Food research international (Ottawa, Ont.)最新文献

In this study, two polysaccharides were isolated from the flesh and peel of wampee, termed as PWP-F and PWP-P respectively, and their structural characteristics, in vitro antioxidant and hypoglycemic activities and digestion were investigated. Results indicated the molecular weight of PWP-F was higher than that of PWP-P and they were both mainly composed of galactose and arabinose. Both polysaccharides exhibited α-type and β-type glycosidic linkages based on FTIR analysis. NMR spectroscopy revealed that PWP-F mainly consisted of α-Araf-(1→, →3,5)-α-Araf-(1→, →2,5)-α-Araf-(1→, →4) → β-Galp-(1 → and α-GalpA-(1→, while PWP-P was composed of α-Araf-(1→, →3)-α-Araf-(1→, →5)-α-Araf-(1→, →3,6) → β-Galp-(1→ and α-GalpA-(1→. Scanning electron microscopy showed that PWP-P had more porous surface structure compared to PWP-F. Moreover, PWP-P exhibited superior antioxidant activity and significant inhibition of both α-glucosidase and α-amylase compared to PWP-F. Specifically, PWP-P demonstrated mixed inhibition against α-glucosidase and α-amylase. In vitro digestion results showed the molecular weight, polysaccharide and reducing sugar content of PWP-F and PWP-P decreased after simulative gastrointestinal digestion. Overall, PWP-P has great potential as a kind of new antioxidant and hypoglycemic agent.

The antinutrients and off-flavors present in plant-based foods are some of the major organoleptic and consumer acceptance drawbacks considered when developing plant-based fermented dairy alternatives (PBFDA). Here, we investigated a combination of genotypical and phenotypical consecutive screening methods to find out the optimal single- and combination of lactic acid bacteria (LAB) strains based on volatile off-flavors, phenolic acids, saponins, and trypsin inhibitor degradation through the fermentation of a pea, oat, and potato (POP) blend. Lactiplantibacillus plantarum strains were the most optimal for the partial/complete degradation of p-coumaric (>98 %) and ferulic acid (10-20 %) compounds in the POP blend. Leuconostoc pseudomesenteroides strains, and their PII-type proteinases were demonstrated to be effective degrading trypsin inhibitors. Also, specific Leuconostoc mesenteroides and L. plantarum strains achieved higher degradation rates of plant saponins such as avenacoside A (10-40 % degradation) and soyasaponin B (55-75 % degradation) present, correlated with their β-glucosidase activity (30-50 U/mL). Strict heterofermentative LABs such as Leuconostoc spp. strains were significantly better at removing hexanal, pentanal, benzaldehyde, and nonanal up to 85 % after 6 h. Finally, 384 combinations of 2 and 3 LAB selected strains (L. plantarum - L. mesenteroides - L. pseudomesenteroides) were tested at different strain-ratios, which demonstrated synergistic effects at degrading ferulic acid to more than 80 %, increasing acidification rates, and producing higher concentrations of diacetyl and acetoin (up to 3.28 and 28.13 µg/g sample) when L. pseudomesenteroides 1993 was included in the mix. This study demonstrated the potential of using unconventional plant-adapted LAB strains as starter cultures for the elimination of multiple unwanted compounds for the development of higher quality PBFDA without the use of conventional dairy-based LAB isolates. Finally, the screening approach could be used for microbial screening purposes throughout the development of starter cultures for plant-based yogurts, cheese, and other non-dairy fermented products.

Since overconsumption of animal-sourced foods is directly linked to multiple environmental and health issues, a dietary shift is imperative. One approach to facilitate this change is the production of substitutes for animal-sourced foods based on plant-based or novel ingredients. However, to be a valid alternative, substitute products must match animal-sourced foods regarding their nutritional value while being price competitive. To understand where substitutes currently stand in that regard, this study presents a novel dataset containing the prices, main ingredients, and nutritional composition of almost 2600 substitute products as well as prices of approximately 7500 conventional products sold in major supermarket chains in France, Germany, Italy, the Netherlands, Spain, and the United Kingdom. Although comparative analyses (non-parametric two-sided Wilcoxon rank-sum tests at a 5 % significance level) of the results indicate that the meat substitutes generally contain a higher level of dietary fiber with lower saturated fats, these meat substitutes often also have lower protein quality and higher salt and sugar levels than the conventional products. On average, meat substitutes were found to be 24 to 115 % more expensive compared to conventional meat, except for the German samples where price parity has been reached. Among milk substitutes, only soy-based products have favorable macronutrient profiles. The average price premium charged for milk substitutes compared to cows' milk is 35 to 58 %. In general, fortification rates of substitutes should be increased to ensure sufficient supplies of micronutrients, particularly among meat substitutes where fortification rates are below 20% except for the Netherlands. Following these results, certain individual products already provide high nutritional value at low costs. However, further improvements are required for substitutes to become a compelling alternative at scale.

Objective: This study aimed to assess the risk of foodborne outbreaks associated with household food handling practices in China and identify the consumer groups that are at higher risk for foodborne outbreaks.

Methods: A national survey of household pork handling practices was conducted in China. The risk of foodborne outbreaks stemming from consumers' improper handling practices was assessed utilizing the Weighted Harmonic Outbreak Prevention Index (WHOPI). The index categorized these practices into three levels of good hygienic practice (GHP): low (WHOPI≤0.35), medium (WHOPI: 0.36-0.70), and high (WHOPI>0.70). Logistic regression analyses were used to identify groups at higher risk for foodborne outbreaks.

Results: A total of 2730 households from seven provinces in mainland China were analyzed. Based on WHOPI, only 0.4 % of households demonstrated a high level of GHP, while 55.4 % showed a low level of GHP. The primary non-conforming stage was separation practices, followed by cooking and purchasing practices. Nearly two-thirds of households (64.8 %) didn't have a separate cutting board for raw meat, and 44.9 % of them claimed to use the same board to handle ready-to-eats afterward. Logistic regression indicated more attention is required for those living in southern and rural areas, working in non-public institutions, possessing lower levels of education, and being single or widowed.

Conclusion: The household food handling practices of Chinese consumers involve serious food safety risk. Education programs and interventions concerning safe handling practices in households are urgently needed.

Among the fruit species of the Brazilian cerrado is pequi (Caryocar brasiliense Camb.), recognized for its nutritional properties and profile of bioactive compounds. However, it is necessary to evaluate techniques that promote its stability, reducing the moisture content without degrading the content of natural antioxidants. Therefore, this study aimed to evaluate the drying of pequi pulp in an oven at different temperatures (40 °C and 55 °C), as well as determine its kinetics and influence on the content of bioactive compounds and antioxidant capacity. The increase in temperature showed a reduction (∼50 %) of the drying time, from 720 min (40 °C) to 360 min (55 °C), with a final moisture content of approximately 39 %, which is the optimized condition of the process. (360 min - 55 °C). Drying at 55 °C showed better retention of carotenoids (β-carotene, α-carotene, and β-cryptoxanthin), especially β-carotene, an important precursor of vitamin A, with retention of approximately 57 %. The results for antioxidant capacity (ABTS and DPPH), total phenolic compounds, total phenolic acids and total flavonoids confirmed that a longer drying time resulted in greater degradation of bioactive compounds, even at lower temperatures. The profile of phenolic compounds of the sample subjected to drying under optimized conditions was identified by HPLC-DAD-ESI-MSⁿ, which showed the presence of six phenolic acids, one isoprenoid plant hormone, nine flavonols, and one flavonoid. Optimizing pequi pulp drying in ovens, and controlling time and temperature, can significantly reduce energy expenditure. This practice not only meets the demands of the food industry but also increases the use of fruits from the cerrado, promoting the diversification and valorization of these products.

The dynamic changes in physicochemical properties, microbial communities, and volatile compounds in kombucha made from Flos sophorae (FLSK) and Elm fruit (EFK) were compared to those of black tea (BTK) and green tea (GTK) over a 12-day fermentation period. The results revealed that overall flavonoid and polyphenol content, as well as antioxidant activity, increased initially and then decreased, accompanied by a steady reduction in pH within the fermentation broths investigated. Notably, the GTK exhibited stronger antioxidant activity than the other fermentation broths. Furthermore, 16S rRNA gene sequencing revealed that Komagataeibacter rhaeticus, Komagataeibacter saccharivorans, and Acidovorax wautersii were the dominating microbial species in the fermentation broths under this study. Komagataeibacter rhaeticus initially reduced and then increased throughout the FLSK fermentation, whereas Komagataeibacter saccharivorans increased from day 0 to day 6, and remain stable by day 12 during the EFK fermentation. Comparative analysis revealed that Komagataeibacter rhaeticus was more abundant in the FLSK and GTK than in the EFK and BTK, whereas Komagataeibacter saccharivorans showed a higher abundance in the EFK relative to the other fermentation broths. Gas chromatography-mass spectrometry identified acetic acid, linalool, ethanol, and ethyl acetate as the major volatile chemicals that rose significantly in fermentation mixtures of the examined substrates. The FLSK had a much higher linalool concentration than the other fermentation broths, although the EFK and GTK had higher ethanol content. Correlation study found that Komagataeibacter rhaeticus was negatively related with alcohol compounds, but Komagataeibacter saccharivorans was positively associated with a diverse spectrum of acids, alcohols, and esters. The study found changes in bioactive chemicals as well as interactions between bacterial populations and volatile compounds throughout fermentation in the substrates investigated.

Hydrogel microspheres are promising for food applications. The water-in-oil (W/O) emulsion template is commonly used to prepare the hydrogel microspheres. However, this method often involves synthetic surfactants and toxic organic solvents to remove the oil phase. The swelling problem of the resultant microspheres is another obstacle. In this study the water-in-water (W/W) emulsion template of gelatin-in-dextran was used to prepare the hydrogel microspheres, without the addition of surfactants, toxic reagents and high energy input. To prevent swelling, zein particles modified with alginate were served as a hydrophobic shell of the gelatin core. The formation evolution of these core-shell microspheres and its relevant factors including phase behavior of the immiscible gelatin/dextran, the binding of zein/alginate and the addition of the modified zein particles were investigated. It was found that small amount of alginate could induce zein particles to adsorb on the gelatin surface, whereas the excess led to adsorption competition. When using 0.6 wt% particles with zein/alginate ratio of 1:0.5, the ideal core-shell microspheres which were fully covered by the particles and with a self-supporting architecture in uniform size (18.8 ± 0.1 μm) and spherical shape were obtained. These microspheres showed remarkable stability under the conditions of heat treatment, varied pHs and salt concentrations and long-term storage either in refrigerator or room environment. Their sizes were easily manipulated by adjusting the concentration and molar mass of the biopolymers. It is believed that the desired stability and tunable sizes of these edible core-shell microspheres could contribute the development of their applications in foods.

Glutenin macropolymer (GMP) plays an important role in wheat gluten fractions, and extensively presents in the frozen dough. However, the effects of freezing treatment on GMP remain not abundantly understood. In this study, we investigated the structure and physico-chemical properties of GMP under frozen storage through experimental methods and bioinformatics algorithms. Results revealed that freezing treatment weakened the structure and properties of GMP to varying degrees, and GMP might have tolerance to short-term freezing storage. During frozen storage, portions of α-helix in GMP were converted into β-turn and random coil, slight changes in the tertiary structure, and its surface hydrophobicity increased by 4.8 %. SDS-PAGE profiles indicated that the depolymerization behavior mainly occurred above the Mw of 70.0 kDa. Slight changes were observed in the content of free thiol groups and disulfide bonds during frozen storage. Combination of fluorescence spectroscopy and intermolecular interactions suggested that hydrogen bonds and hydrophobic interactions were probably important indicators for evaluating the deterioration of GMP. Frozen storage resulted in an unfolded and open protein network. Moreover, freezing treatment led to a main conversion from strongly bond water to weakly bond water. However, no significant changes in water distribution were observed during the first 7 days of frozen storage. The viscoelastic loss of GMP primarily occurred in the first fourteen days, but tan δ did not significantly increased, indicating that protein has not been seriously deteriorated. Molecular dynamics simulation further supplemented and validated these experimental results from molecular level through analysis of root mean square deviation, root mean square fluctuation, solvent-accessible surface area, radius of gyration and the number of hydrogen bonds.

Lotus rhizome soup, renowned as a unique delicacy made from lotus rhizome, is cherished by many consumers. However, the varying colors of soup are sure to influence individuals' appetites. This research focused on the Miancheng lotus Rhizome (MLR) and Elian No. 6 lotus rhizome (ELR) to investigate the relationship between the variations in polyphenols, organic acids and iron levels in MLR and ELR soups during the cooking process. The findings indicated that cooking MLR for 12 min resulted in a red soup with a* value of 8.65 ± 0.12, whereas the soup made from ELR remained white with a* value of 3.43 ± 0.08. The correlation analysis results indicated that polyphenols, specifically epigallocatechin (0.0169 ± 0.00029 μg/100 mL FW after cooking for 12 min) and epicatechin (0.0211 ± 0.00047 μg/100 mL FW after cooking for 12 min), exhibited a significant positive relationship with a* (p < 0.05). Moreover, lowering the pH, removing polyphenols and incorporating metal-chelating agents can also prevent the development of red pigment. The analysis from HPLC-MS, UV-Vis, FT-IR spectra and ESI-Q-TOF-MS indicated that the development of the red soup color involved i) the generation of epicatechin gallate through the enantiomeric reaction of epigallocatechin, ii) the co-chromic red interaction between anthocyanin cations and catechol structures, and iii) the formation of polyphenol oligomers (i.e., procyanidin A2, (+)-procyanidin B2, procyanidin C1 and prodelphinidin B4) due to heating, while the creation of phenol-iron chelates could inhibit the development of red coloration. In sum, this research introduces a new idea for managing the color of lotus rhizome soup and similar soup products.