含乳食品中动物水解蛋白L-羟脯氨酸的检测

采用硫酸溶液烘箱恒温水解法,建立了适合含乳食品中动物水解蛋白L-羟脯氨酸的检测方法。结果表明:该方法简便快速、线性范围宽、检出限低、灵敏度高、重复性好适用于大批量样品的测定。方法加标回收率为92.4%~96.2%,变异系数CV为1.6%~2.5%。方法准确度、精密度都满足GB/T27404-2008实验室质量控制规范食品理化检测附录F检测方法确认的技术要求。可作为含乳食品中动物水解蛋白L-羟脯氨酸检测的首选方法。     

原料奶粉及乳饮料中L-羟脯氨酸的含量测定

采用对二甲氨基苯甲醛分光光度法测定奶粉及乳饮料中L-羟脯氨酸,具有较好的稳定性。奶粉及乳饮料经浓盐酸水解,得到的L-羟脯氨酸经过氯胺T氧化,与对二甲氨基苯甲醛反应生成红色物质,在558nm下测定吸光值。该方法操作简单、准确率高、检测费用相对少,可用于企业奶粉原料掺水解蛋白及产品中是否掺有水解蛋白的检测提供依据。     

乳与乳制品中动物水解蛋白鉴定方法

动物水解蛋白是利用皮革下脚料等水解制成,其中的特有成分为L-羟脯氨酸和羟赖氨酸,且羟脯氨酸的含量较高,达10％以上,而大豆蛋白与乳蛋白中不含有此成分。利用这一特性就可进行动物水解蛋白质的鉴定,即通过对羟脯氨酸的测定来鉴定乳与乳制品中是否添加了动物水解蛋白的成分。     

乳与乳制品中动物水解蛋白L-羟脯氨酸测定法

通过试验论证,建立了L-羟脯氨酸测定法来鉴定乳与乳制品中是否添加了动物水解蛋白的成分.该方法结果稳定,准确性高,可以作为乳与乳制品中动物水解蛋白的鉴定方法.     

乳与乳制品中L-羟脯氨酸检测技术的研究进展

近几年来由于一些企业为降低生产成本,常常会在乳与乳制品中掺假,这种行为严重影响了乳品加工企业的产品质量,同时也对消费者的身体健康造成了严重损害。在各种乳与乳制品掺假方法中,添加蛋白类掺假物如水解蛋白是比较常见的方法。L-羟脯氨酸是水解蛋白特有的氨基酸,而乳蛋白质中是不含L-羟脯氨酸的,因此检测乳与乳制品中是否含有L-羟脯氨酸是判断乳与乳制品是否掺假的一个重要手段之一。目前,针对L-羟脯氨酸的检测方法主要有分光光度法、液相色谱法、氨基酸分析仪法、液相色谱质谱法等。本文综述了近几年来国内外乳与乳制品中L-羟脯氨酸的检测技术及其研究进展,对上述几种检测方法各自的优缺点进行了详细的分析,同时对未来的L-羟脯氨酸检测技术发展进行了展望。     

乳及乳制品中L-羟脯氨酸的测定

采用比色法对乳及乳制品中的L-羟脯氨酸质量分数进行测定.结果表明,本方法的检出限为2.1 μg/g,回收率为91.6%～101.3%.RSD为1.71%～2.45%,可用于判定乳及乳制品中是否添加动物胶原水解蛋白或者舍有游离L-羟脯氨酸.     

乳及乳制品中动物水解蛋白L-羟脯氨酸的检测技术

介绍了检测乳及乳制品中L-羟脯氨酸的常用方法,主要包括高效液相色谱法、高效液相色谱-质谱联用法、氨基酸自动分析仪测定法,毛细管电泳-激光诱导荧光检测法和分光光度法,并对今后乳及乳制品中动物水解蛋白检测技术的发展趋势进行了分析。     

对酱油中添加动物水解蛋白的鉴定方法

介绍了一种测定酱油中可能存在的添加物——动物水解蛋白的方法。羟脯氨酸是组成动物肌体胶原蛋白的主要成份之一,在大豆蛋白和乳蛋白中不存在此成分。因此,可用定量检测羟脯氨酸的方法来确定酱油中是否添加了动物水解蛋白。该方法的检测限、平均回收率等均能满足日常检测工作的需要。     

乳及乳制品中L-羟脯氨酸的测定

本实验采用比色法对乳及乳制品中的L-羟脯氨酸含量进行测定,结果表明,本方法的检出限为2.1μg/g,回收率为91.6%～101.3%,RSD为1.71%～2.45%,可用于判定乳及乳制品中是否添加动物胶原水解蛋白或者含有游离L-羟脯氨酸。     

比色法检测乳中掺加的动物胶原水解蛋白

采用比色法快速定量检测乳中掺加的动物胶原水解蛋白。首先通过比色方法测得羟脯氨酸的质量浓度，由测得的羟脯氨酸换算得出乳中掺加的动物胶原水解蛋白的量。此法快速、简便、重复性好、回收率高。     

Invited review: Human,cow, and donkey milk comparison: Focus on metabolic effects

Milk is an important food of the daily diet. Many countries include it in their dietary recommendations due to its content in several important nutrients that exert beneficial effects on human health. Human milk is a newborn's first food and plays an important role in the growth, development, and future health of every individual. Cow milk is the type of milk most consumed in the world. However, its relatively high content of saturated fats raises concerns about potential adverse effects on human health, although epidemiological studies have disproved this association. Indeed, dairy consumption appear to be linked to a lower risk of mortality and major cardiovascular disease events. In the last few years many researchers have begun to focus their attention on both the production and quality of cow milk as well as the analysis of milk from other animal species to evaluate their effect on human health. The need to investigate the composition and metabolic effects of milk from other animal species arises from the adverse reactions of individuals in several groups to certain components of cow milk. It has emerged that donkey milk compared with that of other animal species, is the nearest to human milk and an excellent substitute for it. Milk from various animal species shows substantial differences in nutritional composition and distinct metabolic effects. In this review, we discussed the main compositional features and metabolic effects of 3 types of milk: human, cow, and donkey milk.     

Development of an LC-MS/MS method to quantify sex hormones in bovine milk and influence of pregnancy in their levels

Hormones work in harmony in the body, and this status must be maintained to avoid metabolic disequilibrium and the subsequent illness. Besides, it has been reported that exogenous steroids (presence in the environment and food products) influence the development of several important illnesses in humans. Endogenous steroid hormones in food of animal origin are unavoidable as they occur naturally in these products. The presence of hormones in food has been connected with several human health problems. Bovine milk contains considerable quantities of hormones and it is of particular concern. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, based on hydroxylamine derivatisation, has been developed and validated for the quantification of six sex hormones in milk [pregnenolone (P?), progesterone (P?), estrone (E?), testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA)]. This method has been applied to real raw milk samples and the existence of differences between milk from pregnant and non-pregnant cows has been statistically confirmed. Basing on a revision of existing published data, it could be concluded that maximum daily intakes for hormones are not reached through milk ingestion. Although dairy products are an important source of hormones, other products of animal origin must be considered as well for intake calculations.     

乳品中蛋白质检测方法的研究进展

对乳品中蛋白质质量分数的各种检测方法进行了评述。蛋白质的质量分数是评价乳品质量的重要指标。近年来,围绕着乳品蛋白质的食品安全事件接连发生,对人们的生命和健康造成了极大的危害。目前,传统的评价乳品蛋白质的检测方法均存在着一定的缺陷,并给不法分子带来可乘之机,而现代的仪器分析方法尚不成熟。因此,开发出更加合理的蛋白质测定方法成为研究的焦点课题。     

大豆-动物蛋白混合体系功能性质研究进展

近年来利用植物蛋白,特别是大豆蛋白部分替代动物蛋白在食品加工领域中的应用受到广泛关注。目前,已有较多研究表明大豆蛋白与某些动物蛋白在特定条件下对混合体系的功能性质具有协同作用,如有效调节凝胶结构、增强凝胶强度、提高蛋白膜的机械性能以及产生稳定的乳液和泡沫等。因此,本文综述了大豆蛋白与常见动物蛋白(如牛奶蛋白、肌原纤维蛋白和胶原蛋白等)混合体系行为及相关机制,为大豆-动物混合蛋白功能性质的研究及其在食品领域中的应用提供参考。     

牛奶大豆双蛋白营养酸奶的研究

大豆蛋白质的氨基酸组成与牛奶蛋白质相近,除蛋氨酸略低外,其余必需氨基酸含量均较丰富,是植物性的完全蛋白质,在营养价值上,可与动物蛋白等同。大豆磷脂作为营养补助品已有七十多年历史,国外称其为“头脑补助食品”。用大豆分离蛋白、大豆磷脂和鲜牛奶制作的酸奶具有很高的营养价值和保健功能。     

Development of an LC-MS/MS method to quantify sex hormones in bovine milk and influence of pregnancy in their levels

Hormones work in harmony in the body, and this status must be maintained to avoid metabolic disequilibrium and the subsequent illness. Besides, it has been reported that exogenous steroids (presence in the environment and food products) influence the development of several important illnesses in humans. Endogenous steroid hormones in food of animal origin are unavoidable as they occur naturally in these products. The presence of hormones in food has been connected with several human health problems. Bovine milk contains considerable quantities of hormones and it is of particular concern. A liquid chromatography–tandem mass spectrometry (LC-MS/MS) method, based on hydroxylamine derivatisation, has been developed and validated for the quantification of six sex hormones in milk [pregnenolone (P₅), progesterone (P₄), estrone (E₁), testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA)]. This method has been applied to real raw milk samples and the existence of differences between milk from pregnant and non-pregnant cows has been statistically confirmed. Basing on a revision of existing published data, it could be concluded that maximum daily intakes for hormones are not reached through milk ingestion. Although dairy products are an important source of hormones, other products of animal origin must be considered as well for intake calculations.     

Composition and Nutrient Value Proposition of Brewers Spent Grain

Brewer's spent grain (BSG), a major brewing industry byproduct, is generated in large quantities annually. This review summarizes research into the composition and preservation of BSG, different extraction techniques for BSG proteins and phenolic acids, and the bioactivities of these phenolic components. Moreover, this article also highlights BSG integration into foodstuff for human consumption and animal feed supplements. BSG is considered a rich source of fiber, protein, and phenolic compounds. The phenolic acids present in BSG are hydroxycinnamic acids (ferulic, p‐coumaric, and caffeic acids), which have many biofunctions, such as antioxidant, anticarcinogenic, antiatherogenic, and antiinflammatory activities. Previously, attempts have been made to integrate BSG into human food, such as ready‐to‐eat snacks, cookies and bread, to increase fiber and protein contents. The addition of BSG to animal feed leads to increased milk yields, higher fat contents in milk, and is a good source of essential amino acids. Therefore, many studies have concluded that integrating the biofunctional compounds in BSG into human food and animal feed has various health benefits.     

猪皮中羟脯氨酸含量的测定

猪皮中含有丰富的胶原蛋白,胶原蛋白以其独特的结构与生物学性质,被广泛应用于食品、化妆品与医药等工业领域.胶原蛋白中含有高比例的羟脯氨酸,由测定的羟脯氨酸乘以相应系数即可得出胶原蛋白含量.本文采用比色法测定猪皮中羟脯氨酸(Hyp),结果表明,采用比色法测定具有较好的稳定性和较高的回收率.羟脯氨酸的平均回收率达85.97%,其在猪皮中含量的平均值为23.18mg/g(羟脯氨酸/猪皮).     

The Nutritive Value of Humanized Milk Food Based on Buffalo Milk and Fortified with DL-Methionine

SUMMARY— The nutritive value of infant foods (prepared from buffalo milk) containing 10%, 12.5% and 15% protein and fortified with DL-methionine has been studied in experiments with albino rats. The mean weekly growth rate of rats receiving milk food II (10% protein and 20% fat) and fortified with DL-methionine was of the same order as those obtained with milk foods containing 12.5%, 15%, 22% and 26% protein. Milk food II containing 10% protein (not fortified with DL-methionine) promoted significantly less growth than the same food fortified with DL-methionine and other milk foods containing 12.5% to 28% protein.
The protein efficiency ratio of the milk food fortified with DL-methionine (4.0) was significantly higher than that (3.3) of the unfortified milk food at 10% level of protein in the diet. The results indicate that humanized milk food from buffalo milk containing about 12.0% protein and 20% fat and fortified with DL-methionine will be suitable for feeding infants in place of full cream milk powder in developing countries where milk is in short supply. Adoption of the above formula for infant milk food manufactured in the country will help to double the output of infant food from the same quantity of buffalo milk without appreciable increase in cost.     

Food in an evolutionary context: insights from mother's milk

In the emergence of diverse animal life forms, food is the most insistent and pervasive of environmental pressures. As the life sciences begin to understand organisms in genomic detail, evolutionary perspectives provide compelling insights into the results of these dynamic interactions between food and consumer. Such an evolutionary perspective is particularly needed today in the face of unprecedented capabilities to alter the food supply. What should we change? Answering this question for food production, safety and sustainability will require a much more detailed understanding of the complex interplay between humans and their food. Many organisms that we grow, produce, process and consume as foods naturally evolved adaptations in part to avoid being eaten. Crop breeding and processing have been the tools to convert overtly toxic and antinutritious commodities into foods that are safe to eat. Now the challenge is to enhance the nutritional quality and thereby contribute to improving human health. We posit that the Rosetta stone of food and nourishment is mammalian lactation and ‘mother's milk’. The milk that a mammalian mother produces for her young is a complete and comprehensive diet. Moreover, the capacity of the mammary gland as a remarkable bioreactor to synthesise milk, and the infant to utilise milk, reflects 200 million years of symbiotic co‐evolution between producer and consumer. Here we present emerging transdisciplinary research ‘decoding’ mother's milk from humans and other mammals. We further discuss how insights from mother's milk have important implications for food science and human health. Copyright © 2012 Society of Chemical Industry