Food Chemistry: X最新文献

This study sought to validate the external calibration curve (CAL) method for iodine analysis in 26 selected foods and then to compare the test result with the isotope dilution mass spectrometry (IDMS). Iodine was extracted by tetramethylammonium hydroxide (TMAH) and determined by ICP-MS using CAL and IDMS methods. The results showed that iodine determination using the IDMS method had higher precision than the CAL method (LOD of the method were 0.01 and 0.02 mg/kg, respectively). However, both methods showed good accuracy and precision for all SRM and the 26 food samples. Test results from both methods had a strong correlation (R² > 0.998) and no significant difference between the determination methods, even within test sample sectors based on the distribution in the AOAC food triangle (p > 0.970). ¹²⁹I spiked into the sample before or during alkaline extraction showed no significant difference in the test results (p = 0.989).

Hyperlipidemia is a common endocrine metabolic disease in humans. Long-term medications often have adverse effects, making the search for safer and more effective treatments crucial. This study aimed to explore the impacts and mechanisms of Lactiplantibacillus plantarum HY127 fermentation on enhancing bile acid-binding capacity (BABC). We fermented corn by-product juice (CBJ) by HY127 and investigated the BABC of HY127 bacterial cells and their metabolites. Our results indicated that HY127 cells (95.25 %) played a major role in enhancing BABC, with metabolites (31.50 %-66.41 %) also contributing. Compared to unfermented CBJ, the contents of phenolics, flavonoids, polysaccharides, and organic acids were significantly higher. Non-targeted metabolomics revealed upregulated amino acids, alkaloids, terpenoids, and other bioactive substances associated with BABC in the supernatant. This study confirmed that HY127 fermentation enhances the BABC of CBJ (increased by 32.02 %-78.76 %), providing a research foundation and technical reference for the development of LAB-fermented corn by-product beverages with hypolipidemic activities.

Duck meat has a unique taste and nutritional value, but age probably affects meat quality. In this study, ducks of different ages (60-day-old, D60; 900-day-old, D900) were chosen, and the odor, taste, amino acid, nucleotide, and free fatty acid components of breast meat were evaluated to investigate the differences. The results showed that the amino acid contents of breast muscle in D900 ducks, especially in Asp (umami) and Thr (sweet), were richer than those in D60 ducks. In addition, the levels of guanosine-5'-monophosphate (GMP), inosine-5'-monophosphate (IMP), monounsaturated fatty acid (MUFA; C18:1 t), and polyunsaturated fatty acid (PUFA; C18:2) in D900 ducks were higher than those in D60 ducks. Proteomic approach was further performed to analyze the difference of breast muscle between young and older ducks in protein level. We found that 496 differentially expressed proteins (DEPs) were screened. GO and KEGG analysis mainly enriched in glycine, serine, and threonine metabolism, tyrosine metabolism, and pyruvate metabolism. Moreover, correlation analysis revealed that BPGM, ADH5, ME2, ME3, GLO1, and PDHB, were specifically correlated with amino acids, nucleotides, and free fatty acids in meat from D60 ducks, whereas only two proteins, GRHPR and COMT, showed specific correlations with amino acids, nucleotides, and free fatty acids in meat from D900 ducks. This study proposes several candidate protein biomarkers for older duck meat that should be evaluated in the future.

Potato is the fourth-most important food crop around the world, and most of the potatoes are used for foodstuffs and starch products. The aim of this paper is to identify the volatile compounds and metabolites in potatoes with different processing properties. The results showed large differences of volatile and metabolite compounds such as 2,4-Heptadienal and rhoifolin in potatoes and indicated the potential regulations between volatile compounds and metabolites. Moreover, the differences in volatile and metabolite compounds were compared between fresh eating and processing type potatoes. Compared to process type potatoes, fresh eating potatoes contained a higher proportion of aldehyde and alcohol compounds, but being lower in hydrocarbon, furan, and ketone compounds. Moreover, the different expressed metabolites were involved in the metabolism of amino acids, flavone and flavanol biosynthesis, and tryptophan metabolism. The Random forest showed that the fresh eating and processing type potatoes could be distinguished by the content of amino acids and phenols.

The ambition to utilize agricultural by-products has spotlighted tomato leaves as a promising source for plant-based proteins. High-yielding protein extractability is key for its industrial use, but previous studies reported decreased protein extractability at later stages of plant development. This study investigated the underlying factors in protein extractability through a comprehensive proteomics analysis across four plant developmental stages (vegetative, flowering, fruit-forming, mature-fruit). The findings linked reduced yields to a shift in leaf function, from anabolic to catabolic processes and (a)biotic stress responses. This functional shift is accompanied by decreased protein synthesis and increased protein degradation, leading to an overall decrease of the soluble protein fraction. Furthermore, incomplete extraction of soluble proteins from leaves of later developmental stages, suggested the presence of inhibitory molecules hindering the extraction process. These findings indicate that breeding strategies towards increased amounts of soluble proteins and reduced concentration of inhibitory molecules could enhance protein extraction yields.

Few studies have explored the impact of blue light-emitting diode (BL) irradiation combined with different storage temperatures on antioxidant defense and cell wall metabolic activities related to the quality deterioration of postharvest strawberries. This study investigates the effects of BL exposure as a non-chemical preservation strategy to improve the postharvest quality of strawberries stored at 22 °C and 8 °C. Over a 10-day storage period, BL irradiation significantly reduced respiratory and ethylene production rates, while preserving fruit firmness and increasing the contents of soluble sugar and total phenol at both temperatures. Additionally, increases of the enzymatic activities of antioxidant defense metabolism (e.g. superoxide dismutase (SOD) and peroxidase (POD)) accompanied with decreased levels of reactive oxygen species (ROS) (e.g. superoxide anion (O₂ ^-), and hydrogen peroxide (H₂O₂)) and the content of secondary metabolites (e.g. ascorbic acid (AsA)) accompanied with enhanced activities of ascorbate peroxidase (APX) and glutathione reductase (GR) were found in BL irradiated postharvest strawberries at the later stages of storage. Meanwhile, BL irradiation also mitigated the activity of cell wall-degrading enzymes, thereby reducing the degradation rates of protopectin (PP), cellulose (CEL), and hemicellulose (HCEL), while maintaining the structural integrity of cell walls. According to fuzzy mathematics analysis, the membership function values for BL irradiated postharvest strawberries at different storage temperatures ranked as follows: BL + 8 °C (0.60) > BL + 22 °C (0.52) > 8 °C (0.46) > 22 °C (0.36). These findings suggest that BL irradiation not only extends the shelf life of strawberries by modulating antioxidant defense and cell wall metabolic activities but also maintains their commercial quality, particularly under low-temperature storage conditions. Therefore, BL irradiation holds significant promise for minimizing quality deterioration in postharvest strawberries during cold storage.

The study investigated the impact of low-dose sodium nitrite on yak meat color and mitochondrial functional characteristics during the wet curing. The results showed that sodium nitrite significantly enhanced the redness (a ^⁎ value) of yak meat by increasing the activities of mitochondrial complexes I, II, III and IV, which are critical for electron transport and aerobic respiration. Additionally, sodium nitrite reduced mitochondrial swelling and membrane permeability, and slowed the production of lipid oxidation products, indicating protective effects against mitochondrial damage and preserving mitochondrial integrity. Correlation analysis and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) identified mitochondrial complex I activity, NADH-dependent metmyoglobin reductase activity, and specific lipid oxidation products as key factors influencing the a ^⁎ value of yak meat. These findings highlighted the significant role of mitochondrial function and structure in meat color stability.

Cassava is a starchy staple typically consumed in tropical countries; however, its high moisture content renders it susceptible to post-harvest deterioration. Fermentation has been used to improve shelf-life, functional properties, nutrient bioavailability, minimize toxic compounds, and alter aroma. In this study, the effect of added salt (5-25 %) on the pH, titratable acidity (TTA), and volatile compounds (VOCs) in cassava fermented was investigated. A sharp reduction in pH from 6.98 to 6.20 to 4.81-4.00 and concomitant increase in TTA (0.027-0.297 %) was observed in all the samples on day 2 except the 25 % added salt ferments. The 32 VOCs quantitated on day 50 by headspace solid-phase microextraction (HS-SPME) arrow coupled with gas chromatography-mass spectrometry (GC-MS) and classified as: alcohol (9), aldehydes (6), ketones (5), carboxylic acids (5), esters (3), nitriles (2), phenol (1) and hydrocarbon (1) were affected by the amount of added salt. PCA explained 68.50 % of the variance and cluster samples based on the similarities between the identified VOCs and showed that fermentation mediated by 15 % added salt presented a VOCs profile comparable to using 20 % of salt, with the former representing a lower cost. The addition of salt can be used to control acidification, adopted as an effective preservation technique, and mediate VOCs production during cassava fermentation.

The individual (poly)phenols of red wines cultivated in two different Western Balkan wine-growing regions were determined using the HPLC method, while the ABTS and DPPH tests were employed to investigate antioxidant activity. The reduction potential of antioxidants was determined by FRAP assay. Five distinct classes of phenolic compounds, including phenolic acids, flavan-3-ols, flavonols, stilbenes, and anthocyanins, were identified. The analyzed wines showed very good antioxidant properties. All of the studied wines exhibited a very strong correlation between their antioxidant potential and the concentration of significant antioxidants. Phenolic components that were the most represented in the investigated samples were selected for the theoretical investigation of the antioxidant effect. For this purpose, epicatechin gallate and sinapic acid were used. Their concentrations in the tested samples ranged up to 132.76 mg/mL and 125.66 mg/mL. Theoretical aspects of reactions of the mentioned compounds towards DPPH and ABTS radicals were examined.

This study investigated the probiotic potential of fermented beverages derived from Gnaphalium affine (G. affine). Three different beverages were prepared by fermenting G. affine water extract with Limosilactobacillus fermentum A6-3 (L. fermentum A6-3), Lactobacillus reuteri A27-1 (L. reuteri A27-1), or both for 48 h. The results demonstrated that bioactive compounds from G. affine promoted the growth of these two probiotics and preserved their viability for at least 28 days at 4 °C. Following fermentation, the concentrations of chlorogenic acid, coniferin, lactic acid, glycolic acid, and behenic acid were significantly elevated. Additionally, the G. affine fermented beverages promoted the growth of intestinal probiotics such as Lactobacillus, Bifidobacterium, while inhibiting pathogens like Clostridium, Shigella. Moreover, the G. affine fermented beverages exhibited beneficial effects, including antibacterial, antioxidant, anti-inflammatory activities. In conclusion, G. affine preserved the viability of probiotics, and probiotic, in turn, enhanced the beneficial functions of the G. affine fermented beverages.