Decoding the Effects of High Hydrostatic Pressure and High-Temperature Short-Time Sterilization on the Volatile Aroma Profile of Red Raspberry Juice.

The loss of distinctive aromas due to sterilization significantly hinders efforts to enhance the sensory quality of fruit and vegetable juices. This study aimed to elucidate the impacts of high-hydrostatic pressure (HHP) and high-temperature short-time (HTST) sterilization methods on the loss of C6 aldehyde aroma-active compounds in red raspberry juice. External standard quantification and quantitative descriptive analysis (QDA) revealed a notable decline in the levels of hexanal and (Z)-3-hexenal following the HHP and HTST treatments (p < 0.05), resulting in a marked attenuation of the grassy aroma characteristic of red raspberry juice. Furthermore, a comprehensive examination of the precursors, pivotal enzymes, intermediates, and downstream aromas within the fatty acid metabolism pathway in different raspberry juice samples indicated that the C6 aldehydes loss induced by HHP and HTST sterilizations was primarily ascribed to the competitive inhibition of ß-oxidation and the hindered enzymatic oxidation of fatty acids. These insights suggest that modifying sterilization protocols and enhancing enzymatic stability may help preserve the aroma integrity of raspberry juice. Our findings offer practical guidance for optimizing juice processing techniques to maintain flavor.

Encapsulation of roast beef flavor by soy protein isolate/chitosan complex Pickering emulsions to improve its releasing properties during the processing of plant-based meat analogues.

During the production of plant-based meat analogues (PBMA), a significant loss of flavor characteristic compounds in meat-flavor essences could be observed. Pickering emulsion-based encapsulation is an effective method to improve their stability. Therefore, a soy protein isolate (SPI)/chitosan (CS) complex Pickering emulsion was fabricated to encapsulate roast beef flavor (RBF) and further applied in the processing of PBMA. Our results indicated that the network structure of emulsions was dominated by elasticity, while hydrogen and covalent bonding interactions played important roles in the encapsulation process. The release rate of flavor compounds gradually increased with the increase of pH value, glutamine transaminase, NaCl content, heating temperature or heating time, while encapsulation significantly reduced the loss of characteristic aroma compounds. In addition, the releasing characteristics of aroma compounds and textural properties of PBMA were greatly improved by treating with RBF-loaded emulsions. Consequently, the emulsions were promising to improve the flavor quality of PBMA.

Analysis of odor compounds in Lee Kum Kee brand oyster sauce and oyster enzymatic hydrolysate: Comparison and relationship.

Oyster sauce (OS) is a highly processed oyster product. However, the significant price difference between OS and fresh oysters raises a question: Does authentic OS truly contain components from oysters or oyster enzymatic hydrolysates (OEH)? Therefore, the odor compounds of Lee Kum Kee oyster sauce (LKK), 4 OEHs, and 6 other seafood enzymatic hydrolysates (SEHs) were analyzed by using solid-phase microextraction and gas chromatography-olfactometry-mass spectrometry technology (SPME-GC-O-MS). The results of multivariate statistical analysis demonstrated the effective discrimination between LKK and OEHs from other SEHs. According to the VIP value and the differences in the composition of odor compounds among different samples, 15 essential odor compounds were screened out, which could distinguish whether the samples contained OEHs. Among them, acetic acid, 2-pentylfuran, 2-ethyl furan, 2-methylbutanal, and nonanal were only detected in LKK and OEHs, which further indicated the existence of OEH in LKK.

Screening of Yeast in Various Vineyard Soil and Study on Its Flavor Compounds from Brewing Grape Wine.

In order to screen out Saccharomyces cerevisiae suitable for table grape fermentation, and compare it with commercial Saccharomyces cerevisiae in terms of fermentation performance and aroma producing substances, differences of fermentation flavor caused by different strains were discussed. In this experiment, yeast was isolated and purified from vineyard soil, 26s rDNA identification and fermentation substrate tolerance analysis were carried out, and the causes of flavor differences of wine were analyzed from three aspects: GC-MS, PCA and sensory evaluation. The results showed that strain S1 had the highest floral aroma fraction, corresponding to its high production of ethyl octanoate and other substances, and it had the characteristics of high sugar tolerance. The fruit sensory score of S3 wine was the highest among the six wines. Through exploration and analysis, it was found that compared with commercial Saccharomyces cerevisiae, the screened strains had more advantages in fermenting table grapes. The flavor of each wine was directly related to the growth characteristics and tolerance of its strains.