不同影响因素对三元食品胶溶液粘度的影响

利用德国HAAKE公司生产RS75应力控制流变仪,考察了改变pH、添加蔗糖、氯化钠和柠檬酸钠、进行冻融处理、添加大豆多肽等因素,对三元混合胶(卡拉胶∶魔芋胶∶刺槐豆胶为2∶2∶1)溶液粘度的影响。结果表明,在强酸、强碱条件下,溶液粘度均有所下降,但是碱性条件下胶体溶液的粘度相对稳定;在一定范围内蔗糖、氯化钠和柠檬酸钠均能降低胶体溶液的粘度,而两种钠盐降低胶液粘度的幅度较大;无论是冷冻处理还是冷藏处理都可降低胶体溶液的粘度;大豆多肽的加入也会在一定程度上降低混合胶溶液的粘度,改变加料方式可以减小这种影响。      

盐及非盐物质对常用低浓度食品胶溶液粘度影响的研究

对饮料生产中常用的食品胶－黄原胶、海藻酸钠、瓜尔胶和琼脂在低浓度水相体系中外加盐（阴、阳离子）、乙醇、蔗糖及柠檬酸对溶液粘度的影响作了探讨性研究,结果表明四种胶溶液（０．１０％黄原胶、０．３０％海藻酸钠、０．２５％瓜尔胶、０．１０％琼脂）中、瓜尔胶溶液对盐的耐受性最好,即大多数阴阳离子都不会对其粘度产生影响,而常用金属盐阳离子及Ｃｌ＾－、ＳＯ３＾２－对黄原胶溶液粘度的影响与阴阳离子对海藻酸钠和琼脂     

凉粉草胶溶液粘度的研究

从温度、PH值、剪切速度、盐、糖和质量浓度这几个方面对凉粉草胶溶液的粘度进行探讨。结果表明,凉粉草胶溶液呈现出牛顿流体或假塑性流体行为,在其他条件一定时,凉粉草胶的粘度总是随着剪切速度的增大而降低。在剪切速度为40 r/min时,凉粉草胶的粘度随着温度的升高而降低,溶液粘度随着氯化钠添加量的增加而降低,随着糖添加量的增加而增大,随着凉粉草胶质量浓度的增大而变大。     

三元混合胶复配体系胶冻性能及其溶液粘度的研究

通过正交试验,考察了卡拉胶、魔芋胶和刺槐豆胶的三元复配胶的持水性、粘度和凝胶强度,并以此为评价标准,确定三元复配胶较优的质量配比为:m(卡拉胶)∶m(魔芋胶)∶m(刺槐豆胶)=2∶2∶1;在此基础上,考察了不同浓度的混合胶体溶液的流体类型,以及浓度和温度的变化对混合胶体溶液粘度的影响。结果表明:在45℃下,浓度为2g/L的胶体溶液是牛顿流体,其余的浓度的胶体溶液均为假塑性流体,且随着浓度的增大,非牛顿指数(n)降低;体系的粘度与浓度呈二项式的关系;温度和粘度的关系可用Arrhenius方程拟合。     

盐及非盐物质对低浓度魔芋胶溶液粘度影响的研究

研究了盐（阴、阳离子）及非盐乙醇、蔗糖及柠檬酸对低浓度（0.25%）魔芋胶溶液粘度的影响。结果表明,大多数阴、阳离子对其粘度影响不大,低浓度NaCl、KCl、Na2SO4和Na2HPO4使溶液粘度略有增高,低浓度FeCl3、AlCl3和Na2CO3使溶液粘度略微降低;乙醇能使溶液粘度增高;蔗糖和低浓度（小于7.50mg/L）柠檬酸能使溶液粘度略微增高。     

常用食品胶粘度和悬浮力关系的研究

以琼胶、黄原胶、卡拉胶、海藻酸钠、ＣＭＣ－Ｎａ５种常用食品胶为研究对象，系统地探讨了食品胶溶液的粘度和悬浮力受食品胶浓度、环境温度、ｐＨ值、电解质加入的影响情况，对食品胶粘度和悬浮力的关系等进行了深入的研究和分析，为食品工业更好地选用合适的食品胶提供理论和方法的指导。     

醇洗豆粕对大豆分离蛋白溶液粘度影响

该文主要探讨醇洗豆粕对大豆分离蛋白粘度影响。以醇洗豆粕为原料制备大豆分离蛋白, 溶解度增加,溶液粘度下降。通过正交试验优化,制备低粘度型大豆分离蛋白最佳工艺条件为:乙 醇浓度95％(v／v)、浸提温度30℃、浸提时间45分钟、固液比1:4,所得产品蛋白含量(干基)为 93.21％,蛋白质分散指数为96.27％,而3％、8％和12％大豆分离蛋白溶液粘度分别为2.7、8.1和 82.3 mPas。     

用黄原胶调节酱油粘度的初步研究

介绍用黄原胶调节酱油粘度随温度,时间,黄原胶加入量以及增大盐量等的变化规律,结果表明,当温度升高时酱油粘度先降低后趋于稳定,随黄原胶加入量的增加而增加等,从而通过对操作条件控制及添加方法的选择调节酱油的粘度,来保证酱,油粘度的相对稳定。     

银耳溶液在不同影响因素下的粘度特性

对pH值为5.2、粘度为51.5mPa·s的银耳溶液在不同影响因素下的粘度特性进行了研究。结果表明,增大浓度、搅拌作用、添加蔗糖,溶液的粘度升高;升高温度、热力作用、添加酸、碱、氯化钠,溶液的粘度下降。     

复合黄原胶的粘度及其悬浮能力初探

介绍黄原胶的基本特性，测定了５种复合黄原胶粘度及变化规律。还进行了使磷脂球保持稳定悬浮状态的饮料悬浮能力实验，初步找出悬浮能力好的浓度配比，可供悬浮饮料生产厂家和研究者参考。     

金属离子及pH对谷氨酰胺发酵的影响

试验了金属离子及pH对谷氨酰胺发酵的影响。结果表明,在下述条件下谷氨酰胺产量最高:Zn2+为1.0mg,Fe2+为1.0mg,Mn2+为2.0mg（每100g培养基）;初始pH为7.0。      

活性炭pH对甜菊糖精制液甙含量的影响

研究了不同pH的活性炭对甜菊糖精制液甙含量的影响,结果表明:当活性炭pH<4.3时,甜菊糖精制液含甙量随活性炭pH的下降而下降;活性炭的较适pH在6～8之间.     

pH值和金属离子对大豆分离蛋白凝胶形成的影响

在90℃,研究了大豆分离蛋白浓度、pH值、金属离子、加热时间等因素对大豆分离蛋白凝胶形成的作用。结果显示,酸性条件下大豆分离蛋白形成凝胶的最适pH值为3.0,碱性条件下形成凝胶的最适pH值为9.0;凝胶溶液中CaCl2浓度为0.4%的时,形成凝胶的透明性最高,时间为22min。     

馒头蒸制过程中pH值、微生物、还原糖含量的变化

探讨了馒头蒸制过程中微生物生存状态、pH值、以及还原糖含量的变化。发现酵母、乳酸菌和醋酸菌在蒸制15min内死亡 ,pH呈下降趋势 ,还原糖含量变化不大。     

Effect of pH on non-enzymatic browning reaction during γ-irradiation processing using sugar and sugar–glycine solutions

Effects of pH on the non-enzymatic browning reaction caused by γ-irradiation processing were investigated. The brown colour development of irradiated sugar–glycine solutions was greater in a buffer system than in deionized distilled water (DDW) with higher pH. Although browning of irradiated sugar solution without glycine was highly increased was in alkaline buffer, no browning was developed in DDW. The maximum browning of the solutions of sugar and sugar–glycine were observed at pH 10 and pH 8, respectively. The browning intensity was in the following order: sucrose ? fructose > glucose. Non-constant pH was observed in DDW (dropped pH between 1.58 and 2.03 units); however, the use of buffers was partially effective in keeping pH constant (pH dropped between 0.03 and 0.56 units). When the irradiated solutions of sugar with and without glycine were analyzed using reverse phase high performance liquid chromatography with diode-array detection (HPLC-DAD), three peaks were separated at 3.37 ± 0.04, 4.60 ± 0.02, and 2.53 ± 0.26 min, and the λ_max values of these peaks were the range 259–288 nm. The sum of the areas of these peaks at 260 nm increased with increasing pH. The results of this study indicated that conditions of the system, such as pH and media, can influence the non-enzymatic browning reaction during γ-irradiation.     

The effect of pH on shelf-life of pork during aging and simulated retail display

The pork industry uses pH to differentiate product of varying quality; thus, the effect of pH on shelf-life is important as time during transport is extended. The objective was to develop regression equations to predict shelf-life over a range of ultimate pH (5.42–6.26). Shelf-life was evaluated after vacuum aging pork loin sections 0, 7, 14, 21, or 28 d and during 3 d of simulated retail display (4.5 °C) for pork loin chops. Correlation coefficients indicated a strong relationship between pH and quality measurements. Regression analysis with Aging Day and pH was able to explain 87% of the variation in aerobic plate counts for pork. After 28 d of vacuum aging, loin sections from the upper end of the pH distribution had about a 3 log(1000X) greater aerobic plate count than did the lower end pH product. An increase in pH resulted in pork with lower L*, a*, b* and R₆₃₀ − R₅₈₀ values and as Aging Day increased, instrumental measurements of color increased slightly. Although higher pH is associated with improved pork quality, higher pH and longer aging periods will result in increased microbial proliferation and decreased shelf-life. Thus, an intermediate pH may provide the most desirable combination of quality and shelf-life when extensive aging is used.     

The effect of silicon on sugar cane growth in pure nutrient solution

Si, supplied as silicic acid significantly increased cane yields of two sugarcane varieties growing in pure nutrient solution and the sucrose yield of one variety. “Leaf freckling” symptoms only developed on those plants not receiving Si.     

Effect of light,pH, metal ions and antioxidants on the colour stability of norbixin in aqueous solution

Norbixin, a carotenoid extracted from the seeds of the annatto (Bixa orellana) plant, can be used in aqueous food applications, where other carotenoids are too hydrophobic to solubilise in a water environment. The aim of this work was to investigate the effect of pH, antioxidants and transition metal ions with and without hydrogen peroxide (H₂O₂) on the stability of norbixin in aqueous solutions as well as determining the interaction between these factors and light. The stability of norbixin in buffered aqueous solution stored in light or in the dark was evaluated using absorbance spectrophotometry. Light, reduced pH and metal ions both with and without H₂O₂ increased the bleaching of norbixin, whereas chelators and the natural antioxidants, ascorbic acid and tocopherol, reduced the bleaching of norbixin. Light significantly increased the loss of norbixin alone and in combination with the other factors.     

The effect of pH,salts and sugars on the rheological properties of cress seed (Lepidium sativum) gum

Effect of shear rate (15–600 s^?1), gum concentration (1–2%), pH (3–9), sucrose (10–40%), lactose (5–15%), NaCl (100–300 mm ) and CaCl₂ (5–50 mm ) was evaluated on apparent viscosity (η_a), flow behaviour index (n), consistency coefficient (K) and yield stress (τ₀) indices of cress seed gum (CSG) solutions. Different rheological models were used to fit the experimental data, although the Herschel–Bulkley model was found the best model. An increase in gum concentration led to an increase in τ₀, η_a, and k and a decrease in n values. The addition of salts lowered the k value; however, the n value showed slight significant change. The presence of sugar resulted in the enhancement of n, k, τ₀ and η_ap values. The existence of yield stress and pseudoplastic behaviour of CSG, its stability against salts, wide range of pH and synergic effect of sugar make it a good thickener and stabiliser in food formulations.     

水分、温度、时间和pH对板栗淀粉颗粒形态的影响

以安徽大红袍板栗为原料,采用光学显微镜分析其在不同水分、温度、时间和pH条件下表观形态的变化.结果表明:随着淀粉体系中水分含量的升高,板栗淀粉颗粒越易膨胀破裂,水分含量达到70%后,大部分淀粉颗粒膨胀:加热温度和加热时间都能促进板栗淀粉颗粒膨大破裂,而加热温度对颗粒形态变化的影响较加热时间大;常温下中性和酸性条件对板栗淀粉颗粒膨胀的影响不大,而强碱性条件对板栗淀粉糊化有明显的作用,当pH达到13时,淀粉颗粒明显膨胀.