Non-linear viscoelasticity modeling of tomato paste products

This paper deals with the characterization and modeling of the non-linear rheological properties of tomato paste samples manufactured under different conditions (sieve pore size and breaking temperature). With this aim, flow measurements, dynamic linear viscoelastic and linear and non-linear stress relaxation tests have been carried out on the above-mentioned tomato paste samples. Different geometries with smooth and serrated surfaces have been used to optimize the viscous flow measurements and avoid wall-depletion phenomena. The viscous flow properties of tomato paste samples depend on water insoluble solids (WIS) content and particle size, which may be highly influenced by processing conditions. In general, viscosity follows a power-law relationship with tomato paste water insoluble content and particle diameter. A factorable non-linear viscoelasticity model, the Wagner integral equation, predicts the non-linear rheological response of these products under shear fairly well. The time-dependent part of this model is described by a continuous linear relaxation spectrum, calculated from regularization techniques. The use of the Soskey–Winter damping function provides the best predictions of the viscous flow curves.     

Effect of tomato paste and nitrite level on processing and quality characteristics of frankfurters

Fourteen treatments of frankfurters (18% fat) were produced with two levels of sodium nitrite, 0 and 150mg/kg (0.015%), and seven levels (0%,2%,6%,8%,12% and 16%) of tomato paste with 12% soluble solids The higher the tomato paste level the higher the preference of consumers for frankfurters based on their colour. Frankfurters with 16% tomato paste had a sour taste while those with 12% tomato paste were the most acceptable. In a 2nd experiment three treatments of frankfurters (18% fat) were produced with 0, 50 and 100mg/kg of sodium nitrite and 12% tomato paste and a fourth (control) with only 150mg/kg sodium nitrite. Treatments with 12% tomato paste had lower (p<0.05) pH values and residual nitrite, and higher (p<0.05) thiobarbituric acid values, lightness and yellowness than control. Frankfurters with reduced levels of sodium nitrite (50 and 100mg/kg) and 12% tomato paste had the highest (p<0.05) redness. Storage time affected (p<0.05) all quality attributes. The nitrites added to frankfurters can be reduced from 150mg/kg to 100mg/kg in combination with 12% tomato paste without any negative effect on the quality of the product.     

Rheological and structural characterization of tomato paste and its influence on the quality of ketchup

Three hot break tomato pastes were investigated to determine the effect of their characteristics on the properties of tomato ketchup, processed in an industrial-scale facility (i.e. diluted, heated, homogenized and cooled). Pastes and ketchups were characterized by particle size distribution, volume fraction, and rheological behavior in steady and dynamic shear. The ketchups were also subjected to sensory assessment. The processing of pastes into ketchups induced large structural changes, which were reflected in all parameters studied. The volume fraction of solids (φ) accurately reflected the changes that the paste suspensions underwent during processing and it appeared to be a good predictor of the flow behavior of both the pastes and the ketchups. The corresponding flow curves were found to be well described by the Carreau model in a large range of shear rates and concentrations. However, the rheological characteristics of the commercial pastes studied did not directly correlate to those of the corresponding ketchups. Instead, our results suggest that the change in structure induced by processing might be governed by other properties of the paste, such as the fraction of small and large particles and their sensitivity to breakage, together with the viscosity of the aqueous phase.     

Comparison of the main analytical methods used in quality control of tomato paste

Methods commonly used in quality control analysis of tomato paste were compared as a means of selecting improved means of specification for trade. Methods studied included reducing sugars using Fehling's reagent, HPLC, and enzymatic analysis; total acidity by volumetric titration (with indicator and combined electrode); volatile acidity with two different steam distillation apparatus and separation columns; and citric acid using HPLC and enzymatic methods. The use of nonspecific methods of analysis, such as Fehling's method and volumetric titration using phenolphtalein for total acidity determination, causes significant errors; moreover, the results strictly depend on the concentration of the samples.     

A new quality parameter in tomato and tomato products: ergosterol

The poor precision of the "percentage of discarded fruits" and "Howard mold count" methods has increased the importance of ergosterol for the microbiological quality evaluation of tomato and tomato products. Ergosterol, a constituent of the cell wall of some important vegetable parasites, such as molds, has been recently recognized as a potential objective parameter useful for the characterization of the quality of processing tomatoes. Thus, 15 mg of ergosterol/kg total solids has been stated as an acceptability maximum limit of tomato products.     

不同条件下存放时番茄皮中番茄红素的降解动力学

光照、空气及温度等对番茄皮中番茄红素降解动力学参数的影响表明，温度对反应影响最为显著，番皮原料中番茄红素的含量变化遵从假一级反应规律，其ＬｎＫ－１／Ｔ关系为一条直线。作者计算出了番匣红素在光＋空气、光＋氮气、暗＋空气及暗＋氮气条件下降解反应的活化能分别为９．４５，１０．４６，９．７７及１４．５０ｋＪ／ｍｏｌ。     

Degradation Kinetics of Lycopene and Visual Color in Tomato Peel Isolated from Pomace

Kinetics of lycopene and visual color degradation of tomato peel was studied at selected temperatures (50–100°C). Models based on lycopene and Hunter (a?×?b) values of fractional conversion were applied to determine the kinetic parameters. The degradation of lycopene and Hunter color values adequately followed first order reaction model with R²?>?0.97. The temperature dependence of the rate constants was adequately modeled by the Arrhenius equation. The activation energies of lycopene and color parameters were 18.27 and 29.07 kJ/mol, respectively, indicating greater temperature sensitivity of visual color parameters. Correlation of lycopene content and Hunter (a?×?b) values showed that they can be used interchangeably with good accuracy.     

Antioxidative capacity of tomato products

The antioxidative capacity of methanol/water and hexane extracts of five tomato juices, four canned tomatoes and four tomato pastes was measured using two test systems: with 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS⁺) and with linoleic acid emulsion. In both the ABTS assay and the linoleic acid system, most of the antioxidative capacity of analysed products was from the methanol-water fraction, which contained polyphenols and ascorbic acid. On the basis of the wet weight of the tomato products, tomato pastes had the highest activity towards ABTS⁺ (micromoles of Trolox equivalents per gram) followed by tomato juices, and canned tomatoes. The inhibition of formation of thiobarbituric acid-reactive substances in the linoleic acid emulsion was strongly dependent on antioxidant concentration. The results suggest that tomato products, in addition to fresh tomatoes, may also be important in supplying dietary antioxidant, especially polyphenols and carotenoids.     

不同品种番茄对发酵番茄酱品质的影响

为了丰富番茄加工品种,开发一种发酵番茄酱。以四种新鲜的番茄品种为原料,添加凯里红酸汤来制作发酵型番茄酱并跟踪发酵过程中总酸、pH值、亚硝酸盐、番茄红素、可溶性固形物含量变化以及对成品感官评价。结果显示：美宝、奥宝番茄感官评价较好,品种间pH值变化无显著差异（P＞0.05）,美宝总酸含量、亚硝峰峰值最高,发酵结束后美宝总酸比市售番茄酱高出34%。美宝、经典欧卡番茄其与市售番茄酱番茄红素含量相近。美宝可溶性固形物含量最高为42%,各品种可溶性固形物含量均大于市售番茄酱。不同品种番茄酱发酵后成分具有一定的差异,结合不同品种的发酵番茄酱之间的特点,美宝番茄发酵后风味比市售番茄酱更佳。     

Effects of air-impingement jet drying on drying kinetics and quality retention of tomato slices

Food Science and Biotechnology - The purpose was to explore the drying kinetics, the moisture effective diffusivities, color, total polyphenols, lycopene and antioxidant activities of dried tomato...     

Degradation kinetics of folate (5-methyltetrahydrofolate) in navy beans under various processing conditions

The 5-methyltetrahydrofolate (5MTHF) is the predominate folate form that exists in navy beans and possesses health benefit to human beings. Understanding the degradation kinetics of 5MTHF during navy bean processing would provide useful information that characterizes the influence of processing conditions in order to minimize folate degradation and to maintain overall products quality during the beans’ production. The bio-specific procedures were used for sample preparation and purification, and HPLC techniques were subsequently used for identification and quantitative analysis of 5MTHF in the different treated bean samples. Losses of 5MTHF have been observed in all processed navy beans. Experimental results showed that the soaking time and the seed-to-water ratio were the two most critical factors that affected the stability of 5MTHF during the soaking process. The longer soaking times with larger amounts of soaking water caused higher degradation of 5MTHF. Cooking time and cooking media also played a key role in the degradation of 5MTHF in beans. Pressurized cooking showed the highest reduction of 5MTHF among all the treated bean samples. The treatment causes greater folate loss mainly through the promotion of water penetration and high diffusion, leading to more folate being released from the bean matrix, and accelerating the oxidation and decomposition of folates during cooking.     

Stability of carotenoids in tomato juice during storage

The stability of carotenoids in tomato juice during storage was studied. Tomato juice was processed by hot-breaking of tomatoes at 82 °C, screening, heating at 121 °C for 40 s and then storing in the dark or under light at 4, 25 and 35 °C for 12 weeks. Results showed that the amounts of all-trans-lutein and its cis isomers decreased with increasing storage time for all the treatments. Light enhanced the degradation and isomerization of all-trans-lutein, and 13-cis-lutein was more susceptible to formation than 9-cis-lutein. Similar trends were observed for β-carotene and lycopene. However, light exposure promoted the formation of di-cis-, 9-cis- and 13-cis-β-carotene. For lycopene, 15-cis-lycopene was the major isomer formed during dark storage at 4 °C, while 9-cis- and 13-cis-lycopene were favoured at 25 °C and 5-cis- as well as 13-cis-lycopene dominated at 35 °C. Under light storage, both 9-cis- and di-cis-lycopene (II) were the main isomers generated at 35 °C, whereas 13-cis- and 15-cis-lycopene were the most abundant at 4 and 25 °C.     

The dissipation of cyazofamid and its main metabolite CCIM during tomato growth and tomato paste making process

ABSTRACT

In several studies focused on the residues of cyazofamid and its main metabolite 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM) on tomato where it is widely used, CCIM has been shown to have higher acute toxicity than cyazofamid, and this is crucial to evaluate the potential food risk of cyazofamid and CCIM. In this study, the dissipation of cyazofamid and CCIM during tomato growth and tomato paste making process were assessed. The targeted compounds cyazofamid and CCIM were determined by LC-MS/MS. The results indicated that the half-life of cyazofamid was 4.6 days after applying in the field, and the maximum value of CCIM was 0.08 mg/kg at 3 days after the last application of cyazofamid, then gradually decreased. In addition, the concentrations of cyazofamid and CCIM were affected by different processing steps including washing, peeling, homogenisation, simmering, and sterilisation. Results showed that the mean losses of cyazofamid and CCIM were 92.3% and 75.2% after washing and peeling. The Processing Factor (PF) values were all less than 1. Especially for peeling, the PFs of cyazofamid and CCIM were 0.12 and 0.04, respectively.     

疑似胀袋番茄酱中几种微生物的检测研究

依照现有国标及相关资料提供的方法对疑似胀袋番茄酱中的霉菌和酵母菌进行了计数及菌落总数进行了检测。按照国标方法测出此番茄酱中的霉菌和酵母计数为1.1×105cfu/g;菌落总数未检出,而按照相关资料方法却从此番茄酱中分离出了嗜温革兰球菌和芽孢杆菌。     

番茄酱中白色云状凝聚物形成机理的探讨

对番茄酱产品在保质期内出现的白色云状凝聚物的形成机理进行了初步探讨。显微镜观察以及微生物检测结果表明,白色云状凝聚物不含番茄细胞组织,也未发现任何微生物存在。白色云状物经热水浸提、离心后,得到水溶性物质(WSS)和水不溶性物质(WIS)。分析结果显示,白色云状凝聚物的形成可能是由于蛋白质的凝聚造成的,它与蛋白质中碱性氨基酸以及非极性氨基酸的比例有密切的关系;蛋白质凝聚过程还通过酸性氨基酸以氢键结合的方式吸附少量的果胶物质。     

Influence of processing on the rheological properties of tomato paste

This paper deals with the influence that some processing variables (sieve pore size and breaking temperature) and tomato variety exert on the linear viscoelastic properties of tomato paste. With this aim, 16 tomato paste samples from four different varieties (with different contents of the pectolytic enzymes polygalacturonase and pectin methylesterase) have been manufactured at different breaking temperatures (65–85 °C) and screen sizes (0.8–2.2 mm). From the experimental results obtained, we conclude that tomato paste behaves as a weak gel, showing a wide plateau region in its linear relaxation spectrum. The linear viscoelastic properties of tomato paste depend dramatically on water‐insoluble solids content and particle size, which may be greatly influenced by processing variables. Nevertheless, the specific action of the above‐mentioned pectolytic enzymes must also be taken into account. © 2002 Society of Chemical Industry     

Profibus-DP现场总线在番茄酱厂螺杆泵控制系统中的应用

螺杆泵电动机的运行速度对番茄酱的加工品质有着重要影响,为了对螺杆泵电动机的运行进行实时监控,提出了一种基于Profibus-DP现场总线的控制方法。该方法采用以触摸屏为上位机、PLC为控制器,并以变频器作为执行器的应用系统方案,给出调试步骤,对运行结果进行分析。结果表明,系统能够很好地监控螺杆泵电动机的运行,实时反馈运行状态及报警信息,具有稳定性好、响应速度快等特点。系统的应用保证了螺杆泵电动机运行速度的准确控制,实现了系统的数字化管理,延长了螺杆泵的使用寿命,节省电能,为同类农产品加工设备的自动控制提供参考。     

婴幼儿番茄鱼泥罐头工艺的优化研究

采用了感官评定和正交实验法,对婴幼儿番茄鱼泥罐头的工艺和配方进行了优化。通过反复实验,确定婴幼儿番茄鱼泥罐头的最佳配方为:30%番茄、14%蛋黄、6%奶粉。对按该配方生产的产品进行理化及微生物检测,结果表明,该产品具有鱼肉与番茄的独特滋味,酱体橙红色,呈半固态状,料质均匀,粘稠适中,乳化效果好,实为目前婴幼儿的最佳营养食品。     

Detection of ten biogenic amines in Chinese commercial soybean paste by HPLC

This paper aimed to develop a high-performance liquid chromatography (HPLC) method that can simultaneously detect ten biogenic amines (BAs) in commercially available soybean paste and to determine the contents of BAs in these products. Heptylamine (Hep) was used as the internal standard reagent and benzoyl chloride as the sample derivatization reagent; Inertsil ODS-3 chromatographic column was set as the stationary phase while the acetonitrile and 5 mmol/L ammonium acetate solution as the mobile phases; the samples were treated with gradient elution and detected at 254 nm (UV). Perchloric acid solution (0.4 mol/L) was employed as the sample extraction solvent to determine the contents of ten BAs in soybean paste products. All BAs were separated within 20 min. The methodological validation suggested good linearity, whereas the linear correlation coefficient of all standards was greater than 0.99 with the linear range of 0.1–80 μg/g, detection limits of 0.01–0.03 μg/g, and quantitation limits of 0.03–0.10 μg/g. For 17 commercially available soybean paste products involved in our study, different samples were distinguished from each other not only by the dramatic differences in the contents of BAs but also by the variance in BA types. Of these BAs, tyramine (Tyr) and agmatine (Agm) were found to be the highest contents in soybean paste products; the contents of histamine (His), 2-phenylethylamine (Phe), serotonin (Ser), spermidine (Spd), and putrescine (Put) were lower, followed by cadaverine (Cad), tryptamine (Try), and spermine (Spm). This method proved to be highly sensitive and effective in determining the contents of BAs in soybean paste products; there was a dramatic difference in the contents of ten BAs among different soybean paste products.     

Proteomic response of LAP-activated RAW 264.7 macrophages to the anti-inflammatory property of fungal ergosterol

Ergosterol is the principal fungal sterol in edible mushrooms and yeast lees in wine. In this study, the immunoregulatory action of ergosterol was evaluated by a proteomic approach using two-dimensional gel electrophoresis to identify proteins with modified expression in LPS-challenged RAW 264.7 macrophages treated with ergosterol. By comparing the proteome signatures, alterations of multiple proteins were observed, including NF-κB cascade-related proteins, Rho family GTPase protein, and cytoskeleton-related proteins. The down-regulation of NF-κB cascade-associated proteins coincided with the inhibition of TNF-α production and COX-2 expression in the ergosterol-treated RAW 264.7 cells. Western blotting analysis indicated that ergosterol inhibits LPS-induced inflammation in RAW 264.7 macrophages by suppressing the NF-κB signalling pathway.