催化剂在山梨醇生产中的应用

山梨醇又名山梨糖醇，是一种重要的大吨位医药、化工、轻工、食品工业的原料。我国山梨醇行业的发展源于维生素C生产，习惯上人们常把山梨醇称作Vc醇。但山梨醇在很多方面都有广泛的应用。同国外山梨醇消费结构相比，我国存在明显的不足和差距，我国山梨醇50％用于Vc生产，而美国12％用于Vc生产，日本13％用于Vc生产。随着我国经济的发展和人民生活水平的提高，山梨醇行业近年来在我国得到迅猛发展，山梨醇市场呈现出巨大商机和发展潜力，特别近期大成公司山梨醇裂解生产乙二醇的新工艺，使山梨醇的应用实现了质的飞跃，市场潜力特别巨大。     

异山梨醇制备技术研究

以固体山梨醇为原料,以全氟磺酸树脂+钯催化剂(二者6∶1混和)为催化剂制备异山梨醇产品,研究转化条件和后精制过程。通过单因素和正交试验,确定异山梨醇的最佳工艺条件为:反应时间4h、反应温度150℃、催化剂用量为山梨醇重量的12%,同时通入氢气作为还原剂,避免了原料山梨醇的过度氧化,在此条件下,测得的山梨醇对异山梨醇的转化率在75%以上。在后续异山梨醇液的精制处理过程中,采用碳酸钙作为中和试剂,以电渗析技术代替传统的离交工艺,用乙酸乙酯溶剂低温自然结晶代替传统的高温减压蒸馏工艺,经离心分离得到了纯度为99.6%的异山梨醇产品,品质高,节能降耗,符合国家倡导的清洁生产要求,值得在行业内推广、应用。     

甘露醇/山梨醇共结晶体性质及在鱼糜中的应用优势

甘露醇和山梨醇是一对同分异构体,在化学合成法生产甘露醇时,所产生的山梨醇母液,不可避免的含有部分甘露醇。论述甘露醇/山梨醇共晶体的性质,说明该产品在鱼糜产品的应用优势。     

山梨醇基聚醚多元醇的研制

用结晶山梨醇与环氧丙烷合成山梨醇基聚醚多元醇,经过试验,探索出了最佳的配方及工艺条件,合成出合格的产品。经应用试验检测,指标全部合格。证实了以山梨醇替代甘露醇制备山梨醇基聚醚多元醇的可行性,也为结晶山梨醇的应用开辟了新的途径。     

山梨醇的制法、用途、市场概述

1. 山梨醇用途及特征概述 山梨醇是山梨糖醇的简称,它是以玉米淀粉制得的葡萄糖为原料,经过氧化制得。最初制造山梨醇是为了取得维生素C的原料。后来又在制药、化妆品、麦面活性剂、牙膏、皮革加工等方面得到应用。近年来,山梨醇又广泛地用于食品添加剂。山梨醇作为食品添加剂,已被联合国添加剂委员会批准,ADI不作特殊规定。我国山梨醇生产多数是为维生素C配套,有少量用于牙膏生产,而用于表面活性剂就更少、日本和美国,每年用于食品的山梨醇达5万吨以上。     

山梨醇液的纳滤分离特性

针对传统生产山梨醇产品存在的生产成本高、工艺过程复杂、流程长、水电汽等辅料消耗高、生产效率低等问题,根据纳滤膜可以截留或透过不同分子量物质的原理,研究采用截留分子量为200的纳滤膜分离提纯山梨醇液,通过单因素和试生产试验,考察了各操作参数对纳滤膜分离性能的影响,确定了较优的山梨醇液纳滤分离工艺条件:操作压力0.8MPa、操作温度40℃、错流流速8m/s、进料浓度35%,此时,纳滤膜对山梨醇液的平均膜通量为94.7 L/(m~2·h),对大分子物质的截留率为91.89%,山梨醇的透过率为93.28%,透过液中山梨醇的纯度达到99%以上,在满足制备医药级或食品级山梨醇产品的同时,得到了日化级或化学工业品级的山梨醇副产品,并降低了水耗和能耗,具有较好的经济效益和环保效果。     

山梨醇中糖类物质对Span60产品的影响

阐述了以山梨醇和硬脂酸为原料,合成失水山梨醇单硬脂酸酯(Span60)。通过试验得出了山梨醇中糖类物质含量对目标产物中黑点及色泽会产生较大影响的结论,同时提出了相应解决的办法。     

提高结晶山梨醇熔点的工艺分析

文章分析了结晶山梨醇的基本含义,同时以试验分析的方式,针对提高结晶山梨醇熔点的工艺进行了分析与讨论。旨在有效提升结晶山梨醇熔点的工艺水平,科学保证结晶山梨醇品质。     

甘露醇／山梨醇共结晶体性质及在鱼糜中的应用优势

甘露醇和山梨醇是一对同分异构体，在化学合成法生产甘露醇时，所产生的山梨醇母液，不可避免的含有部分甘露醇。本文论述甘露醇／山梨醇共晶体的性质，说明该产品在鱼糜生产的应用优势。     

在六元醇生产中蒸发设备的比较

在蔗糖水解法生产甘露醇、山梨醇的生产工艺中,用板式蒸发器替代薄膜刮板蒸发器,对甘露醇-山梨醇混合液、甘露醇母液及液体山梨醇的蒸发效果、能耗等方面进行比较。     

山东、四川不同类型萝卜营养品质分析与综合评价

目的 研究山东、四川不同类型萝卜综合营养品质的差异。方法 以山东主产的4种类型萝卜和四川主产的3种类型萝卜为研究对象,以维生素C、莱菔素等12个营养成分和功能活性成分为品质评价指标,采用相关性分析、主成分分析与聚类分析进行综合评价。结果 绿皮绿肉萝卜的莱菔素含量显著高于其它类型萝卜(p<0.05),而山东绿皮绿肉萝卜的莱菔素含量显著高于四川绿皮绿肉萝卜(p<0.05)。综合评价显示,山东萝卜和四川萝卜显示出明显的分离,且同一产地不同类型萝卜也显示出一定的分离趋势,营养品质综合得分由高到低依次为：山东绿皮绿肉萝卜＞四川绿皮绿肉萝卜＞四川红皮白肉萝卜＞山东红皮白肉萝卜＞山东绿皮红肉萝卜＞山东白皮白肉萝卜＞四川白皮白肉萝卜。结论 山东、四川不同类型萝卜在营养品质方面存在明显差异,综合营养品质最佳的为绿皮绿肉萝卜。     

木瓜复合果醋的酿制

以湖北长阳县的木瓜为基料，配以含糖量较高的苹果汁，制备营养丰富的复合木瓜果醋。结果表明，木瓜汁与苹果汁制成的复合果醋，色泽清亮自然，具有两种果汁的复合香味，口感和香味都优于纯木瓜醋和木瓜菠萝复合果醋。     

Genetic parameters of blood β-hydroxybutyrate predicted from milk infrared spectra and clinical ketosis,and their associations with milk production traits in Norwegian Red cows

The aim of this study was to estimate genetic parameters for blood β-hydroxybutyrate (BHB) predicted from milk spectra and for clinical ketosis (KET), and to examine genetic association of blood BHB with KET and milk production traits (milk, fat, protein, and lactose yields, and milk fat, protein, and lactose contents). Data on milk traits, KET, and milk spectra were obtained from the Norwegian Dairy Herd Recording System with legal permission from TINE SA (Ås, Norway), the Norwegian Dairy Association that manages the central database. Data recorded up to 120 d after calving were considered. Blood BHB was predicted from milk spectra using a calibration model developed based on milk spectra and blood BHB measured in Polish dairy cows. The predicted blood BHB was grouped based on days in milk into 4 groups and each group was considered as a trait. The milk components for test-day milk samples were obtained by Fourier transform mid-infrared spectrometer with previously developed calibration equations from Foss (Hillerød, Denmark). Veterinarian-recorded KET data within 15 d before calving to 120 d after calving were used. Data were analyzed using univariate or bivariate linear animal models. Heritability estimates for predicted blood BHB at different stages of lactation were moderate, ranging from 0.250 to 0.365. Heritability estimate for KET from univariate analysis was 0.078, and the corresponding average estimate from bivariate analysis with BHB or milk production traits was 0.002. Genetic correlations between BHB traits were higher for adjacent lactation intervals and decreased as intervals were further apart. Predicted blood BHB at first test day was moderately genetically correlated with KET (0.469) and milk traits (ranged from ?0.367 with protein content to 0.277 with milk yield), except for milk fat content from across lactation stages that had near zero genetic correlation with BHB (0.033). These genetic correlations indicate that a lower BHB is genetically associated with higher milk protein and lactose contents, but with lower yields of milk, fat, protein, and lactose, and with lower frequency of KET. Estimates of genetic correlation of KET with milk production traits were from ?0.333 (with protein content) to 0.178 (with milk yield). Blood BHB can routinely be predicted from milk spectra analyzed from test-day milk samples, and thereby provides a practical alternative for selecting cows with lower susceptibility to ketosis, even though the correlations are moderate.     

Modeling portal-drained viscera and liver fluxes of essential amino acids in dairy cows

The objective of this work was to predict essential amino acid (EAA) use and release by the portal-drained viscera (PDV) and liver of dairy cows. Previously derived equations were tested using data assembled from the literature, refit to the data, and modifications were undertaken to determine the best model for each EAA. The refitted model has the same structure as the original equations but is parameterized using a database of group means, as the original equations were derived using a single study with individual cow data and found to be biased. The PDV clearance model predicted portal vein concentrations given inputs of absorbed and arterial fluxes of EAA with root mean squared errors (RMSE) ranging from 3.3 to 12.1% of the observed means, and concordance correlation coefficients (CCC) ranging from 0.86 to 0.99 when using previously reported parameters. The reparameterized model generated from the assembled data set resulted in predictions of EAA portal vein concentrations with RMSE ranging from 3.2 to 8.6% and CCC ranging from 0.93 to 1.00. Slope bias ranged from 12.4 to 55.3% of mean squared errors and was correlated with arterial EAA concentrations. Modifying the model to allow rate constants to vary as a function of arterial EAA concentrations reduced slope bias, resulting in RMSE ranging from 1.9 to 6.5% and CCC from 0.97 to 1.00. Alternatively, splitting the model to account for use of EAA from absorption separately from arterial use resulted in poorer predictions and biologically infeasible parameter estimates. The liver clearance model predicted hepatic vein concentrations from arterial and portal vein input fluxes with RMSE across EAA ranging from 1.9 to 6.8% and CCC ranging from 0.97 to 1.00 when using reported parameters. The reparameterized model generated from the assembled data set resulted in predictions of EAA hepatic vein concentrations with RMSE ranging from 1.9 to 6.7% and CCC ranging from 0.97 to 1.00. Significant slope bias was present for Arg, His, Lys, Phe, Thr, and Val. Altering the model to represent the clearance rate constant as a function of arterial concentrations resulted in RMSE ranging from 1.8 to 6.5% and CCC ranging from 0.97 to 1.00. The combination of PDV and liver clearance models provided predictions of total splanchnic use similar to those of an empirical model representing splanchnic use as a fractional proportion of absorption that had RMSE ranging from 3.0 to 8.6% and CCC ranging from 0.95 to 0.99, with significant slope bias for the majority of EAA.     

Coagulation and proteolysis of high-protein milks in the gastric environment

Gastric digestion of 2 commercial ultrafiltered milks and milk enriched with skim milk powder (to simulate concentration by reverse osmosis) was investigated and compared with the digestion of nonconcentrated milk. Curd formation and proteolysis of high-protein milks in simulated gastric conditions were studied using oscillatory rheology, extrusion testing, and gel electrophoresis. The presence of pepsin in the gastric fluid triggered coagulation at pH >6 and the elastic modulus of gels from high-protein milks was ~5 times larger than the gel from reference milk. Despite similar protein concentrations, the coagulum from milk enriched with skim milk powder showed higher resistance to shear deformation than the coagula from ultrafiltered milks. The gel structure was also more heterogeneous. During digestion, the degradation of coagula from high-protein milks was slowed down compared with the coagulum from reference milk, and intact milk proteins were still detected after 120 min. Differences in the digestion patterns of coagula from high-protein milks were observed and were associated with the proportion of minerals bound to caseins and the denaturation rate of whey proteins.     

沙城产区酿酒酵母多样性研究

对沙城产区龙眼葡萄相关环境中分离筛选的酿酒酵母进行多样性研究。在连续3年(2008、2009、2010年)的实验中,共从葡萄园土壤、葡萄酒厂设备表面、接触过葡萄酒厂设备的葡萄汁和自然发酵过程中采集菌源样品227份,共分离得到1358株酵母菌。用5.8S-ITS区域RFLP方法进行分子水平的分类鉴定及赖氨酸培养基复筛,得到了270株酿酒酵母。再利用Interdelta PCR指纹图谱法将酿酒酵母区分为16类,其中土壤5类,自然发酵过程中第2、3、4期分别得到4类、10类和11类;酒厂设备表面3类;接触酒厂设备的葡萄汁3类。酿酒酵母的种类因样品采集时间、采集地点等不同有明显区别。自然发酵过程中得到的酿酒酵母被认为是本土酵母的可能性最大。     

豉香型白酒酒饼微生物的分离

通过平板稀释法微生物分离试验，认为分离豉香型白酒酒饼微生物时，在麦芽汁琼脂培养基中加入质量浓度为500mg/L的去氧胆酸钠，在高氏合成1号琼脂培养基中加入质量浓度为100mg/L的重铬酸钾后，有利于酒饼微生物的生长和分离，豉香型白酒大小酒饼的微生物分离结果表明，大酒饼中的细菌含量较小酒饼中的明显升高，小酒饼提供的根霉和酵母等微生物来源在大酒饼中得到扩大培养，而大小酒饼中放线菌含量变化则不大。     

Analysis of extra virgin olive oils from stoned olives

This paper focuses on comparing the main chemical characteristics of 16 fresh commercial samples of extra virgin olive oil obtained from four harvest years (1999–2002) and derived from both stoned and whole fruits. The qualitative and quantitative contents of minor polar compounds (MPCs) together with other reference analytical parameters (acidity, peroxides, UV absorption values and Rancimat test) were evaluated. An investigation of the MPCs and oil composition obtained from only stoned olives was also carried out. The acidity values of the oils from stoned fruits were always similar to or lower than those of the corresponding oils from whole fruits. For almost all the samples from stoned olives a better resistance to oxidation was revealed in comparison with the corresponding traditional oils. Five pairs obtained from the 2000 and 2001 harvests showed higher concentrations of both MPCs and hydroxytyrosol derivatives in the oils from stoned fruits, in agreement with their higher Rancimat values. Overall, our findings with regard to acidity values, % hydrolysis, the Rancimat test and the qualitative and quantitative distribution of MPCs suggest a higher antioxidant capacity of the oils from stoned olives. Copyright © 2004 Society of Chemical Industry     

豉香型白酒酒饼微生物的分离

通过平板稀释法分离试验 ,得知分离豉香型白酒酒饼微生物时 ,在麦芽汁琼脂培养基中加入质量浓度为 5 0 0mg/L的去氧胆酸钠 ,在高氏合成 1号琼脂培养基中加入质量浓度为 10 0mg/L的重铬酸钾后 ,利于酒饼微生物的生长和分离。豉香型白酒大小酒饼的分菌结果表明 ,大酒饼中细菌含量较小酒饼中明显升高。小酒饼提供的根霉和酵母等微生物来源在大酒饼中得到扩大培养 ,而大小酒饼中放线菌含量变化则不大。     

Restructured Reindeer Steaks: Effects of Flake Size, Phosphate, and Salt on Sensory Properties

Steaks, fabricated from forequarters from field-slaughtered Alaskan reindeer, were prepared from meat flaked to two sizes (1.295 and 1.905 cm), with (0.5%) and without phosphate, and with (0.5%) and without salt. Phosphate did not appreciably affect sensory properties. Larger flakes and salt improved quality and acceptability, therefore, additional steaks were fabricated from meat flaked with a larger cutting head (4.064-cm) and with three levels of salt (0.0, 0.5 and 0.75%). Steaks containing 0.75% salt were less chewy, softer, juicier, and more acceptable than those made with 0.5% salt but did not differ from those containing no salt. Feasibility of producing restructured steaks from reindeer forequarters was demonstrated.