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。     

提高结晶山梨醇熔点的工艺探讨

山梨醇是一种用途广泛的化工、食品、医药原料,结晶山梨醇应用更广,但必须掌握好其结晶的条件才能制备出熔点高的结晶山梨醇。本文对山梨醇结晶的工艺条件进行了深入研究,通过对结晶温度、结晶时间、晶种用量及晶种粒度进行了单因素对比试验,并用三因素三水平正交试验表安排了正交试验,优化结晶工艺条件。根据正交试验结果的极差分析及方差分析,对三因素的显著性作出了判断,确定了影响结晶山梨醇熔点的显著因素为结晶温度,也找出了原来产品熔点低的主要原因,对原装置上的结晶温度控制系统进行了改造,并对操作人员进行了培训,按优化的条件生产后,结晶山梨醇的熔点稳定达到101℃以上,达到进口样品的水平,其优化的条件为:结晶温度:70℃,结晶时间:40min,晶种用量:10%。     

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。     

结晶山梨醇的研制

本研究采用两种不同的工艺制备出两种γ－晶型含量较高的结晶山梨醇，食品级结晶山梨醇和药用结晶山梨醇。它们都具有熔点高，吸湿性小，稳定性好等特点。     

共晶体木糖醇的功能及应用

共晶体木糖醇是山梨醇和木糖醇按一定比例，以r-山梨醇或木糖醇的晶格结晶形成的一种熔融共晶体，本文阐述了共晶体木糖醇的主要功能及应用。     

木糖醇介稳区宽度与晶体生长速率测定

用激光散射法测定纯木糖醇水溶液和含有山梨醇和葡萄糖杂质的木糖醇水溶液的结晶介稳区宽度;在介稳区内测得不同结晶温度下纯木糖醇溶液中过饱和度对晶体生长速率的影响,同时研究杂质的添加对木糖醇结晶生长速率的影响。结果表明：相同结晶温度下,生长速率随过饱和度的增大而增大;在相同结晶温度和过饱和度下,木糖醇水溶液中分别加入山梨醇和葡萄糖杂质导致生长速率下降,并随杂质含量的增大而下降,山梨醇对晶体生长的抑制作用比葡萄糖更明显。     

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。     

山梨醇结晶温控系统的研究

山梨醇广泛应用于食品行业,针对山梨醇结晶温控系统存在时变大滞后特性,研究了一种融合遗传算法和神经网络的PID控制器。该控制算法采用RBF网络在线辨识被控对象,先利用遗传算法优化神经网络的初始权值,再结合神经网络所具有的自学习和任意非线性表达能力,用BP神经网络自整定PID参数,对结晶过程温度进行控制。仿真结果表明:该控制器提高了系统的控制性能,具有很强的自适应性和鲁棒性,满足山梨醇生产的要求。     

粉末结晶山梨醇

粉末结晶山梨醇金树人（南宁化工研究设计院南宁，５３００２２）我国的山梨醇工业经过近十多年的迅速发展，已经成为国内熟悉的化工行业。目前，我国绝大多数山梨醇产品是５０％与７０％浓度的水溶液。用途主要是两方面，一方面用其吸湿性能，用于牙膏、化妆品及一些食品...     

特殊营养食品——山梨醇

山梨醇是和甘露醇、木糖醇、麦芽糖醇等相同的可食用糖醇,在自然界广泛存在于水果,如苹果、梨、樱桃、乌梅中,在烟草,海藻中也含有少量山梨醇.由于食用糖醇在自然界的原料中含量太低,所以商品山梨醇是用较纯的结晶葡萄糖氢化制得.山梨醇和其他糖醇比较,具有原料广泛、工艺简单、成本低廉、用途广泛的特点.     

山梨糖醇对面包储藏期间品质的影响

利用质构仪﹑低场核磁共振(LF-NMR)等方法研究山梨糖醇对面包储藏期间的品质变化以及水分含量的影响。结果表明:山梨糖醇的加入使得面团发酵速率有所下降,也能够显著降低面包的硬度和咀嚼性(P0.05),减小储存期间的老化度。LF-NMR测试表明山梨糖醇的加入能提升面包的持水性能。利用面包硬度拟合Avrami方程,面包的老化速率常数有所减小,且得到的相关系数较高,说明面包硬度是面包老化在质构上的表征。总体而言,山梨糖醇能提升面包的持水性能,改善面包的口感。     

Optimization of Incorporation of Low-molecular-weight Cryoprotectants into Intact Fish Muscle

ABSTRACT: Chunks of freshwater trout muscle were immersed in sorbitol solutions (0% to 60%), under different vacuum conditions, for up to 30 min at 5 °C. Moisture loss, weight change, and sorbitol uptake were measured or calculated by mass balance, and cryoprotection during subsequent freezing and thawing was monitored as change in myosin Ca2+ ATPase activity. Vacuum treatment had no effect on measured parameters. Initial sorbitol uptake and weight loss were greater at higher sorbitol concentrations, but adequate cryoprotection was achieved by all treatments when diffusion time following immersion was extended sufficiently. Injection of 60% sorbitol was faster in achieving desired levels of sorbitol in fish meat and induced excellent cryoprotection.     

Rheological, Textural, Microstructural, and Sensory Properties of Sorbitol-Substituted Mango Jam

Production of low-calorie mango jam was investigated by substituting sucrose with sorbitol. Quality of sorbitol jam was evaluated with respect to rheological, textural, microstructural, color, and sensory attributes. Principal component analysis revealed that sucrose- and sorbitol concentration, hardness, and work of shear were the most relevant parameters in sorbitol jam manufacturing. Sorbitol-substituted mango jam behaved as pseudoplastic fluid exhibiting yield stress. The Herschel–Bulkley (HB) model described adequately the steady-state rheological behavior of jam. Temperature dependence of the consistency index followed Arrhenius relationship. Yield stress of the jam increased with total soluble solids (TSS) content during gelation process and decreased with increasing temperature. Time-dependent structural breakdown characteristics of mango jam followed Hahn model. Hardness of mango jam decreased with increasing sorbitol concentration because of weaker junction zones of pectin molecules. Lightness (L*) and yellowness (b*) decreased, but redness (a*) increased with TSS in mango jam for selected sorbitol levels. The mango jam manufactured at sorbitol level?=?70 with 75% sorbitol substitution received the highest overall acceptability score. Microstructure of sorbitol jam was found to be composed of network regions with large pores as well as dense, compact regions with small pores.     

氧化葡萄糖酸杆菌培养及生物转化性能的研究

对氧化葡萄糖酸杆菌在山梨醇培养基中的生长及其静息细胞对山梨醇的氧化做了动态研究。实验结果表明:作为碳源的山梨醇对该菌的生长具有明显的抑制作用,当山梨醇的浓度为2%时,该菌生长最好,底物利用率高。当装液量为20ml时,该菌静息细胞浓度为1.0mg干细胞重/ml时,转化效果最好,34h产物收率就达到77%,当装液量为10ml时,该菌静息细胞浓度为2.0mg干细胞重/ml时,转化效果最好,16h产物收率就达到90%。另外,在该菌的生长和其静息细胞转化山梨醇时,都不加入镁离子,该菌静息细胞对山梨醇无转化。     

Preparation and structural analysis of chitosan films with and without sorbitol

The purpose of this study was to clarify the structural changes in chitosan films made with sorbitol. The degree of deacetylation (DD) in the starting chitosan was 85% or 95%. The appearance and cross-sectional characteristics of the films were analyzed by SEM. This showed sorbitol to be a good crosslinking agent, generating the desired miscibility with both types of chitosan. XRD revealed an increase in crystallinity for films without sorbitol and a decrease for films spiked with sorbitol compared with the original chitosan. FT-IR showed that the addition of sorbitol did not change the chemical structure of chitosan and no new types of bonds were created during film formation. Changes in the chemical surrounding of carbon atoms analyzed by CP/MAS ¹³C NMR indicated that the acetic acid solution used partially destroyed the chitosan powder and protonized some groups, enabling sorbitol to be inserted and to form hydrogen bonds in the matrix.     

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。     

Effect of Plasticizers on Mechanical and Barrier Properties of Rice Starch Film

The effect of plasticizers, glycerol, sorbitol and poly(ethylene glycol) 400 (PEG 400), on mechanical and barrier properties of rice starch film has been investigated. Sorbitol‐ and glycerol‐plasticized starch films appeared homogeneous, clear, smooth, and contained less insoluble particles compared to unplasticized rice starch films. PEG 400 did not form plasticized films of suitable characteristics. The softness and stickiness of films improved with increasing concentrations of glycerol and sorbitol. In general, films plasticized with glycerol and sorbitol displayed a better solubility in water than unplasticized films, i.e. 35% (w/w) glycerol and 45% w/w (sorbitol) (optimum solubility). The tensile strength of films decreased especially in the high concentration regime of plasticizers, between 20–45% (w/w) of plasticizer/rice starch film. Through the entire concentration regime, the tensile strength of glycerol‐plasticized films was significantly lower than that of sorbitol‐plasticized films, but their elongation was larger. The water vapor transmission rate (WVTR) through plasticized films and the oxygen transmission rate (OTR) increased with glycerol and sorbitol concentrations, however, glycerol was revealed to be significantly more effective in reducing the tensile strength as well as increasing the WVTR and the OTR compared to sorbitol. With the higher tensile strength and the smaller OTR and WVTR, the 30% sorbitol‐plasticized film reveals an improved coating performance in terms of a reduction of coating failures.     

壳聚糖成膜溶液及其膜相关性质研究

以不同体积分数的乙酸溶液为分散剂,不同质量浓度的山梨醇为增塑剂,配制不同质量浓度的两种脱乙酰度壳聚糖溶液,探讨不同质量浓度基质对壳聚糖溶液pH值和电导率的影响,阐述壳聚糖溶液在成膜过程中各离子的聚合情况。对壳聚糖成膜溶液的流变学性质进行研究,并对其形成的膜进行表征,分析山梨醇对壳聚糖成膜溶液及其膜性质的影响。结果表明：壳聚糖成膜溶液体系中,主要是山梨醇、乙酸与壳聚糖中的各种离子结合形成黏稠的溶液。含与不含山梨醇作为增塑剂的壳聚糖成膜溶液均表现出假塑性流体,山梨醇与两种脱乙酰度的壳聚糖均有很好的相容性,能够形成均匀、连续的膜,使壳聚糖膜的吸热峰和放热峰发生一定的迁移,对其热稳定性有一定的影响。     

Die spezifische Drehung des Sorbits und des Sorbit-Molybdat-Komplexes

The Specific Rotation of Sorbitol and of the Sorbitol Molybdate Complex.

• 1 The specific rotation of the hexite at 365, 405, 436, 546 and 578 nm has been determined in solutions of different concentration with a commercial sorbitol preparation as well as with a self-produced sorbitol. Contents of both preparations had been determined enzymatically and by means of periodate. The specific rotation [α]_D was obtained mathematically from these data as well as by graphic extrapolation.
• 2 Conditions, under which the sorbitol molybdate complex shows its maximum of specific rotation were defined by systematic experiments at varying sorbitol, molybdate and hydrogen-ion concentration.
• 3) From these results a diagram was set up, which shows the molybdate and acid doses in order to determine sorbitol polarimetrically in the widest possible range.
• 4) The specific rotation of the sorbitol molybdate complex was determined at the same wavelengths as that of the sorbitol. It was also mathematically and graphically extrapolated for [α]_D.

     

不同比表面积山梨醇粉体的吸湿性实验研究

山梨醇有四种不同的晶型,在不同的结晶工艺条件下,得到的山梨醇往往是多种晶型的混合体,由于不同晶型的山梨醇性质不同,其混合物的吸湿性不同,而比表面积的大小可间接反应出山梨醇混合体中γ晶型的含量,故在25℃,相对湿度为75%条件下测定不同比表面积山梨醇的吸湿速率与吸湿百分率,并根据25℃不同湿度条件下的吸湿平衡曲线测定其临界相对湿度。实验证明,当山梨醇粉体的比表面积在0.79m2/g时,其临界相对湿度在70.80%,在空气湿度不大于70%条件下,吸湿性很小,不易结块,适于工业化生产。