Food Chemistry: X最新文献

The solid-phase adsorption principles and fundamental mechanism of isobutyric acid, 1-octen-3-ol, and octanal (three key off-odor compounds of oyster peptides) were explored using electrospun octenyl succinylated starch-pullulan (OSS-PUL) nanofiber mat. The nanofiber mats had selective adsorption behaviors as indicated by the selective adsorption rates of isobutyric acid, 1-octen-3-ol, and octanal, which were 94.96%, 85.03%, and 65.36%. The contents of the II-type inclusion complexes (ICs) formed with the nanofiber mats by the three off-odor compounds mentioned above were significantly different. The mean fiber diameter of the octanal/nanofiber mat IC with the highest content of II-type IC was significantly decreased (p < 0.05). In contrast, the isobutyric acid/nanofiber mat IC did not significantly change. The findings suggested that nanofiber mats interacted most strongly with octanal and weakly with isobutyric acid. This study will provide the theoretical foundation for deodorizing aquatic products using electrospun starch-based nanofiber mats.

Nongxiangxing Baijiu is the most famous Baijiu flavor in China, and its characteristic style is closely related to Nongxiangxing Daqu used in fermentation. However, there are few reports about the difference of Daqu quality between seasonal variations. In this study, precipitation and temperature drove changes in microbial communities that resulted in differences in the flavor of Daqu produced in different seasons. For example, the average daily temperature in summer was as high as 27.29 ± 2.24 °C, which was significantly higher than other seasons (p < 0.01). Bacillus was abundant in the Daqu produced in this season, while tetramethylpyrazine flavor was more prominent, up to 1556.95 ± 153.92 μg/kg. Metabolomics studies identified major pathways associated with the weak flavor of spring_Daqu. In addition, LEFSe analysis revealed the marked microorganisms in different seasons. These results revealed the differences in seasonal Daqu, thus contributing to the scientific and rational use of Daqu.

The study aimed to improve the barrier characteristics of polyvinyl alcohol (PVA) film by adding beeswax (BW) and glycerin and by heat treatment in order to become a potential suitable material for bread packaging. XRD, FTIR and XPS showed new cross-links between PVA and beeswax demonstrating the composite nature of the film. TGA-DTA showed that glycerin reduced the dehydration and that the beeswax improved theirs thermal stability. The best PVA-beeswax film formula has water vapor permeability (WVP) only 7.5 times higher than that of polyethylene (PE), while PVA is 29 times more permeable. The correlation coefficients, linear (MLR) and stepwise (SR) regression modelling showed a direct correlation between WVP, solubility in food simulants, swelling capacity and biodegradability. Principal Component Analysis (PCA) demonstrated that the analyzed films have different behavior from PE, and among them the most similar is that of the PVA with 2 g of beeswax and no glycerin sample. This film type also showed efficiency in bread packaging.

Gardenia jasminoides Ellis is widely used as healthy food and herbal medicine for its anti-inflammatory, analgesic, antihypertensive, and antiviral functions. The drying behavior and physicochemical quality of Gardenia jasminoides Ellis were studied to evaluate its adaptability under four drying techniques: hot air drying (HAD), medium-and short-wave infrared drying (MSWID), pulsed vacuum drying (PVD), and radio frequency-HAD (RF-HAD). Compared with HAD and MSWID, PVD and RF-HAD can form beneficial microporous channels for moisture migration inside Gardenia jasminoides Ellis, thus shortening drying time by 32.56-42.51 % and increasing geniposide content by 3.31-13.77 %, while better preserving the brightness and redness. In addition, Pearson correlation analysis confirmed the RF-HAD dried samples showed the best antioxidant activity with the highest content of active ingredients (chlorogenic acid, geniposide), and there was a significant positive correlation between sample color and yellow pigment content. After comprehensive comparison, RF-HAD is proposed to be the most suitable method for Gardenia jasminoides Ellis drying. This research could provide scientific basis and technical support for promoting the high quality development of industrial processing of Gardenia jasminoides Ellis.

The quality issues of ultra-high-temperature (UHT) milk, such as protein hydrolysis and aging gels throughout shelf life, are caused by proteases from psychrophilic bacteria. However, existing enzyme activity detection techniques have low sensitivity and cannot accomplish the detection of product deterioration caused by low enzyme activity. In this study, an attempt was made to analyze the relationship between enzymatically cleaved peptides and product quality using peptidomics techniques. The impact of psychrophilic bacteria proteases on the quality of UHT milk was investigated based on peptidomics by exogenously adding proteases. The results indicated that the protease activity and protein hydrolysis increased significantly in UHT milk over the storage period. Through peptidomic analysis, 2479 peptides were identified, in which 32 proteins linked to the identified peptides. 17 potential marker peptides, including αS ₁ -casein_143-156, β-lactoglobulin_99-108, and β-casein_39-66, were screened. The correlation of all identified peptides with protease activity and protein hydrolysis was explored by the weighted gene co-expression network analysis (WGCNA) method. The peptidomics technology helps to study the release or degradation of peptides in UHT milk during storage, which can be applied to monitor the shelf life of UHT milk and predict spoilage.

Sweetpotato with different flesh colors exhibits significant differences in flavor. Nevertheless, research on the identification of the key aromatic compounds in sweetpotato is scarce. Therefore, 40 primary sweetpotato varieties with different flesh colors were analyzed by HS-SPME/GC-MS to characterize the volatile compounds. A total of 121 volatile compounds were detected, with aldehydes, furans and terpenes being the most abundant components. Additionally, 35 compounds were identified as the key aromatic compounds by OAV > 1, of which 17 were found in all varieties and hence considered as the major components of sweetpotato aroma. Further analysis demonstrated that the yellow-fleshed sweetpotato had the strongest aroma, which was presumed due to the aldehydes like (E,E)-2,4-heptadienal, nonanal, (E,E)-2,4-decadienal,etc. that were produced during the degradation of unsaturated fatty acids. The unique sweety and floral aroma of orange-fleshed sweetpotato might be attributed to apocarotenoid volatiles (trans-beta-ionone, β-ionone, geranylacetone, etc.), the derivates of carotenoids. The purple-fleshed sweetpotato exhibited weak aroma with a significantly high terpenoids concentration. Overall, these findings may be the main reason for the different aromas of different colored sweetpotatoes and provides insights into sweetpotato aroma and a theoretical basis for improving sweetpotato aroma.

Most commercially available red wines undergo alcoholic fermentation by Saccharomyces yeasts, followed by a second fermentation with the lactic acid bacteria Oenococcus oeni once the initial process is complete. However, this traditional approach can encounter complications in specific scenarios. These situations pose risks such as stalled alcoholic fermentation or the growth of undesirable bacteria while the process remains incomplete, leaving residual sugars in the wine. To address these challenges and the issue of low acidity prevalent in warmer viticultural regions, several novel alternatives are available. The alternatives involve the combined use of Lachancea thermotolerans to increase the acidity of the musts, lactic acid bacteria (Oenococcus oeni and Lactiplantibacillus plantarum) to ensure malic acid stability during early alcoholic fermentation stages, and Saccharomyces cerevisiae to properly complete alcoholic fermentation. The study showed variations in the final chemical parameters of wines based on the microorganisms used.

This study analyzed the nutritional composition, bioactive compounds, antioxidant activities and estimated potential renal acid load (PRAL) score of orange-fleshed sweet potato (OFSP) grown in Vietnam. In addition, important functional groups of carotenoid compounds in OFSP were identified by Fourier transform infrared spectroscopy (FTIR); carotenoid pigments were detected and quantified by high-performance liquid chromatography (HPLC). The results showed that, OFSP had outstanding physicochemical characteristics, containing many nutrients, bioactive substances, minerals and fiber. The negative PRAL score (< 0 mEq/day) of OFSP indicated that this was an alkaline food. FTIR spectroscopy provides a versatile tool for food analysis, and the analysis results showed that the carotenoid composition in OFSP grown in Vietnam have contained 14 complete functional groups detected, with 14 spectral peaks spanning the wavelength range from 433.98 cm^-1 to 3288.63 cm^-1. HPLC analysis identified the main carotenoid pigment in OFSP as β-carotene. The detailed evaluation of the physicochemical characteristics, functional groups and colorants in OFSP has shown that it is possible to use this raw material to develop different food products, playing a useful role in vitamin A deficiency management and improving the quality of human life.

To prepare dual-functional seasoning ingredients with a salty-umami taste, five proteases were applied to hydrolyze Monetaria moneta proteins, preparing enzymatic hydrolysates. Their taste compounds along with the salty-umami taste, were investigated. The results revealed that enzymatic hydrolysis facilitated the release of taste compounds from M. moneta. The whiteness and < 3 kDa peptides of enzymatic hydrolysates significantly increased. Moreover, flavorzyme and protamex, with high DHs, could thoroughly hydrolyze the proteins, generating the enzymatic hydrolysates abundant in taste compounds (e.g., amino acids, nucleotides) that synergistically provided a strong salty-umami taste. Saltiness and umami posed a strong positive correlation, with a correlation coefficient exceeding 0.90, resulting in the highest levels of equivalent salty intensity (ESI = 80.05 gNaCl/L) and equivalent umami concentration (EUC = 84.56 gMSG/100 g) in the flavorzyme-treated hydrolysate, followed by the protamex-treated hydrolysate. In summary, these findings offer novel insights into preparing dual-functional seasoning ingredients with a salty-umami taste, ideal for use in low-salt food production.

Dried Zanthoxylum bungeanum Maxim (DZM) is one of the popular categories in spices and condiments market. The flavor and quality of DZM products determine its value and application scope. This study evaluated the flavor and quality of DZMs from various origins, considering physical, chemical, and safety attributes. Notable variations were observed, with DZMs from Maoxian and Jinyang excelling in aroma, pungency, and appearance. Chromatic analysis distinguished green and red DZMs from Meishan and Hancheng. HPLC results revealed high pungency compound levels in Maoxian and Wudu samples, while GC-MS identified 173 volatile compounds, dominated by linalool and d-limonene. Microbial contamination was minimal in DZMs from Hanyuan and Jiangjin, and the lowest heavy metal levels were in samples from Hanyuan, Hancheng, and Jingyang, indicating superior environmental conditions. The research offered insights into origin and processing influences on DZM, aiding in selection and food safety assurance.