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食品冷杀菌技术研究进展 总被引:20,自引:0,他引:20
食品冷杀菌技术是指不用热能杀死微生物,不影响食品营养、质构、色泽和风味的新兴杀菌技术。通过介绍超高压杀菌、射线杀菌、超高压脉冲电场杀菌、脉冲强光杀菌、磁力杀菌、紫外线杀菌和二氧化钛光催化杀菌技术,详述其基本原理及其在食品工业中应用研究进展。 相似文献
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食品物理冷杀菌技术研究进展 总被引:4,自引:0,他引:4
物理冷杀菌技术是一种新技术,既能杀灭食品中微生物、又能最大限度保持食品色泽、香味及营养成分。该文着重介绍超高压杀菌、高压脉冲电场杀菌、脉冲非热等离子体杀菌、脉冲强光杀菌、磁力杀菌、膜分离除菌、紫外线杀菌、辐照杀菌、微波杀菌、超声波杀菌、电阻杀菌、半导体光催化杀菌等技术的杀菌原理及其在食品中应用。 相似文献
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福建和云南烤烟烟片的最佳醇化期及适宜贮存时间 总被引:11,自引:3,他引:11
研究了福建烤烟烟片 (S0 4 - 98、S0 5 - 98、Z0 5 - 98)和云南烤烟烟片 (S0 1- 98A、S0 1- 98B)醇化过程中外观、化学成分及吸味品质的变化规律 ,确定的福建S0 4 - 98、S0 5 - 98和Z0 5 - 98烟片的最佳醇化期分别为 2 1个月、18~ 2 1个月和 2 1个月 ,适宜贮存时间分别为 12~ 2 4个月、18~ 30个月及 18~ 30个月 ;云南S0 1- 98A和S0 1- 98B烟片的最佳醇化期均为 2 1个月 ,适宜贮存时间分别为 18~ 30个月和12~ 2 4个月 相似文献
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The biosynthetic pathway of PP-V, a new monascorubramine homologue, was elucidated by 13C-labeling studies. The [1-13C] of acetate was incorporated into 2-, 3a-, 4a-, 6-, 8-, 9-, 11-, 13-, 15-, 17-, and 19-Cs of PP-V, and the [2-13C], into 3-, 4-, 5-, 8a-, 9a-, 10-, 12-, 14-, 16-, 18-, and 20-Cs. These incorporation patterns coincide with those reported in the biosynthesis of a Monascus azaphilone pigment, monascorubrin. 相似文献
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Diane Jouanneau Marion Guibet Patrick Boulenguer Jacques Mazoyer Michael Smietana William Helbert 《Food Hydrocolloids》2010
Hybrid κ-/μ-carrageenan, water-extracted from Kappaphycus alvarezzi, was incubated with Pseudoalteromonas carrageenovora κ-carrageenase. The five most abundant hybrid κ-/μ-carrageenan oligosaccharides were purified and their structure was determined by NMR and mass spectrometry. Since the enzyme-resistant fraction was small, these five oligosaccharides were representative of the distribution of the μ-carrabiose moieties along the carrageenan chain. Three main distributions of μ-carrabiose were found: -μ-, -μ-μ- and -μ-μ-μ-. Interestingly, the chemical shifts of the anomeric proton and carbon were strongly influenced by the identity of the adjacent carrabiose, which explains the asymmetrical D6S-H1 NMR signal that we observed. Although μ-carrabiose chemical shifts are usually attributed to blocks of μ-carrabiose as expected in ideal μ-carrageenan, we demonstrate that they are in fact due to μ-carrabiose units positioned between κ-carrabiose units. Using NMR and chromatography to monitor the alkaline conversion of μ- to κ-carrabiose, we found that the μ-carrabiose distribution (-μ-, -μ-μ-, -μ-μ-μ-) did not influence the conversion rate. 相似文献
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Principal component and multivariate analysis of milk long-chain fatty acid composition during diet-induced milk fat depression 总被引:2,自引:0,他引:2
The objective of this study was to assess the relationship between individual milk fatty acids (FA) and diet-induced milk fat depression (MFD) using principal component analysis (PCA) and multivariate analysis (MA). Cow treatment observations (n = 63) from 3 published feeding experiments with lactating dairy cows were used in the analyses. In the PCA, principal component loading plots 1 (PC1) and 2 (PC2) described 55.9% of the total variation in milk FA and fat concentrations. Saturated FA (14:0, 16:0, and 17:0) and milk fat percentage showed negative loading for PC1. Trans-18:1 isomers (trans-6+7+8 to trans-15), trans-7, cis-9 conjugated linoleic acid (CLA), and trans-10, cis-12 CLA showed positive (opposite) loading, suggesting a negative relationship between these isomers and milk fat percentage. Cis-11, trans-13 CLA and cis-9, trans-11 CLA were associated with the PC2 axes (neutral), indicating that they were not associated with MFD. Multivariate analysis with milk fat percentage as the dependent variable and individual PC1 positive loading variables showed a breakpoint relationship for trans-6+7+8-, trans-9-, trans-10-, and trans-13+14-18:1 and a linear relationship for trans-11-, trans-12-, trans-15-18:1, trans-10, cis-12 CLA, and trans-7, cis-9 CLA. Subsequent MA was conducted on 41 treatment means from 12 independent experiments from the literature, in which concentrations of trans-6+7+8-, trans-9-, trans-10-, and trans-11-18:1, and cis-9 trans;-11, and trans-10, cis-12 CLA were reported. Significant negative effects of trans-9-18:1, trans-10-18:1, and trans-10, cis-12 CLA on milk fat percentage were observed. In this study, the PCA and MA showed that among trans-18:1 isomers, trans-10-18:1 was the most negatively correlated to milk fat percentage. However, the threshold concentration related to maximum MFD indicated that the relative potency was greatest for trans-6+7+8- and lowest for trans-10-18:1. These results suggested that trans-6+7+8-18:1 might be more important than trans-10-18:1 in MFD. Principal component analysis also showed that trans-10, cis-12 and trans-7, cis-9 CLA were the isomers most negatively correlated to milk fat percentage, implying a possible role of trans-7, cis-9 CLA in MFD. Additional experiments are needed to establish whether trans-7-18:1 is involved in MFD or that its effects are mediated via the endogenously synthesized trans-7, cis-9 CLA. 相似文献
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Jun Ogihara Jun Kato Kunio Oishi Yoshinori Fujimoto 《Journal of Bioscience and Bioengineering》2000,90(6):678
The biosynthetic pathway of PP-V, a new monascorubramine homologue, was elucidated by 13C-labeling studies. The [1-13C] of acetate was incorporated into 2-, 3a-, 4a-, 6-, 8-, 9-, 11-, 13-, 15-, 17-, and 19-Cs of PP-V, and the [2-13C], into 3-, 4-, 5-, 8a-, 9a-, 10-, 12-, 14-, 16-, 18-, and 20-Cs. These incorporation patterns coincide with those reported in the biosynthesis of a Monascus azaphilone pigment, monascorubrin. 相似文献
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14-3-3 proteins form a family of highly conserved proteins which are present in all eukaryotic organisms investigated, often in multiple isoforms, up to 13 in some plants. They interact with more than 200 different, mostly phosphorylated proteins. The molecular consequences of 14-3-3 binding are diverse: this binding may result in stabilization of the active or inactive phosphorylated form of the protein, to a conformational alteration leading to activation or inhibition, to a different subcellular localization, to the interaction with other proteins or to shielding of binding sites. The binding partners, and hence the 14-3-3 proteins, are involved in almost every cellular process and 14-3-3 proteins have been linked to several diseases, such as cancer, Alzheimer's disease, the neurological Miller-Dieker and spinocerebellar ataxia type 1 diseases and bovine spongiform encephalopathy (BSE). The yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe both have two genes encoding 14-3-3 proteins, BMH1 and BMH2 and rad24 and rad25, respectively. In these yeasts, 14-3-3 proteins are essential in most laboratory strains. As in higher eukaryotes, yeast 14-3-3 proteins bind to numerous proteins involved in a variety of cellular processes. Recent genome-wide studies on yeast strains with impaired 14-3-3 function support the participation of 14-3-3 proteins in numerous yeast cellular processes. Given the high evolutionary conservation of the 14-3-3 proteins, the experimental accessibility and relative simplicity of yeasts make them excellent model organisms for elucidating the function of the 14-3-3 protein family. 相似文献
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采用顶空固相微萃取-气相色谱-质谱联用技术对抗坏血酸/精氨酸反应体系在不同反应温度和时间下的产物进行鉴定,共鉴定出包括吡嗪、醛、呋喃、醇和吲哚在内的24种化合物,其中14种吡嗪化合物为主要香味化合物。考察了反应温度和时间对产物特别是对吡嗪化合物的影响。结果表明,随着反应温度的升高和反应时间的延长,吡嗪类化合物的总量均增加;其中,随反应温度的升高,相对其他吡嗪化合物2-乙基-6-甲基吡嗪、3-乙基-2,5-二甲基吡嗪的量明显增加;随反应时间的延长,2-乙基-6-甲基吡嗪的量明显增加。 相似文献
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大庆自然发酵酸菜中乳酸菌的分离鉴定及耐酸菌株初步筛选 总被引:1,自引:0,他引:1
从黑龙江大庆地区采集7份采用传统方法制作的自然发酵酸菜发酵液,从中分离和筛选出14株乳酸菌疑似菌株,提取其16S rDNA,并经测序、同源性分析和系统发育树构建等方法,对其属种进行鉴定。初步筛选出在pH值为2.5、3.0和3.5的酸性条件下均能够生长的耐酸菌株6株,并进一步利用活菌计数法得出菌株在pH3.0条件下的存活率。结果表明:14株菌株均为乳酸菌,其中4株为弯曲乳杆菌(HD12-1、HD13-5、HD14-1和HD15-1),1株为短乳杆菌(HD18-2),3株为清酒乳杆菌(HD12-2、HD13-1和HD16-5),1株为肠膜明串珠菌(HD18-3),5株为植物乳杆菌(HD14-3、HD15-2、HD16-2、HD17-3和HD17-4),且筛选出pH 3.0条件下存活率在2%以上的6株菌株,分别为HD12-1、HD13-1、HD14-1、HD15-1、HD16-2和HD16-5。 相似文献
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A new colorimetric method to quantify β-1,3-1,6-glucans in comparison with total β-1,3-glucans in edible mushrooms 总被引:2,自引:0,他引:2
Jörg Nitschke Hendrik Modick Ekkehard Busch Reimund Wantoch von Rekowski Hans-Josef Altenbach Helga Mölleken 《Food chemistry》2011
Mushroom β-glucans are known for their activity as biological response modifiers and anticarcinogenic agents. β-1,3-1,6 Branched glucans with a triple helix tertiary structure are recognised as the most potent ones. In the present work, a colorimetric method for β-1,3-1,6-glucan quantification based on the dye Congo red is introduced. This method is specific for β-glucans with a triple helix. The β-1,3-1,6-glucan content of mycelia and fruiting bodies from various mushrooms was determined and compared with the total β-1,3-glucan content, measured by a fluorimetric method. The results show equal amounts of β-1,3-1,6- and total β-1,3-glucans in the analysed species but obvious differences between mycelia and fruiting bodies. On the average, 3% of mycelia and 8% of fruiting body dry mass consist of β-1,3-1,6-glucans. The average percentage of β-1,3-1,6-glucans in the total β-1,3-glucan content differs between mycelia (46%) and fruiting bodies (87%). 相似文献
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Naphthalene and its C1- and C2-alkyl derivatives are semivolatile polycyclic aromatic hydrocarbons expected to be in the gas phase in ambient atmospheres and subject to degradation by gas-phase reactions with the hydroxyl (OH) radical. Using a relative rate method, rate constants for the gas-phase reactions of OH radicals with a series of alkylnaphthalenes have been measured at 298 +/- 2 K and at atmospheric pressure of air. The compounds studied include naphthalene, 1- and 2-methylnaphthalene (1-, 2-MN), 1- and 2-ethylnaphthalene (1-, 2-EN), and the 10 dimethylnaphthalene isomers (1,2-; 1,3-; 1,4-; 1,5-; 1,6-; 1,7-; 1,8-; 2,3-; 2,6-; and 2,7-DMN). Using 1,2,3-and 1,3,5-trimethylbenzene as reference compounds, the rate constant obtained for the OH radical reaction of naphthalene was (2.39 +/- 0.09) x 10(-11) cm3 molecule(-1) s(-1). Relative to naphthalene, the rate constants measured for the alkylnaphthalenes were (in units of 10(-11) cm3 molecule(-1) s(-1), where the errors given are two standard deviations and include the above uncertainty in the naphthalene rate constant) 1-MN, 4.09 +/- 0.20; 2-MN, 4.86 +/- 0.25; 1-EN, 3.64 +/- 0.41; 2-EN, 4.02 +/- 0.55; 1,2-DMN, 5.96 +/- 0.55; 1,3-DMN, 7.49 +/- 0.39; 1,4-DMN, 5.79 +/- 0.36; 1,5-DMN, 6.01 +/- 0.35; 1,6-DMN, 6.34 +/- 0.36; 1,7-DMN, 6.79 +/- 0.45; 1,8-DMN, 6.27 +/- 0.43; 2,3-DMN, 6.15 +/- 0.47; 2,6-DMN, 6.65 +/- 0.35; 2,7-DMN, 6.87 +/- 0.43. These data show that, under atmospheric conditions, the DMN isomers react most rapidly with the OH radical with calculated lifetimes of 1.9-2.4 h, followed by the MNs and ENs with lifetimes of 2.9-3.8 h and naphthalene with a lifetime of 5.8 h. These differences in reactivity were confirmed by the nighttime/daytime concentration ratios of the alkylnaphthalenes measured in ambient Riverside, CA, samples. 相似文献