiles of yak jerky produced by longissimus thoracis (LT), triceps brachii (TB) and biceps femoris (BF) through electronic nose (E-nose), electronic tongue (E-tongue), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS). The results indicated that different muscles played an important role on the flavor profile of yak jerky. And E-nose and E-tongue could effectively discriminate between yak jerky produced by LT, TB and BF from aroma and taste points of view, respectively. In particular, the LT group exhibited significantly higher response values for ANS (sweetness) and NMS (umami) compared to the BF and TB groups. A total of 65 and 47 volatile compounds were characterized in yak jerky by GC-MS and GC-IMS, respectively. A principal component analysis (PCA) model and robust principal component analysis (rPCA) model could effectively discriminate between the aroma profiles of the LT, TB and BF groups. Ten molecules could be considered potential markers for yak jerky produced by different muscles, filtered based on the criteria of relative odor activity values (ROAV) > 1, p < 0.05, and VIP > 1, namely 1-octen-3-ol, eucalyptol, isovaleraldehyde, 3-carene, D-limonene, γ-terpinene, hexanal-D, hexanal-M, 3-hydroxy-2-butanone-M and ethyl formate. Sensory evaluation demonstrated that the yak jerky produced by LT exhibited superior quality in comparison to that produced by BF and TB, mainly pertaining to lower levels of tenderness and higher color, taste and aroma levels. This study could help to understand the specific contribution of different muscles to the aroma profile of yak jerky and provide a scientific basis for improving the quality of yak jerky.

Characterization of flavor and taste profile of different radish (Raphanus Sativus L.) varieties by headspace-gas chromatography-ion mobility spectrometry (GC/IMS) and E-nose/tongue

A comprehensive study of the overall flavor and taste profile of different radishes is lacking. This study systematically compared the volatile profile of six radish varieties using HS-GC-IMS and their correlation with the E-nose analysis. Organic acids and amino acids were quantified, and their association with the E-tongues analysis was explored. A total of 73 volatile compounds were identified, with diallyl sulfide and dimethyl disulfide being the primary sulfides responsible for the unpleasant flavor in radish. Compared to other varieties, cherry radishes boast a significantly higher concentration of allyl isothiocyanate, which likely contributes to their characteristic radish flavor. Moreover, oxalic acid was identified as the most abundant organic acid in radish, accounting for over 97% of its content, followed by malic acid and succinic acid. In conclusion, the distinct flavor and taste characteristics of different radish varieties partially explain their suitability for diverse culinary preferences.

Evaluation of Loquat Jam Quality at Different Cooking Times Based on Physicochemical Parameters, GC-IMS and Intelligent Senses

The study compared and analyzed the quality of loquat jam with different cooking times through physicochemical parameters, headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) and intelligent senses. The results showed that with the prolongation of the cooking time, the color of loquat jam slowly deepened, the energy significantly increased, the adhesiveness, gumminess, hardness and chewiness enhanced, the free amino acid content increased from 22.40 to 65.18 mg/g. The organic acid content increased from 1.64 to 9.82 mg/g. Forty-seven volatile flavor compounds were identified in five types of loquat jam using HS-GC-IMS, among which the relative content of aldehydes was sharply higher than that of other chemical substances, playing an important role in the flavor formation of loquat jam. LJ0, LJ1 and LJ2 had higher aldehyde content, followed by LJ3 and LJ4 had the lowest aldehyde content. The orthogonal partial least squares-discriminant analysis (OPLS-DA) screened 15 marker compounds that could distinguish five types of loquat jam. The E-nose results showed a significant difference in olfactory sense between loquat jam cooked for 100 and 120 min. The E-tongue results corroborated the results of free amino acids (FAAs) and organic acids, indicating that the gustatory sense of loquat jam changed significantly when the cooking time reached 120 min. The results provided a basis for further research on the relationship between the cooking process and quality characteristics of loquat jam.

Effect of Capsaicin Stress on Aroma-Producing Properties of Lactobacillus plantarum CL-01 Based on E-Nose and GC-IMS

Capsaicin stress, along with salt stress, could be considered the main stressors for lactic acid bacteria in traditional fermented pepper products. Until now, insufficient attention has been paid to salt stress, while the effect of capsaicin on the aroma-producing properties of Lactobacillus plantarum (L. plantarum) is unclear. The present study attempted to illustrate the effect of capsaicin stress on the aroma-producing properties of L. plantarum CL-01 isolated from traditionally fermented peppers based on E-nose and GC-IMS. The results showed that E-nose could clearly distinguish the overall flavor differences of L. plantarum CL-01 under capsaicin stress. A total of 48 volatile compounds (VOCs) were characterized by means of GC-IMS, and the main VOCs belonged to acids and alcohols. Capsaicin stress significantly promoted L. plantarum CL-01 to produce alpha-pinene, ethyl crotonate, isobutyric acid, trans-2-pentenal, 2-methyl-1-butanol, 3-methyl-3-buten-1-ol, 1-penten-3-one, 2-pentanone, 3-methyl-1-butanol-D, and 2-heptanone (p < 0.05). In addition, under capsaicin stress, the contents of 1-penten-3-one, 3-methyl-3-buten-1-ol, 5-methylfurfuryl alcohol, isobutanol, 2-furanmethanethiol, 2,2,4,6,6-pentamethylheptane, 1-propanethiol, diethyl malonate, acetic acid, beta-myrcene, 2-pentanone, ethyl acetate, trans-2-pentenal, 2-methylbutyl acetate, and 2-heptanone produced by L. plantarum CL-01 were significantly increased along with the fermentation time (p < 0.05). Furthermore, some significant correlations were observed between the response values of specific E-nose sensors and effective VOCs.

Exploring the Profile Contributions in Meyerozyma guilliermondii YB4 under Different NaCl Concentrations Using GC-MS Combined with GC-IMS and an Electronic Nose

Using Meyerozyma guilliermondii YB4, which was isolated and screened from southern Sichuan pickles in the laboratory, as the experimental group, we investigated the changes in growth, total ester content, and volatile flavor substances of M. guilliermondii YB4 under different NaCl concentrations. The growth of M. guilliermondii YB4 was found to be inhibited by NaCl, and the degree of inhibition increased at higher NaCl concentrations. Additionally, the total ester content of the control group (CK) was significantly lower compared to the other groups (p < 0.05). The application of NaCl also resulted in distinct changes in the volatile profile of YB4, as evidenced by E-nose results. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS) were employed to analyze the volatile compounds. A total of 148 and 86 volatiles were detected and identified using GC-MS and GC-IMS, respectively. Differential volatiles among the various NaCl concentrations in YB4 were determined by a variable importance in projection (VIP) analysis in partial least squares-discriminant analysis (PLS-DA). These differentially expressed volatiles were further confirmed by their relative odor activity value (ROAV) and odor description. Ten key contributing volatiles were identified, including ethanol, 1-pentanol, nonanal, octanal, isoamyl acetate, palmitic acid ethyl ester, acrolein, ethyl isobutanoate, prop-1-ene-3,3'-thiobis, and 2-acetylpyrazine. This study provides insights into the specificities and contributions of volatiles in YB4 under different NaCl concentrations. These findings offer valuable information for the development of aroma-producing yeast agents and the subsequent enhancement in the flavor of southern Sichuan pickles.

Effect of Sichuan Pepper (Zanthoxylum genus) Addition on Flavor Profile in Fermented Ciba Chili (Capsicum genus) Using GC-IMS Combined with E-Nose and E-Tongue

This study examined the flavor profiles of fermented Ciba chili, comparing samples with Sichuan pepper (HJ) to those without Sichuan pepper (CK), using three analytical techniques: E-tongue, E-nose, and gas chromatography-ion mobility spectrometry (GC-IMS). The results obtained from the E-tongue and E-nose exhibited a clear difference in taste and flavor between CK and HJ. In detail, CK mainly exhibited a sour flavor profile, whereas HJ displayed an intricate and rich flavor. The HS-GC-IMS results identified a total of 60 compounds in the samples, with terpenes, alcohols, and esters being the primary volatile flavor compounds. Additionally, Zanthoxylum was found to significantly enhance the concentration of these compounds in fermented Ciba chili. Through robust principal component analysis (rPCA), 17 distinct flavor compounds were selected. Correlation analysis revealed that most terpenes exhibited positive correlations with LY2/LG, LY2/gCT1, LY2/Gct, LY2/G, LY2/Gh, and terpenes were found in higher concentrations in HJ. This study contributes a theoretical basis and provides data support for optimizing the fermentation process and elucidating the underlying mechanism of characteristic aroma formation in Ciba chili after fermentation.