COFFEE CHERRY DRYING: A TWO-LAYER MODEL

Drying of Coffea arabica cherry was carried out in a thin layer dryer at air temperatures of 40, 50, 60 and 70°C at bed depths of 50, 62.5 and 75mm with air flow rates of 1.5 and 2m³/m²/ min. Since the coffee cherry consis ts of skin and bean, a two layer drying model was developed to characterize the overall drying process for relative humidity range of 46 to 83 per cent. The diffusion coeffcient was determined using drying and equilibrium data and expressed as an Arrhenius- type function. The study revealed that the qualityof the coffee was unaltered over the temperature range studied.     

辛硫磷微胶囊悬浮剂的研制

采用界面聚合法研究了多种囊壳单体及不同配比对辛硫磷微胶囊成囊的影响,其中以占油相5％的N1单体与2．5％的S1单体聚合所得的微胶囊理化性能较为稳定,54℃热贮14d有效成分分解率仅为5．4％。选定了制剂适宜的分散剂F和稳定剂H,成功地研制出理化性能高度稳定的35％辛硫磷微胶囊悬浮剂小样。该小样具有较好的控制释放性能,水中24、120h释放率分别为24．9％和44．8％。田间药效试验表明此小样对甘薯茎线虫病持效期明显比乳油长,药后180d的防效为81．5％,远高于乳油的63．2％;对甘薯的增产效果比乳油高21％。     

微波辅助法提取紫甘薯中的原花青素及含量的测定

研究了以紫甘薯为原料,利用微波辅助法提取原花青素时提取剂浓度、料液比、微波处理时间等因素对提取率的影响。结果表明,在此最佳实验条件下,即以盐酸的乙醇溶液为提取液,在乙醇的体积分数为50％,料液比（g：mL）为1．70,微波处理70s,所得的原花青素浸提量为0．96mg／g。     

阳离子聚丙烯酰胺对甜高梁混合汁中泥沙的絮凝效果研究

以阳离子型聚丙烯酰胺（CPAM）为澄清剂,对甜高粱混合汁中的泥沙进行絮凝处理。实验结果表明,CPAM对水样的絮凝效果良好,糖分损失很小,且在投加量为1．5mg／L时,絮凝效果达到最佳,絮凝率达到78．54％;CPAM最佳投药量处水样的吸光度值随着泥沙含量的升高而变大;甜高粱混合汁中含糖量越低,CPAM的除泥沙效果越好;沉降时间对CPAM的絮凝效果无明显影响;pH对CPAM除泥沙效果有较大的影响,且在pH为5时絮凝效果达到最佳,絮凝率达到85．86％。     

Process optimization of sweet potato pulp‐based biodegradable plastics using response surface methodology

Biodegradable plastics were produced from sweet potato pulp (SPP) and cationic starch (CS) or chitosan composite (CC) by compression molding and their mechanical properties were tested. A universal testing machine, Rockwell hardness tester, and Izod impact tester were used for testing the mechanical properties (flexural strength, Rockwell hardness, and Izod strength) of the plastics. A central composite second‐order design was used to study the effects of temperature, time, and moisture content on the flexural strength, Rockwell hardness, and Izod strength of SPP/CS and SPP/CC blended plastics. The flexural strength, Rockwell hardness, and Izod strength of SPP‐based plastics was 101.1–305.9 kg/cm², R29.0–R96.7, and 0.6–3.0 kg cm cm^?2, respectively. Regression analysis predicted the optimal mechanical properties (flexural strength, Rockwell hardness, and Izod strength) to be attained with a 150–160°C temperature, 15–20‐min reaction time, and 20–23% moisture content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 423–434, 2002     

甘薯贮藏保鲜剂的研制

研制了甘薯贮藏保鲜剂 .简要论述了该保鲜剂的组成、制备工艺、效能 ,使用效果及经济效益     

非蛋白氮对单细胞蛋白生产菌株生长影响的研究

主要研究了非蛋白氮对选育的山芋淀粉渣单细胞蛋白生产菌株生长的影响。采用选育的扣囊拟内孢霉 K991株、产朊假丝酵母 C986株、绿色木霉 T995株混合发酵山芋渣生产单细胞蛋白 ,结果表明适宜的非蛋白氮可有效促进不同发酵方式中菌株的生长。尿素添加量在质量分数为 2 .5 %时对扣囊拟内孢霉 K991单菌株生长有利 (7.7× 1 0 8个 /g) ,在质量分数 2 %对产朊假丝酵母 C986单菌株生长较好 (1 .2× 1 0 7个 /g)。多菌株混菌发酵好于单菌株发酵 ,尿素或硫酸铵添加量均在质量分数为 2 .0 % ,产朊假丝酵母 C986菌数和产品蛋白含量较高 ,分别为 7.0× 1 0 7个 /g和 2 5 .82 %。     

Physical characteristics of sweet potato pulp/polycaprolactone blends

Sweet potato pulp (SSP) obtained as a by‐product from starch extraction was blended with polycaprolactone (PCL) to prepare a biodegradable plastic material. In the blends, PCL was used as a reinforcing agent. The SPP/PCL blends were prepared by compression‐molding under high temperature and pressure, at different SPP/PCL ratios, and the mechanical properties of the molded specimens were tested. Matrix structure and thermal properties were measured by using a Fourier transform infrared (FTIR) spectrophotometer, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). Mechanical properties (tensile and flexural properties) were also measured to find the most suitable ratio in a SSP/PCL blend. During compression molding of the SPP/PCL blends under high pressure and temperature, chemical reaction occurred between SPP and PCL, and thus, thermal stability and mechanical strength of the blends increased and water uptake decreased. Also, by increasing the PCL content in the blend, the matrix in the blend became more homogeneous, and consequently, mechanical strength of the molded specimen increased. At 7/3 or 6/4 weight ratio of SSP/PCL, water uptake of the molded specimen became substantially less than that at 8/2. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 861–866, 2004     

甜橙皮精油提取及其主要化学成分分析

采用冷磨法提取甜橙皮精油,研究了浸泡液质量浓度、浸泡时间、果皮破碎度、破乳剂添加量等因素对甜橙皮精油提取率的影响。结果表明,当浸泡液石灰水的质量分数为3%,浸泡时间为2h,果皮破碎度为0.3cm,破乳剂NaCl添加量为1mg/mL时,甜橙精油提取率为0.57%,GC-MS分析甜橙皮精油主要化学成分为d-苧烯。