Carrez试剂沉淀-气相色谱法测定复杂基质食品月饼中的甜蜜素

建立了应用Carrez试剂沉淀、亚硝酸酯化和气相色谱、氢火焰离子化检测器测定复杂基质食品月饼中甜蜜素的方法.考察了不同提取方式(高速匀浆、超声和研磨)的提取效率和Carrez试剂用量对甜蜜素测定的影响.试样经高速匀浆提取、Carrez试剂沉淀分离杂质后,在硫酸介质中经亚硝酸酯化,衍生物经气相色谱分离、氢火焰离子化检测器测定.方法的检出限为2mg/kg(S/N=3).在添标水平为0.25、0.50和1.0 mg/g时的平均添加回收率为85.12%～99.38%,相对标准偏差6.44%～8.31%.衍生物的峰面积与样品浓度在0.125～1.0g/L范围内呈良好的线性关系,相关系数为0.9992.该方法仪器设备简单,测定结果准确、可靠,适合复杂基质食品中甜蜜素的测定.     

云南剑川县山羊乳饼化学组成与微生物学分析

对云南剑川不同地区13个家庭的山羊乳饼化学成分和微生物学组成进行分析。分析指标包括脂肪、游离脂肪酸、总蛋白质、水溶性氮、非蛋白氮、游离氨基氮、干物质、灰分、总钙、游离钙、总磷、游离磷、pH值和乳酸度；微生物组成包括乳酸菌数和酵母菌数。结果表明，山羊乳饼中含有较高的蛋白质、脂肪、钙和磷；同时乳酸菌数高于酵母菌数。     

油基泥饼解除液体系研制及性能评价

针对东海油田钻井过程中油基钻井液在井壁和筛管上形成的泥饼难以清除等复杂问题,室内经过有机溶剂、有机酸、增溶剂等处理剂优化筛选,研制出一套油基泥饼解除液体系,其配方为:55%5#白油+45%增溶剂HZRJ+5.5%有机酸HTS+5%有机溶剂RJ;通过API滤失实验、配伍性实验、渗透率恢复值实验对体系进行了性能评价,结果表明该体系具有良好的泥饼解除效果和较强的储层保护能力,且与钻井液及储层岩石、原油具有较好的配伍性。     

Kinetics and Thermodynamics of Oil Extraction from Olive Cake

The kinetics of oil extraction from olive cake by using ethanol 96% was studied for different solvent-to-solids ratios and temperatures. The thermodynamic aspect of the extraction process was also examined. In the kinetic study, the results produced by the model of So and Macdonald (a model involving two main mechanisms of oil extraction: a washing process and a diffusion process with two stages) were found to be in good agreement with the experimental data. The yield of oil in the extract increased with increasing contact time, solvent-to-solids ratio and extraction temperature. The calculated values of the mass transfer coefficients of various stages of the extraction were found to increase linearly with solvent-to-solids ratio and temperature. In all cases, the predominant mechanism in the extraction was the washing of the oil occurring on the particle surface. The values of the activation energy were 8.56 kJ mol⁻¹ for the washing stage, 9.88 kJ mol⁻¹ for the first stage of diffusion and 17.55 kJ mol⁻¹ for the second stage of diffusion by changing temperature from 20 to 50 °C. Further, the results obtained from thermodynamic study of extraction process gave positive values of enthalpy and entropy changes and negative values of change in free energy. Under the equilibrium conditions, the temperature coefficient was found to be 1.02.     

水浸法提取油茶饼中茶皂素的水解抑制实验研究

研究了水浸法提取茶皂素的浸提工艺。利用除酶剂苯甲酸钠抑制茶皂素水解,对浸提过程中茶皂素的水解问题进行了初步探讨。采用正交试验法,考察了除酶剂加入量、浸提pH、浸提温度、浸提时间、粒度、料液比、搅拌次数7个因素对茶皂素提取率的影响。结果表明较优浸提条件为:除酶剂加入量0.5%,浸提pH 9,浸提温度60℃,浸提时间3 h,粒度40目,料液比1∶10,搅拌次数5次。在此条件下,茶皂素提取率为9.18%。     

冷冻调理马铃薯饼加工技术的探讨

对马铃薯的预糊化实验结果揭示,在各种加热方法中,马铃薯经蒸煮25min后的糊化效果最好.正交试验结果表明,奶粉含量和黄油含量对冷冻调理马铃薯饼的感官指标有高度显著的影响.对冷冻调理马铃薯饼的油脂的测试结果显示,未经油炸的马铃薯饼的脂肪含量为4.24%,而经过油炸后的马铃薯饼的脂肪含量为11.18%.经过一个月的冻藏后,未经油炸的冷冻调理马铃薯饼的油脂的过氧化值为1.94%,而经过油炸的冷冻调理马铃薯饼的油脂的过氧化值为7.79%.     

大豆低聚糖的制备工艺研究

研究从脱脂豆粕中提取大豆低聚糖的制备工艺。经多次实验,确定了浸提、活性炭脱色和离子交换脱盐等过程的优化工艺参数,并对成品糖浆的成分进行了测定。     

低糖菊粉甜品的研制

绿豆糕是流行于全国各地的传统甜品,试验改进传统绿豆糕的制作工艺,以菊粉部分替代绿豆糕中蔗糖和黄油,筛选出低糖营养和风味俱佳的绿豆糕配方。与传统绿豆糕相比,该产品强化菊粉,具有低糖低能量的特点,迎合消费者对天然健康的追求,同时拓展菊粉在食品工业中的应用领域。     

Staling of cereal bran enriched cakes and the effect of an endoxylanase enzyme on the physicochemical and sensorial characteristics

Abstract: The staling of cakes enriched with untreated brans and endoxylanase‐treated brans was evaluated by monitoring the changes in physicochemical, thermal, and sensorial properties of cakes during 7‐d storage. Oat and rice bran were treated with different levels (0, 70, and 700 ppm) of an endoxylanase enzyme and added to cakes on 30% flour weight basis. Moisture losses, water activity, crumb firmness, starch retrogradation, and sensorial characteristics were used as staling indicators. Avrami‐type equations were efficiently used for modeling the starch retrogradation kinetics, while linear models most adequately described crumb firming kinetics. Cake staling induced an increase in crumb firmness and enthalpy of amylopectin retrogradation, and a decrease in crumb moisture and sensory quality and acceptability scores of cakes. Oat bran‐containing cakes better maintained their characteristics compared to the ones containing rice bran along the 7‐d storage. Endoxylanase treatment of brans delayed the changes naturally induced during staling in crumb moisture content, amylopectin retrogradation enthalpy, and crumb firmness in the respective cakes. Deterioration of the sensorial characteristics was slower for the cakes containing endoxylanase‐treated brans, as well. The level of endoxylanase treatment did not differentiate significantly (P < 0.05) any of the staling indicators. Overall, this study demonstrated that addition of endoxylanase‐treated brans can result in cakes with improved nutritional characteristics and increased shelf life. Practical Application: The results of the study show the potential of using enzymes to modify underutilized food sources that can be properly incorporated in baked goods, improving their nutritional value, their quality characteristics, and providing longer shelf life. The developed procedure and results can be utilized by the bakery industry to make high fiber and low cost bakery products with improved sensorial characteristics that are appealing to the consumers.     

利用豆粕制作保健食品

经过脱脂的大豆粕含有丰富的营养成分及微量活性物质。具有综合利用及开发各种保健品基料的可能性。主要微量活性物有大豆皂甙、大豆低聚糖、大豆异黄酮等,是开发抗衰老、降血脂及预防糖尿病功能食品的最好的原料。也是防治高血脂症、肥胖症、心血管疾病药物有希望开发的药物因子。