Kim, Eun-JuCho, Kwang-MoonKwon, Sun JaeSeo, Seung-Ho...
8页
查看更多>>摘要：Vinegar has long been used as condiment, food seasoning, preservative, and beverage. Vinegar is rich in nutrients and bioactive compounds produced during two-stage of alcoholic fermentation (AF) and acetic acid fermentation (AAF). In order to control the production of nutrients and bioactive compounds in vinegar, it is important to evaluate the contribution of two-stage fermentation to the final metabolite content. Therefore, a GC/MS-based metabolomics approach was used to identify factors that have a greater effect on the content of tomato vinegar metabolites during AF and AAF. The metabolite profiling during vinegar fermentation revealed that the levels of ethylene glycol, malonic acid, glutamic acid, glutaric acid, linoleic acid, butyric acid, and glycerol monostearate were more affected by AAF than AF. For example, the levels of lactic acid were more affected by AF (93.8%) than by AAF (6.2%), while the levels of glutamic acid were less affected by AF (3.0%) than AAF (97.0%). The production of final metabolites in vinegar also depends on the strain of yeast and acetic acid bacteria, and the temperature of AF and AAF. These results suggest that the content of each metabolite contained in vinegar can be changed to the desired level by controlling the fermentation conditions.
查看更多>>摘要：Gluten-free diets are characterized by being deficient in dietary fibre and minerals. The use of rice or maize wholegrain flours is complicated due to the presence of lipids that cause rancidity in a short period of time. The aim of the work was to make layer cakes using wholegrain maize flours stabilized by different extrusion processes to evaluate their effect on the final quality of the cakes. The viscosity and density of the batter, and specific volume, texture, colour and acceptability of cakes were measured.
查看更多>>摘要：In this work, phenolics and antioxidant activity (AOA) of Chinese organic hawthorn berry (Crataegus pinnatifida) infusion (OHBI, brewed at 100 degrees C for 5/10/15 min) and decoction (OHBD, kept boiling for 5/10/15/30 min) were investigated and their digestive fate was further assessed by in vitro gastrointestinal model (VGIM). Nine phenolic acids, six flavonoids and two procyanidins were detected by HPLC-ESI-MS/MS with the most abundant being procyanidins (1275 +/- 9-1531 +/- 2 mu g/g). Hawthorn berry was a great food matrix for phenolics extraction by infusion (52.7-58.8%)/decoction (62.8-64.3%), and OHBD10 presented the highest amount of phenolics (4148 +/- 20 mu g/g). OHBD kept boiling for 5-15 min exhibited higher AOA than OHBD30 as longer boiling resulted in a greater loss of phenolics. Digestive stability of phenolics varied depending on their structure (phenolic acids > others), digestive phase (small intestinal > gastric) and existing form (bound > free). Overall, 28.2% of phenolics became available for absorption after VGIM, and chlorogenic acid, epicatechin and procyanidin B2 were still the predominant antioxidant contributors. Catechin displayed the highest digestive recovery (244.7%) whereas only 24.4-27.9% were found in the mentioned predominant contributors. Although phenolics decreased after VGIM, relevant AOA (66.5 +/- 1.9-132 +/- 4 mu mol Trolox/g) was observed. OHBI and OHBD could be regarded as bio-accessible sources of antioxidant phenolics for the dietary supplement as well as potential applications in food/pharmaceutical/nutraceutical industries.
查看更多>>摘要：The physiological performance and whole-cell metabolomic response of Pediococcus pentosaceus R1 to oxidative stress were investigated. The response to a sublethal concentration (3 mM) of H2O2 resulted in a time-dependent decrease in viable cells. After 1 h of oxidative stress, the level of reactive oxygen species (ROS) and the activities of antioxidant enzymes significantly increased (P < 0.05). Metabolomics analysis identified 74 metabolites as significant differentially metabolites (P < 0.05). The increased levels of amino acids were mainly involved in the supply of energy, and two major amino acids (L-glutamine and L-histidine) can act as antioxidants to protect the bacteria against oxidative stress. The accumulation of saccharides (D-galactose, D-glucose and D-maltose) may be an energy conservation strategy for the bacteria. The levels of saturated fatty acids (myristic acid, caproic acid and dodecanoic acid), which could prevent the entry of H2O2 by decreasing membrane fluidity, significantly increased (P < 0.05). This research facilitates understanding of the antioxidative mechanisms of P. pentosaceus R1 and will benefit the construction of engineering probiotics that can better tolerate stress factors when applied in food industrial processes.
查看更多>>摘要：Egg spoilage is a microecological phenomenon, involving several specific spoilage microorganisms, that is affected by numerous factors. The specific biological characteristics of egg spoilage microorganisms are particularly significant for their survival in eggs. This research focusses on the specific biological characteristics of 24 spoilage bacteria isolated from eggs. Their protease activities, alkalinity tolerance, egg white and lysozyme tolerance, and survival rates in egg whites were analysed. The results showed that the strains of Bacillus spp. had the strongest protease activity, the strains of Staphylococcus spp. had the strongest alkaline pH tolerance, and most of the spoilage bacteria could tolerate an egg white or lysozyme environment. Notably, the survival rate test of egg whites showed that only the strains of Dermacoccus spp. could survive and grow in egg whites. This study of the specific biological characteristics of spoilage microorganisms in eggs aims to extend eggs' shelf life and provide theoretical guidance for controlling spoilage microorganisms during storage.
查看更多>>摘要：The free, soluble-bound (esterified and glycosylated) and insoluble-bound phenolics from the dry raspberry pomace without seeds (RP) and raspberry seeds (RS) were obtained by acidic and alkali treatment. The total phenolic contents of different phenolic fractions from RP and RS by the Folin method followed the order: free > esterified approximate to insoluble-bound > glycosylated. Then 18 phenolics from RP and RS were quantified by HPLC-MS. Free phenolics had the highest total tested phenolic contents, while glycosylated phenolics were the lowest. Their antioxidant activity was increased by the increasing phenolic contents of different fractions. Free phenolics in raspberry pomace had the highest antioxidant activity by DPPH assay. RS-esterified phenolics had the hightest tyrosinase inhibitory activity (TIA) by enzyme activity analysis, which was equivalent to the TIA of 1.57 mM vitamin C. Among 9 typical phenolics, quercetin, chlorogenic acid, gallic acid and p-hydroxybenzoic acid on the TIA showed obvious promoting effects, while catechin, epicatechin, and caffeic acid exhibited a significant background effect. Therefore, p-hydroxybenzoic acid and gallic acid in RS-esterified phenolics were of great significance for the TIA. These results are beneficial to the comprehensive evaluation and utilization of the phenolic compounds in raspberry pomace.
查看更多>>摘要：The physicochemical properties of starch-wheat germ oil complex (SWGOC) and its influences on the water distribution and hardness of noodles were investigated. The results showed that SWGOC retarded the retrogradation, lowered the breakdown value and solubility, and increased the swelling power of starch compared to the control. The T-21 (immobilized water) of starch dough made by SWGOC was lower than that of the control, however, the T-21 of raw noodles increased slightly from 0.12 ms to the maximum 0.13 ms and then decreased to 0.10 ms with the increase of SWGOC. The pasting profile of SWGOC during the holding phase (95 degrees C) suggested the dissociation of starch-lipid complexes during cooking. The released amylose predominantly induced double-helix at 0 h, resulting in the higher initial hardness of noodles, while the combination of liberated lipids and amylose occurred concomitantly but in a slower rate, reducing the firming rate during the first 2 h. Interestingly, the anti-firming effect was not proportion to the content of starch-lipid complexes, and noodles with less starch complexes seemed to be more effective in reducing firming rate. This study provides insight into the importance of starch-wheat endogenous lipids on noodle quality.
de Araujo, Fabio FernandesFarias, David de PauloNeri-Numa, Iramaia AngelicaDias-Audibert, Flavia Luisa...
7页
查看更多>>摘要：In this study, we evaluated for the first time the bioaccessibility and bioactivity of phenolic compounds present in fractions of araca-boi submitted to the in vitro gastrointestinal digestion. For this, were determined the content of phenolics and total flavonoids, antioxidant capacity, as well as heatmap analysis to evaluate the relative intensity of the phenolic compounds identified by ESI-LTQ-XL-MS/MS, before and after digestive process. It was observed that the seed had the highest amount of total phenolic compounds, and that this content was reduced after digestion, mainly in the intestinal phase (-22.0%), while the flavonoid content increased in the edible fraction (92.8%). From the ESI-LTQXL-MS/MS analysis, it was possible to identify 9 flavonoids and 8 phenolic acids in the edible fraction, while in the seed 10 flavonoids and 7 phenolic acids were identified. Heatmap analysis demonstrated that after intestinal digestion, phenolic acids reduced and flavonoids increased their relative intensity, suggesting that these compounds increased their content after this process. The seed showed the highest antioxidant capacity and in general this potential increased after digestion. Thus, the bioaccessibility and bioactivity of the phenolic compounds of araca-boi can be influenced by the fraction and digestive phase evaluated.
Kim, Ji WonLee, Hyun JungShin, Dong-JinBaek, Ki Ho...
7页
查看更多>>摘要：This study aimed to evaluate the efficacy of natural nitrite sources prepared by atmospheric pressure plasma (APP) treatment on onion and egg white mixtures to replace sodium nitrite in processed meat. Onions were treated with APP alone (PO) or in the presence of 30% egg whites (w/w, POE). Although PO also showed an increase in nitrite content, the addition of egg whites during APP treatment resulted in an increase of about 4 times nitrite content in POE compared to PO. To test the practical application of this technique, emulsion sausages were prepared by adding four different nitrite sources: no nitrite source (CON), sodium nitrite (SN), PO powder, and POE powder, then sausage properties were evaluated on a consumer scale. POE sausages showed a similar nitrite content and visual redness to the sausages with sodium nitrite and acquired onion-like odor and significantly reduced warmed-over flavor (WOF). Consequently, we concluded that nitrite-enriched onion powder by egg whites addition during APP treatment has the potential to effectively replace synthetic sodium nitrite in processed sausages without compromising product flavors.
查看更多>>摘要：Microbial fermentation can increase the water-soluble protein (WSP) contents of soybean meal, but the microbial community compositions and its functions remain unclear during the fermentation of soybean meal. In this study, the soybean meal was naturally fermented and the dynamics of bacterial community structure were determined. The results showed that natural fermentation can significantly increase the WSP content and digestive enzyme activities of soybean meal. The bacterial diversity indexes of soybean meal were increased and the community structure was significantly changed after fermentation. The bacterial community composition mainly consisted of Pseudomonas before fermentation, but it was almost completely replaced by Bacillus after 24 h of fermentation. The key operational taxonomic unit (OTU) for fermentation was screened as OTU161 from Bacillus, and its candidate strain was isolated from the fermented soybean meal and identified as Bacillus amyloliquefaciens ZB. Bioaugmented inoculation of ZB significantly increased the WSP content by 110.0%, 47.2%, and 473.7%, respectively, after 24, 72, and 96 h of fermentation and digestive enzyme activities by 16.1-41.8% during 24-48 h of fermentation, and shorten the fermentation time, compared to natural fermentation.
NSTL
Elsevier