高顺式番茄红素制备工艺研究

番茄红素是一种具有优越生理活性的功能因子,相比天然全反式番茄红素,顺式结构的番茄红素具有更高的生物活性和生物利用率。以全反式番茄红素为原料,脂肪酸为溶剂,采用微波加热法对番茄红素进行异构化,探究脂肪酸,微波条件,催化剂对番茄红素异构化的影响。以番茄红素顺式占比为指标,通过单因素试验,对微波加热法制备高顺式番茄红素工艺进行优化。研究结果表明,微波温度81 ℃,微波功率600 W,微波时间11 min,亚油酸和辛癸酸甘油酯1:1比例添加3 mL,催化剂二烯丙基二硫添加量80 mg/mL,此条件下得到13Z,(5Z,9Z)及其他未知未知异构体组分番茄红素总顺式占比为(40.19±0.27)%。稳定性试验表明,温度越低,番茄红素保留率越高,等温条件下,反式最稳定,(5Z, 9Z)次之,13Z最不稳定。此方案可以有效提高番茄红素顺式占比,从而提高番茄红素在人体内的消化吸收,提高生物利用率,并为开发含番茄红素的功能食用油产品提供了理论依据。     

番茄红素异构化及在番茄果汁中的应用

天然存在的番茄红素90%为反式异构体,大量研究表明顺式异构体生物活性较高。所以为提高番茄果汁中顺式异构体的含量,实验以顺式番茄红素占比为指标,通过单因素实验研究微波功率、微波时间、微波温度对番茄红素异构化的影响。在单因素实验的基础上,采用正交实验法优化番茄红素异构化工艺条件,将此条件应用于番茄果汁进行番茄红素异构化处理。结果表明,微波功率250W、微波加热温度90℃、异构化时间6h,顺式番茄红素占比51.62%,将此条件应用到番茄果汁中,异构化后果汁中含有番茄红素28.34±0.02μg/mL,顺式番茄红素含量为14.62±0.05μg/mL。采用微波加热异构化方法可以将番茄果汁中反式异构体转化为顺式异构体,为新型番茄果汁的研发提供一定理论依据。     

番茄红素在有机溶剂中的异构化

采用C 3 0柱 (YMCTM CarotenoidS 5 4 6mm× 2 5 0mm )对番茄红素顺反异构体进行分离测定 ,对番茄红素在不同温度及不同有机溶剂中的异构化程度进行了比较。结果表明 ,在以甲醇 甲基叔丁基醚 乙酸乙酯 (体积比为 5 0∶40∶1 0 )为流动相 ,流速为 1 5mL/min ,温度 2 5℃条件下 ,可将番茄红素全反式与顺式异构体进行分离。番茄红素在不同溶剂中顺反异构化程度不同 ,二氯甲烷 >丙酮 >四氢呋喃 >乙酸乙酯 >正己烷 ;异构化程度与温度有关 ,1 5℃时异构化程度高于 4℃时     

红酸汤烹调过程中全反式番茄红素含量变化规律研究

红酸汤不但是独具贵州民族特色的酸味调味品,而且其中的番茄红素还具有很好的健康效应,不少研究表明食品加工过程会影响番茄红素的构型进而影响其生物活性,因此文章对红酸汤烹调过程中全反式番茄红素含量的变化规律进行了研究。实验表明人们生活中最常采用的烹调方式(大中小的烹调火力顺序)且不加或者少加盐导致红酸汤中的全反式番茄红素含量降低最多,减少的全反式番茄红素可能转变为了顺式番茄红素,可能是最具健康效应的烹调方式。     

番茄红素光异构化及热稳定性研究

采用光照协同光敏剂的方法对全反式番茄红素进行异构化，以顺式占比为指标，优化了全反式番茄红素光异构化的工艺条件并对其稳定性进行研究。响应面优化实验结果表明，番茄红素浓度为0.16 mg/mL、荧光素浓度为0.14 mg/mL、时间为56 min，此条件下得到番茄红素顺式占比最高为33.71%。采用高效液相色谱法进行番茄红素结构的测定，最终得到5种番茄红素异构体，包括(5,9)-顺式番茄红素、13-顺式番茄红素、异构体1、异构体2和全反式番茄红素。稳定性实验结果表明，在不同温度条件下，各异构体均会发生不同程度的降解，番茄红素各异构体在37℃条件下的变化最为显著，而在4℃条件下降解最慢。此外，全反式番茄红素在几种主要番茄红素同分异构体中表现出最高的稳定性，其次是(5,9)-顺式番茄红素，而13-顺式番茄红素的稳定性最低。     

红葡萄柚番茄红素和色泽热降解动力学及降解机制

对红葡萄柚中番茄红素和色泽进行热降解动力学研究。结果表明,不同温度条件下番茄红素和色泽降解均为一级降解动力学,确定红葡萄柚汁中番茄红素含量与色泽可用线性关系C/C_0=1.770 7(a~*/a_0~*)+0.801 2来表示;纯化后番茄红素含量与色泽在70、80、90℃条件下的线性关系分别为:70℃:C/C_0=1.856(a~*/a_0~*)-0.841 5;80℃:C/C_0=1.714(a~*/a_0~*)-0.711 8;90℃:C/C_0=1.492 1(a~*/a_0~*)-0.467 2。高效液相色谱-二极管阵列在线监测发现番茄红素热降解途径为:加热促使全反式番茄红素向单顺式异构体进行转变,继续加热导致全反式和单顺式异构体转变为双顺式异构体,而加热过程中双顺式异构体也可转变为单顺式异构体或发生降解,从而造成总番茄红素含量的下降。     

浓缩对千禧番茄中番茄红素分子构象的影响

研究番茄酱浓缩生产过程对果实中番茄红素构象的影响。采用光谱和色谱结合的方法鉴定出千禧番茄中8种番茄红素,分别为X_1-顺式番茄红素、X_2-顺式番茄红素、9,13-二顺式番茄红素、15-顺式番茄红素、13-顺式番茄红素、9-顺式番茄红素、全反式番茄红素和5-顺式番茄红素。根据番茄红素分子在浓缩过程中的变化率,各组分稳定性强弱为:9-顺式番茄红素13-顺式番茄红素9,13-二顺式番茄红素15-顺式番茄红素。随着浓缩时间的延长,总顺式番茄红素含量在2,3,4,5 h分别增加了5.31%,7.78%,7.93%和9.28%;随着浓缩温度升高,总顺式番茄红素含量增加了1%左右。浓缩时间对番茄红素异构化反应的影响比浓缩温度更显著。     

类胡萝卜素异构化及其对生物活性和生物利用度影响的研究进展

类胡萝卜素是自然界中最常见的脂溶性植物色素，具有抗氧化及预防多种疾病的功能。一般而言，天然类胡萝卜素大多以全反式构型存在，生物活性和生物利用度较低。类胡萝卜素异构化成为顺式异构体是提高其应用价值的重要手段。本文在阐述异构化反应机理的基础上，综述了类胡萝卜素的异构化方法（热致异构化、热促异构化、光致异构化等）、影响异构化反应的因素，以及在不同评估方式下异构化对其生物活性和生物利用度的影响，最后对类胡萝卜素异构化过程中存在的问题及未来研究方向进行展望。     

番茄红素在红葡萄柚汁模拟体系中降解机制研究

为探讨红葡萄柚中番茄红素的降解机制,本文通过构建红葡萄柚模拟体系对番茄红素进行降解动力学研究。结果表明抗坏血酸和糖类能显著促进番茄红素的热降解,而β-胡萝卜素却能延缓番茄红素的降解,且这种保护作用比前两者促进作用更有优势。β-胡萝卜素和抗坏血酸均能降低温度对番茄红素降解速率的影响,而糖类对番茄红素的促降解作用却与温度密切相关。与其他模拟体系不同,有糖存在的模拟体系中的番茄红素热降解并不符合一级反应动力学。糖类对番茄红素的促降解作用影响依次为:葡萄糖蔗糖果糖。红葡萄柚中主要内源因子在不同体系中对番茄红素降解协同表现出促进或保护作用,研究结果为红葡萄柚及番茄红素功能食品的研发提供了理论依据。     

番茄红素稳定性研究综述

番茄红素具有很强的抗氧化活性,能有效降低癌症、心血管病等疾病的发病率,是目前功能食品、药品研究中的一个热点。但番茄红素稳定性差,容易发生降解和异构化。本文综述了热、光、氧气、添加剂等环境因素对番茄红素稳定性的影响规律,并对微胶囊技术提高番茄红素稳定性做了简要介绍。     

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.     

Comparison of lycopene stability in water- and oil-based food model systems under thermal- and light-irradiation treatments

Lycopene can undergo degradation via isomerization and oxidation during processing and storage. These degradative reactions affect its bioactivity and health benefit functionality. Degradation kinetics and isomerization of lycopene in water- and oil-based tomato model systems were investigated as a function of thermal treatments and light irradiation. Results showed that 80 and 100 °C heating favoured the stability of lycopene in oil-based tomato products. The high heating temperatures (120 and 140 °C) increased isomerization of lycopene and resulting in degradation of total lycopene and cis-isomers in both water- and oil-based tomato products. However, the levels of degradation of total lycopene contents and cis-isomers were greater in water-based samples than in oil-based model systems under different treatments. Heat and light both promoted lycopene isomerization of the all-trans form to the cis-isomers and further oxidation of cis-isomers. The major effect of thermal degradation and photosensitized oxidation was a significant decrease in the total lycopene content, especially the content of cis-isomers. These research results could be useful in assisting industry to improve processing technology and to improve the nutritional value and health-benefits of tomato-based foods.     

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.     

Effect of thermal processing on the degradation, isomerization, and bioaccessibility of lycopene in tomato pulp

Thermal processing affects the nutritional value of food products. The nutritional value is not only determined by the content but also by the bioaccessibility of nutrients. The present study was performed to gain detailed insight into the influence of thermal processing on the degradation, isomerization, and bioaccessibility of lycopene isomers in tomato pulp, without adding any other ingredient. The bioaccessibility, which is defined as the fraction of the nutrient that can be released from the food matrix, was measured using an in vitro method. The results demonstrated the rather high thermal stability of lycopene. Although a treatment at 140 °C induced isomerization, the contribution of cis-lycopene to the total lycopene content remained small. Results also confirmed that thermal processing as such can improve the in vitro bioaccessibility of lycopene in tomato pulp, but the improvement was only significant upon treatments at temperatures of 130 and 140 °C. At such intense process conditions, one should be aware of the negative effect on other quality and nutrient parameters. Possibilities of thermal processing as such to improve the nutritional value of tomato pulp (without the addition of other ingredients) thus looks rather limited.     

KINETICS OF LYCOPENE DEGRADATION IN TOMATO PUREE BY HEAT AND LIGHT IRRADIATION

Lycopene as a natural antioxidant may provide protection against a broad range of epithelial cancers. Tomatoes and tomato‐based food products are a major source of lycopene compounds. Thermal processing is the main procedure in tomato puree production. Heat and light induces lycopene oxidation and isomerization of the all‐trans form to the cis form. The level of cis‐isomers increases as treatment time increases but only for a short period during the beginning of the treatment. The major effect of thermal processing was a significant decrease in the total lycopene content. Lycopene is relatively stable if heated at temperatures below 100C, but the duration of heating must be taken into consideration. The kinetics of lycopene degradation was analyzed. A shorter period of time of heating and less light irradiation in processing and storage would reduce lycopene degradation to a great extent.     

Influence of extraction with ethanol or ethyl acetate on the yield of lycopene, β-carotene,phytoene and phytofluene from tomato peel powder

This study evaluated the extraction yield of the food grade solvents ethanol and ethyl acetate by extracting lycopene, β-carotene, phytoene and phytofluene from tomato peel powder at varying heating intensities, and the influence of the solvent and heating intensity on carotenoids isomerization and degradation during extraction. The heat treatments assayed were 25, 35, 50 and 60 °C which were applied for periods of 5, 10, 20, 30 or 40 min. The carotenoid yield was higher in the extractions with ethanol than with ethyl acetate. In general, the temperature increase caused an increase in the carotenoid concentrations; however in the extractions performed with ethanol at 60 °C, the yield of (all-E)-lycopene and their (Z)-isomers was lower than at 50 °C. This could indicate that a great isomerization is produced in the high temperature extractions with ethanol but the oxidative degradation is the predominant reaction. On the contrary, the obtained results in the extractions with ethyl acetate indicate that the isomerization is the predominant reaction.     

Lycopene: Isomerization Effects on Bioavailability and Bioactivity Properties

Lycopene cis-isomers have shown to be more bioavailable and bioactive than the naturally occurring all-trans-isomer. During food processing, lycopene undergoes geometrical isomerization, increasing the proportion of cis-isomers. However, lycopene tends to retro-isomerize during food storage. Because the stability, bioavailability, and distribution of lycopene isomers are physiochemical characteristics critical for health benefits, it is essential to preserve these properties in food products containing lycopene isomers.

The objective of this article is to review thermal and nonthermal technologies available for lycopene geometrical isomerization with a focus on the stability, bioavailability, and bioactivity of lycopene isomers.     

过热蒸汽在肉类调理食品加工中的应用研究

对日本等发达国家肉类调理食品加工中过热蒸汽的研究与应用现状进行了较为系统的阐述.过热蒸汽技术具有缩短加热时间、提高出成率、脱油、减盐、抑制油脂氧化、改善食品质地、表面瞬时杀菌等效果,作为一种新型加热调理技术已被广泛应用于肉类调理食品等食品加工领域.     

Advances in radio frequency pasteurisation equipment for liquid foods: a review

Radiofrequency (RF) heating is an alternative emerging technology to conventional thermal methods; it has been employed for food pasteurisation, providing fast and volumetric heating. However, non-uniformity in the heating pattern has been reported. RF pasteurisation has been studied in different liquid foods. This review provides information about the RF heating mechanism and equipment used to pasteurise liquid food to control deteriorative or pathogen micro-organisms and the effect of the RF treatment on the quality of liquid foods. Developing an effective RF pasteurisation for liquid foods requires knowing the food dielectric properties, which determine the heating uniformity, temperature distribution and heating rate. The efficiency of continuous RF heating systems could depend on the fluid rate, resident time and absorbed power. RF heating can pasteurise liquid food, decrease microbial population and preserve the product's nutritional and physicochemical quality.