无溶剂法合成食品添加剂菜籽油蔗糖酯的研究

在碱催化条件下,先由甲醇和菜籽油反应制得脂肪酸甲酯.然后以脂肪酸甲酯和蔗糖为原料,在催化剂和乳化剂的作用下进行酯交换反应合成了蔗糖脂肪酸酯.详细考察了反应过程中乳化剂及催化剂用量,反应时间,反应温度,酯糖比,压力等因素对合成蔗糖酯产率的影响.确定了最佳的合成工艺条件,即乳化剂用量为反应物总质量的9%,催化剂用量为7%,反应温度130℃,反应时间5h,n(脂肪酸甲酯)∶n(蔗糖)=3∶1,压力4.45KPa.该条件下,菜籽油蔗糖酯的产率可高达72.4%,其临界胶束浓度(CMC)为1.86g/L,表面张力为29.4mN/m,乳化力为122s,亲水性能为9.86mL,HLB值为11.5.     

蔗糖混合脂肪酸酯制备工艺研究

以KOH与混合脂肪酸甲酯首先皂化反应生成部分中性皂作为乳化分散剂,蔗糖和脂肪酸甲酯在碳酸钾催化下发生酯交换反应合成蔗糖酯。正交试验得到最佳反应工艺条件：蔗糖0.3mol（102g）、脂肪酸甲酯／蔗糖摩尔比2、皂化剂KOH8.2％（蔗糖质量）、甲醇用量40％（蔗糖质量）、碳酸钾催化剂2％（蔗糖质量）、反应温度135℃、-0.03MPa负压下反应3h,蔗糖酯产品的最高得率为64.2％,并对蔗糖酯产品进行红外表征。     

逆相转移催化合成葵花籽油蔗糖酯

先由食用葵花籽油和甲醇在碱性催化剂条件下酯交换反应制得脂肪酸甲酯,然后脂肪酸甲酯与蔗糖通过水溶剂法,以逆相转移催化剂DMAP催化制备蔗糖脂肪酸酯.通过对酯糖摩尔比、催化剂用量、反应温度、反应时间进行考察,确定最佳合成条件为:酯糖摩尔比2.5∶1,催化剂用量4％,反应温度 85℃,反应时间7h.在最佳合成条件下,葵花籽油脂肪酸甲酯的转化率高达65.32％,所得产品具有良好的表面活性,其临界胶束质量浓度(CMC)为6.5 g/L,表面张力为27.41 mN/m,乳化力为79 s,浊点指数为7.2 mL,HLB值为10.1,碘值(Ⅰ)为126.9 g/100 g.     

硫酸化脂肪酸甲酯加脂剂制备工艺的研究

以脂肪酸甲酯为原料、离子液体为催化剂,以碘值为指标考察硫酸化脂肪酸甲酯反应条件.在单因素实验基础上,通过正交实验确定了硫酸化脂肪酸甲酯合成的最佳工艺条件:离子液体用量1.0％(以甲酯质量为基准),浓硫酸用量30％,反应温度25℃,反应时间3h.在最佳工艺条件下,硫酸化脂肪酸甲酯的碘值(Ⅰ)可达最低,为42.45 g/100 g.通过红外分析,证明了目标产物的生成.     

响应面法优化蔗糖多酯的合成工艺

以油酸甲酯和蔗糖为原料,十六烷基三甲基溴化铵为相转移催化剂,采用两步无溶剂法合成蔗糖多酯。以蔗糖多酯收率和酯化度为指标,考察反应时间、反应温度、催化剂用量、反应物摩尔比对蔗糖多酯合成效果的影响,用响应面法对蔗糖多酯的合成工艺条件进行优化。实验结果表明,蔗糖多酯最佳合成条件为:反应时间5.1 h,反应温度139.5℃,催化剂用量2.86%,油酸甲酯与蔗糖的摩尔比10∶1。在最佳条件下,蔗糖多酯收率达到86.20%,酯化度为6.69。     

非水相条件下酶法制备蔗糖油酸酯的研究

以蔗糖与油酸甲酯为主要原料,研究非水相条件下酶法制备蔗糖油酸酯的影响因素及其工艺条件。在丙酮反应体系中,筛选出Novozyme435为最佳催化剂,并且酶用量、酯糖比、反应温度、反应时间等条件对蔗糖油酸酯(SFAE)的转酯反应和转化率有重要影响;通过响应面试验设计,优化的蔗糖油酸酯合成工艺条件是:酶添加量39.8mg,酯糖物质的量比为6.0,丙酮用量4.0mL,反应温度45.4℃,反应时间24.6h,在此条件下蔗糖油酸酯转化率约为50%。     

水力空化强化酯交换合成蔗糖月桂酸单酯工艺的研究

以月桂酸甲酯和蔗糖为原料,通过水力空化强化酯交换合成蔗糖月桂酸单酯。研究了水力空化压力、水力空化时间、水力空化温度、糖酯摩尔比等对蔗糖月桂酸单酯产率的影响。以单因素实验为基础,利用响应面优化了水力空化强化酯交换合成蔗糖月桂酸单酯工艺条件,并对蔗糖月桂酸单酯产物表面活性性能进行了测定。结果表明:水力空化强化酯交换合成蔗糖月桂酸单酯最佳工艺条件为水力空化时间85 min、水力空化压力0.35 MPa、催化剂无水碳酸钾用量11.5%(以月桂酸甲酯用量为基准)、溶剂二甲基亚砜用量8.5 m L(以0.01 mol蔗糖为基准)、水力空化温度65℃、糖酯摩尔比3.5∶1,在最佳条件下产率为85.07%,蔗糖月桂酸单酯产物表面活性性能优越。     

一种高效聚醚酯消泡剂的制备及性能研究

通过分子设计合成了一种适用于低温多效海水淡化过程中泡沫快速消除的高效聚醚酯消泡剂,通过正交试验分析确定了聚醚酯消泡剂的最佳合成条件:原料GPE聚醚中的羟基和正辛酸中的羧基比例为1:0.8,酯化反应温度为90℃,控制反应时间为6 h,催化剂用量为反应体系总质量的0.3％.对得到的产物进行了结构表征及表面张力测定,利用全自...     

常压碱催化合成菜籽油蔗糖酯的研究

以K2CO3为催化剂,DMSO作溶剂,由蔗糖和菜籽油醇解所得脂肪酸甲酯制备了非离子表面活性剂蔗糖脂肪酸酯（Sucrose fatty acid esters,SE）,考察了反应温度、反应时间、酯糖比、催化剂用量对试验结果的影响,确定了最佳的合成工艺条件。试验结果表明：反应温度130℃,反应时间7h,酯糖摩尔比为3.0∶1,催化剂用量为反应物总量的4 wt%时,菜籽油蔗糖酯的产率可高达66.7%,临界胶束浓度（CMC）为0.006mol/L,表面张力为32.4mN/m,稳泡能力为8.0/6.5mm/mm（5min后）,乳化力为30s,浊点指数为14.90mL,HLB值为14.2。     

废油脂制备烷醇酰胺表面活性剂的工艺研究

以废油脂为原料,在自制DYD催化剂作用下制得脂肪酸甲酯,再以氢氧化钾为催化剂,与二乙醇胺合成烷醇酰胺.考察了催化剂用量,脂肪酸甲酯与二乙醇胺摩尔比、反应温度、反应时间、真空度等因素对反应的影响,通过单因素试验和析因试验确定出最佳工艺条件为:n(脂肪酸甲酯):n(二乙醇胺)=1:1.55,反应温度110℃,反应时间2.5 h,真空度0.08 MPa,催化剂用量0.65%(基于脂肪酸甲酯的质量).最佳条件下,烷醇酰胺的收率达96.3%.通过红外光谱仪对产物进行了结构表征,并对其界面张力进行了测定.结果表明,合成了目标产物,产物具有较好的界面活性.     

植物甾醇酯和植物甾烷醇酯制取及应用

植物甾醇和植物甾烷醇在化学催化剂或生物催化剂作用下与脂肪酸酯化或与脂肪酸甲酯或三甘油酯酯交换可形成植物甾醇酯和植物甾烷醇酯。该文介绍国外近年来植物甾醇酯和植物甾烷醇酯各种制备方法及其应用。     

Contamination of some foodstuffs marketed in Italy by fatty acid esters of monochloropropanediols and glycidol

ABSTRACT

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-MCPD and glycidol (Gly) are food-processing contaminants that cause concerns about possible adverse health effects. The present study evaluates the contamination levels of the three ester classes in 130 samples of foodstuffs marketed in Italy covering 10 food categories, namely margarines, oils, roasted coffee, breakfast cereals, salted crackers, cookies, infant biscuits, rusks, breads and potato crisps. The analytical method employed is a so-called indirect method that entails MCPD/glycidol cleavage from their esterified forms, cleanup, derivatisation and GC-MS analysis. The MCPDs and glycidol concentrations (from esters) were found to be equal or a little higher than the levels reported in previous studies conducted in other European countries and described in the literature. 3-MCPD was the predominant compound in all foodstuffs analysed with the exception for rusks where Gly levels were slightly higher. Considering the sum of MCPD and Gly esters, the most contaminated foodstuffs were seed oils, followed by margarines and cookies, whereas roasted coffee, bread, rusks, cornflakes and infant biscuits were less contaminated with MCPDs and Gly concentrations often below LOQ or LOD values. Refined olive oil, potato chips and salted crackers showed contamination levels intermediate between the two above groups. The results of this study also confirm that the use of palm oil as an ingredient or frying medium is an important cause of increase of the levels of MCPD and Gly esters, especially in salted crackers, rusks and potato crisps. Finally, the Italian intake of 3-MCPD due to the various foods analysed has been calculated and related to TDI. The MoE for Gly was also estimated.     

Preparation of Alkyl Esters of Pectin and Pectic Acid

Alkyl esters of pectin and pectic acid have been prepared via three different synthetic routes. Enhancements of intrinsic viscosity, binding to bile acids and to isolated soy protein were shown for these novel pectin derivatives. The development of new and improved pectin-containing products may be enhanced by the ease of preparation and improved functionality of such compounds.     

玉米油脱臭条件对3-氯丙醇酯和缩水甘油酯影响的研究

以玉米油为原料,研究水蒸气蒸馏脱臭过程以及脱臭条件对玉米油中3-氯丙醇酯和缩水甘油酯生成的影响。结果表明:脱臭过程造成3-氯丙醇酯和缩水甘油酯含量的大幅升高,脱臭温度越高、脱臭时间越长,3-氯丙醇酯和缩水甘油酯的增加量越大,其中脱臭温度比脱臭时间对二者生成的影响更大;在脱臭温度不超过230℃时,60~120 min的脱臭时间,3-氯丙醇酯含量仅增加了0.047~2.581 mg/kg,缩水甘油酯含量仅增加了0.300~3.883 mg/kg,当脱臭温度达到250℃时,即使脱臭时间仅为60 min,3-氯丙醇酯和缩水甘油酯含量均显著升高了5.039 mg/kg和8.354mg/kg,尤其在270℃、120 min的极限脱臭条件下,3-氯丙醇酯和缩水甘油酯含量更是分别上升至13.004 mg/kg和34.864 mg/kg,达到待脱臭玉米油中其含量的4倍和15倍左右。为防范和控制玉米油脱臭过程3-氯丙醇酯和缩水甘油酯的生成,降低脱臭温度是非常必要的。     

酶催化法合成食品乳化剂的研究进展

食品乳化剂是现代食品工业不可或缺的添加剂。与化学合成法相比,酶催化法合成食品乳化剂具有很多优势,如催化效率高、反应条件温和、产品纯度高、色泽浅且容易分离纯化等。本文介绍了脂肪酸单甘酯、脂肪酸糖酯、丙二醇脂肪酸酯以及失水山梨醇脂肪酸酯四类常用食品乳化剂的酶催化法合成研究进展,对酶催化合成方法、反应媒介的选择及存在的主要问题等方面进行了综述。     

上海市市售婴幼儿配方乳粉中氯丙醇酯和缩水甘油酯的监测及膳食暴露评估

目的 了解上海市市售婴幼儿配方乳粉中氯丙醇酯（MCPDE）和缩水甘油酯（GE）的污染水平，评估婴幼儿膳食暴露风险。方法 利用2020年上海市市售90件婴幼儿配方乳粉中MCPDE和GE的风险监测数据，结合婴幼儿膳食消费量数据，采用点评估法对婴幼儿经婴幼儿配方乳粉的3-MCPDE、2-MCPDE和GE进行膳食暴露评估。结果 上海市市售婴幼儿配方乳粉中3-MCPDE、2-MCPDE和GE的检出率分别为100%、100%和12.2%，含量平均值分别为0.084、0.021和0.005 mg/kg，最大值分别为0.231、0.034和0.031 mg/kg。上海市0~6月龄婴儿每日经婴幼儿配方乳粉摄入3-MCPDE的平均暴露量和P₉₅暴露量分别为1.262和2.166 μg/kg·BW，分别占3-MCPDE每日耐受摄入量（TDI，2 μg/kg·BW）的63.1%和108.3%。6~12、12~36月龄婴幼儿每日经婴幼儿配方乳粉摄入3-MCPDE的平均暴露量和P₉₅暴露量均低于TDI值。不同月龄组婴幼儿每日经婴幼儿配方乳粉摄入2-MCPDE的平均暴露量为0.118~0.319 μg/kg·BW。不同月龄组婴幼儿每日经婴幼儿配方乳粉摄入GE的平均暴露边界比（MOE）和P₉₅ MOE均大于10 000。结论 上海市0~36月龄婴幼儿每日经婴幼儿配方乳粉摄入3-MCPDE和GE的健康风险总体上处于可接受水平。但对于高食物消费量的0～6月龄婴儿，其通过婴幼儿配方乳粉暴露3-MCPDE的健康风险需引起关注。     

尼泊金酯生产技术回顾和展望

本回顾了尼泊金醇类食品防腐剂的生产历史，讨论了尼泊金醇类食品防腐剂的抗菌机理和复配增效效果，同时展望了尼泊金醇类食品防腐剂的开发应用前景和研究趋势。     

Gradient density isolation and fractionation of haze-causing solids of canola oil

An occasional problem in retail canola (Brassica sp) oil is a precipitate or haze. By combining centrifugation at 2°C and an aqueous-methanol flotation medium of an appropriate density the bulk of the triacylglyceride oil could be cleanly removed from the haze solids. The residue of solids could then be divided, also at 2°C, into a hexane-insoluble fraction (HIP) of C₄₂-C₆₃ normal and branched-chain wax esters, and a hexane-soluble fraction (HSP) including steryl esters and sometimes shorter chain (C₄₂-C₆₃) wax esters. However, the HSP was primarily composed of triacylglycerides with an unremarkable fatty acid composition similar to that of the original oil. The application of infrared and nuclear magnetic resonance spectroscopy. of gas chromatography, and of Chromarod-latroscan thin-layer chromatography with flame-ionisation detection to the HIP and HSP identifications is described. Phospholipids were found only in crude oils and do not appear to contribute to the haze in refined retail oils.     

The comparison of several lipid extraction methods on infant formula for 3-monochloropropanediol esters and glycidyl esters analysis

This study aimed to determine the best lipid extraction method for infant formula; therefore, it can be used as a routine analysis. The samples were some commercial infant formulas in Indonesia. The research was conducted with three steps: (i) Lipid extraction of infant formula using five lipid extraction methods; (ii) 3-monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) analysis of lipid extract from three lipid extraction methods in the first step; and (iii) 3-MCPDE and GE analysis of six commercial infant formulas using the best lipid extraction method. The results showed that lipid extraction using the Dubois method gave the best results than other lipid extraction methods. The level of 3-MCPDE and GE also had no significant difference with the addition of NaCl in the Folch method, compared with the addition of Na₂SO₄. The level of 3-MCPDE and GE using the Dubois method was significantly different and higher compared with the other lipid extraction methods. 3-MCPDE and GE levels of commercial infant formula were 6.62–52.84 µg kg⁻¹ and <1.43–17.06 µg kg⁻¹, respectively. The values obtained were still within the standard according to Commission Regulation EU 2018/290 by the European Food Safety Authority (125 µg kg⁻¹ for 3-MCPDE (on progress) and 50 µg kg⁻¹ for GE).