Processing of tomato: impact on in vitro bioaccessibility of lycopene and textural properties

BACKGROUND: Human studies have demonstrated that processing of tomato can greatly increase lycopene bioavailability. However, the difference between processing methods is not widely investigated. In the current study different thermal treatments of tomato were evaluated with regard to their impact on in vitro bioaccessibility and retention of lycopene and β‐carotene as well as textural properties. Thermal treatments used were low (60 °C) and high (90 °C) temperature blanching followed by boiling. RESULTS: Lycopene was relatively stable during thermal treatment, whereas β‐carotene was significantly (P < 0.05) reduced by all heat treatments except for low temperature blanching. In vitro bioaccessibility of lycopene was significantly increased from 5.1 ± 0.2 to 9.2 ± 1.8 and 9.7 ± 0.6 mg kg^?1 for low and high temperature blanching, respectively. An additional boiling step after blanching did not further improve lycopene bioaccessibility for any treatment, but significantly reduced the consistency of low temperature treated samples. CONCLUSION: Choice and order of processing treatments can have a large impact on both lycopene bioavailability and texture of tomato products. Further investigations are needed, but this study provides one of the first steps towards tomato products tailored to optimise nutritional benefits. Copyright © 2010 Society of Chemical Industry     

Lycopene degradation, isomerization and in vitro bioaccessibility in high pressure homogenized tomato puree containing oil: Effect of additional thermal and high pressure processing

In the present study, the effect of equivalent thermal and high pressure processes at pasteurization and sterilization intensities on some health related properties of high pressure homogenized tomato puree containing oil were investigated. Total lycopene concentration, cis-lycopene content and in vitro lycopene bioaccessibility were examined as health related properties. Results showed that pasteurization hardly affected the health related properties of tomato puree. Only the formation of cis-lycopene during intense thermal pasteurization was observed. Sterilization processes on the other hand had a significant effect on the health related properties. A significant decrease in total lycopene concentration was found after the sterilization processes. Next to degradation, significant isomerization was also observed: all-trans-lycopene was mainly converted to 9-cis- and 13-cis-lycopene. High pressure sterilization limited the overall lycopene isomerization, when compared to the equivalent thermal sterilization processes. The formation of 5-cis-lycopene on the other hand seemed to be favoured by high pressure. The in vitro lycopene bioaccessibility of high pressure homogenized tomato puree containing oil was decreased during subsequent thermal or high pressure processing, whereby significant changes were observed for all the sterilization processes.     

Dense phase carbon dioxide treatment of tomato juice: effect on physico-chemical properties,phenolic composition,lycopene isomerisation and in vitro bioaccessibility

The effect of dense phase carbon dioxide (DP-CO₂) technology on tomato juice qualities was investigated. Results showed that DP-CO₂ treatment induced a significant decrease in pH and an increase in titratable acid. Flavour profile and apparent viscosity were more close to the control (untreated) as compared to the heat-treated (95 °C for 20 min). Consumer acceptance test indicated that DP-CO₂ juices were more liked than the heat-treated in flavour, taste and overall acceptability. DP-CO₂ treatments at 30 MPa for 40 and 60 min had positive effects on the content of phenolic compounds, including myricinic acid, ferulic acid, naringin and chlorogenic acid. A significant increase in the relative content of sum cis-isomers was observed after DP-CO₂ treatment at 20 MPa. The in vitro lycopene bioaccessibility increased significantly after treatment at 20 MPa for 20, 40, 60 min as compared to the control and heat-treated.     

Effect of ultrasound treatments of tomato pulp on microstructure and lycopene in vitro bioaccessibility

The influence of ultrasound treatments of tomato pulp on microstructure and lycopene in vitro bioaccessibility was investigated. To this purpose, samples were subjected to ultrasound at a frequency and amplitude of 24 kHz and 100 μm, respectively, for increasing lengths of time. Results showed that ultrasound was responsible for loss of tomato cell integrity, as well as a decrease in the degree of pectin esterification. In contrast, rheological measurements showed that ultrasonically treated tomato pulp had greater gel-like properties than an untreated sample. It was inferred that ultrasound promoted the formation of a new network due to hydrogen bonding and hydrophobic interactions among the de-esterified pectin molecules. Such a reinforcement of the tomato pulp structure resulted in a decrease in lycopene in vitro bioaccessibility of the ultrasonically treated tomato pulp, probably due to the fact that the presence of a stronger network may make lycopene less available to the digestion process.     

Kinetic and thermodynamic investigation of mancozeb degradation in tomato homogenate during thermal processing

BACKGROUND: The kinetic and thermodynamic parameters of mancozeb degradation in tomato homogenates under the conditions prevailing in the manufacture of tomato products (at 60–100 °C for 0–60 min) were investigated. A gas chromatography–mass spectrometry method was used to analyse residual mancozeb in tomato homogenate. Ethylenethiourea (ETU), the main toxic degradation product of mancozeb, was measured by high‐performance liquid chromatography (HPLC)–with photodiode array detector (PDA). RESULTS: The degradation of mancozeb and the formation of ETU in tomato homogenates were adequately described as first‐order kinetics. Dependence of the rate constant followed the Arrhenius relationship. Apparent activation energies, temperature coefficients, half time and time to reduce to 90% of the initial value of mancozeb were calculated as kinetic parameters. The thermodynamic parameters of mancozeb were also described as Δg^d = ? 2.440 and 7.074 kJ mol^?1; Δh^d = ? 32.555 and ? 42.767 kJ mol^?1; Δs^d = ? 0.090 and ? 0.150 kJ mol^?1 K^?1; K_e = 0.414 and 9.797 L g^?1 for 333 and 373 K respectively. CONCLUSION: Current findings may shed light on the reduction of mancozeb residue and its toxic degradation product during thermal processing of tomatoes and may also be valuable in awareness and prevention of potential risks from dietary exposure. Copyright © 2011 Society of Chemical Industry     

Effect of pilot-scale aseptic processing on tomato soup quality parameters

Tomatoes are often processed into shelf-stable products. However, the different processing steps might have an impact on the product quality. In this study, a model tomato soup was prepared and the impact of pilot-scale aseptic processing, including heat treatment and high-pressure homogenization, on some selected quality parameters was evaluated. The vitamin C content, the lycopene isomer content, and the lycopene bioaccessibility were considered as health-promoting attributes. As a structural characteristic, the viscosity of the tomato soup was investigated. A tomato soup without oil as well as a tomato soup containing 5% olive oil were evaluated. Thermal processing had a negative effect on the vitamin C content, while lycopene degradation was limited. For both compounds, high-pressure homogenization caused additional losses. High-pressure homogenization also resulted in a higher viscosity that was accompanied by a decrease in lycopene bioaccessibility. The presence of lipids clearly enhanced the lycopene isomerization susceptibility and improved the bioaccessibility. PRACTICAL APPLICATION: The results obtained in this study are of relevance for product formulation and process design of tomato-based food products.     

加工方式对两种贝类中8种重金属元素生物可及性的影响

目的 分析水煮和烘烤两种加工方式对两种贝类元素中8种金属元素生物可及性的影响。方法 采用体外模拟消化实验,利用电感耦合等离子体质谱仪(inductively coupled plasma-mass spectrometry, ICP-MS)分析牡蛎(Crassostrea gigas)和扇贝(Azumapecten farreri)体内8种元素(铁、砷、镉、铜、铁、锌、锰、汞)的生物可及性和含量的变化。结果 两种贝类元素含量的趋势大体一致,从高到低依次为锌>铁>铜>镉>砷>铅>汞。两种贝类中生物可及性最高的是牡蛎中的砷元素,为98.4%。生物可及性最低的是扇贝中的铁元素,为3.4%。经过不同的加工方式处理后,能显著提高两种贝类锰元素的生物可及性及显著降低牡蛎中铜、砷、铅元素的生物可及性。加热处理后扇贝中砷和镉元素的生物可及性增加。相较于蒸煮的加热方式,烘烤的加工方式对贝类元素生物可及性的影响更大。通过相关性分析可以看出,贝类元素生物可及性不仅与元素种类、加工方式相关,也与其他元素浓度相关。结论 水煮和烘烤两种加工方式对贝类中8种重金属元素浓度和生物可...     

Lycopene in tomatoes: chemical and physical properties affected by food processing

Lycopene is the pigment principally responsible for the characteristic deep-red color of ripe tomato fruits and tomato products. It has attracted attention due to its biological and physicochemical properties, especially related to its effects as a natural antioxidant. Although it has no provitamin A activity, lycopene does exhibit a physical quenching rate constant with singlet oxygen almost twice as high as that of beta-carotene. This makes its presence in the diet of considerable interest. Increasing clinical evidence supports the role of lycopene as a micronutrient with important health benefits, because it appears to provide protection against a broad range of epithelial cancers. Tomatoes and related tomato products are the major source of lycopene compounds, and are also considered an important source of carotenoids in the human diet. Undesirable degradation of lycopene not only affects the sensory quality of the final products, but also the health benefit of tomato-based foods for the human body. Lycopene in fresh tomato fruits occurs essentially in the all-trans configuration. The main causes of tomato lycopene degradation during processing are isomerization and oxidation. Isomerization converts all-trans isomers to cis-isomers due to additional energy input and results in an unstable, energy-rich station. Determination of the degree of lycopene isomerization during processing would provide a measure of the potential health benefits of tomato-based foods. Thermal processing (bleaching, retorting, and freezing processes) generally cause some loss of lycopene in tomato-based foods. Heat induces isomerization of the all-trans to cis forms. The cis-isomers increase with temperature and processing time. In general, dehydrated and powdered tomatoes have poor lycopene stability unless carefully processed and promptly placed in a hermetically sealed and inert atmosphere for storage. A significant increase in the cis-isomers with a simultaneous decrease in the all-trans isomers can be observed in the dehydrated tomato samples using the different dehydration methods. Frozen foods and heat-sterilized foods exhibit excellent lycopene stability throughout their normal temperature storage shelf life. Lycopene bioavailability (absorption) can be influenced by many factors. The bioavailability of cis-isomers in food is higher than that of all-trans isomers. Lycopene bioavailability in processed tomato products is higher than in unprocessed fresh tomatoes. The composition and structure of the food also have an impact on the bioavailability of lycopene and may affect the release of lycopene from the tomato tissue matrix. Food processing may improve lycopene bioavailability by breaking down cell walls, which weakens the bonding forces between lycopene and tissue matrix, thus making lycopene more accessible and enhancing the cis-isomerization. More information on lycopene bioavailability, however, is needed. The pharmacokinetic properties of lycopene remain particularly poorly understood. Further research on the bioavalability, pharmacology, biochemistry, and physiology must be done to reveal the mechanism of lycopene in human diet, and the in vivo metabolism of lycopene. Consumer demand for healthy food products provides an opportunity to develop lycopene-rich food as new functional foods, as well as food-grade and pharmaceutical-grade lycopene as new nutraceutical products. An industrial scale, environmentally friendly lycopene extraction and purification procedure with minimal loss of bioactivities is highly desirable for the foods, feed, cosmetic, and pharmaceutical industries. High-quality lycopene products that meet food safety regulations will offer potential benefits to the food industry.     

A study on thermal stability of lycopene in tomato in water and oil food systems using response surface methodology

Thermal processed tomato‐food products rich in Z‐lycopene isomers have demonstrated higher bioactivity compared to fresh products which contain mainly all‐E‐lycopene isomer. The objectives of this study were to optimise processing conditions for production of tomato products rich in Z‐lycopene isomers in water and oil systems. The results showed that the optimal conditions for water and oil systems were temperature 120 °C, heating time 2.14 h, and the percentage of Z‐lycopene isomers content was 51 ± 1% and 57 ± 2%, respectively. The ratio of tomato extract to oil/water had no influence on the Z‐lycopene formation. Therefore, from these results it can be concluded that the combination of high temperature and relatively short heat treatment time could improve formation of Z‐lycopene isomers or degradation of Z‐isomers is lower during tomato processing .These research results could be useful in assisting the industry to improve processing technology, nutritional value and health‐benefits of tomato‐based foods.     

固定化混合酶提取番茄红素的工艺研究

以三种不同嵌段比例的聚乙二醇单甲醚-聚乳酸（mPEG-PLA）共聚物为载体,通过乳化-溶剂挥发法制备了番茄红素胶束（M-LYC）,采用高效液相色谱法（HPLC）测定M-LYC中番茄红素（LYC）各异构体的含量,计算其包封率（EE）和载药量（DL）,采用动态光散射纳米粒径分析仪测定粒径及Zeta电位,并通过透析法测定M-LYC在不同释放介质中的体外释放度,以筛选包载LYC的最佳嵌段比例的mPEG-PLA共聚物。结果表明,mPEG₄₅-PLA₃₆-M-LYC、mPEG₁₁₄-PLA₉₀-M-LYC、mPEG₁₁₄-PLA₁₈₀-M-LYC中总LYC的EE分别为65.04%、71.73%、23.62%,DL分别为3.96%、4.43%、1.39%,粒径分别为164.6、190.1、210.3 nm,Zeta电位分别为−15.38、−9.43、−10.96 mV。mPEG₁₁₄-PLA₉₀-M-LYC中各异构体及总LYC的EE最高,其次为mPEG₄₅-PLA₃₆-M-LYC,三种胶束中各顺式异构体包封率大小顺序均为5Z>9Z>13Z;mPEG₄₅-PLA₃₆-M-LYC在三种胶束中粒径最小且Zeta电位绝对值最大,说明其稳定性最好。LYC原料在不同释放介质中均未检测到LYC释放出来,三种胶束中,mPEG₄₅-PLA₃₆-M-LYC的总LYC在不同释放介质中72 h累积释放百分率均最高,分别为42.35%（pH6.8）和60.82%（pH7.4）;三种胶束在pH7.4释放介质中的累积释放百分率均高于pH6.8;三种胶束中全反式番茄红素（All-E）72 h累积释放百分率比总LYC略高,5Z在初期无释放,经过72 h后累积释放百分率高于All-E。综上所述,mPEG₄₅-PLA₃₆对LYC的包载效果较佳,以其为载体制备的M-LYC在三种胶束中粒径最小、Zeta电位绝对值最大、稳定性最好,且72 h总LYC的累积释放百分率最高,是一种极具潜力的包载LYC的高分子聚合物载体材料,并有望提高脂溶性营养物质在体内的生物利用度。     

Effect of moisture content, storage temperature and storage period on colour, ascorbic acid, lycopene and total flavonoids of dried tomato halves

Dried tomato halves with three storage moisture contents [18%, 24% and 30%, wet basis (wb)], packed in glass jar, plastic container and polyethylene bag were stored in room and cool-chamber environments for 5 months. During storage period average room and cool-chamber temperatures were 20 ± 4 and 5 ± 1 °C respectively. Changes of colour, ascorbic acid, lycopene, total flavonoids and moisture contents were monitored 1-month interval. Significantly higher losses of colour, ascorbic acid, lycopene and total flavonoids were found for room environment than those of cool chamber. A set of regression equations had been developed for colour, ascorbic acid, lycopene and total flavonoids as a function of storage time. No visible microorganisms were detected in the samples during the storage period. Dried tomato with ≤24% (wb) moisture content may be recommended to store in cool chamber (5 °C) and ≤18% (wb) to store in room environment (20 °C) both to be packed in glass jar.     

Lycopene content and antioxidant activity of fresh and processed tomatoes and in vitro bioavailability of lycopene

BACKGROUND: Lycopene, a phytochemical, has attracted a great deal of interest over the past few years. This has triggered research on the biological properties of lycopene and on the numerous factors that control these properties. Therefore, the aim of the study was to investigate lycopene content and antioxidant activity of fresh, sun‐dried and canned tomatoes. In addition, in vitro bioavailability of lycopene was determined. RESULTS: Lycopene contents of fresh, sun‐dried and canned tomatoes were found to be 1.74, 5.51 and 3.55 mg 100 g^?1, respectively, on a fresh wet basis. The highest lycopene bioavailability was obtained for sun‐dried tomatoes (58.05%) and this was followed by fresh (28.67%) and canned tomatoes (21.83%). Fresh tomatoes showed the highest antioxidant activity against ABTS radical oxidation. This was followed by sun‐dried tomatoes and canned tomatoes. The inhibition effect of intestinal dialysates of the samples on ABTS radical oxidation was between 51.34% and 92.96%. CONCLUSION: Maintenance antioxidant activity and existence of lycopene following an in vitro digestion process were the main findings, which might contribute forthcoming studies in this scientific field. Copyright © 2007 Society of Chemical Industry     

Effect of osmotic pre-treatment and microwave heating on lycopene degradation and isomerization in cherry tomato

Cherry tomato were dehydrated by a combination of different techniques (osmotic dehydration, convective drying, and microwaves assisted air drying) in order to evaluate the effect of the process variables on the degradation and isomerization of lycopene, as well as on the optical properties. Specifically, the effect of prior osmotic treatment, air drying temperature (40, 55, and 80 °C) and level of microwave energy (0, 1, and 3 W/g) were studied. Obtained results showed that the osmotic pre-treatment limited the isomerization during the later stage of drying, whereas both the loss of total lycopene and the trans–cis isomerization, mainly to the 13-cis form, were favored by an increase in temperature and the microwave power. Furthermore, a positive correlation between the degree of isomerization experienced by the samples during drying and the hue (h*) were obtained. This correlation was reflected in the colour of the sample with predominantly more orange tones and less reddish ones.     

Effect of increasing manganese concentration in nutrient solution on the antioxidant activity,vitamin C,lycopene and polyphenol contents of tomato fruit

ABSTRACT

This study evaluated the effect of increasing manganese (Mn) nutrition on the content of antioxidative compounds such as vitamin C, lycopene and polyphenols, and the antioxidant activity of tomato (Lycopersicon esculentum Mill., cvs ‘Alboney F1’ and ‘Emotion F₁’) fruit. Plants were grown in rockwool using a nutrient solution with the following content of Mn (mg dm^–3): 0.0, 0.3, 0.6, 1.2, 2.4, 4.8, 9.6 and 19.2. The level of vitamin C and lycopene decreased with the increasing Mn nutrition. Since the colour of fruits was correlated with the change in carotenoid content, the decrease in lycopene content promoted the reduction of redness and increase of yellowness of fruits. However, total polyphenol content and antioxidant activity significantly increased when plant were exposed to toxic levels of Mn. Observed changes could be the result of the oxidative stress induced by high concentrations of Mn. Polyphenolic compounds play a crucial role in the plant’s response to Mn stress and affect predominantly the total antioxidant properties of fruits, which could be used as a source of phenolics. Moreover, total phenolic content measurement, as an easy and inexpensive method, could be used as an indicator of Mn-induced stress in fruits of tomato.