VELOCITIES OF FALLING FILMS OF WATER ON TEFLON®, GLASS AND STAINLESS STEEL SURFACES

SUMMARY— The velocities of falling films of water on a stainless steel plate (8 by 1.5 ft) with No. 4 surface finish were measured by the salt conductivity method for flows varying from 50 to 250 Ib/min. The downflow times between 2 fixed electrodes, 6 feet apart on the plate, were measured by a Solu-Bridge flow timer. The film velocity measurements were made with the plate vertical and inclined 30 degrees from vertical, with water at 70 and 140°F. Another setup with a smaller plate (4 by 1.5 ft) and a constant flow of 45 lb/min was used to study the characteristics of falling films of water on Teflon, glass and stainless steel surfaces. The plates could be positioned at any positive or negative angle. The effects on wave structures were recorded photographically. The results showed highest velocities when the plates were vertical. Velocities increased with flow rate and temperature. At a given slope, film velocities were higher for the flow clinging to the underside of the surface than for the flow down the upper side of the surface.     

玉米醇溶蛋白膜的降解性能和水蒸气透过率的研究

对玉米醇溶蛋白（zein）与3%油酸增塑的玉米醇溶蛋白（OA-zein）膜的降解性能和水蒸气透过率进行了研究,实验结果表明：zein膜和OA-zein膜具有良好的抗酸性,但在pH 10以上时开始发生降解,蛋白酶水解实验表明了24h内蛋白膜不被酶水解.这些数据说明了蛋白膜在人体内不能被消化,但在碱性环境中可以降解.水蒸气透过率实验证明了蛋白膜所具备良好的阻气性能,可以作为疏水性的包覆材料应用于医药、食品和化工领域.     

增塑剂对壳聚糖膜性能的影响

以甘油、山梨醇、聚乙二醇和硬脂酸作为增塑剂,制备壳聚糖复合膜,通过测定膜的渗透和机械性能,并与壳聚糖单纯膜进行比较,研究不同增塑剂对壳聚糖膜性能的影响.结果表明,甘油、山梨醇和聚乙二醇能明显的增大膜的柔韧性,降低膜的抗拉强度.并增大膜的渗透性及吸湿性能;添加硬脂酸,膜的抗拉强度、柔韧性、渗透性及吸湿性能都不同程度的降低.     

STUDIES ON THE MALTING POTENTIAL OF BARLEY AND MALT WITH THE FALLING NUMBER APPARATUS

The Falling Number Apparatus was investigated as a possible technique for the identification of barleys and malts with high malting potential. The FN method was not as accurate or as rapid as that based on Pearling Resistance. The effect of increasing times of malting on the Falling Times of malts was also investigated to determine whether the progress of malting could be monitored, as was the effect of different cultivars. Testing under conditions inhibitory to amylolytic activity was found necessary to give useful results. Some comparisons with the Rapid Visco Analyser (RVA) are presented.     

EFFECT OF CHLORINE TREATMENT ON CUT WATER CRESS AND ONION

Chlorine treatment was evaluated for cut vegetables to reduce microbial populations and improve keeping quality. Water cress and onion were selected because they are representative vegetables having high potential for processing into cut prepared products. Cut water cress had a high initial microbial contamintion of 10^7.5 cfu/g, while cut onion had only 10^1.7 cfu/g. The cut produce was treated by soaking in chlorine solutions of different concentrations at 25C for 1 min. Treatment with ≤100 ppm chlorine effectively reduced the microbial load of the produce without significant quality losses. High concentrations of chlorine resulted in greater microbial proliferation after 7 days, ascorbic acid destruction and significant color change in stored cut vegetables. The effectiveness of chlorine treatment was limited to short-term storage of precut vegetables, and did not provide extended shelf-life.     

STUDIES ON THE EFFECT OF GERMINATION TIME AND TEMPERATURE ON MALTING OF RICE

The effect of germination conditions on rice malt quality was studied by germinating rice for different periods of time up to 7 days over a range of temperatures (22° to 32°C). Germination time and temperature had a significant effect on rice malt diastatic power, cold and hot water extracts, total reducing sugars, and free alpha amino nitrogen. In general, diastatic power, cold water extract, hot water extract, total reducing sugars and free alpha amino nitrogen, all increased with germination time and temperature. Germination temperatures of 28°C and 30°C were good for the development of diastatic power, cold water extract, hot water extract, total reducing sugars and free alpha amino nitrogen. However germinating at 30°C gave maximum result. The mashing trials with rice malted for 6 days showed a slow and incomplete saccharification, slow filtration rate, and high total available extract in spent grains.     

EFFECT OF INSOLUBLE PARTICLES UPON SOLID INCLUSION LEVELS IN ICE FORMED ON A SUBCOOLED STAINLESS STEEL SURFACE

This study employed an insoluble solid particle, i.e. a potato starch used as an example, to investigate the impact of the concentration of such particles suspended in water (with solid loading of 5, 10, 20 and 30 wt%) upon the solid inclusion levels in ice layers formed on a sub‐cooled smooth stainless steel plate surface. The effects of ice growth rate, bulk concentration and suspension velocity on insoluble solid inclusion, i.e. potato starch mass fraction, in ice layer were studied. The experiments, where potato starch is added into aqueous sucrose solutions or the reverse where sucrose is added into starch suspension, were also carried out to investigated effect of the starch particles on sucrose inclusion in ice and effect of solute (sucrose) on starch particle inclusion in ice. It has been found that solid inclusion in ice increases with increasing bulk concentration and average ice growth rate, at constant solution and coolant velocities, and increasing suspension velocity can help pure ice formation. The average distribution coefficient of sucrose in ice layer formed from sucrose solution does not appear to be affected by the addition of potato starch. However, the average distribution coefficient of potato starch in ice layer formed from suspension is influenced by sucrose concentration quite significantly.     

2—异戊烯酸酯的合成及香气研究

２－异戊烯酸酯是一类重要的香气物质，是合成保幼激素系列物质的重要中间体．为此研究了以异丙叉丙酮氧化合成异戊烯酸的方法，从而进一步以酰氯酯化法合成了一系列相应的酯类，并对酯类香气进行了感官评定，找出了其香气衍变的规律．     

不同酶种及助剂对酶活影响的研究

几种生物酶应用于棉织物前处理．采用DNS法和紫外分光光度法研究了生物酶的专一性和不同酶种及助剂对酶活的影响．结果表明，淀粉酶、纤维素酶及果胶酶均具有良好的专一性，不同种类酶之间及与所选用的非离子助剂均有较好的相容性，为混合酶前处理的一浴法研究提供了理论基础．     

EFFECT OF GAMMA RADIATION ON WHEAT STARCH AND ITS COMPONENTS

SUMMARY– Studies on the susceptibility of irradiated wheat starch, amylose and amylopectin to alpha- and beta-amylolysis reveal that they are more susceptible to enzyme actions, compared to their unirradiated controls; however, irradiated amylose seems to be comparatively more vulnerable. From irradiated starch, series of oligosaccharides of the maltose series are discernible, while glucose appears only above 200 Krad dose level. Quantitative analysis of the radiolytic breakdown products of starch reveal that at high dose levels (1 Mrad) maltose, maltotriose and maltotetrose are the main products. Results on the separation of radiolytic breakdown products suggest they resemble those produced by alpha-amylolysis of starch.     

毛蚶中天然牛磺酸的提取及其对果蝇寿命的影响

研究了热水浸提法从毛蚶中提取天然牛磺酸的工艺,确定最佳提取条件为90℃提取2h,上柱液调至pH4～5后进行阳离子树脂交换层析;通过纸层析、熔点测定及其红外图谱对制备样品进行理化性质鉴定,表明得到的天然牛磺酸的纯度较高;通过果蝇寿命实验比较了天然牛磺酸与合成牛磺酸延寿功效的差别,表明天然牛磺酸较合成牛磺酸的延寿效果好.     

饮料中胭脂红的测定及其电化学行为的探讨

人工合成色素胭脂红广泛用作饮料、化妆品等的着色剂，由于它有一定毒性，因此对其进行分析测定具有极其重要的意义，文章利用吸附溶出伏安法对饮料中的胭脂红色素进行了测定，所得结果令人满意，且方法简单，便于推广，对胭脂红的电化学行为也进行了一定探讨，测定出胭脂红在悬汞电极上的还原反应是不可逆的，其电极反应的总电子数为２。上述结果为进一步开发和利用胭脂红提供了一定的基础。     

THE REMOVAL OF β-LACTOGLOBULIN FROM STAINLESS STEEL SURFACES AT HIGH AND LOW TEMPERATURE AS INFLUENCED BY THE TYPE AND CONCENTRATION OF CLEANING AGENT

In the food industry, severe fouling of equipment surfaces is common and frequent cleaning is necessary. The aim of this work was to contribute to an understanding of the cleaning process. The adsorption of β-lactoglobulin (β-LG) onto stainless steel surfaces and its removal by detergent were followed at 24 and 82C using in situ ellipsometry. Soil removal using different concentrations of sodium hydroxide was studied. Furthermore, NaOH was combined with the anionic surfactant sodium dodecyl sulphate (SDS). Increasing the NaOH concentration resulted in an enhanced cleaning rate and better cleanability. When the concentration was increased to 0.8 mg/mL, the cleaning process could no longer be monitored by ellipsometry. Combining SDS with NaOH resulted in improved cleaning compared to if using the individual components. Adsorption and removal of β-LG at high temperature led in all cases to decreased cleanability compared to the results obtained at room temperature.     

EFFECT OF TEMPERATURE AND WATER CONCENTRATION DURING PROCESSING ON FOOD QUALITY

Water content and temperature during food processing have a pronounced influence on the rates of those changes in food properties which are the object of the process such as reduction in water content or sterilization. However, they also strongly influence adverse side effects such as browning, loss of nutrients or shrinking. When the effects of temperature and water concentration on the process rates of the desired and adverse processes are known, the processes can be optimized. An example of the optimization procedure is given for the spray drying of heat-labile aroma containing liquid foods. Both temperature and moisture content of the droplets change with time in spray-drying. In a second example a new and simple calculation method is introduced for the optimization of quality retention in the sterilization of packed foods.