咖啡牛奶果冻工艺研究

通过单因素试验和正交试验,研究了以咖啡、牛奶为主要原料,以果冻粉、白砂糖、柠檬酸为辅料的果冻的加工工艺,得到的咖啡牛奶果冻的最佳配方为：白砂糖8.0%、果冻粉0.8%、咖啡粉0.2%、柠檬酸0.1%。产品呈奶咖啡色,酸甜可口,不含防腐剂,不添加色素,是值得信赖的健康食品。     

复配胶糯米牛奶果冻的研制

以糯米和牛奶为主要原料,辅以3种胶凝剂卡拉胶-CMC-琼脂,白砂糖和柠檬酸研制出一种新型复配胶糯米牛奶果冻。探讨糯米牛奶果冻的加工工艺,运用单因素和正交试验确定产品的最佳配方为:糯米汁的添加量为12.5%,牛奶的添加量为10%,卡拉胶-CMC-琼脂的质量比为3∶1∶1、总添加量为1.5%,白砂糖和柠檬酸的质量比为50∶1、添加量为12%,产品糯米清香、色泽均匀、口感细腻。     

酸化枸杞红枣胡萝卜乳饮料的研制

用柠檬酸，乳酸良用酸降低枸杞红枣胡萝卜乳饮料的ｐＨ值对３．５；并通过正交试验设计筛选出最佳稳定剂种类，用量，以及不添加合成色素的最佳配方和工艺。     

牛奶中微量铁的动力学测定方法研究

pH=2.5-3.5的含柠檬酸等有机酸的Fe^3 -phen溶液，在一定波长的光的照射下，能够宣 的生成Fe^2 -phen。据此，提出并建立了一种光致催化动力学测定牛奶中微量铁的新方法。实验研究结果表明，该方法具有选择性好及灵敏度高等特点，其测定线性范围为0．1mg/L－0．8mg/L，回收纺高达98％以上。     

牛奶中微量铁的动力学测定方法研究

在PH－2．5－3．5的含柠檬酸等有机配体的Fe^3 -Phen溶液，在一定长光的照射下，能够定量的生长Fe^2 -Phen。据此笔者提出了一种光致催化动力学测定牛奶中微量铁的新方法。实验研究结果表明，该方法具有选择性好灵敏度高等特点，其测定线怀范围为0．1－0．8μg/mL，回收率高达98％以上。     

盐对勾兑牛奶酒体系稳定性的影响

试验了不同浓度的柠檬酸三钠对于勾兑牛奶酒体系的影响,结果表明随着柠檬酸三钠浓度的增大,勾兑牛奶酒体系的pH值和粘度也随之增大,当柠檬酸三钠的浓度由0.002mol/L增大到0.02mol/L,酒精质量分数大于20%时,其体系的pH值表现出了几乎相同的增加值;而对所有体系来讲,随着酒精质量分数的增大,粘度的增加值却越来越小.试验结果还发现,加入0.008mol/L柠檬酸三钠能够使得牛奶蛋白在乙醇存在下达到最好的稳定效果.     

红枣牛奶复合饮料的研制

以红枣、牛奶为主要原料研制成红枣牛奶复合饮料。通过单因素实验和正交试验可以得出红枣牛奶复合饮料的最佳配方为牛奶加入量为50%,红枣浆加入量为17%,白砂糖添加量为4.0%,柠檬酸的加量为0.2%。用该配方制成的复合饮料酸甜适口,具有浓郁的红枣香气和牛奶的奶香味,是集营养和保健于一体的饮品。     

试论柠檬酸三钠的生产

以含淀粉物质或糖类物质为主要原料，经黑曲霉菌种发酵得含柠檬酸的发酵醪以后，可分别提取制备柠檬酸和柠檬酸三钠产品。本文主要论述柠檬酸的黑曲霉菌种发酵和柠檬酸三钠的生产工艺技术，针对不同要求的柠檬酸三钠产品，设计了不同的工艺路线，有利于取得最佳的经济效益。     

决明子乳饮料的工艺研究

以新鲜牛乳为主要原料,添加决明子浸提液,研制一种具有咖啡风味的决明子乳饮料.实验结果表明,最优配方为:决明子浸提浓缩液15%,标准化牛奶75%,稳定剂0.2%,蔗糖7%,柠檬酸0.3%;稳定剂配比为CMC-Na:卡拉胶:海藻酸钠=2:1:1.最佳工艺参数为:45℃温度下搅拌3min预热;80℃温度下杀菌15min.     

木瓜牛奶多肽饮料的研制

以牛奶和木瓜为原料,利用木瓜自身所含的蛋白酶水解牛奶中的蛋白质。研究木瓜牛奶比例、温度、pH值、时间等因素对水解后溶液中多肽质量浓度的影响,以及配方对其风味的影响。通过水解工艺实验得到最佳水解条件为木瓜与牛奶的比例为50%,水解温度为65℃,水解pH值为6,水解时间为7 h。通过调配实验得到木瓜牛奶多肽饮料的最佳配方为木瓜、奶粉、β-环糊精、柠檬酸、蔗糖添加量分别为13.33%,4.44%,1.25%,0.20%,15%。     

Studies on the granular structure of resistant starches (type 4) from normal,high amylose and waxy corn starch citrates

Granular and crystalline structure of starch citrates from normal, high amylose and waxy corn starch were characterized using scanning electron microscopy (SEM), optical microscopy, X-ray diffraction and Fourier transform infrared spectroscopy (FT-IR) in this study. SEM showed that citric acid treatment induced changes in the morphology of starch granules. The granule structure of starch citrates was not collapsed or destroyed even after heating. Normal and high amylose corn starch citrates maintained birefringence but lost it upon heating at 100 °C for 30 min. However, waxy corn starch citrate showed no birefringence, even before heating. Starch citrates showed different X-ray diffraction patterns before and after heating. A new peak at 1724 cm⁻¹ (ester bond) was observed in FT-IR for all starch citrates before and after heating, indicating starch citrates were heat-stable. After the deconvolution of spectra, the intensity ratio of 1016 cm⁻¹/1045 cm⁻¹ was used to calculate the ratio of amorphous to crystalline phase in the starch citrates. The ratio of 1016 cm⁻¹/1045 cm⁻¹ increased with an increase in the degree of substitution.     

Production of Low Substituted Cassava Starch Acetates and Citrates

Starch acetates and citrates were prepared by treating starch with sodium hydroxide at room temperature with and without 1% concentrated sulphuric acid (per dry weight of starch) as catalyst. Starch acetates were obtained by varying the reaction time (2h, 4h, 6h and 8h) while starch citrates were obtained using citric acid monohydrate conentrations of 5, 10, 15 and 20% (per dry weight of starch). The yields of acetylated starches were greater than those of the starch citrates. Use of catalyst significantly increased the rate and extent of acetylation. Also there were progressive increases in the acetyl values of the catalysed reaction with time. Citrate substitution in catalysed and uncatalysed reactions were not significantly different at citric acid concentrations higher than 10%.     

Physicochemical and Functional Properties of Low DS Cassava Starch Acetates and Citrates

Physicochemical and functional properties of low degree of substitution (DS) cassava starch citrates and acetates were compared with properties of native cassava starch. Substituted starches have lower ash content and pH, but the solubility in water at room temperature was not significantly different from that of the native starch. Swelling power of the substituted starches was dependent on the extent of substitution. Apparent viscosities were generally lower in starch acetates and citrates than the native starch. The substituted starches had better cooking properties in terms of lower setback viscosity, reduced gelatinization time and better stability at low pHs. Substituted starches also have better colour, improved freeze-thaw stability and better storage characteristics at room temperature compared to native starch.     

Effect of citric acid esterification conditions on the properties of the obtained resistant starch

This study was aimed at comparing selected properties of starch citrate obtained from native or retrogrades of potato starch at various temperatures (100, 130 or 160 °C) and at various doses of reactant (10, 20 or 40 g per 100 g). Higher susceptibility to esterification was demonstrated for retrograded starch, whereas the degree of esterification of the produced esters varied considerably (1.4 to 10.0 g per 100 g preparation) and was increasing along with increasing roasting temperature and dose of citric acid. The process of pasting occurred only in the esters obtained at a temperature of 100  °C, which resulted in a significant decrease in swelling power and solubility in water of the citrates produced at higher temperatures. The resultant starch citrates were characterised by significant resistance to amylolysis (ranging from 22 to 100 g per 100 g). There was observed an increase in starch resistance along with the increase in the acid dose and roasting temperature. All analysed properties of starch citrates were not correlated with the degree of esterification, but appeared to depend on the roasting, which may point to a significant effect of this factor on the mechanism of starch cross‐linking with citric acid.     

有机相脂肪酶催化合成柠檬酸甘油酯

以脂肪酶为催化剂,在有机介质中合成柠檬酸甘油酯。对催化合成反应的脂肪酶和反应介质进行了筛选,最佳溶剂为叔丁醇,固定化于大孔丙烯酸树脂的Candida antarctica脂肪酶B(Novozym 435)的催化活性最好。同时对底物浓度、底物摩尔比、脂肪酶用量、吸水剂用量、反应温度和反应时间等条件进行了优化,确定最佳工艺参数为:酸浓度0.12mol/L,单甘酯和柠檬酸摩尔比2∶1,脂肪酶用量为质量分数8%,吸水剂用量0.12g/mL,50℃反应48h,柠檬酸转化率可达70.97%。经电喷雾质谱和红外光谱分析,反应产物主要是α-柠檬酸单硬脂酸甘油酯。     

白鲢鱼糜-大豆蛋白复合物性能改良的研究

本实验就结冷胶对白鲢鱼糜-大豆蛋白复合物的凝胶性能做了一些探讨,并初步确定了改良剂结冷胶、钙离子及柠檬酸钠的添加量。结果表明:在鱼糜-大豆蛋白复合物中加入结冷胶有助于增强其凝胶性能,其凝胶强度显著增强,失水率下降,折叠性能提高。钙离子、柠檬酸钠含量对结冷胶的功效有很大的影响。本研究确定在鱼糜-大豆蛋白-红薯淀粉比例等于85g:5g:10g时,结冷胶的含量为0.2g、CaCl2含量为0.5579g、柠檬酸钠含量0.60g时,其凝胶性能最好。     

Alkali Metal Salts of Hydroxy Acids as Catalysts in Durable Press Finishing with Butanetetracarboxylic Acid

Alkali metal salts of hydroxy acids have been investigated as catalysts for esterification cross-linking of cotton with 1,2,3,4-butanetetracarboxylic add to produce cotton fabrics with smooth drying properties. Of the sodium salts of several acids studied, the sodium citrates produce fabrics with the best appearance properties. The sodium citrates serve both as donors of citric acid for cross-linking and of sodium ions for catalysis of the esterification of cotton cellulose by the two polycarboxylic acids. Although the use of citric acid as an extender for the more expensive butanetracarboxylic acid has been reported in non-formaldehyde finishing of cotton fabrics for smooth drying properties the catalyst used was sodium hypophosphite. Comparisons are made between fabrics finished with the phosphorus-containing system and the butanetetracarboxylic acid/sodium citrate systems. Textile properties, fabric whiteness, effect of pad bath pH, and extent of esterification are discussed.     

Effects of microwave-discharged cold plasma on synthesis and characteristics of citrate derivatives of corn starch granules

The objectives of this study were to identify the potential function of microwave-discharged cold plasma (MCP) treatment in preparing starch citrate (SC) non-thermally and to investigate the physicochemical properties of MCP-induced starch citrates. SCs were prepared by either dry heating in a convection oven (as a reaction control; COV) or MCP treatment using N₂ (N₂-MCP) and N₂–O₂ (N₂/O₂-MCP). Fourier transform-infrared spectra of the MCP-induced SCs revealed new peaks indicating ester bonds. The molar degree of substation was 0.013–0.015 depending on the reaction conditions. The plasma-formed dents were observed more on the surfaces of granular starch citrates (GSCs) treated with N₂/O₂-MCP than N₂-MCP. Relative to COV, MCP-induced GSCs possessed lower resistant starch content, solubility, and gelatinization temperatures and higher swelling power. The pasting viscosities were higher with N₂-MCP GSCs and lower with N₂/O₂-MCP GSCs. The results suggest that MCP can be used as a novel catalyst for non-thermal starch citration.     

茶多酚对鱼糜保藏效果的研究

为解决鱼糜易氧化腐败的难题,将天然抗氧化剂茶多酚、茶多酚＋Vc、茶多酚＋Vc＋柠檬酸添加到鱼糜中,通过对冷藏鱼糜的水分含量、凝胶强度、酸价、过氧化值、挥发性盐基氮等因素变化的研究,探讨茶多酚对鱼糜的保鲜效果。结果表明：茶多酚对冷藏鱼糜具有保鲜效果,Vc有一定增效作用．而柠檬酸增效作用不明显。     

Buffering curves of ideal whey fractions obtained from a cascade membrane separation process

Skimmed milk was fractionated via a cascade system: Graphic plotting of microfiltration (MF); ultrafiltration (UF); nanofiltration (NF); and reverse osmosis (RO). The buffering curves of each fraction were studied over the pH range 4–7. Depending on their composition, the individual permeate streams showed different buffering capacity values and pH ranges where the buffering occurred. The concentration of active buffering substances in the permeates decreased (in mmol/L) from ~26.6 (MF) to ~17.4 (UF) to 1.39 (NF) to 0.07 (RO). Contributions to the total buffering capacity for MF permeate, which represents the serum phase of milk, were ~37% from whey proteins and ~63% from milk salts (especially citrates, phosphates and carbonates) including lactose and water.