LWT - Food Science and Technology最新文献

Red arils, derived from the yew tree (Taxus spp.), are renowned for their edible and nutritional properties. In this study, a novel red aril (RA) wine was produced and evaluated for its quality characteristics and sensory attributes. The flavor compounds in RA wine changed dynamically during fermentation, with a total of 26 differential volatiles identified. PLSR analysis indicated that ketones positively contributed to the citrus odor. Furthermore, RA wine exhibited high levels of organic acids, polyphenols, and amino acids after fermentation, influencing its bitterness and sourness profile. Molecular docking revealed that the activation of receptor OR1G1 by 6-methyl-5-hepten-2-one, a key ketone volatile, generated the citrus odor in RA wine. Furthermore, the taste profile of RA wine was inclined towards bitterness and sourness. Molecular docking analysis also demonstrated interactions between the key differential taste compounds with bitter-taste receptor TAS2R14 and sour-taste receptor OTOP1. Moreover, an intricate metabolic profile of RA wine was revealed through an overall metabolic map, providing insights into the underlying formation mechanisms contributing to RA wine quality.

Xanthan gum (XG) is a widely used thickener known for its high viscosity and excellent stability. However, the presence of ascorbic acid (AA) leads to a clear decrease in its viscosity, thereby affecting the application of xanthan gum in food products containing AA. Therefore, the aim of this study was to uncover the mechanism by which AA reduces the viscosity of xanthan gum. Ascorbic acid (0.1 mmol/L) caused a viscosity loss reaching up to 96% for xanthan gum solutions (2 g/L). The reaction was further enhanced by heating at 60 °C for 1 h without stirring, a weakly acidic system at pH 5.4, and the addition of hydrogen peroxide or metal ions (Fe²⁺ and Cu²⁺). Interestingly, AA induction produces free radicals and changes in their content correlate with a decrease in XG viscosity. Moreover, removing dissolved oxygen by heating and nitrogen purging treatment effectively reduced AA-derived free radical levels and prevented the decrease in XG viscosity. The decrease in viscosity of XG caused by AA involved its free radicals generated through an oxygen-dependent pathway.

The fortification of staple foods and the exploitation of agri-food by-products are the goals of modern food technologies. In this study, we prepared fortified pasta by replacing semolina flour with 5%, 10%, and 15% dried red chicory by-product powder (RCP), rich in fiber (27%) and healthy bioactive compounds (4.3%). The UHPLC-DAD-HRMS indicated hydroxycinnamic acids (HA), flavonoids (F), anthocyanins (A), and sesquiterpene lactones (SL) as the main bioactive compounds of RCP. The extraction recoveries of phenolic-fortified pasta (ranging from 0.2 to 13% for HAs to 5–28% for Fs and < 0.2% for As) suggest a high affinity with the semolina components, likely gluten or starch. The addition of RCP influenced (p < 0.05) the pasta's technological properties by inducing an increase in cooking loss, fully cooked time, and a decrease in the swelling index. The texture analysis showed that firmness and adhesiveness increased in the fortified sample. The sensory characterization showed a greater perception of vegetable and bitter flavor with increasing fortification levels. The RC15 sample had optimal technological, nutritional, and sensory characteristics. In conclusion, RCP could be an ingredient used to produce pasta with high fiber and bioactive compounds.

The European production of seaweed, including kelp species, is increasing, but efficient processing schemes for complete biomass valorization are still lacking. In this study, we investigated the effect of combining pulsed electric field (PEF) processing and soaking/blanching treatments (10, 45, and 60 °C) on the chemical composition of sugar kelp. Furthermore, we suggest applications for the various fractions resulting from the different pre-processing steps.

More dry matter was extracted from the biomass with increasing degree of processing. Combining PEF and blanching gave the highest extraction yield (˜60 %) compared to only using one of the steps (˜40 %). The extracted compounds contained ash (including iodine), polyphenols, and mannitol. Proteins, heavy metals, other sugars, and (presumably) fiber were concentrated in the solid fractions. Based on the composition, applications within food, feed, agriculture, nutraceuticals, and cosmeceuticals are suggested for the fractions and extracts.

These results can be relevant to researchers investigating novel technologies, processing of seaweed, and food safety, as well as to the seaweed industry, for the selection of processing technologies and product applications.

Enzymatic browning is one of important factor causing quality deterioration of Goji berries (GB). To understand the enzymatic browning process of GB and its mechanism, changes of L*, a*, b* values, and the total color difference and whiteness index during the air contact storage were evaluated. Then changes of moisture content, total phenolics and the activities of the key browning enzymes, peroxidase (POD), Polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL) and Superoxide dismutase (SOD), were determined during storage. Finally, the chemical constituents of GB were determined by targeted metabolomics and HPLC, and the possibility that these constituents were endogenous substrates of key enzymes for browning were evaluated. The results show that brightness and reddish-yellowness diminished are the general characteristics of GB discoloration. The activity of browning related enzymes (POD, PPO, PAL) was consistent with that of phenolics and flavonoids, which increased first and then decreased during storage. The content of chlorogenic acid decreased most rapidly under the action of the enzyme, which degraded 75% within 5min, followed by ferulic acid and rutin. Therefore, it is suggested that chlorogenic acid is the main endogenous substrate of GB enzymatic browning. In conclusion, these studies provide experimental basis for the browning mechanism of GB.

Salmonella and Vibrio cholerae are the deadliest foodborne pathogens, requiring effective routine screening for food safety assurance. Hence, a duplex polymerase chain reaction integrated with a lateral flow immunoassay (PCR-LFIA) was developed for rapid detections of Salmonella and V. cholerae to overcome the laborious, time-consuming, complicated, and costly limitations of standard bacterial culture. The duplex PCR-LFIA could simultaneously detect Salmonella invA and V. cholerae lolB targets at lower limits of 0.1 and 1 ng, respectively. Without requiring culture enrichment, the duplex PCR-LFIA method enabled rapid and simple naked-eye identification of Salmonella and V. cholerae in spiked raw oysters and chicken meat at a limit of detection (LOD) of 10⁶ CFU/mL. A LOD of 10⁴ CFU/mL was achieved by visualizing the PCR amplicons by agarose gel electrophoresis (AGE). This novel duplex PCR-LFIA offers rapid and simple visual detections of pathogenic Salmonella and V. cholerae contaminations, potentially enhancing the capability to monitor and control foodborne illnesses, thereby ensuring food safety.

The antioxidant yeast strains isolated from the traditional dry sausage of northern China were screened, and their antioxidant role in dry sausage was evaluated. The survival abilities of seven strains were relatively superior when exposed to 12 mM H₂O₂ after 48 h, and these were subsequently inoculated into dry sausage. Among them, Debaryomyces hansenii HRB1 and Rhodotorula mucilaginosa SH9 treatments yielded lower peroxide value (0.48 and 0.51 mmol/kg, respectively), thiobarbituric acid reactive substance value (0.51 and 0.50 mg MDA/kg, respectively), and carbonyl content (8.67 and 8.70 nmol/kg protein, respectively) values (P < 0.05), indicating the superior antioxidant activity of these two strains. Meanwhile, yeast inoculation reduced the alcohol content and increased the ester content in the dry sausage. In particular, the level of hexanal, a byproduct of lipid oxidation, was reduced. A sensory evaluation demonstrated that the inoculated dry sausage had the higher salty taste and the lower sour taste and rancid taste. Overall, D. hansenii HRB1 not only effectively inhibited lipid and protein oxidation and reduced the perception of oxidative taste, but also enhanced the aroma profile of dry sausage and improved overall sensory quality. This study offers a novel perspective for the development of antioxidant starters and enhancement of fermented meat product quality.

Bianba is a Chinese fermented food with a long history, whereas the microorganisms involved in its fermentation remain poorly understood. Currently, a strain of Lactiplantibacillus plantarum was isolated from Bianba and named L3. Genomic analysis emphasized the functional annotation of protein-coding genes in L3 specifically for carbohydrate utilization. Risk sequences (antibiotic resistance and virulence genes) were detected, and L3 was deemed safe based on the outcomes of tests for antibiotic resistance, hemolysis, and gelatinase production. The L3 strain shows promise as an ideal culture for initiating yogurt fermentation due to its robust acid production and high tolerances to acid, bile salts, and gastric acids. Compared with the commercial starter fermented yogurt, the yogurt produced by L3 (L3Y) had a lower pH value, viscosity, and hardness, higher acidity, syneresis, and gumminess. Notably, the L3 cells in L3Y remained viable at levels greater than 10 log CFU/g even after being stored at 4 °C for 21 d without a significant decrease, and L3Y showed higher concentrations of important volatile flavor compounds, such as acetoin and diacetyl. Our results showed L3 carried safety characteristics and good potential to be applied in yogurt, which would be of interest to the dairy industry.

This study aims to evaluate the impact of different corn varieties (Lancaster Sure Crop-LSC, Hickory King White-HKW, and Yellow Dent Corn-YDC) on baijiu fermentation especially focusing on ethanol yield and flavor compounds) and characteristics of dried distillers grains (DDG); and reveal the relationship between flavor compounds and the microbial community in baijiu fermentation. The results showed that LSC generated the highest ethanol (14.73%, v/v) and least methanol (6.6 g/L) concentrations in zaopei (fermented grains before distillation) among the three studied varieties. The DDG from the LSC variety had higher protein (21.14%) and fat (12.20%) contents (dry weight basis) compared to the other two varieties. The results of High-throughput sequencing indicated that both Bacillus and Weissella were dominant bacteria, while Saccharomyces, Saccharmycopsis, and Rhizopus were predominant fungi in all zaopei. In addition, 17 different flavor compounds were found in zaopei, including esters, alcohols, acids, and phenolics. Based on the Pearson correlation analysis, Bacillus, Pediococcus, Leuconostoc, Enterococcus, Weissella, and Pseudomonas, along with Saccharomyces, Saccharmycopsis, Rhizopus, and Mucor fungi, played significant roles in the formation of flavor compounds. These findings deepen our understanding of the microbial contribution to flavor compounds and will help improve baijiu quality.

The market of dry aged meat is rapidly increasing. However, few papers report the impact of specific dry aging parameters on quality and microbiological safety of dry aged meat. In this study we assessed the impact of a 90 days dry aging process, performed in a commercial cabinet, on the quality parameters and microbiological safety of Holstein beef loins. Meat pH, colour indexes and fatty acids were stable during the process. Main volatile compounds’ concentration increased over time. Any oxidation of protein residues was detected and the main proteins undergoing proteolytic degradation early in the process were myoglobin, myofibrillar constituents and sarcoplasmic enzymes. The most significant histological changes started at 30 days and striation impairment was observed, not related to oxidative processes. The total bacteria count increased without signs of spoilage, Enterobacteriaceae were not enumerated and few reads of foodborne pathogens were detected by shotgun metagenomic. These results show that when the dry aging process is performed in a dedicated cabinet under strictly controlled process parameters, the microbiological safety of the meat is preserved. Our study provides the first insights of dry aged Holstein loins, whose valorisation would certainly enhance the economic, social and environmental sustainability of the Parmigiano Reggiano food system.