Chemical and electrophoretic properties of Holstein cow milk as affected by somatic cell count

Chemical and electrophoretic properties of raw milk samples with different somatic cell counts (SCCs)(<200 000, 200 000–800 000 and >800 000 cells/mL) were determined. Milk was analysed for fat, lactose, total nitrogen (TN), non‐casein nitrogen (NCN), ratio of casein nitrogen to total nitrogen (CN/TN), pH, titratable acidity (TA), solid‐non‐fat (SNF), total solid (TS), the amount of α _s ‐casein and β‐casein. Milk SCC had no significant effect (P ≥ 0.05) on fat and TN. An increase in the SCC resulted in an increase in pH and NCN content, and a significant decrease in lactose, TA, SNF, CN/TN, α_s‐casein and β‐casein. Milk quality of Holstein dairy cattle deteriorate due to higher proteolytic activity associated with high SCC.     

Numerical and experimental investigation on the breast cancer tumour parameters by inverse heat transfer method using genetic algorithm and image processing

This study presents numerical and experimental investigation on breast cancer tumour parameters by inverse heat transfer method using genetic algorithm (GA) and image processing (IP) to determine the depth and rate of heat generation of a breast cancer tumour. To simulate the problem, using the energy equation in a cylinder including a heater, the surface temperature distribution was obtained. Then, the temperature surface of the cylinder was analysed by the GA in MATLAB software to determine the depth and rate of heat generation of heater. The validity of the numerical method was evaluated using the IP from a laboratory sample. A thermal heater was placed inside a cylinder and was covered by a tissue similar to the human body tissue. According to the obtained results, it was determined that the results of the laboratory sample and the numerical method were in agreement with each other. Finally, these steps were applied on the thermal image of a patient’s cancer breast to determine the depth and rate of heat generation of the breast tumour. It is shown that the average computational error between numerical and experimental results in this method to determine the depth of the tumour is about 8–10% and to determine the rate of tumour heat generation is about 0.01–1%.     

EFFECT OF VARIOUS DRYING METHODS ON TEXTURE AND COLOR OF TOMATO HALVES

Tomatoes were pretreated with osmotic solutions (NaCl and sucrose) at different concentrations and then dried using hot air (75C, 1.5 m/s), a vacuum (55C, 75 kPa) or hot-air drying followed by microwave treatment (400 W, 10 s). The effects of pretreatment and drying method on the drying kinetics were examined. A puncture test and scanning electron microscopy were used to analyze the effects of these processes on texture and microstructure. Hunter values ( L, a, b ) were used to measure color. Measurements showed that two osmotic solutions, S₃ (40% sucrose, 5% NaCl) and S₄ (40% sucrose, 10% NaCl), performed better, reducing drying times and having a positive effect on microstructure, but an adverse effect on hardness. Apart from the type of process, dehydration reduced firmness and collapsed the structure of tomato halves. The subsequent microwave treatment then caused further damage, especially on the surface of the dried samples, but enhanced their color when combined with appropriate osmotic treatment.

PRACTICAL APPLICATIONS

This study shows that the color and structural changes of tomato during drying can be reduced using appropriate procedure. This may find application in the production of dried tomato with better appearance and lower drying cost.     

The effect of Lallemantia royleana (Balangu) seed, palmate-tuber salep and carboxymethylcellulose gums on the physicochemical and sensory properties of typical soft ice cream

This study was aimed primarily at determining the suitability of two Iranian sources of hydrocolloid, Balangu seed and palmate-tuber salep (PTS), for the production of ice cream mix. For this purpose, the effect of these gums and carboxymethylcellulose (CMC) on some physicochemical and sensory characteristics of a typical soft ice cream was investigated. In comparison with carboxymethylcellulose, Balangu seed did not make a significant difference ( P  > 0.05) to most characteristics and could be used as a suitable stabiliser. Although products prepared using only the palmate-tuber salep showed more differences from the corresponding ones with carboxymethylcellulose, the variations were not significant.     

Effect of commercial adjunct lactobacilli on biochemical and sensory characteristics of Iranian white-brined cheese

Iranian white-brined cheese was made in open vats using commercial adjunct culture of Lactobacillus helveticus Lh.Bo2 in viable and freeze-shocked (FS) forms. Biochemical and sensory characteristics of the trial cheese were studied during 2 months of ripening. Assessment of primary proteolysis by SDS-PAGE and water soluble nitrogen for the trial cheese showed no or small differences throughout ripening. However, the experimental cheeses exhibited significantly greater rates of free amino group formation. Lipolysis as measured by total free fatty acid was consistently higher in cheese made with the FS adjunct culture. Expert panellists detected significant differences between the control and the experimental cheese.     

Use of silane coupling agent for surface modification of zinc oxide as inorganic filler and preparation of poly(amide-imide)/zinc oxide nanocomposite containing phenylalanine moieties

A series of novel poly(amide?Cimide)/ZnO nanocomposites with modified ZnO nanoparticles contents was prepared by ultrasonic irradiation. For this purpose, surface of ZnO nanoparticle was modified with $\boldsymbol\gamma$ -aminopropyltriethoxysilane as a coupling agent. Then the effect of surface modification on dispersion of nanoparticles, thermal stability and UV absorption property of the obtained nanocomposites were investigated. The resulting novel nanocomposites were characterized by several techniques. Field emission scanning electron microscopy and transmission electron microscopy analyses of the nanocomposites were performed in order to study the dispersion of nanofillers in the polymer matrix. According to thermogravimetry analysis results, the addition of ZnO nanoparticles improved thermal stability of the obtained nanocomposites. Since the resulting nanocomposites contain phenylalanine amino acid and ZnO, they are expected to be biocompatible as well as biodegradable.     

基于Adams和Matlab联合仿真的双足机器人越障研究

与轮行机器人相比,双足机器人具有更灵活的机械结构,具有跨越静态或动态障碍物的能力,使其可以在更复杂的环境中工作;以往的双足机器人路径规划控制策略只能解决静止或以可预测速度运动的障碍物的越障问题,提出了一种基于模糊Q学习算法的路径规划策略,在Adams软件中建立机器人的三维虚拟样机模型,在Matlab软件中设计控制器,进行联合仿真;仿真结果表明所设计的控制策略可以有效地克服机器人在线学习时间长的问题,并且可以成功跨越速度不可预测的运动障碍物,有很好的鲁棒性。