Comparison and discrimination of the terpenoids in 48 species of huajiao according to variety and geographical origin by E-nose coupled with HS-SPME-GC-MS

Evaluation of the effect of Torulaspora delbrueckii on important volatile compounds in navel orange original brandy using E-nose combined with HS-SPME-GC-MS

Simultaneous inoculation of non-Saccharomyces cerevisiae during the alcoholic fermentation process has been found to be an effective strategy for enhancing wine flavor. This study aimed to investigate the effect of Torulaspora delbrueckii NCUF305.2 on the flavor of navel orange original brandy (NOOB) using E-nose combined with HS-SPME-GC-MS. The results showed a significant increase (p < 0.05) in the sensitivity of NOOB to W5C, W3C, W1S, and W3S sensors by mixed fermentation (MF). Esters in NOOB increased by 4.13%, while higher alcohols increased by 21.93% (p < 0.001), terpenes and others increased by 52.07% and 40.99% (p < 0.01), respectively. Notably, several important volatile compounds with relative odor activity values above 10 showed an increase. Sensory analysis revealed that a more pronounced citrus-like flavor and higher overall appearance scores were found in MF than in pure fermentation (PF). These findings offer valuable theoretical guidance for enhancing the quality of fruit brandies.

Tea Quality of the Mysterious "Dahongpao Mother Tree" (Camellia sinensis)

The quality of the Dahongpao mother tree (Camellia sinensis) remains a mystery to this day. In this study, for the first time, the differences between the Dahongpao mother tree (MD) and Dahongpao cuttings (PD), in terms of odor characteristics and taste characteristics were analyzed by metabomics. The results showed that MD had stronger floral, fruity, green, and woody odor characteristics than PD, and that the contributions were mainly from dihydromyrcenol, methyl salicylate, 2-isobutylpyrazine, 1,6-dihydrocarveol, gamma-terpineol, and linalyl acetate. Further, fresh and brisk taste and mellowness taste characteristics of MD were significantly higher than PD, with contributions mainly from amino acids and derivatives and organic acids. Secondly, bitterness taste characteristics of PD were significantly higher than MD, with contributions from phenolic acids, flavones, and flavonols. This study preliminarily unraveled the legend of the superior quality of the Dahongpao mother tree, and also provided an important reference for the breeding of tea-tree cuttings.

Organic acid and aromatic compounds create distinctive flavor in the blackening process of jujube

Previous studies demonstrated jujube blackening effectively increased cyclic adenosine phosphate and triterpene acid levels, improving its nutritional value. However, compositional changes during this process require further elucidation. The objective aimed to analyze compositional transformations during this process with SEM, TPA, UPLC-MS, E-nose. Results showed decreased hardness, springiness, and chewiness coupled with increased gumminess over blackening durations. Untargeted omics analysis revealed increases of 2-aminooctadec-8-ene-1,3,4-trioland carbendazim. Targeted organic acid analysis showed initial citric acid accumulation (1481.62 to 1645.78 mg/kg) in the first 24 h, then declines to 1072.96 mg/kg. Meanwhile, oxalic and lactic acids steadily rose, peaking at 96-120 h before slightly decreasing. E-nose analysis implied alterations in organic sulfide aromatics engendered the characteristic flavors. Organic acid fluctuations likely resulted from sugar biotransformation and thermal degradation. These comprehensive analyses demonstrate jujube blackening imparts a rich and unique flavor, providing theoretical support for investigating the mechanisms and products underlying this process.

Impact of cooking methods on the quality, sensory and flavor compounds of Sichuan pepper oleoresin

Sichuan pepper oleoresin (SPO) is highly appreciated by the food industry as well as consumers for flavor. To understand the overall flavor of SPO and how the quality changes during practical application, this study investigated the effects of five cooking methods on the quality, sensory, and flavor compounds of SPO. The differences in physicochemical properties and sensory evaluation responded to potential changes in SPO after cooking. The SPO after different cooking could be clearly distinguished by E-nose and PCA. Based on the qualitative analysis of volatile compounds, 13 compounds were screened by OPLS-DA that had the ability to explain above differences. Further analysis of taste substances revealed that pungent substances (hydroxy-α-sanshool) were significantly reduced in SPO after cooking. And the conclusion that the degree of bitterness significantly increased was predicted by E-tongue. The PLS-R model was developed to achieve correlation analysis between aroma molecules and sensory quality.

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

Sour meat is a highly appreciated traditional fermented product, mainly from the Guizhou, Yunnan, and Hunan provinces. The flavor profiles of sour meat from goose and pork were evaluated using gas chromatography-ion mobility spectrometry (GC-IMS) combined with an electronic nose (E-nose) and tongue (E-tongue). A total of 94 volatile compounds were characterized in fermented sour meat from both pork and goose using GC-IMS. A data-mining protocol based on univariate and multivariate analyses revealed that the source of the raw meat plays a crucial role in the formation of flavor compounds during the fermentation process. In detail, sour meat from pork contained higher levels of hexyl acetate, sotolon, heptyl acetate, butyl propanoate, hexanal, and 2-acetylpyrrole than sour goose meat. In parallel, sour meat from goose showed higher levels of 4-methyl-3-penten-2-one, n-butyl lactate, 2-butanol, (E)-2-nonenal, and decalin than sour pork. In terms of the odor and taste response values obtained by the E-nose and E-tongue, a robust principal component model (RPCA) could effectively differentiate sour meat from the two sources. The present work could provide references to investigate the flavor profiles of traditional sour meat products fermented from different raw meats and offer opportunities for a rapid identification method based on flavor profiles.