STUDIES ON THE EFFECT OF TEMPERATURE ON THE MOISTURE SORPTION CHARACTERISTICS OF POTATOES

An understanding of the moisture sorption characteristics of food systems is an important objective in food engineering, in particular with respect to the mass transport phenomena during drying. A standard gravimetric technique was employed to examine the influence of temperature on the adsorption and desorption behavior for potatoes. The type II sorption isotherms were analysed using the Guggenheim-Anderson-de Boer model, with the observed hysteresis phenomena displaying a temperature dependence. The moisture dependent net isosteric heats of sorption were determined using the Clausius-Clapeyron equation.     

助剂对苎麻脱胶的影响

对苎麻脱胶进行了小试,研究了其化学组成及脱胶对苎麻的影响,筛选出一种独特有效的煮炼助剂,并结合生产实际,证明其碱煮炼脱胶效果相当明显。     

谷氨酰胺转氨酶对猪肉糜失水率和硬度影响的研究

研究了谷氨酰胺转氨酶对猪肉糜保水性及对猪肉糜糕弹性的影响。结果表明最佳作用添加量为0.45%、最佳作用温度为35℃、最佳作用时间为2.0h;辅料大豆蛋白GsNa、大豆蛋白EGP和大豆蛋白HTP对谷氨酰胺转氨酶作用影响结果表明添加4%的大豆蛋白GsNa和添加0.1%的大豆蛋白EGP能显著改善猪肉糜的保水性及猪肉糜糕的弹性,而大豆蛋白HTP对其影响则不明显。     

有色涤纶的细度对织物质量的影响

本文主要讨论了在毛精纺生产过程中，使用原液染色涤纶条与羊毛混纺时，原液涤纶条的细度对产品质量的影响。实践证明：只有采用细度分布适中的涤纶条，才能保证产品的最终质量。     

茶多酚与葡萄多酚协同抑制幽门螺杆菌的研究

采用含毒介质法测试不同浓度茶多酚和葡萄多酚对幽门螺杆菌（H．pylori）的体外抑制效果，并将茶多酚与葡萄多酚以不同比例混合，测试两种物质对H．priori抑制效果是否具有协同效应，结果表明，一定比例混合的茶多酚与葡萄多酚对于体外抑制幽门螺杆菌具有增效作用，当混合物中以不同浓度的茶多酚与2mg／mL的葡萄多酚配伍时，增效效果明显；而以不同浓度的葡萄多酚与0．08mg／mL的茶多酚配伍时，增效效果显著。     

α—单甘酯含量测定方法的研究

通过对 α-单甘酯含量两种测定方法进行比较,得到一种较为简单、快速而且较为科学的测定方法。     

植物提取物用于果蔬防腐保鲜研究进展

致腐菌是诱发果蔬采后病害,造成果蔬在货架期间和贮藏过程腐败变质的主要原因.主要从植物提取物对果蔬采后致腐菌的抑制作用,不同提取方法对致腐菌的抑制效果,提取物用于果蔬防腐保鲜效果三个方面概述了植物提取物在果蔬防腐保鲜上的研究进展.     

ON THE MEASUREMENT OF THE FLOCCULATION CHARACTERISTICS OF BREWERS' YEAST

The capacity of certain yeast strains to flocculate is important to the brewing industry. So is the determination of the flocculation characteristics of a yeast strain. In this study we subdivided the flocculation characteristics into three phenomena. A proposal for the most suitable method to quantify each phenomenon is given. For this, four parameters (bond strength, floc size, settling rate and number of single cells) that serve as a measure to these phenomena have been studied. Next to this, attention is payed to the influence of environmental conditions (temperature, calcium concentration, pH and the hydrodynamic conditions during the test) on the result of the test. During this part of the study the flocculence of the yeast cells was constant, so the effect of the yeast on the results of the test is excluded. It turned out that the temperature of the medium and the hydrodynamic conditions during the test most strongly influence floc formation. Next to this, medium viscosity is important if the flocculation characteristics are quantified via settling experiments.     

反应条件对酪蛋白水解度的影响

通过单因素实验和正交实验研究了用胰蛋白酶水解牛乳酪蛋白的工艺条件。研究结果表明：胰蛋白酶水解酪蛋白的最佳工艺条件是：pH7．5，温度60℃。底物浓度5％，酶添加量62．44U／g，水解时间140mino在此条件下酪蛋白的水解度达到16．8％。     

THE INFLUENCE OF THE GRAIN MICROFLORA ON THE GERMINATIVE PHYSIOLOGY OF BARLEY

Barley samples, which varied in maturity, were either steeped with calcium hypochlorite and then with a mixture of antibiotics, or in water, for twenty or sixty hours. The steeped grains were placed on agar and were scored for germination, growth of rootlets and α-amylase production at intervals up to ninety six hours after draining. The rates and final percentages of germination, rootlet growth per germinated corn and α-amylase per germinated corn were all greater where grain had been steeped with antimicrobial agents compared to water-steeped control samples of grain. It was confirmed that the antimicrobial agents reduced the extent of inhibition of germination which followed extended steeping. Thus controlling microbes increased grain germinability and the vigour of the grains which germinated. However, the vigour of more water sensitive grain was not increased enough to be equal to that of mature grain by reducing microbial activity . Experiments in which grain was reinfected with a suspension of microbes, following steeping with antibiotics, supported the theory that the observed effects were due to reductions in microbial activity and not any secondary effects of the antimicrobial agents.     

THE EFFECT OF COLD BREAK ON THE FINING OF BEER

After fermentation the suspended particles in unfined beer can be classified into two groups: a) yeast and b) proteinaceous material associated with carbohydrates and polyphenols. These can be differentiated in terms of particle size using a Coulter Counter. Clarification by fining applied either in cask or as a pre-filtration technique is greatly affected by large concentrations of particles other than yeast. The majority of this mainly proteinaceous material has been shown to be derived from ‘cold break’ which remains suspended in the beer after fermentation. The amount of this material can be reduced significantly by the effective use of copper finings. In consequence, reduced levels of both auxiliary and isinglass finings have been shown to give more rapid overall clarification whilst producing a smaller volume of sediment.     

“衬”心如意

随着中国国际化进程的加快，服装衬布企业将面对越来越多的竞争者，怎样的企业才能经受住这场严峻的考验？[编者按]     

共混对淀粉玻璃化转变特性的影响

采用DSC曲线分析法对各种添加刑与淀粉的相容性进行了判断，首次给出了这些添加剂与淀粉的相客性结果。对黄原肢与淀粉的共混体系的玻璃化转变行为进行了实验研究，根据高分子聚合物的共混模型对糯米淀粉与黄原胶共混物的玻璃化转变实验数据进行了拟合，得到适用于此体系的经验关联式，并应用玉米等其他淀粉与黄原胶共混后的实验数据进行验证，表明该关联式可用于定量预计淀粉与黄原肢共混后的玻璃化温度。     

THE EFFECT OF LACTIC ACID DECONTAMINATION ON THE MICROFLORA ON MEAT

Meat acquires a characteristic microflora after slaughter and butchering. This normal microflora may be beneficial in that it occupies a niche that would otherwise permit unimpeded growth of potential pathogens. Lactic acid decontamination (LAD) is intended to eliminate pathogens but also affects the normal microflora. The immediate effect was studied by means of an in-vitro model. Experiments using this model achieved a reduction in the mesophilic Enterobacteriaceae on meat by 1 to 3 log₁₀ colony forming units and shifted the predominant microflora in the direction of Gram-positive bacteria and yeasts. Colony counts were an unreliable indicator of LAD-induced reductions in Gramnegative foodborne pathogens. Their reduction depended on the ratio of the more lactic acid resistant Gram-positive bacteria to the more sensitive Gram-negative bacteria. The rank order of lactic acid-resistance of nonpathogens present on meat was yeasts = lactobacilli > psychrotrophic Gram-positive bacteria > mesophilic Enterobacteriaceae. Psychrotrophic Gram-negative bacteria were the most sensitive.     

论仓房气密性及其对储粮安全的影响

对仓房气密性的测定和标准进行了阐述，分析了仓房气密性对储粮安全的影响，并对提高仓房气密性的措施进行了探讨。