Yi, YueAbdelhamid, Ahmed G.Xu, YuminYousef, Ahmed E....
9页
查看更多>>摘要：Salmonella enterica contaminates many food matrices, particularly poultry products. This study was initiated to characterize newly isolated lytic Salmonella phages and to evaluate their efficiency against S. enterica serovar Enteritidis and Typhimurium in liquid whole eggs. Two phages (OSY-STA and OSY- SHC) isolated from livestock farms in Ohio, USA, exhibited lytic activities against 14 and 5 Salmonella serovars, respectively, including Salmonella Typhimurium and Salmonella Enteritidis. Based on their morphological characteristics, the lytic phages belong to Siphoviridae family. The OSY-STA and OSY-SHC phages had similar latent periods (similar to 20 min) and burst sizes of 176 and 256, respectively. The phages remained viable after exposure to acidic and alkaline environment (pH 5-11) and during holding at 4 degrees C-55 degrees C. Liquid whole egg was inoculated with Salmonella serovars at similar to 2.7 log CFU/ml, a level comparable to that encountered in naturally contaminated product, treated with the phages at 4 degrees C for 24 h, then mildly processed at 55 degrees C for up to 13 min. The combined process resulted in 1.8 and more than 2.5 log CFU/ml reduction in Salmonella Typhimurium and Salmonella Enteritidis, respectively. Therefore, Salmonella phages in combination with mild heat could be beneficial in controlling the pathogen in liquid whole eggs.
查看更多>>摘要：This work was undertaken to evaluate the effectiveness of using sodium lactate (SL), encapsulated (e) and unencapsulated (u) polyphosphates (PP; sodium tripolyphosphate, STP; sodium acid pyrophosphate, SPP), and various combinations of these additives on growth of Listeria monocytogenes and Pseudomonas fluorescens in cooked ground beef during 30 d refrigerated storage. The study consisted of two independent work packages as L. monocytogenes and P. fluorescens in the same experimental settings. During storage, analysis of oxidation-reduction potential (ORP), water activity (a(w)), pH, and counts of L. monocytogenes and P. fluorescens were carried out. Results indicated that there was no difference among the groups in terms of L. monocytogenes or P. fluorescens counts on processing day. Although only PP incorporated groups had higher (P < 0.05) P. fluorescens counts compared to those groups formulated with only SL at the end of storage, there were no differences among these groups regarding L. monocytogenes load. The lowest L. monocytogenes and P. fluorescens counts were determined in the samples containing a combination of SL with uSPP or eSPP or ueSPP at the end of storage (P < 0.05). A combinations of SL with uSTP or eSTP or ueSTP did not create further reduction in L. monocytogenes load then reduction level obtained by SL which had lower (P < 0.05) load compared to MO. The same combination groups had lower (P < 0.05) P. fluorescens counts then those of MO and SL groups. The lower (P < 0.05) ORP values were determined in all PP added groups during storage compared to control, MO and SL groups. ORP in all treatments generally increased (P < 0.05) with storage. There was no significant changes in pH during storage. A slight decrease (P < 0.05) in aw was determined during storage in P. fluorescens experiments, whereas aw levels was stable in case of L. monocytogenes. In general, the use of ePP did not create any significant changes on pH, aw, ORP values and counts of L. monocytogenes and P. fluorescens compared to that of uPP.
查看更多>>摘要：The aim of this study was to assess the presence of norovirus, rotavirus and infective enterovirus in leafy green vegetables and irrigation waters collected from a farm located at the province of C ' ordoba, Argentina, and to estimate the quantitative risk of infection by consuming these vegetables. During June 2014-July 2015, vegetables (n = 101) and their corresponding irrigation waters (n = 24) were collected. Viruses were concentrated in both matrices by polyethylene glycol precipitation and then were subjected to RT-PCR to assess the presence of norovirus and rotavirus. The concentrates were also inoculated in CaCo-2 cells to monitor the occurrence of infective enterovirus. The frequency of detection of norovirus, rotavirus and infective enterovirus in irrigation waters was 37.5%, 20.8% and 37.5% and in crops 60.4%, 22.7% and 35.6% respectively. Similar profiles of norovirus genogroups and rotavirus G-types distribution were observed in green vegetables and irrigation waters. The estimated risk of rotavirus infection associated with raw consumption of the vegetables harvested in that rural farm was 0.2 per person per day. This study demonstrates a wide distribution of human pathogenic viruses in irrigation waters and green leafy vegetables, which is of concern when, as in this case, the vegetables are eaten raw.
查看更多>>摘要：In this study, the polyphenol oxidase (PPO) activity of whole potatoes was inhibited by ultrasound. A 17-run Box-Behnken Design was used to optimize the ultrasound conditions for inhibiting the PPO activity. Three factors of ultrasound treatment including power, time, and temperature were investigated. Moreover, the effects of ultrasound treatment on the PPO activity of ultrasound-treated bruising damaged whole potatoes as well as on the micro-structure of the ultrasound-treated whole potatoes were evaluated. The adjusted coefficients of determination for models of Y-1 and Y-2 were 0.9980 and 0.9991, respectively. The p-values of two models for the responses were below 0.05, implying that the models can well represent PPO activities. The optimal ultrasound conditions were determined to be: ultrasound power 540 W, ultrasound time 15 min, and temperature 20 degrees C. Under these conditions, the mean PPO activities of the whole potatoes were 44.948 U/g, in accordance with the values predicted by the model. Besides, the PPO activity increases in the damaged whole potatoes. Nevertheless, the PPO activity of the ultrasound-treated whole potatoes was lower than that of untreated whole potatoes. Moreover, the power and time of ultrasound have a large impact on the micro-structures of the whole potatoes.
查看更多>>摘要：In this study, the effect of proteins (10%, w/w) on the formation of starch-lipid complexes (measured by Rapid Visco Analyzer (RVA)) in pure starch and noodles supplemented with different fatty acids (such as, lauric acid (LA), glycerol monolaurate (GML), stearic acid (SA), and glycerol monostearate (GMS), 3% w/w), in addition to their impacts on in vitro enzymatic digestion were assessed. The addition of protein and lipids increased the viscoelastic properties of wheat starch (WS) samples. The V-type diffraction intensity of WS-lipid sample mixed with protein was increased compared to WS-lipid samples without protein. Noodles enriched with fatty acids (particularly LA) showed higher relative crystallinity and enzyme resistant starch (ERS) compared to noodles without fatty acid incorporation. As shown by microscopic computed tomography (mCT), the crystalline pattern of noodles supplemented with LA and GML displayed a higher density than those incorporated with SA and GMS; the findings which are in line with thermal resistance and X-ray diffraction analysis. In sum, this study could foster a better understanding of the interplay between biomolecules during processing.
查看更多>>摘要：Rice bran, an underutilized by-product obtained from outer rice layers, has received wide interest due to its abundance, eco-friendliness, and low cost. In this research, cellulose, hemicellulose and lignin as the main components of rice bran were fractionated, and their Cd(II) adsorption capacity, behavior and mechanism were further studied. The adsorption capacity of cellulose for Cd(II) was 5.79 mg/g within the equilibrium time of 10 min, which was 1.8 and 3.6 times those of hemicellulose and lignin, respectively. The Cd(II) adsorption onto cellulose exhibited monolayer surface behavior, whilst the heterogeneous adsorption behavior was observed for hemicellulose and lignin. These differences were related to the discrepancy of morphology and chemical composition in three polymers. The multi-hole sticks morphology of cellulose and porous blocky structure of hemicellulose were observed, while lignin showed compact and agglomerated blocky structure. Cellulose had numerous available adsorption sites including the oxygen-containing functional groups, which bonded with Cd (II) driven by chemical interaction. In conclusion, it highlights that cellulose from rice bran has the great potential of being applied as adsorbent for the Cd(II) removal.
查看更多>>摘要：Widely distributed in Ginkgo leaves, the amino acids play an important role in the tree growth and Ginkgo products quality determination. Nevertheless, the biosynthesis and accumulation of amino acids have not been fully studied, especially in response to complex environmental conditions. Here, we integrated and analyzed transcriptome and metabolome from Ginkgo leaves originated from clonal homogeneous materials including their different genders (female and male) grown in three different habitats to reveal the environmental response mechanism of amino acid metabolism. Principal component analysis revealed the environmental dependence of amino acid accumulation in Ginkgo leaves, that is, the content of amino acids differed significantly between samples from different environments, while it was similar between female and male samples grown in the same environment. Weighted gene correlation network analysis suggested that the overexpression of structural genes in phenylpropanoid biosynthesis pathway and genes encoding receptor-like kinases, which was regulated by multiple transcription factors, were closely related to the amino acids' accumulation. Further, we indicated that environmental conditions directly affected the C and N flow allocation in leaves, thereby having an impact on the yield and quality (carbohydrates and amino acids contents) of Ginkgo tea.
查看更多>>摘要：In this study, accelerated solvent extraction (ASE) and gel permeation chromatography (GPC) were used for the extraction and cleanup of clotrimazole residue in animal-derived food (pork, chicken, beef, fish, beef kidney and chicken liver), and gas chromatography-tandem mass spectrometry (GC-MS/MS) was used for qualitative and quantitative analysis. Matrix-matched calibration combined with an isotope internal standard overcame the matrix effects and achieved correct recovery. The average recoveries were 75.4-109.3%, with RSD <7.2%. The limits of quantification were 1.0 mu g/kg. The detected positive samples were further confirmed by gas chromatography-quadrupole-orbitrap high-resolution mass spectrometry (GC-Orbitrap HRMS), which ensured the accuracy of the results. The developed method is rapid, accurate, and sensitive and can be applied for the determination of clotrimazole residue in animal-derived food.
Sinrod, Amanda J. G.Li, XueqiBhattacharya, MrittikaPaviani, Bruna...
11页
查看更多>>摘要：Chardonnay marc (pomace), an agricultural waste product, has demonstrated significant potential health benefits in previous studies. This study represents the first comprehensive chemical characterization of chardonnay marc, its seed and seedless fractions, and a seed extract to uncover the bioactive compounds inducing their observed health benefits. Chardonnay marc and its processing fractions' gross composition (i.e. protein, lignin, fat, carbohydrates, polysaccharides), phenolic contents, and oligosaccharide profiles were determined. The chardonnay seeds contained higher quantities of protein, fat, and polysaccharides than the seedless marc while the seedless marc contained more total carbohydrates and sugars. All samples had abundant phenolics with the seed extract being the most concentrated (34.72 +/- 0.13 mg/g). (-)-Gallocatechin was the most abundant phenolic in the marc (1.4905 +/- 0.0393 mg/g) and seedless marc (0.94 +/- 0.04 mg/g), and (-)-epicatechin was the most concentrated phenolic in the seeds (9.4093 +/- 0.1018 mg/g) and seed extract (14.22 +/- 0.09 mg/g). Thirty-six distinct oligosaccharides were discovered between the four samples with three to nine degrees of polymerization and eleven distinct monosaccharide subunits. Overlap existed between the samples' oligosaccharides with six of the same hexose and hexose-pentose oligosaccharides present in all. Each sample, however, had a distinct oligosaccharide profile such as with eight oligosaccharides unique to the seed extract.
查看更多>>摘要：The present study aimed to investigate the effects of alcoholic fermentation on the physicochemical and phytochemical characteristics of the tissues flavedo and albedo from five citrus fruits, namely grapefruit (Citrus paradisi), lemon (Citrus limon), and sweet oranges (Citrus sinensis) cvs. 'Tarocco', 'Washington navel', and 'Moro'. The tissues were fermented with pure and mixed cultures of Saccharomyces cerevisiae, Brettanomyces bruxellensis, and Torulaspora delbrueckii. Flavedo and albedo increased the water holding capacity (WHC) and oil binding capacity (OBC) when subjected to fermentation. The treatment with B. bruxellensis resulted the most effective at enhancing WHC and OBC, e.g., lemon flavedo achieved the highest WHC (9.67 +/- 0.15 g/g; P < 0.001). Concerning the phytochemicals, samples increased the total contents of phenolic compounds and carotenoids upon fermentation. The orange 'Tarocco' benefited markedly as regards phenolic compounds, e.g., the naringenin and hesperidin contents reached 244 +/- 15.5 and 2900 +/- 160 mg kg(-1) DW, respectively, when the albedo was fermented with T. delbrueckii, with increases above 4-folds. Likewise, the total carotenoids were augmented (P < 0.001) when flavedo samples were treated with T. delbrueckii. Overall, the performed alcoholic fermentations ameliorated the physicochemical and phytochemical characteristics of the selected citrus tissues, and are recommended to expand their utilization in the nutraceutical sector.
NSTL
Elsevier