Journal of the Science of Food and Agriculture最新文献

Background: Tea is the second most consumed beverage worldwide and its health benefits have been extensively studied because of its rich flavanol content. This study aims to evaluate the efficacy of a novel continuous step-wise temperature extraction process in maximising antioxidant activity, total phenolic content and flavanol concentration of different tea beverages.

Results: Continuous step-wise temperature extraction produced the highest absolute antioxidant capacity, total phenolic content and concentration of major tea flavanols in Yuhua tea compared to the other tea types at all extraction points. Despite having the lowest baseline concentration of tea flavanols, Lapsang Souchong tea showed the greatest increase in catechin and epigallocatechin-3-gallate levels with the continuous step-down temperature process, by over 500% and 300%, respectively. In addition, Moonlight White tea showed the greatest percentage change in total antioxidant capacity and phenolic content at the end of the process compared to the baseline. Furthermore, the continuous step-wise temperature extraction showed a moderate increase in caffeine concentration in all the tea samples.

Conclusion: Our findings revealed a beneficial impact of continuous step-wise temperature extraction on the antioxidant capacity, phenolic content and flavanol profile in different types of tea, which may be valuable in the production of added-value tea beverages. © 2024 Society of Chemical Industry.

Background: Protein hydrolysates possess various bioactive functions (e.g. antioxidant), but their bitter taste is unacceptable to most consumers. In the present study, a novel approach for debittering was introduced, which involved the utilization of a hydrophobic compound, curcumin (Cur). Soy protein hydrolysates (SPH), prepared through alcalase hydrolysis, served as the research model for this investigation.

Results: It was found that bitter intensity of SPH was dominated by the hydrophobic amino acid residues, and the addition of Cur could remarkably reduce bitterness. The debittering mechanism is attributed to the direct binding of Cur to the exposed hydrophobic amino acid residues of SPH via hydrophobic interaction, thereby shielding the hydrophobic bitter groups and hindering their interaction with the bitter taste receptors. Moreover, this debittering strategy leads to the generation of stable nanoparticles with a Cur-core/SPH-shell architecture, which can significantly improve the antioxidant capacity of SPH compared to those using biomacromolecules for encapsulation.

Conclusion: Using curcumin as a hydrophobic core is a facile and feasible strategy with bifunction of debittering as well as improving bioactive effect of SPH, which may extend its application in foods. © 2024 Society of Chemical Industry.

Background: Agronomic uses of biochar have been intensely explored in the last 15 years. Recently, a new generation of biochar-based fertilizers has been developed. Raw biochar (BCH), nitrogen-enriched biochar (N + BCH) or urea were added to a coir fiber-based substrate for tomato cultivation, to assess seed germination, growth and fruiting of two cultivars (Cuarenteno and Moneymaker).

Results: BCH stimulated seed germination and early radicle growth, possibly because of the presence of karrikins detected in both BCH and N-BCH (0.039 and 0.044 mg kg^-1, respectively). However, BCH reduced growth in adult plants in both cultivars, probably because of ammonium retention, causing low-N-stress-related symptoms such as accumulation of flavonoids in the leaf. Urea was toxic for seed germination because of the fast release of ammonium, but caused a positive effect on adult plant growth and yield, increasing chlorophyll in both cultivars, quantum yield and ascorbic acid in cv. Cuarenteno, and decreasing flavonoids and peroxide in leaves of both cultivars. Unlike urea, N + BCH showed a positive impact on plant growth and yield, but without releasing high amounts of ammonium or negatively affecting seed germination. Nitrogen-rich amendments reduced phosphorus and increased iron leaf content in both cultivars.

Conclusion: BCH can be effectively used as a growth medium constituent in nurseries for seedling production, whereas N + BCH offers a promising alternative to urea or other nitrogen mineral fertilizers for crop cultivation. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Background: Pediococcus acidilactici is an effective adsorbent for removing of pyrethroid insecticides. This study investigated the biosorption characteristics and mechanisms of P. acidilactici D15 using adsorption measurement, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Isotherm and kinetic models were used to analyze the biosorption process.

Results: The Langmuir isotherm model best described the cypermethrin biosorption process, with the maximum adsorption capacity of P. acidilactici D15 being 21.404 mg/g. The biosorption appeared to involve monolayer coverage with uniform forces. The pseudo-second-order model also fits well. The rate-controlling steps involved intraparticle diffusion, film diffusion and chemosorption. The main cellular components involved in cypermethrin biosorption were exopolysaccharides, spheroplast, and cell wall, especially peptidoglycan. The functional groups (-OH, -NH, -CH₃, -CH₂, -CH, -CONH-, -CO, and -C-O-C-) from proteins, polysaccharides, and peptidoglycan on the cell surface likely played a role in binding cypermethrin. Additionally, P. acidilactici D15 effectively reduced cypermethrin in pickle wastewater.

Conclusion: These findings suggest that P. acidilactici D15 could be a potential agent for reducing pesticide residues, laying the groundwork for treating pickle wastewater containing such pesticide residues. © 2024 Society of Chemical Industry.

Background: Polyphenolic compounds in millet vinegar are crucial functional substances, but the mechanisms underlying their formation and metabolism remain unclear. Acetic acid fermentation (AAF) represents the most active microbial metabolism stage and is pivotal for forming polyphenolic compounds. This study comprehensively analyzed the role of the microbiome in polyphenolic compound production and metabolism during AAF.

Results: Changing patterns were observed in both the microbiome and polyphenolic monomer compounds during AAF of millet vinegar. Lactobacillus harbinensis (0.624-0.454%) was identified as the dominant species in the pre-AAF stage, exhibiting a significant positive correlation with caffeic acid, kaempferic acid and kaempferolide (P < 0.05). Lactobacillus harbinensis-mediated polyphenolic compound metabolism was further confirmed through genomic analysis and pure culture fermentation techniques. Lactobacillus harbinensis encodes enzymes such as carbohydrate hydrolases, glycosidases and cellulases, which promote the release and metabolism of polyphenolic compounds from grain hulls.

Conclusion: This study confirmed that L. harbinensis, as a core microorganism in millet vinegar fermentation, can significantly augment the content of total phenols and specific polyphenolic compounds. These findings provide valuable insights for optimizing millet vinegar production. © 2024 Society of Chemical Industry.

Background: Oat (Avena sativa L.) is a valuable crop due to its strong adaptability to marginal environments, making it an important component of agricultural systems in regions where other cereals may not thrive. The application of chemical fertilizer can influence oat hay and grain yield significantly. However, large-scale meta-analytical studies of the size and variability of oat hay and grain yields in response to fertilizer addition are still lacking. Based on 83 studies worldwide, this meta-analysis quantifies the impact of the addition of fertilizer on oat hay and grain yields under varying environmental conditions (e.g., soil nutrient levels, texture, and climate).

Results: The results confirmed that the fertilizer application increased oat hay yield by 48.9% and grain yield by 36.2%. This study demonstrated that balanced fertilization with nitrogen, phosphorus, and potassium generally enhances oat hay and grain yield despite large temporal and spatial variations. Boosted regression tree (BRT) models suggest that changes in hay and grain yield were primarily dominated by soil pH and nitrogen fertilizer. The response ratio (the natural logarithm of the mean values of hay yield or grain yield with and without fertilization, respectively) of hay yield declined linearly with soil pH. Elevation was the second most important factor affecting the change in response ratio of hay yield and the third most important factor affecting the change in response ratio of grain yield but climatic conditions were not the dominant factors affecting changes in oat hay or grain yield.

Conclusion: Overall, these results will benefit producers considering site-specific fertilization management of oat. They could increase yields and save investment in fertilizer, and help to facilitate the genetic breeding of oat varieties with high nutrient use efficiency. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Background: Elevated potentially toxic elements (PTEs) in aquatic products could threaten the health of ordinary consumers. Levels of chromium (Cr), arsenic (As), lead (Pb), and mercury (Hg) in Cyprinus carpio in karst plateau freshwater Lake, Caohai Lake, China were quantified using inductively coupled plasma mass spectrometry (ICP-MS) and evaluated using a risk method with Monte Carlo simulation.

Result: Levels of Cr, As, Pb, and Hg in muscle tissue were substantially lower than those in viscera. The maximum concentration of muscle-bound Cr, As, Pb, and Hg were less than the standard references set by Chinese Food Codex (GB 2762-2022). The levels of Cr, As, Pb, and Hg in muscle tissue were independent of fish weight and length. The hazard index of all investigated elements in muscle tissue were less than one for adults and children, whereas the target hazard quotients of muscle-bound PTEs for children were higher than those for adults. Results indicated that exposure duration was the largest contributor to the hazard quotient of Cr, As, and Hg, whereas the concentration of Pb in muscle was the most sensitive factor affecting the variation in hazard quotient of Pb.

Conclusion: There is no risk related to the normal intake of muscle-bound Cr, Pb, As and Hg with the consumption of Cyprinus carpio. A better definition of the probability distribution for exposure duration and PTEs concentration could result in a more accurate hazard quotient. © 2024 Society of Chemical Industry.

Background: Probiotics have excellent antioxidant and antibacterial effects and are also considered to be promising natural biological preservatives. This study examined the freeze-thaw stability of the antioxidant and antibacterial activity of probiotic Bacillus velezensis PJP10, and evaluated the effect of different concentrations of PJP10 (10⁶, 10⁷, and 10⁸ CFU mL^-1) on microbial growth, textural characteristics, physicochemical properties, and lipid oxidation of grass carp fillets during repeated freeze-thaw cycles.

Results: Freeze-thaw cycles had little effect on the antioxidant and antibacterial stability of PJP10. Treatment with the PJP10 strain slowed effectively the increase in Aeromonas spp. counts (ASC), pH, total volatile basal nitrogen (TVB-N), and thiobarbituric acid (TBA) values of the freeze-thaw fish fillets. It maintained the textural quality of fillets, inhibiting the reduction of hardness, springiness, gumminess, cohesiveness, chewiness, and resilience values, and reduced lipid oxidation, as evidenced by decreased carbonyl values and conjugated diene values after multiple freeze-thaw cycles.

Conclusion: Probiotic B. velezensis PJP10 had protective effects on microbiological, textural, and physicochemical properties, and lipid oxidation of grass carp fillets during repeated freeze-thaw storage, suggesting a potential application of this strain in the freeze-thaw preservation of freshwater fish. © 2024 Society of Chemical Industry.

Background: The aqueous extraction of sesame oil is a traditional process that generates a large amount of melanoidins. However, little is known about the characteristics and bioactive functions of these melanoidins.

Results: Electronic tongue, fluorescence emission spectroscopy, and Fourier transform infrared spectroscopy analyses indicated that melanoidins from sesame residues (MELs) are brown macromolecular compounds with protein skeletons and heteroaromatic ring structures, a bitter taste, and instability in strong oxidative and reductive environments. The MELs demonstrated inhibitory effects on α-glucosidase, α-amylase and pancreatic lipase in vitro. These MELs mitigated weight loss in mice with type 2 diabetes (T2DM), reduced their fasting blood glucose to 54.73% (500 mg kg^-1 day^-1) of the initial value, increased the glycogen levels in the liver and skeletal muscles, lowered blood lipid levels, and protected the liver. Western blot analysis revealed that MELs inhibited the activities of enzymes such as PEPCK, FBPase, and G6Pase through the IRS-1/PI3K/Akt and AMPK pathways, increased the activity of the enzymes hexokinase (HK) and pyruvate kinase (PK), enhanced liver glycolytic ability, and promoted liver glycogen synthesis, thereby reducing blood glucose levels in T2DM mice. Moreover, MELs reduced the ratio of Firmicutes to Bacteroides (F/B) in the intestines of T2DM mice, increased the relative abundance of beneficial bacteria such as Lactobacillus, Coprococcus, and Ruminococcus, and reduced the propionic acid content.

Conclusions: Melanoidins can regulate T2DM by activating the IRS-1/PI3K/Akt and AMPK-signaling pathways and ameliorating gut microbiota imbalances in T2DM mice. © 2024 Society of Chemical Industry.

Background: The effectiveness of whey obtained by either enzyme (sweet) or acid treatment on wound healing remains unclear. This study investigated the effectiveness of camel and bovine whey prepared enzymatically (CSW and BSW) or by pH reduction (CAW and BAW). After removing the cream from milk, HCl or rennet was used to remove casein, resulting in acid or sweet whey, respectively, followed by lactose removal using dialysis. Casein removal was verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Wound-healing activity was measured in vitro on HT-29 cells by scratch assay. All four whey samples (0-1000 mg L^-1) were applied on the cells, and the closure of the cell-free scratched areas was monitored for 48 h.

Results: All whey samples increased the cell migration significantly (P < 0.05) to help close the cell-free areas as an indication of wound healing compared to the negative control. However, the closure amounts between the highest dose (1000 mg L^-1) and the control were not significantly different (P > 0.05). Acid whey samples significantly (P < 0.05) elevated the closure speed compared to the sweet whey samples. The highest closure percentage (64.69%) was achieved after treatment with 10 mg L^-1 CAW for 48 h. Between the sweet whey samples, BSW was significantly (P < 0.05) more effective in closing the cell-free zone compared to CSW.

Conclusion: This study investigated the wound-healing potential of camel and bovine whey in vitro by comparing their effects on HT-29 cell migration. CAW showed the greatest activity and may find uses as a treatment agent in wound healing. © 2024 Society of Chemical Industry.