Characterization of the Red Layer and Pericarp of Processing Tomato using Magnetic Resonance Imaging

Abstract: The characteristics of tomato pericarp are closely associated with peelabililty, an important quality attribute of processing tomatoes. Different types of tissue exist in the pericarp of tomato. The outermost region of the pericarp, the red layer, is removed with the skin during peeling. This study investigated the morphological features and tissue properties of red layer and pericarp for 3 processing tomato cultivars using magnetic resonance imaging (MRI). The red layer can be visualized in MR images with T₂ weighting, indicating the red layer has different properties compared to the rest of the pericarp region. Tomatoes were imaged with a set of MRI sequences with signal intensity dependent on different water proton properties. Principal component analysis (PCA) of the statistical features revealed clustering of fruit by cultivar. The spatial distribution of cultivars in the PCA score plot followed their rank of peeling performance. MRI demonstrated potential as a nondestructive method to characterize tomato pericarp and evaluate the peelability of processing tomatoes. Practical Application: Peelability of tomatoes affects the quality of value‐added whole peel and diced tomato products. The properties of the pericarp of tomato are directly related to the peelability of tomatoes. MRI provided a fast and nondestructive method to characterize the properties of tomato pericarp. The result of this work gives insight into the correlation between tomato pericarp characteristics and peelability.     

西红柿催化红外去皮过程三维传热模型的建立和设备能耗计算

为提高西红柿红外干法去皮的加工性能,本研究建立了红外辐射加热的三维传热模型,利用该模型对西红柿红外去皮过程中表面和内部不同位置的温度进行预测,并通过比较温度预测值和实测值来验证模型的拟合度;进一步通过能耗计算对比分析两种不同的红外设备,筛选出较优的红外设备。结果表明,与静态催化红外设备相比,燃气-滚轮传送式催化红外设备可以实现对西红柿表皮的快速加热（表面最高温度为60.32℃）,且西红柿表面温度分布更均匀（最大温差约6.44℃）;内部温度增幅较低（内部最高温度为49.10℃）,且内部温度分布也较均匀（最大温差约18.25℃）。模型预测值与实测值之间的拟合较好（R2≥0.93）,且两者之间的估计标准误差EESE值较低（0.13～10.80℃）,表明三维传热模型的拟合效果良好,能够很好地反映不同红外设备下西红柿表面和内部的温度分布。与静态式催化红外设备相比,燃气-滚轮传送式催化红外设备更优,即缩短了16.60%的加工时间,又节约了34.80%的能耗,更高效节能,在果蔬去皮领域具有广阔的应用前景及工业化推广价值。     

Numerical Simulation of Variable Water Diffusivity during Drying of Peeled and Unpeeled Tomato

Abstract: A mathematical model was formulated for the estimation, in conjunction with experimental measurements, of water diffusivity parameters during convective drying of peeled and unpeeled tomatoes. Fick's 2nd law of diffusion was solved numerically for a sphere, by explicit finite differences, considering shrinkage effect, variable diffusivity, and constant boundary conditions. Experiments were performed in a laboratory tunnel dryer. The equivalent radius of tomato decreased by 50% until the end of the process, which explains the necessity for shrinkage inclusion in the mass transfer model. The mean estimated diffusivities varied between 2.03 × 10^?10 and 15.1 × 10^?10 m²/s for peeled tomatoes and 0.59 × 10^?10 and 15.2 × 10^?10 m²/s for unpeeled tomatoes. The estimated water diffusivities and their variation with the tested drying temperatures (45, 55, and 65 °C) provide an insight of peeling effect during air‐drying. Peeling was beneficial since yielded greater drying rates and shortened significantly drying times, thus saving energy during drying. In all the studied cases, good agreement was found between experimental and predicted drying curves (≥ 0.99, mean relative deviation [MRD]≤ 0.12, and root mean square error [RMSE]≤ 0.03). In overall, the proposed methodology provides a reliable and easy estimation of temperature and moisture‐dependent mass transfer properties and drying simulation of shrinkable food products such as tomato. Practical Application: Water diffusivity is a food property, difficult in estimation but essential in drying processing optimization. This property was estimated as a function of moisture content and drying temperature employing a numerical simulation procedure. The peeling effect was also studied and found beneficial for lower temperature drying (<55 °C) which is useful in the energy optimization of the drying process as well as the retention of the end‐product quality.     

基于催化式红外的西红柿干法去皮技术

目的：探寻一种高效且绿色环保的西红柿去皮方法。方法：利用催化式红外设备进行西红柿干法去皮,考察工艺参数对西红柿去皮性能和果肉品质的影响,并与传统的热水和碱液去皮方式进行对比。结果：双板距离、红外加热温度和红外加热时间均对西红柿去皮率和果肉品质有显著影响（P<0.05）,西红柿催化式红外干法去皮的最优工艺参数为催化红外温度450 ℃,双板距离25 cm,红外处理时间5 min,此时西红柿去皮率高达98%,且果肉硬度（7.60 g/mm²）和番茄红素含量（30.39 mg/kg）最优,颜色鲜红。与传统热水和碱液去皮方式相比,红外去皮属于干法去皮,是一种环境友好型的去皮方法;红外去皮处理后西红柿果肉具有最高的硬度、番茄红素含量,颜色更红润,果肉完整性良好;红外去皮处理对果皮和果肉微观结构的影响最小,对果皮果肉连接层的微观结构有明显影响,促进了果皮与果肉的分离,表明红外去皮机制与其他几种去皮方式不同。结论：催化式红外去皮方式更适合西红柿的去皮加工,可以实现高效去皮、绿色环保且能保障产品品质。     

取汁方式对热破碎番茄汁品质的影响

研究了2种取汁方式在不同的热处理条件下对热破碎番茄汁品质的影响。结果表明,破碎-加热-打浆取汁方式(简称为BHJ)的番茄汁粘度、果胶含量和番茄红素含量显著高于打浆取汁-加热的取汁方式(简称为JH),但取汁方式对汁的色差影响不大。在本试验范围内,BHJ取汁的番茄汁品质优于JH取汁。     

不同去皮方法对番茄去皮效果和品质的影响

为优化现有番茄去皮工艺,开发新的去皮方法,以去皮难易程度和质量损失评价去皮效果,比较手工去皮、热水去皮、碱液去皮、功率超声去皮和超声与碱液联用去皮对去皮效果和产品质地、颜色、番茄红素提取率、p H值和可滴定酸含量等品质的影响,并结合扫描电子显微镜观察不同去皮方法果皮微观结构。结果表明,功率超声去皮较传统的热水去皮和碱液去皮,去皮难度小,质量损失少,且产品品质良好,番茄红素含量较高,而超声与碱液联用去皮较其他去皮方法虽去皮难度小,但质量损失过高。扫描电子显微镜观察结果表明,功率超声去皮较热水去皮、碱液去皮对果皮角质层的破坏力更大,可能是超声的空化效应使果皮与果肉更易分离,从而降低去皮损失。因此,功率超声去皮是一种潜在的新型环境友好型去皮方法。     

番茄加工新趋势

综述了当今番茄加工的新趋势:采用新方法、新技术生产高质量传统番茄制品,科学合理地从番茄中分离番茄红素,综合利用番茄皮渣,并给我国番茄加工的研究和发展提出一些有用的建议。     

番茄酱中果胶含量与番茄粉品质特性相关性研究

以番茄酱为原料,研究原料酱中果胶含量与喷雾干燥番茄粉品质特性的关系,对不同果胶含量番茄酱制得的番茄粉的得率、显微特征和色泽变化规律进行研究。结果表明：在相同喷雾干燥工艺条件下,番茄粉的得率与番茄酱的果胶含量成正比;相同果胶含量的番茄粉随着颗粒度的减小与不同果胶含量的番茄粉随着果胶含量的增加,其色泽变化趋势相同,由红色向橘红色过度,即L 值逐渐增大,a 值逐渐减小,b 值逐渐增大;不同果胶含量的番茄粉随着果胶含量的增加,粒径分布更均匀、分散性更好。     

高效液相色谱测定番茄制品中的三种功能性脂肪酸

通过高效液相色谱-质谱技术和高效液相色谱技术对番茄制品中9-羟基-10(E),12(Z)-十八碳二烯酸、9-羰基-10(E),12(Z)-十八碳二烯酸和9-羰基-10(E),12(E)-十八碳二烯酸三种功能性脂肪酸进行定性定量分析。结果表明,在色谱柱为Eclipse XDB-C18(4.6 mm×250 mm,5 μm),流动相为0.005%的三氟乙酸水溶液和0.005%的三氟乙酸乙腈溶液,检测波长为234、280 nm的条件下,番茄制品中的三种脂肪酸在20 min内得到较好分离,重复性好(RSD ≤ 2.13%),精密度高(RSD ≤ 0.70%),稳定性好(RSD ≤ 0.98%),加标回收结果准确可靠(平均回收率分别为99.78%、99.70%、99.39%,RSD ≤ 3.38%)。该色谱方法快速、准确、可靠;测试结果表明,新鲜番茄中不含有这三种功能性脂肪酸,其仅存在于番茄制品中,且加工工艺对其含量影响较大;此外9-羟基-10(E),12(Z)-十八碳二烯酸为首次在番茄制品中发现。     

Rheological Properties of Tomato Paste: Influence of the Addition of Tomato Slurry

ABSTRACT: This article deals with the influence that the addition of tomato slurry into tomato juice exerts on the viscous flow and linear viscoelastic behavior of the final tomato paste. With this aim, 5 tomato paste samples, manufactured at industrial scale, have been studied. Three breaking temperatures and 2 different screen sizes were used to prepare 4 regular tomato paste samples. Moreover, a tomato paste sample with addition of "treated tomato slurry" was manufactured using a breaking temperature of 80 °C and a sieve screen size of 1.2 mm. The results obtained suggest that the addition of treated tomato slurry may be of great interest for tomato paste production.     

樱桃番茄与普通番茄部分品质指标及氨基酸组成比较

以樱桃番茄（YT）和普通番茄（PT）各9 个品种为材料,比较2 种番茄果实相关品质指标,包括可溶性固形物、可溶性糖、可滴定酸、糖酸比、VC、番茄红素及氨基酸。结果表明：所有YT品种可溶性固形物含量均高于PT品种,YT的平均含量比PT高48%;9 个YT品种可溶性糖的平均含量比PT高34.08%,而可滴定酸的平均含量比PT低10%,糖酸比高出46.10%,VC的平均含量比PT高84.59%,番茄红素的平均含量比PT高76.30%。YT的果实品质要明显高于PT。对综合指标表现最好的YT-5和PT-3果实中氨基酸含量及组成进行鉴定,测出13 种氨基酸,总含量分别为2.176%和1.115%,其中含量最高的为谷氨酸,含量最低的为甘氨酸,人体必需氨基酸有5 种,分别占氨基酸总量的24.82%和30.94%。YT品种与PT品种相比,增加幅度最大的是精氨酸,为241.67%;变化幅度最小的为缬氨酸,增加了38.71%。与YT相比,PT的人体必需氨基酸含量与非必需氨基酸含量之比为0.448,较接近理想蛋白质的要求。YT中各种人体必需氨基酸,苯丙氨酸＋酪氨酸、赖氨酸、异亮氨酸、亮氨酸的含量占氨基酸总量的比例,与1973年FAO/WHO修订的人体必需氨基酸含量模式谱基本一致,仅缬氨酸较缺乏;而PT中均基本一致。YT中的儿童必需氨基酸含量显著高于PT;YT中鲜味类、芳香族、甜味类氨基酸含量均高于PT。因此,与PT相比,YT的品质更高,且氨基酸组成更加优质合理。     

几种壳聚糖复合保鲜剂对番茄的保鲜作用研究

用四种壳聚糖配制的复合保鲜剂保鲜番茄。贮藏期间,定期测试其生理生化指标。结果表明:保鲜剂C(1%壳聚糖溶液:1‰阿米西达溶液=1:1(V/V))对番茄的保鲜效果比其它三种保鲜剂更好,保鲜时间更长,处理12d后,失水率为1.17%,腐烂率为0,呼吸强度是5.82mg/kg·h,(VC)含量为180mg/100g。     

农杆菌介导的反义LeERF2基因转化番茄

利用根癌农杆菌(Agrobacterium tumefaciens)介导的叶盘法将LeERF2反义基因导入中蔬四号番茄(Lycopersicon esculentumcv.No.4 Zhongshu)进行遗传转化研究。在卡那霉素选择压力下获得的再生植株,经过PCR、点杂交和Southern杂交鉴定,证实了该反义基因已导入番茄基因组中,共获得了25棵转基因植株,并建立了一个高效的番茄转化体系。Northern杂交结果表明,转反义LeERF2基因番茄果实外果皮LeERF2基因表达水平比野生型番茄低。     

Lycopene Stability in Tomato Powders

The chemical stability of lycopene in 2 commercial tomato powders was evaluated during storage. Liquid chromatography and spectral analysis were used to determine lycopene loss and the formation of cis isomers and degradation products. Tomato powder products were stored at 6 and 45 °C or under fluorescent light for up to 6 wk. Several lycopene degradation products were tentatively identified in the initial and stored powders. After 6 wk at 45 °C, 60% of the lycopene was degraded. At lower storage temperatures the losses were about 30% after 6 wk. Mechanisms of loss appear to be both isomerization and oxidation.     

植酸对番茄保鲜效果的影响

以变色期番茄为材料,分别采用浓度为0.05%、0.10%、0.15%的植酸溶液浸泡30s,在室温下贮藏33d,研究不同浓度植酸溶液涂膜处理对番茄果实的保鲜效果。结果表明,植酸溶液处理能推迟番茄果实呼吸跃变时呼吸高峰的出现时间,降低呼吸强度峰值;对保持果实硬度、可溶性固形物、维生素C、可滴定酸有较好作用;能减少水分蒸发,降低果实失重率;其中浓度为0.10%的植酸溶液对番茄果实进行涂膜处理保鲜效果最好。     

番茄汁饮料的开发

本文报道了酸甜番茄汁、番茄汁汽水生产工艺研究，制定了这两种新产品的质量标准，并就生产过程的的注意事项进行了探讨，为增加风味各异的番茄制品和更好地利用我国丰富的番茄资源提供了商条新途径。     

浑浊型番茄饮料稳定性研究

本研究主要对番茄饮料在加工贮藏过程中易出现分层、色泽变淡等稳定性降低的现象进行研究。结果表明:单一稳定剂的稳定效果是:琼脂>黄原胶>CMC-Na。单一稳定剂的口感效果是:琼脂>CMC-Na>黄原胶。正交试验结果表明:使用质量比为0.05%的黄原胶、0.1%的琼脂的复配增稠剂饮料的稳定性最好。番茄红素对热有较好的稳定性,在100℃以下加热损失率不大;对光不稳定,在强烈的日光直射下,1h后残存率就降到36.7%;茶多酚对番茄红素保护效果浓度在0.06%时的效果最好,VC浓度为0.08%时保护效果最佳。由正交试验得到的最佳工艺参数为:番茄原汁、白砂糖、复合增稠剂、柠檬酸、VC和茶多酚的含量分别30%、8%、0.15%、0.20%、0.013%和0.02%。     

西红柿籽营养成分的分析

为了进一步开发利用新疆的西红柿籽资源，分析了西红柿籽的营养成分。西红柿籽含23．12％的油，19．60％的蛋白质，22．35％的总糖，0．208％的维生素E。还分析了西红柿籽的免基酸和微量元素组成。西红柿籽油中含亚油酸51．34％。西红柿籽油的理化指标为：密度d4^20 0.0367，碘值196．69gI/100g，折光指数n^20 1．4626，皂化值190.29mgKOH/g，不皂化物8．26％。     

赤霉素对番茄保鲜效果的影响

将变色期番茄果实浸入浓度为40mg/L、80mg/L、120mg/L的赤霉素溶液中30s,在常温下贮藏33d,研究赤霉素对番茄果实保鲜效果的影响。结果表明,赤霉素处理能推迟番茄果实呼吸跃变的出现时间,降低呼吸强度峰值;对保持果实硬度、可溶性固形物、维生素C、可滴定酸有较好作用;能减少水分蒸发,降低果实失重率。使用浓度为80mg/L的赤霉素溶液对番茄果实进行涂膜处理有较好的保鲜效果。