Feeding Tomatoes to Hamsters Reduces their Plasma Low-density Lipoprotein Cholesterol and Triglycerides

Hamsters were fed semipurified diets containing green or red freeze‐dried tomato powders. Compared to the control diet devoid of tomatoes, a 59% and 44% reduction low‐density lipoprotein (LDL) cholesterol was induced by both the green and red tomatoes, respectively. The corresponding reductions in very low‐density lipoproteins (VLDL) were 45% and 35% and in plasma triglyceride concentrations 47% and 31%, respectively. Plasma levels of high‐density lipoproteins (HDL) were unaffected. Fecal deoxycholic and lithocholic acid concentrations of hamsters on tomato diets were higher than those on control diets. Possible contributions of major components of green and red tomatoes to these beneficial effects are discussed.     

不同成熟期番茄及其储藏过程中超弱发光特性的研究

本文分别研究了不同成熟期番茄的超弱发光特性，为番茄采摘的质量检验和分级提供了一种无损伤的检测方法；同时跟踪测试了番茄在储藏过程中的超弱发光特性，与国家标准相对应，初步确定了储存期限和果品质量的关系。为确定番茄的采摘期和存储时间提供了相应的依据。     

Green-ripe(Gr)基因植物表达载体的构建及在Micro-Tom番茄中的遗传转化

Green-ripe(Gr)是一种番茄果实成熟突变体,有报道表明番茄中的Gr基因以某种形式参与乙烯信号转导途径,导致番茄果实成熟过程中的乙烯不敏感特性。从番茄果实中克隆Gr基因,成功构建Gr基因的植物表达载体pCAMBIA-1300-Gr,并以Micro-Tom番茄品种为材料,采用农杆菌介导叶盘法转化得到转基因植株,经PCR初步验证为阳性植株,为进一步研究Gr基因的功能奠定了基础。     

Extraction and Analysis of Metabolic Phosphates in Plants

We have developed a method for extraction and simultaneous detection and quantification of nucleotides and other phosphate compounds in various tissues. Analyses were based on modification of a method previously applied to animal tissue using an automated chromato-graphic analyser developed in our laboratory. Utilizing perchloric acid extracts of peas (fresh and frozen), tomatoes, and other plant tissues, we detected 19 organic phosphate compounds with the automated phosphate analyzer. The method is generally applicable to plant tissue.     

不同烹调和贮藏方式对番茄中V_C含量的影响

采用2,6二氯酚靛酚法来测定番茄中VC含量,研究不同家庭烹调方法和贮藏方式对VC的影响,旨在为促进烹调工艺标准化提供相关理论依据。结果表明:随着烹调时间增加,番茄中VC含量越来越少,说明其损失程度越来越大。炒制番茄比煮制番茄更易于保持番茄中维生素C。烹调时加入食醋,有利于保护番茄中VC。加醋炒制3min的番茄最适于食用。烹调后番茄中VC含量与贮藏时间成反比,0℃保藏比25℃保藏更有利于保护VC,贮藏时间24h后食用价值较低。      

Preference Mapping of Fresh Tomatoes Across 3 Stages of Consumption

Tomatoes (Solanum lycoperiscum) are a popular produce choice and provide many bioactive compounds. Consumer choice of tomatoes is influenced by flavor and visual appearance and external texture cues including hand firmness and sliceability. The objective of this study was to determine drivers of liking for fresh tomatoes across 3 stages of consumption. Seven tomato cultivars were ripened to a 6 on the USDA color chart. Trained panelists documented appearance, flavor, and texture attributes of tomatoes in triplicate. Tomato consumers (n = 177) were provided with knives and cutting boards and evaluated tomatoes across 3 stages: appearance (stage 1), slicing (stage 2), and consumption (stage 3). Consumers evaluated overall liking at each stage. Analysis of variance and external preference mapping were conducted. Overall liking was highest during the appearance portion of the test and lowest during the consumption portion (P < 0.05). Drivers of liking at stage 1 were color intensity, even outside color, and overall aroma. Drivers of liking at stage 2 were wetness/juiciness and overall aroma. Wetness/juiciness, seed presence, ripe flavor, and sweet and umami tastes were drivers of liking for tomatoes at consumption (stage 3). Four separate clusters of tomato consumers were identified. Cluster 1 preferred tomatoes with even color, higher color intensity, and flavor intensity. Cluster 2 preferred firm tomatoes. Cluster 3 preferred tomatoes that were soft and at peak ripeness; this cluster also had the highest liking scores for all tomatoes. Cluster 4 consumers generally consumed tomatoes in sandwiches rather than as‐is and preferred tomatoes with even and intense color. Tomato growers can utilize these results to target cultivars that are well liked by consumers.     

A research note: the potential for transfer of Salmonella from irrigation water to tomatoes

The transmission of Salmonella Enteritidis from soil to fruit by contaminated irrigated water was studied using 20 patio tomato plants. In order to track the presence of Salmonella in the soil and plants a luminescent strain transformed with the full luxCDABE gene cassette from Photorhabdus luminescens was used. The tomato plants were irrigated every other day by direct application of water containing Salmonella Enteritidis (10⁵ CFU ml^?1) to the soil. Samples of soil, stem, leaf and fruit were taken weekly and assayed for Salmonella by plating onto Luria Bertani agar containing 50 µg ml^?1 ampicillin. There was a significant difference (P < 0.05) in Salmonella counts from soils sampled during the course of the study. No Salmonella were recovered from the leaf, stem, and fruit samples taken from the tomato plants. This indicates that, under these test conditions, watering with contaminated water directly into the soil does not result in the transmission of Salmonella, and possibly other pathogens, to tomatoes. Copyright © 2004 Society of Chemical Industry     

电生功能水对番茄的保鲜

利用电生功能水对番茄进行了保鲜试验的研究。结果表明,酸性水或酸性水加氯化钙浸泡10min的番茄果实在室温贮藏12d后,果实硬度明显较对照高。进一步的研究表明酸性水和酸性水加氯化钙处理能后多聚半乳糖醛酸酶活被显著抑制,呼吸强度被明显抑制,失重率降低。     

圣女果保鲜技术研究进展

本文综述了圣女果的保鲜技术的国内外研究现状,对圣女果保鲜常用的物理保鲜法、化学保鲜法及涂膜保鲜法做了详细介绍,并简要提及了采后冷热处理、臭氧处理及加减压处理等保鲜技术,对目前圣女果保鲜中存在的问题进行了简要分析,其目的是为今后更深入的研究和探讨提供参考与借鉴。      

不同贮藏条件对番茄品质的影响

本试验模拟流通环境,研究了不同贮藏条件对番茄品质的影响。结果表明番茄在流通过程中必须在不低于10℃冷链进行贮藏,,在10℃和湿度为78%±5%的条件下对番茄进行贮藏可应用于流通生产。     

Gloss Properties and Surface Morphology Relationships of Fruits

Eggplants exhibited a higher average gloss reading (15.3 Gloss Units (GU)) than mature green tomatoes (12.0 GU) and apples (8.2 GU) using a flat surface glossmeter. The same trend was observed using a novel curved surface glossmeter. Scanning electron micrographs revealed that epicuticular wax covering eggplants had a smoother structure than that of tomatoes and apples, providing a more effective light scattering surface. Wax removal resulted in decreases in gloss, with average readings of 9.5, 7.4 and 6.3 GU for eggplants, tomatoes and apples, respectively. These results indicate the extent to which wax may influence shininess, although roughness measurements of flattened peel after wax removal suggest that surface topography also influences gloss.     

Color and Firmness Classification of Fresh Market Tomatoes

A total of 370 tomatoes from two seasons were analyzed using a vision system and three mechanical properties sensors which measured firmness parameters. Multiple linear regression indicated classification based on color and firmness could be applied in practical sorting and improves overall classification. Hue values provided adequate information for classification. The best model (R²= 0.96) based on 13 specific colors yielded severe misclassification of 2.2% for classification into 12 maturity classes and 79% correct classification with all samples classified ± one maturity stage according to USDA standards. A weighted color parameter provided a stable model invariant to changes in lighting conditions and yielded excellent results (R²= 0.89). Quality classification was successfully achieved using a vision and drop impact sensor.     

Alpha-Tomatine Purification and Quantification in Tomatoes by HPLC

A high-performance liquid chromatographic procedure was developed for purification and quantification of α-tomatine from tomatoes. A crude preparation of glycoalkaloids from tomato fruits was fractionated on a column of Nucleosil NH₂ (10 μm), and eluted with a mixture of tetrahydrofuran/acetonitrile/0.02 M KH₂PO₄ (50/30/20, v/v/v). The column effluent was monitored at 205 run. Total analysis of α-tomatine was completed in < 10 min. It was present at highest concentrations in fruit at the mature-green stage but its level decreased rapidly as fruit approached full maturity. The technique should be useful for analysis of α-tomatine in biological samples.     

Lycopene content of tomatoes and tomato products and their contribution to dietary lycopene

Tomatoes are an integral part of diet world wide. Many population studies have established link between dietary intake of tomatoes, a major source of a carotenoid antioxidant lycopene and reduced risk of chronic diseases. This study evaluates the lycopene contents of various commonly consumed tomato products and estimates its daily intake levels. A fast and simple spectrophotometric method for routine analysis of lycopene was developed and validated against HPLC method. Lycopene content in various tomato products ranged from 42 ppm to 365 ppm. Average daily dietary lycopene intake levels were assessed by administering food frequency questionnaire and were estimated to be 25.2 mg day⁻¹. Fresh tomatoes accounted for 50% of total lycopene intake.     

圣女果番茄红素提取工艺优化

从预处理方法、浸提溶剂、料液比、浸提温度、浸提时间等方面对圣女果中番茄红素的提取工艺进行研究。经单因素试验对预处理方法及浸提溶剂进行选择,结果表明加入等体积无水乙醇、浸泡2h、离心脱水是提取番茄红素的最佳预处理方法,丙酮-正己烷(2:1)混合液是理想的提取溶剂。采用正交试验方法对液料比、提取温度和提取时间进行优化,得到适宜的提取条件为丙酮-正己烷(2:1)溶剂液料比为3:1、提取温度40℃、提取时间2.5h。在此提取工艺下,圣女果中的番茄红素提取量为4.08mg/100g。     

Consumer attitude and behaviour towards tomatoes after 10 years of Flandria quality labelling

In recent years, trust in food safety and food quality has decreased as a result of consecutive food crises. Consequently, numerous quality labels signalling process-related credence characteristics have been established. One of these labels is the Belgian Flandria quality label for fresh fruit and vegetables. Based on cross-sectional data collected through a self-administered consumer survey ( n  = 373), this paper addresses consumer attitudes, behaviour and perception towards tomatoes in general, and the Flandria tomato label in particular. Buyers, who constitute 26.8% of the sample, perceive Flandria tomatoes as superior to other tomatoes because of their guarantee of origin, better taste and stricter production control. However, they also report the strongest perception of Flandria as an ordinary tomato as compared to non-buyer segments. Overall, findings indicate that the Flandria label – after being intensively used for 10 years for a wide range of other fruits and vegetables besides tomatoes – has become fairly standard for tomatoes with little perceived differentiation apart from its certified production and origin.     

Changes in purified tomato pectinmethylesterase activity during thermal and high pressure treatment

The enzymatic reaction of purified tomato pectinmethylesterase on pectin was investigated during a combined high pressure/temperature treatment (0.1–600 MPa/20–65 °C) at pH 8.0 and pH 4.4. The optimal temperature for tomato pectinmethylesterase activity at atmospheric pressure is situated around 45 °C at pH 8.0, and around 35 °C at pH 4.4. At both pH 8.0 and pH 4.4, the optimal temperature shifted to higher values at elevated pressure compared with atmospheric pressure. At both pH values, the catalytic activity of tomato pectinmethylesterase was higher at elevated pressure than at atmospheric pressure, creating possibilities for rheology improvements by pressure processing. Maximal tomato pectinmethylesterase activity in the pressure–temperature domain investigated was observed at 55 °C and 300 MPa for pH 8.0 and at 57 °C and 450 MPa for pH 4.4. However, under all pressure–temperature conditions tested the catalytic activity of tomato pectinmethylesterase at pH 4.4 was much lower than at pH 8.0. The chemical de‐esterification of pectin at pH 8.0 was accelerated by increasing pressure and temperature, whereas no chemical deesterification of pectin was observed at pH 4.4. Copyright © 2004 Society of Chemical Industry     

Qualitative and nutritional differences in processing tomatoes grown under commercial organic and conventional production systems

ABSTRACT:  Organically grown products experienced a doubling in percent penetration of organic sales into retail markets during the period from 1997 to 2003; however, there is still a debate over the perceived quality advantage of organically grown fruits and vegetables. In a study focusing on commercial production of processing tomatoes, samples were analyzed from 4 growers with matched organic and conventional fields. For the 4 growers studied, individual analysis of variance results indicated that tomato juice prepared from organically produced tomatoes on some farms was significantly higher in soluble solids (°Brix), higher in consistency, and titratable acidity, but lower in red color, ascorbic acid, and total phenolics content in the microwaved juice. Results were significantly different among specific growers, and this may be attributed to differences in soil type and soil nutrients, tomato cultivar, environmental conditions, or other production-related factors. Higher levels of soluble solids, titratable acidity, and consistency are desirable for the production of tomato paste, in that tomatoes with these attributes may be more flavorful and require less thermal treatment. This has the potential to result both in cost savings from less energy required in paste manufacture and potentially a higher quality product due to less thermal degradation of color, flavor, and nutrients. Future work may involve a larger number of commercial growers and correlation to controlled university research plots.     

Nondestructive Measurement of Peel Gloss and Roughness to Determine Tomato Fruit Ripening and Chilling Injury

Mature-green tomatoes showed a gradual decrease in peel gloss during ripening at 20°C. Gloss correlated well with parameters such as a* values and °Brix and could possibly serve as criteria for ripeness. When stored at 2°C for 7, 14 or 21 days and then allowed to ripen at 20°C, fluctuations in gloss during ripening were observed. Peel roughness increased as a result of chilling, but did not appear to be related to time elapsed at the chilling temperature and no changes were observed on subsequent ripening. Pink tomatoes showed fluctuations in gloss similar to mature-green fruit. Chilling had no influence on roughness of pink tomatoes.     

Active Modified Atmosphere Packaging of Fresh Fruits and Vegetables: Modeling with Tomatoes and Oxygen Absorber

Design of active modified atmosphere packaging for vegetables was studied by developing a mathematical model predicting gas changes and based on the following independently evaluated parameters: vegetable respiration rate, film permeability, and oxygen absorption kinetic of the absorber. A step‐by‐step model validation was performed on a tomatoes/low‐density polyethylene pouch/commercial iron‐based scavenger system at 20 °C. Without optimization, the model fit experimental data with root mean square error (RMSE) value lower than 1.5. Oxygen absorbers had a strong influence on transient period characteristics by reducing their duration (50 and 100 h with and without absorber, respectively) and suppression of the CO₂ peak owing to a rapid oxygen depletion.