Spray Drying Performance of a Laboratory Spray Dryer for Tomato Powder Preparation

This work investigates the performance of a spray dryer for tomato powder preparation by spray drying of tomato pulp. Samples of tomato pulp with a 14% constant total solids concentration were used, and a pilot scale spray dryer (Buchi, B-191) with cocurrent operation and a two-fluid nozzle atomizer was employed for the spray drying process. Twenty-four different experiments were conducted keeping constant the feed rate, the feed temperature, and the atomizer pressure, and varying the compressed air flow rate, the flow rate of drying rate, and the air inlet temperature. In each experiment the air outlet temperature was recorded. Data for the residue remaining in the chamber and cyclone walls was gathered and two types of efficiencies were calculated as an indication of the spray dryer performance. Analysis of experimental data yielded correlations between residue accumulation and the variable operating conditions. The same operating parameters had a great influence on the air outlet temperature whereas temperature deviations were observed comparing measured air outlet temperatures with corresponding outlet adiabatic saturation temperatures.     

Modelling Industrial Wastewater Ozonation In Bubble Contactors. 1. Rate Coefficient Determination

A study of the ozonation of distillery and tomato wastewaters was carried out in a small bubble contactor in order to obtain kinetic data for scaling-up. Thus, several parameters, such as chemical oxygen demand (COD), 254 nm absorbance (A₂₅₄) and organic carbon content (OC), were followed during ozonation at different experimental conditions.

For distillery wastewaters all parameters investigated have the highest decreases during the first minutes of ozonation, A₂₅₄ showing the highest disappearance rates. Thus, during the first fifteen minutes of ozonation an important decrease of the 254 nm absorbance (? 75%) was observed. At further reaction times values of all parameters studied decrease slowly, eventually reaching a plateau value. During approximately the first two hours of reaction, dissolved ozone was never found, which suggested that fast or moderate gas-liquid reactions took place in the wastewaters.     

基于遗传算法的番茄缺素叶片图像特征选择

在基于计算机视觉技术对无土栽培番茄营养元素缺乏智能识别研究中，如何选择出对缺素叶片分类能力强的特征项组合是识别诊断面临的关键问题，文章利用遗传算法对提取的缺素叶片图像众多颜色和纹理特征项进行优化选择，以达到诊断识别用的信息最优，实验表明，经过优化的特征组合明显优于人工选择的特征组合分类能力。     

Effect of household canning on the distribution and reduction of thiophanate-methyl and its metabolite carbendazim residues in tomato

Tomato in the field was sprayed with thiophanate-methyl to quantify the effect of household processing on pesticide residues. Changes in the residue levels of thiophanate-methyl and its metabolite carbendazim in tomatoes were assessed during home-canning processing. Pesticide residues in tomato were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after washing, peeling, homogenization, simmering, and sterilization. Results showed that washing with tap water reduced thiophanate-methyl residues by 25.0% and carbendazim residues by 13.0%. The peeling process yielded 84.2% loss in thiophanate-methyl and 87.3% loss in carbendazim from tomatoes. Peeling is thus the most effective step to remove pesticide residues from tomatoes. Homogenization, simmering, and sterilization exerted limited effects on the removal of thiophanate-methyl and carbendazim. The processing factors (PFs) of tomato samples after each step were generally less than 1; in particular, the PFs of the peeling process for thiophanate-methyl and carbendazim were 0.19 and 0.14, respectively.     

乳酸发酵番茄汁中间生产试验

将筛选出的保加利亚乳杆菌(L. bulgaricus)和嗜热链球菌(Str. thermophilus)应用于乳酸发酵番茄汁的中试生产中。先在20升发酵罐内进行了两批试验,确立了初步的生产工艺流程,然后在500升发酵罐进行了进一步试验,获得了成功,生产出的乳酸发酵番茄汁pH为4.0～4.3,乳酸含量0.7％左右,加蔗糖3％,不添加防腐剂、香精、色素等化学物质。保存半年后经检测,其理化及微生物学指标均符合国家规定标准。申试结果为工业规模生产奠定了基础。     

四种常用淀粉物理性质的比较研究

主要研究了四种常用淀粉(玉米淀粉、马铃薯淀粉、木薯淀粉、小麦淀粉)的透明度、冻融稳定性、凝沉性、膨胀度及糊化特性，并进行比较。为进一步了解这四种淀粉的特性及应用，提供了理论依据。     

Nondestructive determination of soluble solids content and pH in tomato juice using NIR transmittance spectroscopy

The potential of near-infrared (NIR) transmittance spectroscopy to nondestructively detect soluble solids content (SSC) and pH in tomato juices was investigated. A total of 200 tomato juice samples were used for NIR spectroscopy analysis at 800–2400 nm using an FT-NIR spectrometer. Multiplicative signal correction (MSC), and the first and second derivative were applied for pre-processing spectral data. The relationship between SSC, pH, and FT-NIR spectra of tomato juice were analyzed via partial least-squares (PLS) regression. PLS regression models were able to predict SSC and pH in tomato juices. The r _c, RMSEC, RMSEP, and RMSECV for SSC were 0.92, 0.0703°Brix, 0.150°Brix, and 0.138°Brix, respectively, whereas those values for pH were 0.90, 0.0333, 0.0316, and 0.0489, respectively. It is concluded that the combination of NIR transmittance spectroscopy and PLS methods can be used to provide a technique of convenient, versatile, and rapid analysis for SSC and pH in tomato juices.     

西红柿的贮藏特性研究

以成熟的西红柿为材料,研究不同包装方式和贮藏温度下西红柿品质变化规律,为西红柿贮藏品质的控制提供依据.结果表明,温度和贮藏时间对西红柿的腐烂率、失重率、VC含量﹑总酸含量影响显著,包装方式只对外观和失重率影响显著.随着贮藏时间的延长和贮藏温度的升高,西红柿的腐烂和失重的速度和程度增加,VC含量﹑酸度随着贮藏温度的升高逐渐下降.膜包装比无膜包装的贮藏效果好.西红柿适宜的贮藏条件为采用膜包装于12℃下贮藏.在此条件下贮藏20天后,西红柿品质保持较好.     

Tailoring Cu/Al2O3 catalysts for the catalytic pyrolysis of tomato waste

In this study, pyrolysis of tomato waste has been performed in fixed bed tubular reactor at 500 °C, both in absence and presence of Cu/Al₂O₃ catalyst. The influences of heating rate, catalyst preparation method and catalyst loading on bio-oil yields and properties were examined. According to pyrolysis experiments, the highest bio-oil yield was obtained as 30.31% with a heating rate of 100 °C/min, 5% Cu/Al₂O₃ catalyst loading ratio and co-precipitation method. Results showed that the catalysts have strong positive effect on bio-oil yields. Bio-oil quality obtained from fast catalytic pyrolysis was more favorable than that obtained from non-catalytic and slow catalytic pyrolysis.     

Carotenoids and Their Geometry Isomers in Selected Tropical Fruits

This study determined the carotenoids content in cherry tomato, pink guava, and red grapefruit pulps and juices. Cherry tomato pulp exhibited the highest β-carotene content whereas pink guava pulp had the highest lycopene content. However, β-carotene and lycopene contents in the studied fruit juices were lower than their pulps in the same sample portion. Interestingly, six to twelve cis-isomers of carotenoids were identified in the fruit pulps and juices studied. A higher number of trace amounts of cis-carotenoids was found in fruit pulps as compared to juices. Therefore, consumption of whole fruit is recommended as the studied fruit juices have lower carotenoids content.