HPLC-MS/MS-Detection of Caseins and Whey Proteins in Meat Products

Screening methods for the mass spectrometric detection of caseins and whey proteins in meat products have been developed. After tryptic digestion, two α-S1-casein and two β-lactoglobulin marker peptides were measured by HPLC-MS/MS. For matrix calibrations, emulsion-type sausages with different concentrations of milk and whey protein (ppm level) were produced. The limits of detection (LODs) were below 1 ppm for milk protein and about 3 ppm for whey protein. The determination coefficients for the correlation between peak area of the marker peptides and the concentrations of milk and whey proteins were R²≥0.9899.     

泰山蛹虫草多糖对免疫抑制小鼠血清蛋白含量和体内抗氧化能力的影响

目的:研究泰山蛹虫草多糖(Cordyceps taishanensis polysaccharide,CTP)对免疫抑制小鼠血清蛋白含量和抗氧化能力的影响。方法:通过对小鼠灌服多糖实验,观察CTP对小鼠血清总蛋白、白蛋白及球蛋白含量和抗氧化能力的影响。结果:与环磷酰胺(Cyclophosphamide,CY)模型组比较,三个CTP组的血清总蛋白、球蛋白和白蛋白含量均极显著增高(p<0.01);三个CTP组的红细胞SOD活性和血清CAT活性均显著提高(p<0.01或p<0.05),红细胞MDA含量均极显著减少(p<0.01)。结论:CTP能显著提高CY所致的免疫损伤小鼠的血清蛋白含量,在一定程度上CTP能减轻CY对小鼠肝脏的损害作用;CTP也能改善CY所致免疫损伤小鼠的抗氧化能力。      

Evaluation of processed green and ripe mango peel and pulp flours (Mangifera indica var. Chokanan) in terms of chemical composition,antioxidant compounds and functional properties

BACKGROUND: Mango is a highly perishable seasonal fruit and large quantities are wasted during the peak season as a result of poor postharvest handling procedures. Processing surplus mango fruits into flour to be used as a functional ingredient appears to be a good preservation method to ensure its extended consumption. RESULTS: In the present study, the chemical composition, bioactive/antioxidant compounds and functional properties of green and ripe mango (Mangifera indica var. Chokanan) peel and pulp flours were evaluated. Compared to commercial wheat flour, mango flours were significantly low in moisture and protein, but were high in crude fiber, fat and ash content. Mango flour showed a balance between soluble and insoluble dietary fiber proportions, with total dietary fiber content ranging from 3.2 to 5.94 g kg^?1. Mango flours exhibited high values for bioactive/antioxidant compounds compared to wheat flour. The water absorption capacity and oil absorption capacity of mango flours ranged from 0.36 to 0.87 g kg^?1 and from 0.18 to 0.22 g kg^?1, respectively. CONCLUSION: Results of this study showed mango peel flour to be a rich source of dietary fiber with good antioxidant and functional properties, which could be a useful ingredient for new functional food formulations. Copyright © 2011 Society of Chemical Industry     

柚皮中膳食纤维提取工艺研究

对柚皮中膳食纤维的提取工艺进行了研究，结果表明：在脱色时间60min、H2O2质量分数6％、pH7．0条件下脱色有最佳效果，加热加压时间20min、水料质量比30：1、加热加压时间30min、水料质量比40：1条件下提取，可以将膳食纤维中可溶性膳食纤维的比例提高1．2倍。     

酶法提取鹰嘴豆水不溶性膳食纤维工艺的研究

通过正交试验对酶法提取鹰嘴豆水不溶性膳食纤维的工艺进行了研究,得出最佳工艺参数为：NaOH浓度80mg／mL,浸泡时间50min,蛋白酶浓度4mg／mL,淀粉酶浓度10mg／mL。在此条件下制备的水不溶性膳食纤维的产率为22．84％。     

Significance of Inulin Fructans in the Human Diet

This paper reviews the physicochemical properties and nutritional significance of inulin fructans (oligofructose and inulin). These compounds are naturally present in a large number of food crops and serve in our diet as dietary fiber. Inulin fructans can be isolated and purified from the chicory root and used as ingredients in a large range of foods to improve structure and/or taste and to increase the intake of dietary fiber. Inulin fructans have a low caloric value, are safe, and generally well tolerated up to a level of 20 g/d. They exert a range of effects, which can be differentiated into direct effects on the gut and the intestinal flora and indirect systemic effects. Direct effects on the gut include prebiotic (bifidogenic) effects, improvement of bowel habits and bowel function in constipated subjects, increased colonic absorption of minerals (Ca and Mg), and secretion of satiety hormones. Indirect effects are on blood lipids, bone mineral content, the immune system, and energy homeostasis. These issues are discussed and it is argued that promising avenues for research are particularly in the areas of energy homeostasis and systemic low‐grade inflammation in relation to changes in the composition of the intestinal microbiota.     

松茸菌汤熬制工艺参数优化及风味成分分析

以云南产新鲜松茸菌为主要原料,研究松茸菌汤熬制的主要工艺参数。以菌汤中固形物溶出率和蛋白质溶出率为考察指标,通过单因素试验和正交试验分析和讨论,确定松茸菌汤熬制工艺参数,并对松茸菌汤中的氨基酸、呈味核苷酸和风味成分进行分析。结果表明：松茸菌汤熬制的最佳工艺为料液比1∶60（g/mL）、熬制时间90 min、熬制火力中火（1 000 W）,此时菌汤中固形物溶出率为49.68%,蛋白质溶出率为45.74%;菌汤中总氨基酸和游离氨基酸均为17 种,含量分别为109.60 mg/100 mL和41.20 mg/100 mL;呈味核苷酸5’-肌苷酸二钠和5’-鸟苷酸二钠含量分别为2.0 μg/mL和28.4 μg/mL;气相色谱-质谱联用测得菌汤中挥发性物质共28 种,其中醇类物质所占比例最大。     

绍兴腐乳发酵过程中蛋白质水解及其对成品白点影响的研究

研究了绍兴腐乳发酵过程中蛋白质水解与酪氨酸含量变化的规律,分析了不同发酵时间腐乳样品的氨基酸态氮、三氯乙酸-氮溶指数（TCA-NSI）、游离氨基酸、蛋白质水解度（DH）、酪氨酸含量及蛋白质分子量变化。结果表明:绍兴腐乳发酵过程中坯料中酪氨酸随着氨基酸态氮、TCA-NSI、游离氨基酸、DH的增加而增加;1⁴0d内主要是7S和11S蛋白质的分解,40d以后主要是小分子蛋白质的进一步分解。相关性分析表明,游离酪氨酸的含量与DH的Pearson相关系数最高。同时对成熟腐乳的研究发现有白点腐乳的TCA-NSI、DH和游离酪氨酸显著高于无白点腐乳,这表明了腐乳中白点的形成是由蛋白质过度水解造成的。本研究为绍兴腐乳白点的控制提供了参考。      

Composition and functionality of wheat bran and its application in some cereal food products

Production of wheat bran (WB) for human consumption is estimated to be about 90 million tonnes per year. WB is a cheap and abundant source of dietary fibre which has been linked to improved bowel health and possible prevention of some diseases such as colon cancer. It also contains minerals, vitamins and bioactive compounds such as phenolic acids, arabinoxylans, alkylresorcinol and phytosterols. These compounds have been suggested as an aid in prevention of noncommunicable diseases such as cardiovascular disease. This article discusses WB extraction, its nutritional properties, potential health benefits, effects on quality and sensory properties of some cereal foods, and its application in some baked products as well as in fried cereal snacks, as an additive for oil reduction and fibre enrichment.