An accelerated stability test using the peroxide value as an index

Summary A quick stability test for lard is described which depends on the peroxide content for identification of the rancid point. By its use ordinary samples of lard can be evaluated for stability in a working day. Oleo oil also is being tested by this method. It is applicable to edible fats and oils and hydrogenated shortenings. Typical peroxide curves for various fats and oils are shown. The effect of copper in accelerating oxidative rancidity is discussed.     

复合肥产品质量控制的有效途径

分析复合肥生产过程中影响产品质量的主要因素,指出原料质量、原料配比、工艺控制、配方变化等影响产品的内在质量,造粒、烘干、包裹工序的操作影响产品的外观质量.同时利用质量管理统计技术,提出用控制图方法判断过程中出现的异常原因和偶然原因,通过过程能力指数(CP)及过程流通合格率等指标判断控制过程是否正常,并提出了相应的解决对策.     

The effect of various antioxidants on the keeping quality of yellow grease

Summary Yellow grease was stabilized with varying quantities of BHA, BHT, and propyl gallate under laboratory conditions. Propyl gallate was the best antioxidant with BHA a close second. Yellow grease was stabilized with mixtures of BHA and citric acid; BHA, propyl gallate, and citric acid; and BHA and BHT under laboratory conditions. The BHA-citric acid mix proved to be the best mixture. Grease was stabilized by adding various antioxidant mixtures before and after rendering. It was found better to add the antioxidant after rendering. Propyl gallate showed almost no carry-through properties. It was also shown possible to add the citric acid before rendering and the antioxidant after rendering. It was found that extra citric acid (.1 to .5%) added with an antioxidant increased the effectiveness of the antioxidant when greases of low stability were encountered. The iron content of the initial grease seems to have some bearing on the ease with which it could be stabilized. Presented at fall meeting, American Oil Chemists' Society, Minneapolis, Minn., Oct. 11–13, 1954.     

不黏煤小焦炉炼焦试验研究

为研究预处理不黏煤对配煤炼焦特性的影响,利用小焦炉进行配煤炼焦试验,研究了预处理不黏煤与未处理不黏煤配煤对配煤变质程度、黏结性能、小焦炉炼焦焦炭冷热强度及光学组织的影响。结果表明,预处理后不黏煤的镜质组最大反射率由0.46%上升到1.20%,其根本原因是处理后含氧官能团含量降低;预处理后不黏煤仍没有黏结性,但配煤黏结性的下降幅度减小。小焦炉炼焦试验表明,添加不黏煤的焦炭冷热强度降低,在相同配比下添加预处理煤的焦炭强度降低幅度更小,在配比3%时,预处理不黏煤的焦炭转鼓强度上升了0.5%,反应后强度降低1%;而未处理不黏煤的转鼓强度和反应后强度分别降低了1%和4%,其主要原因是焦炭光学组织中中粒镶嵌结构增加,焦炭各项异性指数提高7.7%~15.8%。     

Radiative heat exchange modeling inside an oven

The 3D nongray radiative heat exchange in a near-infrared commercial oven is modeled. The spectrum is divided into into four gray bands to model the narrow wavelength range in which the halogen heat source radiates, the wavelength dependence of the food surface emittance, and the absorption coefficient of the heat source cover glass. The model is used to estimate the heating of a cuboidal food sample for 1 min at different cyclic settings of a halogen radiant heat source. The model predictions agree with the experimental data, and capture the cover-glass and the food-surface temperature and heat flux histories very well. The band-wise distribution of energy absorption by the food reveals the separate contributions from the source and the oven walls. Comparison of the heating rates between the measured non-gray food-surface and the different gray food-surface emittance values establishes the necessity of the nongray treatment. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Whiteness of talcum powders as a quality index for pharmaceutical uses

Talc is a whitish raw material of mineral origin used in the pharmaceutical industry. Talc quality for pharmaceutical uses is regulated by pharmacopoeias, which include several chemical and physicochemical tests. The aim of this study was to relate various color parameters of twenty-one white talcum powders from five countries, to their suitability for pharmaceutical use, following the tests included in the pharmacopoeias of USA (USP XXIII), Japan (Jap.Ph.XII) and Europe (Eur.Ph.II). The tests for loss on ignition 1000°C (USP XXIII), carbonates, iron and magnesium soluble in H₂SO₄ 1N (Eur.Ph.II), and loss on drying 500°C (Jap.Ph.XII), showed the best relationship with color parameters. The strength of these relationships allows the tests to be estimated from the color parameters or vice versa using regression models, of which Z₁₀-tristimulus value, lightness L*, and CIE whiteness index W₁₀ were the most influential parameters for explaining the models. As an index of suitability of the talc for pharmaceutical use, W₁₀ proved to be the most efficient of the three color parameters with a limit value of W₁₀ = 68.00 for USP XXIII. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23, 178–185, 1998     

Some notes on the keeping quality of fats in baked goods

Summary 1. Six fats have been tested for their stability in baked goods, both under normal and accelerated conditions. 2. Accelerated tests on the fats alone or on biscuits baked with them have not been found satisfactory for evaluating the stability of the fats. 3. The accelerated tests have been found particularly inadequate to properly evaluate the stability of hydrogenated lard in baked products. 4. It is concluded that the practice of evaluating fats for baking purposes by accelerated tests is not indicative of their true stability.     

Improvement of keeping quality of edible fats by some commercially available tannins

Summary The literature on the use of tannins as antioxidants for fats is reviewed. A process is described for the improvement of the keeping quality of edible fats by treatment with tannin in which the tannin and/or tannin compound is removed by filtration. Data are presented for various types of animal and vegetable fats and oils which were treated with U.S.P. tannic acid by the process described. The process is particularly effective on lard and beef fats. Data are presented which show the effects of varying the temperature at which the treatment is made. A method for testing the effectiveness of removal of the tannin is described. The improvement value I_v, is introduced and is defined as the increase in keeping quality of a fat attributable to a process. It is analogous to the I_A value which is defined as the increase in induction period of a fat due to the addition of an antioxidant. A paper presented at the A.O.C.S. Fall Convention at Chicago, Nov. 7–9, 1945. Part of the data were presented at the Conference on Problems Related to Fat Deterioration in Foods under the auspices of Committee of Food Research, Research and Development Branch, Military Training Division, Office of the Quartermaster General in Washington in June 1945.     

PVC-U管件热烘箱试验不合格原因及解决办法

分析了PVC-U管件热烘箱试验中常出现的质量缺陷的原因,并给出了解决办法。     

以氨为碱源的焦炉煤气脱硫工艺

介绍了以煤气中氨为碱源,OMC-对苯二酚为催化剂的湿法脱硫工艺。生产实践表明,该工艺不但脱硫脱氰效率高,而且无废液产生,是一种清洁生产工艺。     

Effect of storage conditions and antioxidants on the keeping quality of packaged oils

Journal of the American Oil Chemists' Society -     

关于开发薄炉墙焦炉的研讨

研究了6m焦炉炉墙减薄对焦炉炉体强度、结焦时间、焦炭产量以及炼焦能耗的影响。经详细计算及采用适当的调节措施,选用薄炉墙焦炉不但能够保持焦炭产量,还可以减少煤气耗量和环境污染等。