牛奶及奶粉中蛋白质的快速测定法

目的:建立一种牛奶及奶粉中蛋白质的快速测定方法。方法:在试管中以双氧水-硫酸加热,快速消解牛奶及奶粉中的蛋白质,使用纳氏试剂比色法测定。结果:快速消解只需5分钟即可完成。两个品种牛奶中蛋白质各测定8次,相对标准偏差分别为3.9%和1.3%,用甘氨酸标准溶液做回收试验,回收率99.4%。用本法测定奶粉标准物质(GBW10017)6次,与标准值比较结果无显著性差异。结论:该方法操作简单,结果可靠。     

苯丙酮尿症患儿特殊奶粉免费补助效果初步分析

目的:探索解决PKU新生儿治疗费用的最佳途径及PKU治疗和管理的模式,评价免费治疗补助的干预效果,为全国范围的推广应用提供科学的依据。方法:200名患儿接受免费特殊奶粉补助,随访患儿的体格和智力发育情况,随访检测患儿血液苯丙氨酸(Phenylalanine,简写为Phe)浓度;开展新筛健康教育,设置PKU患儿募集和特殊奶粉补助流程,规范管理。结果:体格发育正常的补助患儿占检查人数中99.45%,智力发育正常的补助患儿占检查人数中95.97%;患儿血Phe浓度控制在4mg/dl以内的次数占总检测次数的比例能达到80%的人数仅占37.50%。结论:特殊奶粉免费补助能有效提高治疗依从性,但仍需要提高血Phe浓度控制在4mg/dl以内的次数占总检测次数的比例能达到80%的患儿比例。     

乳粉中蛋白质测定条件的改进

目的对乳粉中蛋白质测定条件进行改进,以便于实验的操作和控制。方法参照中华人民共和国国家标准《食品中蛋白质的测定》（GB／T5009．5—2003）对《婴幼儿配方食品和乳粉蛋白质的测定》（GB／T5413．1—1997）中的试样前处理和消化液的蒸馏2个重要步骤用同一乳粉进行蛋白质含量的测定比对。结果测定条件改进前后所测同一乳粉中蛋白质含量结果无差异性。结论改进后的测定条件在乳粉中蛋白质测定时容易操作和控制,不易导致测定实验失败。     

Protein evaluation in growing rats of breast milk and breast milk substitutes with special reference to the content of non-protein nitrogen.

The levels of individual proteins and other nitrogen containing substances differ considerably between cow's milk and human milk. Therefore, during manufacture of infant formulas, attempts are made to simulate the protein composition of human milk. However, the composition and nutritional characteristics of human milk protein are incompletely known. In this paper, the protein quality of breast milk protein with and without the non-protein-nitrogen (NPN) substances present in human milk was studied with growing rats and compared to two formulas, one "adapted" commercial infant formula and a suggested further modified, possibly improved, infant formula. Detailed examinations of protein and amino acid composition of the test diets are given. Breast milk protein with added NPN substances showed a lower protein quality than all other test proteins. Breast milk protein without NPN substances and the protein of the suggested infant formula were of similar quality while the protein of the commercial adapted formula was significantly better than all other test proteins. The use of rat growth assays in the evaluation of protein quality of infant formulas is discussed.     

Effects of bioactive substances in milk on mineral and trace element metabolism with special reference to casein phosphopeptides

Bioactivity of phosphopeptides yielded after tryptic hydrolysis of casein (CPP) was reported more than 50 years ago when CPP were found to improve calcium balance in rachitic newborns. Several investigations have been carried out to study the effects of CPP mainly on calcium metabolism but also on other minerals like iron and zinc. Most of the experiments were in vitro studies or short-term experiments like the effects of CPP after single meals or their effect on mineral disappearance from intestinal everted sac or ligated loop. Investigations on calcium balance were also mainly short term, i.e. 3-4 weeks, and mainly done in rats. A few experiments have been carried out in minipigs, an animal model that is closer to the human than the rat. Studies in human were rare and short term. To date a variety of other peptides have been isolated after enzymatic hydrolysis, and some have been investigated for bioactivity, with equivocal findings. Bioactivity of phosphopeptides seemed to be more obvious when investigations were done in vitro or short term. Results were less clear in metabolic balance studies, especially under physiological conditions. The composition of the basal diet, i.e. content of calcium and phytate, or the protein source had a significant impact on the effect of phosphopeptides. It was concluded that phosphopeptides revealed positive effects on mineral solubility and absorbability, and bone mineralisation under certain experimental conditions. Accordingly they could have a beneficial effect on bone health for some groups of the population.     

Diarrhoeal disease with special reference to the Americas

This article presents data on morbidity and mortality from diarrhoeal disease in infancy and childhood for certain areas of the Americas. The role of the principal etiological agents is discussed, and the importance of various factors, such as availability of water-supply, fly control, malnutrition, and the protective effect of breast-feeding, is evaluated. Some practical measures for the prevention of deaths from diarrhoea are put forward.