卡拉胶与氯化钾用量对中性奶冻品质影响研究

研究了卡拉胶与氯化钾用量对奶冻品质的影响,以粒度分布、质构特性、微观结构与析水率等为分析检测指标。研究结果表明:当卡拉胶用量小于0.10%时,硬度低,凝胶结构差;当卡拉胶用量增至0.15%以上时,硬度适当,凝胶结构较好,但从粒度分布与显微结构判断,体系开始出现絮凝。同时,氯化钾促进凝胶,而高含量的氯化钾有诱导体系失稳絮凝的趋势,在卡拉胶用量0.20%时,影响更为显著,且此时析水率也随之增加。综合考虑,以卡拉胶0.15%用量与氯化钾0.01%用量下奶冻具有良好的质构品质。     

一种基于浓度校正的明胶胶液黏度检测方法

建立了基于浓度校正的明胶胶液黏度检测方法,为不同工序不同浓度胶液黏度的检测提供定量方法。测试条件为:HZ-10B糖量计测定胶液浓度,ND-1勃氏黏度测试仪测定胶液绝对黏度值,根据胶液黏度值和浓度相关性曲线对绝对黏度进行浓度校正得到校正后的胶液黏度值。结果表明:该方法二次曲线相关性良好,线性范围30.0~60.0 mg/m L,相关系数不小于0.99,平均回收率100.4%。该方法操作快捷且重现性良好,适用于生产条件下不同浓度水平胶液黏度值的黏度转换。     

黄原胶和韦兰胶混胶黏度的影响因素研究

本实验研究了放置温度、时间、冻融、pH、盐以及柠檬酸对黄原胶和韦兰胶混胶黏度的影响。结果表明:黄原胶和韦兰胶有协效性,温度、时间对混胶有一定的影响。其中20/80(ml)韦兰胶/黄原胶最为稳定。进一步对其研究表明:冻融、pH、盐以及柠檬酸都对其影响较小。     

卡拉胶和咕吨胶对低脂肪法兰克福香肠组织结构和可接受性的影响

对脂肪含量、卡拉胶(kappa和iota)和咕吨胶对法兰克福香肠(猪肉和牛肉)的成份、水化特性、组织特性、颜色及感官特性的影响进行了评价。脂肪含量和植物胶对香肠的蒸煮损失和pH值无影响。I-卡拉胶降低了低脂肪产品的持水性。咕吨胶在很大程度上增加了低脂肪生香肠和冻藏熟香肠的叨亮度(L)。蒸煮和冻结使香肠的红色(a)增强。I-卡拉胶和咕吨胶使香肠的硬度、弹性和咀嚼性降低。感官检验人员对所有产品都很喜欢。     

碱液浸泡温度对卡拉胶品质的影响

以印尼麒麟菜为原料,通过碱液浸泡处理和乙醇沉淀方法制取卡拉胶,研究了碱液浸泡温度对卡拉胶提取率及成品的黏度、凝胶强度、弹性、硫酸基含量、3,6-AG含量的影响。结果表明,浸泡温度升高有利于碱对卡拉胶分子的修饰及去除麒麟菜表面的蜡质皮层,降低蒸煮难度;浸泡温度升高会加剧卡拉胶分子的降解,卡拉胶提取率、成品黏度、硫酸基含量下降,但凝胶弹性、3,6-内醚半乳糖残基(3,6-AG)含量增加,而凝胶强度呈现先增加后减少的趋势,浸泡温度为60℃时,凝胶强度最高;因此可根据卡拉胶应用特性的要求选择碱液浸泡温度。     

黄原胶与魔芋胶混胶黏度的影响因素研究

黄原胶和魔芋胶都是非凝胶多糖，二者在一定条件下共混可以出现强烈的协同效应。本文研究当黄原胶和魔芋胶以5／5的配比共混，总浓度为1％，温度，柠檬酸，蔗糖和功能型甜味对混胶多糖黏度的影响。结果表明：升高温度使混胶的黏度降低；当柠檬酸的使用量大于0．2％时，混胶的黏度下降；40℃时甜味剂的加入使得混胶的黏度升高。     

影响胡麻胶黏度因素的研究

胡麻胶是一种多功能纯天然的植物胶体。黏度是胡麻胶的基本性质。研究了温度、浓度、酸度、盐类、物理因素及其他共存组分对胡麻胶黏度的影响。     

不同条件对胖大海胶表观黏度的影响

以胖大海胶研究对象,研究pH、钙离子浓度、不同阳离子、蔗糖及其他胶体对胖大海胶黏度的影响。结果表明:pH偏高或偏低、阳离子存在均使胶体溶液表观黏度下降;随着蔗糖浓度增加,溶液表观黏度逐渐增大;胖大海胶与瓜尔豆胶复合后胶体溶液黏度大于原胶体的黏度,而与黄原胶、海藻酸钠、琼脂复合则小于原胶体黏度。     

魔芋胶、卡拉胶与黄原胶复配胶的特性及在肉丸中的应用

主要研究了魔芋胶、κ-卡拉胶与黄原胶复配胶的凝胶特性及在肉丸中的应用效果。通过实验证明,影响复配胶凝胶强度的因素和最佳条件是:魔芋胶、κ-卡拉胶与黄原胶的最佳配比为1.3∶1∶0.3;复配胶的总胶浓度为0.6%,且总胶浓度越高,凝胶强度越高;钾离子在较大程度上能影响复配胶的凝胶强度,氯化钾的浓度控制在0.12%,浓度过高会影响口感,浓度过低则会影响凝胶强度;磷酸盐的浓度与凝胶强度成反比;氯化钠的浓度在0.9%最效果最佳;热处理是复配胶形成凝胶的必需条件,复配胶液保持在恒温90℃,恒温加热时间为20min。并最终通过工艺优化得出最适肉丸的加工条件,总胶浓度为0.6%、淀粉添加量为10%,肉糜擂溃时间为15min,水浴加热成型温度为50℃,时间为15min,杀菌煮制温度90℃,时间为20min。     

卡拉胶/黄原胶和K＋浓度对低脂低盐乳化肠凝胶品质影响的研究

复配胶作为脂肪替代品,K+作为Na+的补充剂,可改善低脂低盐肉糜类产品的品质.本研究将二者加入肉糜中制作低脂低盐乳化肠,研究二者对低脂低盐乳化肠凝胶品质方面的影响.结果表明,复配胶中卡拉胶比例的提高能显著改善制品的凝胶强度和硬度,黄原胶在复配胶中的比例将影响到制品的弹性;K+的添加(浓度为0.6%时)能显著改善制品的硬度和弹性,降低蒸煮损失,但对制品的颜色稍有不利.方差分析结果显示二者存在交互作用,可协同起来改善低脂低盐乳化肠的凝胶品质.     

Effects of low chloride intake on performance, clinical characteristics, and chloride, sodium, potassium, and nitrogen metabolism in dairy calves

Young male Holstein calves were fed either a control (.5% chloride) or a low-chloride (.038% chloride) practical diet for 7 wk. Both groups received low-chloride (.00038% chloride) well water. Feeding the low-chloride diet did not produce definite clinical symptoms of chloride deficiency. Neither body weight gains, feed intake, feed digestibility, nor body retention of chloride, sodium, potassium, or nitrogen were effected adversely. Although the chloride intake of the low-chloride calves was only one-sixteenth that of controls, body chloride retention was similar for the two groups. The similar retention of body chloride was due to effective homeostatic mechanisms in which urinary chloride excretion was reduced by 95% in the low-chloride calves. Low-chloride calves consumed more water and excreted more urine than control calves. Although the exact minimum chloride requirement for growth in calves was not established, .038% chloride was adequate for normal growth for the 7 wk.     

高效液相色谱法测定氯化钾口服液中羟苯乙酯的含量

目的建立高效液相色谱(high performance liquid chromatography,HPLC)测定氯化钾口服液中防腐剂羟苯乙酯含量的分析方法。方法采用Eclipse XDB-C_(18)柱(250 mm×4.6 mm,5μm),甲醇:水(80:20,V:V)为流动相,流速为1.0 mL/min,检测波长为254 nm,柱温为40℃。结果羟苯乙酯在20.16~403.20μg/mL范围内线性良好,标准曲线方程为Y=8.18×10~4X+88.2(r=0.9992),平均加样回收率为99.22%,相对标准偏差(relative standard deviation,RSD)为1.0%(n=6)。结论该方法简便,准确可靠,灵敏度高,适合用于氯化钾口服液中羟苯乙酯含量测定。     

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。     

The effect of temperature on dough viscosity,and its consequence for the control of dough temperature

In bakeries, it is important that successive batches of dough (‘doughs’) for the same product have the same temperature. Dough temperature can be controlled by adjusting the temperature of the water to be used. An automatic calculator for the required water temperature was designed on the basis of the assumption that the final dough temperature is a linear function of flour, water and bakery temperatures.This paper describes a physical model which predicts the values of the coefficients and of the constant term in this linear relationship. The decrease in dough viscosity with increasing temperature is an essential part of the model.It is argued that this effect of temperature on dough viscosity reduces the effects of flour and water temperatures on the final dough temperature. Heat transfer between the dough and the air in the bakery also reduces their effects, but is, under normal mixing conditions, less important than the effect of temperature on dough viscosity; only with small doughs and with slow and long mixing is it more important.     

Texture and colour characteristics,and optimisation of sodium chloride,potassium chloride and glycine of reduced-sodium frankfurter

The three-components mixture design was applied to optimise a ratio of NaCl (0%–65%), KCl (35%–100%) and glycine (0%–20%) in reduced-sodium frankfurters. Fourteen frankfurters were analysed for texture and colour, and consumer (n = 100) acceptability. Results indicated that NaCl levels affected consumer acceptability of reduced-sodium frankfurters. Increasing NaCl generally increased texture hardness. Optimisation of a salt mixture was performed by superimposing contour plots of predicted acceptability scores (≥5.5 on a 9-points hedonic scale) of all sensory attributes and revealed the optimal salt mixture: 40.03%–63.66% NaCl, 35.00%–55.90% KCl and 0.00%–20.00% glycine. The optimal salt mixture contained 220–340 mg Na/100g frankfurter compared with 540 mg Na/100 g of the control formulation (100% NaCl). The mean overall liking score (5.9 vs. 5.9) of the optimal reduced-sodium frankfurter was not different from the control (100% NaCl). This optimal formulation had >25% sodium reduction and could be claimed as ‘reduced-sodium’ according to US Food and Drugs Administration regulation.     

Effect of sodium,potassium, calcium and magnesium chloride salts on porcine muscle proteases

This study is focused on the effect of sodium chloride alternative salts (KCl, MgCl₂ and CaCl₂) on porcine muscle proteases (cathepsins, dipeptidylpeptidases and aminopeptidases). In general, KCl exerted a very similar effect to NaCl for all the studied enzymes, while the effect of divalent salts (CaCl₂ and MgCl₂) was more pronounced. Cathepsins, dipeptidyl peptidase III, dipeptidyl peptidase IV and alanyl aminopeptidase activities were strongly inhibited by all the chloride salts especially by divalent ones. Dipeptidyl peptidase II and leucyl aminopeptidase were little affected and methionyl aminopeptidase was only inhibited by divalent salts. Dipeptidyl peptidase I was strongly activated by low concentrations of the chloride salts except NaCl. Arginyl aminopeptidase was activated by NaCl and KCl and low amounts of MgCl₂, while CaCl₂ showed a strong inhibitory effect. This is very important as these enzymes play important roles in dry-cured meats and their activity is, in general, regulated by sodium chloride. Thus, reductions in the sodium concentration with subsequent increases of other alternative cations may have relevant consequences on enzyme activity that should be taken into account when processing dry-cured meats.     

魔芋葡甘聚糖/明胶复配胶液表观粘性研究

该文研究了胶液浓度、pH、剪切速率对魔芋葡甘聚糖及明胶溶液表观粘度影响,并将两者进行复配,研究了pH、复配胶溶液浓度、复配比例对复配胶液表观粘度影响。研究结果表明,魔芋葡甘聚糖和明胶溶液表观粘度随浓度增加而增加;随pH增高呈现出先升后降趋势。魔芋葡甘聚糖溶液表观粘度随剪切速率升高而降低,并表现出了剪切变稀假塑性。明胶溶液表观粘度随剪切速率增加而趋于稳定。复配胶液表观粘度随魔芋葡甘聚糖所占比例增加而增大,随复配胶液浓度变大而变大,随pH增加先升后降;在总胶浓度为2%、魔芋葡甘聚糖与明胶为7∶5的配比、pH=8情况下,复配胶液表现出较好流动性,且形成富有弹性和咀嚼性凝胶体。     

The effect of cooking and washing temperature during pilot-scale rennet casein manufacture on casein hydration characteristics in disodium orthophosphate solution

Variations were observed in the hydration behaviour of rennet caseins in a solution (0.4%, w/w) of disodium orthophosphate (DSP). These caseins were manufactured on a pilot scale from curds cooked at 45, 65 or 75°C and from curds washed at a hot-wash temperature of 60, 70, 78 or 86°C. The influence of cooking temperature and hot-wash temperature on various compositional characteristics, the electrophoretic resolution and particle size parameters of the milled rennet caseins were determined. Relationships between all of these parameters and hydration characteristics in DSP solution were also investigated. Cooking temperature or hot-wash temperature did not influence electrophoretic resolution, the level of Maillard reaction compounds or the particle size parameters of the caseins. Increasing the cooking temperature increased whey protein levels and decreased calcium levels in the curd, leading to slower hydration rates. This suggested that increased whey protein denaturation and its precipitation onto the rennet casein curd retarded subsequent rennet casein hydration. Hot-wash temperature influenced certain aspects of rennet casein hydration in 0.4% (w/w) DSP; however, the hydration characteristics of these caseins did not appear to be related to any of the other characteristics investigated.