Journal of the Science of Food and Agriculture最新文献

Background: Macadamia peels are the main by-product of postharvest treatment of the whole fresh fruit weight, they contain various bioactive substances, such as polysaccharides, phenols, flavonoids, phenolic acids, saponins, and other nutritional and functional components, that are known to have anti-tumor and anti-oxidation functions.

Results: Two purified polysaccharide fractions were obtained (MPP-1 and MPP-2) by extracting with ultrasonic-microwave-aided water extraction and purifying by with DEAE-52 and Sephadex G-50 columns, and then characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and NMR, and the antioxidant activity was also investigated. The results indicated that MPP-1 and MPP-2 were mainly glucose, the molecular weight was 8.16 kDa and 7.73 kDa, respectively. Methylation with gas chromatography-mass spectrometry and NMR analyses confirmed that two fractions comprised of →4) -α-d- Glcp -(1→, →6) -β-d- Glcp -(1→ and →3,4) -β-d- Glcp -(1→) as the main chain. In addition, MPP-1 and MPP-2 polysaccharides showed significant antioxidant activity with respect to 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl group and reducing power, and MPP-2 demonstrated excellent antioxidant activities compared to MPP-1 with IC₅₀ values of 35.12, 18.82 and 40.12 μg mL^-1, respectively.

Conclusion: The novel polysaccharide, MPP-1 and MPP-2, mainly containing glucose, showed significant antioxidant activity with respect to DPPH, hydroxyl group and reducing power. This study has enhanced waste utilization and reduced environmental pollution, providing some inspiration for the reuse of the waste generated during agricultural production. It may bring good prospects for their use as antioxidants in functional foods. © 2024 Society of Chemical Industry.

Background: The sorption characteristics and glass transition temperature are important attributes that determine the shelf life of foods, particularly in powder form, whereas color is a key factor influencing consumer acceptance. As the popularity of matcha green tea powder is increasing, this study investigated whether the country of origin of examples of matcha products available on the Polish market influenced the sorption properties, glass transition temperature, and color.

Results: All matcha powders exhibited sigmoidal water adsorption isotherms at 25 °C. The monolayer moisture content corresponding to the point of maximum stability ranged from 0.045 to 0.053 g water per g of sample. The glass transition temperature of anhydrous matcha powders varied between 106.3 and 139.0 °C. Based on the sorption and glass transition results, the matcha from Brazil should be the most stable during storage. The same sample showed the highest water solubility index values at temperatures above 80 °C and the lowest bulk density. The color parameters (L*, a*, b*, C*, and h) depended on the matcha powder variant.

Conclusion: The results indicate that the optimal storage conditions for tea powders do not depend directly on the country of origin. Further research should therefore focus on analyzing the impact of climate or fertilization. © 2024 Society of Chemical Industry.

Background: Myofibrillar protein (MP) is essential for the texture and taste of shrimp surimi products. The reactive oxygen/nitrogen species (ROS/RNS) produced by atmospheric cold plasma (ACP) might cause oxidative modification of MP. In this study, the effect of different ACP treatment times on the properties of red shrimp MP was investigated in detail.

Results: The mild oxidation induced by ACP treatment for 1 min (ACP-1 min) promoted the unfolding and refolding of the MP structure, which was manifested as a transition from α-helix to β-sheets. Compared with other groups, more hydrogen bonds and hydrophobic interactions in the ACP-1 min group might enhance the interactions between the myosin heavy chain and actin, which was conducive to the formation of a regular and dense three-dimensional network structure. Person correlation analysis revealed that ROS/RNS mediated the changes in the secondary and tertiary structure of MP. In addition, ACP-1 min has high Ca²⁺-ATPase activity, which reflected that MP maintained structural integrity. While excessive oxidation in the ACP treatments for 3 min and 5 min reduced MP robustness. The stable internal structure in ACP-1 min group gave the MP excellent texture profile (1.79 mJ of adhesiveness and 0.89 mm of springiness) and rheological characteristics (0.373 MPa of storage modulus).

Conclusion: Overall, the excellent quality of MP could be obtained by regulating the oxidation degree of ACP, which would provide valuable information for the in-depth and efficient processing of shrimp products. © 2024 Society of Chemical Industry.

Background: Spine grapes are widely cultivated in southern China because of their strong adaptability to hot and humid climates. As a wild species native to China, spine grape (Vitis davidii Foëx) was studied as a resource of proanthocyanidins (PAs). PA composition, biosynthesis, and histochemistry in different tissues (skins, seeds, and stems) during berry development were analyzed in this study.

Results: The findings revealed that PA accumulation occurred in concurrence with flowering and was completed by veraison. High-performance liquid chromatographic results showed that the epicatechin type was the most dominant. The skins were more likely to accumulate PA polymers. Reverse transcription-quantitative polymerase chain reaction analysis revealed that the expression levels of structural genes (flavonoid-3'-hydroxylase, flavonoid-3'5'-hydroxylase, dihydroflavonol 4-reductase, leucoanthocyanidin reductase, and leucoanthocyanidin dioxygenase) were positively associated with PA dynamic changes. Histochemical results revealed that PAs in skins were mainly found in the hypodermis of the exocarp, PAs in seeds were mainly found in the middle layer of the outer integument of the testa, and PAs in stems were mainly found in the phloem.

Conclusion: This study provides a clear understanding of the spatial and temporal accumulation of PAs in spine grape, and forms a basis for the analysis of structural profiles and synthesis of PAs and their biological effects. © 2024 Society of Chemical Industry.

Background: Consumers require fermented milk that possesses constipation-relieving functions. To cater to the 'natural and additive-free' consumption habit, this study is dedicated to developing probiotic fermented milk with constipation-relief effects. Previously, we isolated two Lactobacillus strains, Lactobacillus MWLp-12 and Lactobacillus MWLf-4, from breast milk. This study evaluated the efficacy of these strains and their fermented milk in alleviating constipation in a Balb/c mouse model of constipation. The evaluation criteria included fecal water content, time for first black feces expulsion and propulsion rate of the small intestine. The mechanisms of constipation relief were investigated using gastrointestinal regulatory peptides, colonic tissue pathology, short-chain fatty acid levels and gut microbiota analyses.

Results: Fecal water content, time for first black feces expulsion and small intestine propulsion rate indicated that both MWLp-12 and MWLf-4, as well as their fermented milk, could alleviate constipation in mice. Fermented milk exhibited superior effectiveness for relieving constipation compared to that of the strains alone. The results related to gastrointestinal regulatory peptides and short-chain fatty acids suggest that the mechanisms of constipation relief by the strains and their fermented milk may involve increased levels of 5-hydroxytryptamine and substance P in the mouse serum, higher concentrations of short-chain fatty acids in the intestines and decreased vasoactive intestinal peptide levels in the serum.

Conclusion: MWLp-12, MWLf-4 and fermented milk relieve constipation in mice. © 2024 Society of Chemical Industry.

Background: Proteolysis during ensiling primarily occurs due to undesirable microbial and plant protease activities, which reduce the protein supply to ruminant livestock and cause a series of environmental problems. The objective of this study was to investigate the effects of the tannin-tolerant lactic acid bacterium strain Lactiplantibacillus plantarum 4 (LABLP4) in combination with tannic acid (TA) on protein preservation in stylo (Stylosanthes guianensis) silage. The stylos were either ensiled without additives (control) or treated with LABLP4 (10⁶ colony-forming units per gram of fresh matter), 1% (fresh matter basis) TA, 2% TA, LABLP4 + 1% TA and LABLP4 + 2% TA. Fermentation quality, protein composition, protease activity and bacterial diversity were determined at 3, 7, 14 and 31 days of ensiling.

Results: The combination of LABLP4 and TA decreased the pH, coliform bacteria count, non-protein nitrogen, ammonia-nitrogen (NH₃-N) content and protease activities (P < 0.05) and increased the true protein content (P < 0.05) compared to the control. LABLP4 + TA led to a lower pH and NH₃-N content than LABLP4 or TA alone (P < 0.05). On the last day (31 days) of ensiling, LABLP4 + TA increased the relative abundances of Firmicutes and Lactiplantibacillus (P < 0.05), except for the LABLP4 treatment, and decreased the relative abundance of Actinobacteria (P < 0.05).

Conclusion: The combination of tannin-tolerant LABLP4 and TA effectively improved the fermentation quality of stylo silage and reduced protein degradation by altering the bacterial community structure. © 2024 Society of Chemical Industry.

Microalgae are widely recognized for their capacity to generate value-added products in a variety of sectors, including the pharmaceutical and food industries, bioenergy industries and wastewater industries. The quality of a microalga is significantly influenced by its proliferation. Along with growth, the biochemical profile may also vary based on the nutrient that is supplemented. The majority of the supplemented nutrients utilized are not in a functional state, as they are typically extracted in liquid form or pretreated prior to use. Parallel to numerous commonly applied pretreatment processes, including chemical, mechanical and biological, thermal pretreatment appears to receive less attention. Hence it is crucial to comprehend the potential for thermal pretreatment as well as its mechanism in militating the solid waste to release additional nutrients in order to enhance the biochemical profile of microalgae. The current review takes a closer look at the impact of various thermal pretreatments on solid waste on influencing microalgal performance in terms of their overall biochemical profiles such as carbohydrates, proteins and lipids. This approach is likely to enhance the circular economy by utilizing waste products and effectively closing the loop on waste. © 2024 Society of Chemical Industry.

Background: This study investigates the effect of microemulsions of 0.8% Ocimum basilicum essential oil (MOBO) on the cooking quality and shelf life of snakehead fillets using different impregnation methods (air environment treatment, vacuum impregnation, ultrasonic impregnation and vacuum impregnation with ultrasonic-assisted). Basil essential oil, recognized for its antimicrobial and antioxidant properties, is utilized in a microemulsion form to enhance its efficacy and application in food preservation.

Results: The findings of the study demonstrated that MOBO markedly enhanced the cooking quality, flavor and overall acceptability of snakehead fillets. The incidence of microbial growth was markedly diminished in the MOBO-treated fillets in comparison to the control group. On day 9, a reduction in the total viable count of a minimum of 1.7 lg CFU/g was observed in comparison to the control group. The treated group exhibited an extended shelf life, with an increase of 3-9 days in comparison to the control group. However, there was a higher cooking weight loss in the treated group compared to the control group. This is from the findings regarding moisture content. The digestibility of the MOBO-treated fillets was enhanced by up to 4.13% in comparison to the control group, while the particle size was reduced by up to 40 nm. MOBO reduced the production of bitter amino acids and thiobarbituric acid.

Conclusion: Incorporating MOBO in the marination process effectively enhances the cooking quality and extends the shelf life of snakehead fillets. These results indicate the potential of basil essential oil microemulsion as a natural and efficient food preservation method, offering significant benefits for the food industry in terms of product quality and safety improvement. © 2024 Society of Chemical Industry.

Background: There are few studies on the effects of electrically stimulated bacteria on anti-nutritional factors and microbial communities in mulberry leaf silage. This study aimed to examine the impact of the combined use of electrically stimulated Bacillus subtilis (EB) and Lactobacillus casei (LC) on the quality and degradation of anti-nutritional factors in mulberry leaf silage.

Results: The results revealed that the synergistic effect of EB and LC significantly enhanced the nutritional value of mulberry leaves, as evidenced by the promotion of lactic acid synthesis, the reduction of anti-nutritional factors, and the augmentation of lactic acid bacteria following a 60-day silage period. Moreover, the EB + LC co-inoculation resulted in the highest quality of mulberry leaf silage, with the degradation rates of tannin and phytic acid at 38.8% and 47.1%, respectively. The combination of EB + LC also enhanced lactic acid content, along with significant reductions in ammonia nitrogen (NH₃-N), soluble protein, and non-protein nitrogen (NPN) (P < 0.05). Spearman correlation analysis showed that Lactobacillus in the silage was significantly positively correlated with crude protein (CP) and lactic acid, while negatively correlated with water-soluble carbohydrates, pH and NPN (P < 0.05). In contrast, Weissella was significantly negatively correlated with CP and lactic acid.

Conclusion: This study represents a pioneering application of electro-stimulation in the field of feed silage, offering a scientifically substantiated approach to degrading anti-nutritional factors in mulberry leaves for livestock feeding. © 2024 Society of Chemical Industry.

Background: The crust characteristics of fried crisps determine their oil absorption. Starch structures, as the main components of fried starchy fruits and vegetables, influence their crust formation and properties. This study investigated the reduction of oil uptake and acrylamide content in infrared-fried (IF) banana slices by modifying starch structures at varying infrared power levels.

Results: Infrared heating improved heat transfer and surface moisture removal in fried banana slices. It facilitated crust formation in the IF samples and produced increased crust uniformity, crust ratio, and hardness. Analysis of the porous properties showed that the volume fraction of pores sized 100-250 μm was reduced in IF samples but the proportion of pores with a diameter ranging from 0.02 to 10 μm was increased. Infrared frying reduced the total oil uptake, surface oil, and structural oil content in banana slices, and each of these measures decreased as infrared power levels increased. Characterization of the starch structures suggested that the damage to the crystalline structure was increased in IF samples and more starch-lipid complexes were generated, which would be responsible for the formation of a denser and thicker crust. The acrylamide content in the IF sample was reduced, as determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Conclusion: Modifications to starch structures (crystalline structures and chemical structures) play a crucial role in oil absorption in fried starchy fruits and vegetables. Infrared frying can be used as an alternative method to produce low-fat fruits and vegetable crisps with reduced acrylamide content. © 2024 Society of Chemical Industry.