基于1H-NMR代谢组学法研究辛硫磷诱导鲫鱼代谢变化

目的:规范辛硫磷的使用,保证水产品安全。方法:以淡水鲫鱼为研究对象,选取农业上经常使用的有机磷农药辛硫磷作为外源性环境污染物代表物,采用¹H-NMR代谢组学方法并结合PCA、PLS-DA、OPLS-DA等多元统计学方法研究辛硫磷暴露下鲫鱼体内正常生理代谢的变化,据此推断辛硫磷对鲫鱼的毒性影响及在鲫鱼体内的毒理机制。结果:辛硫磷组与空白组血清样本之间存在显著的差异性代谢产物。与空白组鲫鱼血清相比,辛硫磷组血清中3-羟基丁酸酯、葡萄糖及苯丙氨酸含量显著升高,而谷氨酸、丙氨酸、天冬酰胺、组氨酸等氨基酸,乳酸,不饱和脂肪酸,脂质,甘油磷酸胆碱,磷酸胆碱,胆碱,鸟嘌呤核苷,肌苷含量显著下降(P<0.05)。结论:辛硫磷能够改变鲫鱼体内的能量代谢和氨基酸代谢,干扰鲫鱼体内神经递质的传递以及诱导鲫鱼氧化应激等。同时,这些内源性代谢产物差异性变化可能与辛硫磷在鲫鱼体内发生的Ⅱ相代谢反应有关。     

Determination of the overall migration from silicone baking moulds into simulants and food using 1H-NMR techniques

Different silicone baking moulds (37 samples) were characterized with respect to potential migrating substances using ¹H-NMR, RP-HPLC–UV/ELSD and GC techniques. In all cases cyclic organosiloxane oligomers with the formula [Si(CH₃)₂–O] _n were identified (n = 6 … 50). Additionally, linear, partly hydroxyl-terminated organosiloxanes HO–[Si(CH₃)₂–O] _n –H (n = 7 … 20) were found in 13 samples. No substances other than siloxanes could be detected, meaning the migrants mainly consist of organopolysiloxanes. Based on this knowledge, a ¹H-NMR quantification method for siloxanes was established for the analysis of both simulants and foodstuffs. Validation of the ¹H-NMR method gave suitable performance characteristics: limit of detection 8.7 mg kg^–1 oil, coefficient of variation 7.8% (at a level of 1.0 mg kg^–1 food). Migration studies were carried out with simulants (olive oil, isooctane, ethanol (95%), Tenax) as well as preparation of different cakes. From the 1st to 10th experiment, siloxane migration into cakes only slightly decreased, with a significant dependence on fat content. Migration never exceeded a level of 21 mg kg^–1 (3 mg dm^–2) and was, therefore, well below the overall migration limit of 60 mg kg^–1 (10 mg dm^–2). However, migration behaviour into simulants differed completely from these results.     

Symbolic Metabolite Analysis of Pickled Wax Gourd in Eastern China by 1H-NMR Spectroscopy and Multivariate Data

Pickled wax gourd is a traditional fermented vegetable product popular in Zhejiang province, eastern China; however, information on their quality is quite limited. In the present study, we investigated the quality of pickled wax gourd at different processing phases using nuclear magnetic resonance, principal component analysis, and orthogonal partial least squares-discriminant analysis. According to the spectra of ¹H NMR, 36 kinds of metabolites were found at the 20th day of fermentation. Principal component analysis score plot showed that diverse marker metabolites occurred in all designated sampling points (every other 5 days), apart from the samples between the 10th day and 15th day of fermentation. Symbolic metabolites at the first 5 days were L-rhamnose, lactate, fatty acid, arginine, N-acetylglutamate, succinate, phosphorylcholine, glutamate, ornithine, lysine, and β-glucose. Lactate, succinate, glycine, proline, and choline were detected at the following period from the 5th to the 10th day of fermentation. Lactate, succinate, glycine, mannitol, choline, and α-ketoglutaric acid were the main metabolites on the 15th and 20th day. The diversity of metabolites fits with the microbial species structure in different pickling periods. This method was proved to be effective for monitoring the pickling process in real time.     

Evaluation of the effect of carvacrol on the Escherichia coli 555 metabolome by using H-NMR spectroscopy

Cultures of Escherichia coli 555 were grown at four levels of carvacrol (0–2 mM) and the E. coli endo-metabolome was extracted and measured by ¹H NMR spectroscopy. The results show that glucose concentration is going up with concentration of carvacrol and so do formate until the highest concentration is reached, from which point it suddenly decreases. This is interpreted as if the bacteria are increasingly unable to further metabolize glucose and as if the bacteria increasingly shifts with higher levels of carvacrol toward sugar fermentation as carbon source, until the level of carvacrol reaches a level (2.00 mM), where the E. coli must give up. Additionally, the multivariate Principal Component Analysis suggests that the adaptation occurring at sub-lethal doses of carvacrol is different from that occurring at higher doses.     

Assessing the association between phenolic compounds and the antioxidant activity of Brazilian red wines using chemometrics

The objective of this study was to evaluate the association among chemical parameters, the commercial value, and the antioxidant activity of Brazilian red wines using chemometric techniques. Twenty-nine samples from five different varieties were assessed. Samples were separated into three groups using hierarchical cluster analysis: cluster 1 presented the highest antioxidant activity towards DPPH (68.51% of inhibition) and ORAC (30,918.64 μmol Trolox Equivalents/L), followed by cluster 3 (DPPH = 59.36% of inhibition; ORAC = 25,255.02 μmol Trolox Equivalents/L) and then cluster 2 (DPPH = 46.67% of inhibition; ORAC = 19,395.74 μmol Trolox Equivalents/L). Although the correlation between the commercial value and the antioxidant activity on DPPH and ORAC was not statistically significant (P = 0.13 and P = 0.06, respectively), cluster 1 grouped the samples with higher commercial values. Cluster analysis applied to the variables suggested that non-anthocyanin flavonoids were the main phenolic class exerting antioxidant activity on Brazilian red wines.     

Effects of noble rot on must composition and aroma profile of Amarone wine produced by the traditional grape withering protocol

The effects of noble rot on the overall quality of Amarone wine, a “Passito” dry red wine, produced by a traditional withering grape process are poorly understood. Wines obtained from healthy and selected grapes infected by noble rot were compared. Validation of the experimental plan was carried out by determining glycerol and gluconic acid content, laccase activity and microbial analysis of the musts. Botrytis cinerea infection produced significant variation in esterase and β-glucosidase activity of grape must. Aroma analysis in healthy and botrytised wines was carried out by SPE extraction followed by GC–MS quantification. A decrease of several fermentative esters was observed in botrytised wine, while wine produced from healthy grapes showed a higher fatty acid content. Molecules such as 1-octen-3-ol, phenylacetaldehyde and furaneol were positively linked to the noble-rotten grapes. Interestingly, γ-nonalactone and 4-carbethoxy-γ-butyrolactone increased, while sherry lactones decreased in botrytised wine. The strong increase of N-(3-methylbutyl)acetamide was related to B. cinerea grape infection.     

Using <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR techniques and artificial neural networks to detect the adulteration of olive oil with hazelnut oil

The lack of any official analytical method to detect the adulteration of olive oil with a low percentage of hazelnut oil is explained by the similarities in the chemical compositions of both kinds of oils. To counter this problem, an artificial neural network based on ¹H-NMR and ¹³C-NMR data has been developed to detect olive oil adulteration, and the results from this ANN are presented here. A training set consisting of hazelnut oils, pure olive oils, and olive oils blended with 2–20% hazelnut oils was used to design and train a multilayer perceptron with 100% correct classifications. This mathematical model was also validated using an external validation set of blend samples (3–15%) and genuine samples. The detection limit of the model was around 8%.     

Effects of the rootstock Ramsey (Vitis champini) on ion and organic acid composition of grapes and wine, and on wine spectral characteristics

The influence of Ramsey, used as rootstock of the scion cvs Muscat Gordo Blanco (syn. Muscat of Alexandria), Shiraz (syn. Syrah), Riesling, Cabernet Sauvignon and Chardonnay, on the characteristics of the grape berries and of wine made from them was investigated, comparing ‘own-rooted’ and ‘grafted’, and comparing wine fermented as juice (without skins) and must (juice and skins). The study involved the partitioning of K+ within berries, changes in juice K+, malic and tartaric acid through fermentation, wine inorganic ion and organic acid composition, and wine spectral characteristics. K+ concentration was higher in berries from grafted than from own-rooted for all varieties except Chardonnay, and highest for grafted Shiraz. It was higher in skin than in pulp and seeds. In the pulp, it was highest for grafted Shiraz. K+ concentrations in all ferments using must (i.e. juice plus skins) increased during the initial two days after crushing, with the increase reflecting extraction from skins, being greatest for Shiraz and Muscat Gordo Blanco. Tartaric acid concentration in must also increased during the initial two days after crushing and then decreased. Malic acid concentration was higher in juice of Ramsey-grafted than own-rooted vines, especially for Shiraz; concentrations did not change markedly during the initial 12 days of fermentation, except where malo-lactic fermentation occurred. Wine made from grapes of grafted contained significantly less tartaric and more malic acid than that made from own-rooted for all varieties and for both fermentation types, with the exception of tartaric acid in wine of Muscat Gordo Blanco fermented as must. Wine made from juice had significantly higher tartaric acid and lower malic acid than that made from must for all varieties except for tartaric acid in wine from grafted Shiraz and malic acid in own-rooted Chardonnay. Wine had a smaller tartaric acid/malic acid ratio when made from must. Wine pH was positively correlated with K+ but negatively with tartaric acid and with the tartaric acid to malic acid ratio. Overall, Shiraz wine contained highest Cl?, Na+ and K+ concentrations. Red wines obtained from grafted had higher colour hue, especially those from Shiraz. Wines made from fruit borne on own-rooted Cabernet Sauvignon had the highest concentration of total anthocyanins, ionised anthocyanins and total phenolics.     

Diffusion of NaCl in meat studied by (1)H and (23)Na magnetic resonance imaging

The effect of sodium chloride (NaCl) diffusion into meat was investigated. Proton and sodium magnetic resonance imaging were used to determine the diffusion behaviour of brine (NaCl) in porcine Longissimus dorsi and semitendinosus. NaCl diffusion was visualized through images and diffusion coefficients were determined to be in the range 3-7×10(-10)m(2)s(-1), which is in agreement with values reported in the literature. The diffusion coefficient was found to increase during curing, suggesting microstructural changes in the meat. A supplementary experiment proved that the diffusion behaviour of sodium chloride in regions of meat with connective tissue/fat is distinctive from regions with pure myofilament tissue, as anticipated. Apparent diffusion coefficient (ADC) maps showed that meat microstructures shrunk when cured with 20% (w/w) NaCl brine. ADC across (⊥) the main muscle fiber direction decreased more than ADC along (‖) the main muscle fiber direction. The greater shrinkage in the direction across muscle fibers suggests that the curing induced shrinkage of the transverse structures rather than reduction in longitudinal structures.     

Phosphorylation of proteins by dry-heating in the presence of pyrophosphate and some characteristics of introduced phosphate groups

Various proteins and dextrin were phosphorylated by dry-heating in the presence of pyrophosphate, and phosphate bonds characterised. The basic proteins were more highly phosphorylated than acidic proteins by dry-heating in the presence of pyrophosphate. The phosphorylated poly-l-lysine hydrobromide (PP-PLy) and lysozyme (PP-Lz) were more highly dephosphorylated than phosphorylated dextrin and ovalbumin (PP-OVA) by phosphatases, and the dephosphorylation of PP-PLy was much higher than that of PP-Lz. The phosphate bonds in all phosphorylated samples were stable during heating at 120 °C. The ³¹P NMR spectral data suggested that different types of phosphate bonds were introduced, and the N–P bond was suggested in PP-PLy. Some phosphorylated tryptic peptides from PP-Lz and PP-OVA were detected by mass spectrometry analysis. Furthermore, the introduced phosphate linkages in peptides from PP-Lz and PP-OVA were identified.     

板栗黄酒渣粉对小麦粉面包品质特性、微观结构、生物活性成分及抗氧化性影响的研究

为了提高板栗资源的利用率,将板栗黄酒渣粉(Chinese chestnut rice wine residue flour,WRF)作为膳食纤维源和生物活性物质源应用于小麦粉面包中,以改善小麦粉面包的营养结构并探讨开发WRF强化面包的可行性。研究了自然干燥板栗黄酒渣粉(Natural-dried Chinese chestnut rice wine residue flour,NDWRF),烘箱干燥板栗黄酒渣粉(Oven-dried Chinese chestnut rice wine residue flour,ODWRF),真空冷冻干燥板栗黄酒渣粉(Vacuum freeze-dried Chinese chestnut rice wine residue flour,VFDWRF)的基本组成成分、理化特性、微观结构以及以WRF作为膳食纤维源和生物活性物质源添加到小麦粉面包中,对其品质特性、微观结构、生物活性成分及抗氧化性的影响。试验表明,3种干燥方式渣粉的基本营养成分、膳食纤维、总多酚、总黄酮和类胡萝卜素含量以及pH、色度L*、a*、b*值、持水力、持油力、溶胀力、DPPH自由基清除率、ABTS自由基清除率、铁还原能力均存在显著性差异,其扫描电镜微观结构差异不显著,傅里叶红外光谱分析其结构基团基本相同,X射线衍射图谱分析其晶体结构存在明显差异。WRF的不同添加水平对小麦粉面包的理化特性、质构特性、微观结构、生物活性物质含量、抗氧化特性以及感官特性均具有显著性影响。2%~4%WRF添加水平对小麦粉面包总体可接受性影响不显著,3种WRF可纳入小麦粉面包的最高水平均达4%。     

Influence of variety and commercial yeast preparation on red wine made from autochthonous Hungarian and Canadian grapes. Part I: phenolic composition

Eight wines were made from two Canadian hybrid grape varieties (Maréchal Foch, Baco Noir) and two Hungarian Vitis vinifera varieties (Kadarka, Lemberger). One half was kept untreated; the other half received a commercial yeast preparation (OptiRed^®) before fermentation. Significant differences were found between varieties for basic measures of wine quality, including pH, titratable acidity, ethanol, colour density, hue and total phenolics. Quercetin was identified only in Maréchal Foch and Baco Noir wines, and quercetin-glucoside only in Baco Noir. Varietal differences were also found in the concentrations of the 11 other colourless phenolic monomers measured, especially gallic acid, protocatechuic acid, tyrosol, caftaric acid, catechin, caffeic acid, GRP, epicatechin, p-coumaric acid, ferulic acid and trans-resveratrol. The Canadian wines had higher concentrations of the four anthocyanins measured (malvidin, delphinidin, petunidin and peonidin), higher anti-oxidative capacity, and were characterised by lower ratios of monomeric/polymeric phenolics. Addition of OptiRed^® had little impact on the basic measures of wine quality. Concentrations of gallic acid, protocatechuic acid, caftaric acid and catechin were, on average, 6% higher in wines made from OptiRed^®-treated musts. A trend was observed for all varieties in OptiRed^®-treated wines of a greater proportion of the procyanidins being presented as polymeric rather than monomeric phenolics.     

Effects of milk fat composition, DGAT1, and SCD1 on fertility traits in Dutch Holstein cattle

Recently, selective breeding was proposed as a means of changing the fatty acid composition of milk to improve its nutritional quality. Before implementing such breeding objectives, effects on other economically important traits should be investigated. The objectives of this study were to examine 1) the effect of milk fat composition, and 2) the effect of polymorphisms of DGAT1 and SCD1 genes on female fertility in commercial Dutch Holstein-Friesian cattle. Data on 1,745 first-lactation cows were analyzed by fitting linear mixed models. We found that higher concentrations of trans fatty acids within total milk fat negatively affected reproductive performance. Furthermore, results suggested a potential effect of the DGAT1 polymorphism on nonreturn rates for insemination 28 and 56 d after the first service. Our results can be used to assess the correlated effects of breeding for improved milk fat composition on reproduction, thereby allowing for better evaluation of breeding programs before implementation.     

The role of acidity,sweetness, tannin and consumer knowledge on wine and food match perceptions

The purposes of this study were to (1) explore significant differences in perception of match for a variety of food and wine styles; (2) evaluate the impacts of wine sweetness level, wine acidity level, and wine tannin level on perception of match; and (3) investigate the impact of food and wine expertise on perceived level of match. The highest perceived wine matches for each food item were: Sauvignon Blanc and chêvre, Chardonnay and brie, Cabernet Sauvignon and spicy Italian salami, and Port and milk chocolate. Wine sweetness, acidity, and tannin levels all significantly impacted the level of match with certain food items. Food and wine expertise also significantly impacted the level of match, indicating differences between the more expert and novice participants in the role wine sweetness, acidity, and tannin had on level of match.     

不同有机酸协同超高压处理对黄酒中醇水缔合影响的研究

新生黄酒乙醇味较烈,口味粗糙。本文采用¹H-NMR共振法研究乙醇水溶液的一维核磁氢谱图,并结合体系粘度变化来确定适用于黄酒体系的氢键缔合强度指标。采用超高压和有机酸分别处理乙醇水溶液,检测体系氢键缔合强度变化;采用有机酸协同超高压处理新生黄酒,并将其氢键缔合强度与新生黄酒、一年陈黄酒进行比较。结果表明:在黄酒的酒度范围内,氢键缔合强度可用理想醇水溶液中乙醇与水的羟基质子化学位移加权平均值与实际溶液下的化学位移加权平均值之间差值(Δδ)及体系粘度(η)表征。超高压处理乙醇-水体系,羟基质子化学位移发生变化。300 MPa、20 min超高压处理乙醇水溶液后,氢键缔合增强最明显。有机酸处理乙醇水溶液,氢键缔合增强。柠檬酸协同超高压处理新生黄酒,体系氢键缔合明显增强,处理后的新生黄酒氢键缔合强度略高于一年陈黄酒。     

Effects of variation in porcine MYOD1 gene on muscle fiber characteristics, lean meat production, and meat quality traits

Three single nucleotide polymorphisms (SNPs) in the porcine MYOD1 gene were used for association analysis and haplotype construction to evaluate the effects of their substitution. Four hundred and three pigs of Yorkshire and Berkshire breeds were used. The mRNA expression levels of MYOD1 were examined. The g.489C>T and g.1264C>A SNPs were significantly associated with several muscle fiber characteristics, the loin eye area, and lightness. Particularly, animals having hetero-genotypes of both sites showed good performance both in lean meat production and meat quality traits. The results of haplotype substitution were similar to the associations of individual SNPs. Moreover, the 2 SNPs had significant effects on mRNA expression. Therefore, the g.489C>T and g.1264C>A SNPs in MYOD1 may be meaningful DNA markers that can be used for improving important porcine economic traits.     

Statistical study of the influence of fungicide treatments (mancozeb,zoxamide and copper oxychloride) on heavy metal concentrations in Sicilian red wine

The aim was to assess the influence of mancozeb, zoxamide and copper oxychloride fungicide treatments on Mn, Zn, Cu, Cd and Pb concentrations in Sicilian red wines, grapes, marcs and grape stalks. The experimentation was carried out over two crop years: 2003 and 2004. Trace metals analysis was performed by derivative stripping chronopotentiometry, which allowed detection of concentrations lower than 1 ng g^?1. The data obtained gave evidence that the levels of Mn and Zn in wines from plots treated with zoxamide–mancozeb were about threefold higher than those observed in the control. Wines treated with Cu oxychloride had a significant increase in Cu(II) concentrations with respect to the control; in particular, samples from 2004 showed a 50% increase in Cu levels. Furthermore, as shown in a previous paper, the fungicides treatments studied led to a moderate increase in Pb(II) and Cd(II) levels in treated samples with respect to the control. Wines from 2004 had higher Cu and Pb amounts than wines from 2003; but the concentrations of all the other metals were similar. Statistical analysis of the data by linear discriminant analysis (LDA) and the Kruskal–Wallis test confirmed that both zoxamide–mancozeb treatments and copper oxychloride treatments exerted a significant influence on Mn(II), Zn(II) Cu(II), Pb(II) and Cd(II) concentrations in wines, grapes, marcs and grape stalks samples from both the studied vintages.