Study on lycopene and antioxidant contents variations in tomatoes under air-drying process

ABSTRACT:  Effects of factors such as tomato cultivars, drying temperatures (40, 80, and 120 °C), and drying time (0 to 240 min) on tomato lycopene and the major antioxidant contents (MACs, herein as the sum of total phenolics and total flavonoids) during an air-drying process were investigated. The results showed that lycopene contents increased under all the drying temperatures during the first 60 min. However, the red tomato cultivars, that is, HR, SN, and TTL, exhibited a significant decrease in lycopene contents under 120 °C after drying for 75 min. According to the experimental data, an MAC threshold value of 500 mg/100 g dry matter of tomato is proposed. When the MAC is lower than this value during air-drying, lycopene contents in all tomato cultivars would drop rapidly. In addition, the tomatoes in yellow color group, containing more MACs initially and retaining more MACs under air-drying at 40 to 80 °C, are proposed to be the proper tomato cultivars for thermal processing.     

Phenolic compounds,lycopene and antioxidant activity in commercial varieties of tomato (Lycopersicum esculentum)

Nine commercial varieties of tomato (Rambo, Senior, Ramillete, Liso, Pera, Canario, Durina, Daniella and Remate) produced in Spain were analysed for their lycopene content, content of phenolic compounds and antioxidant capacity. The phenolic compounds were characterised as flavonoids (quercetin, kaempferol and naringenin) and hydroxycinnamic acids (caffeic, chlorogenic, ferulic and p‐coumaric acids). Antioxidant activity was measured using the DPPH and ABTS assays. The concentrations of lycopene and the various phenolic compounds as well as the antioxidant activity were significantly influenced by the tomato variety. Quercetin, the most abundant flavonoid, was found in concentrations ranging between 7.19 and 43.59 mg kg^?1 fresh weight, while naringenin levels were lower than 12.55 mg kg^?1. The most abundant hydroxycinnamic acid was chlorogenic acid, with values ranging from 14 to 32 mg kg^?1 fresh weight, followed by caffeic acid, while p‐coumaric and ferulic acids showed similar concentrations lower than 5 mg kg^?1. The highest content of lycopene was found in Ramillete, Pera and Durina (>50 mg kg^?1 fresh weight), while the concentration in the other varieties was between 50 and 30 mg kg^?1, with the exception of Liso (less than 20 mg kg^?1). The antioxidant activity of tomato extracts varied with the tomato variety and the assay method used. Individual compounds found to be significantly related to antioxidant capacity were lycopene and ferulic and caffeic acids, but not quercetin and chlorogenic acid. © 2002 Society of Chemical Industry     

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.     

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.     

Effects of genotype and cultivation environment on lycopene content in red‐ripe tomatoes

Lycopene, a natural red pigment found in tomato, is correlated with reduced incidence of some cancers. Forty tomato varieties, including cluster F₁ hybrid tomatoes, round breeding line tomatoes (Lycopersicon esculentum Mill) and cherry tomato types (L esculentum var cerasiforme), grown under greenhouse and field conditions were evaluated for their lycopene content using high‐performance liquid chromatography (HPLC) and spectrophotometry. Lycopene content varied significantly among the tomato varieties, with cherry tomato types having the highest lycopene content. Greenhouse‐grown cluster and round tomatoes contained more lycopene (mean = 30.3 mg kg^?1) than field‐grown tomatoes (mean = 25.2 mg kg^?1), whereas cherry tomato types had a higher lycopene content in field‐grown (mean = 91.9 mg kg^?1) than in greenhouse‐grown (mean = 56.1 mg kg^?1) fruits. HPLC analysis of lycopene isomeric forms revealed a higher content of all‐trans isomers in all tomato genotypes examined. However, the cis isomeric form was exceptionally higher in the field‐ and greenhouse‐grown cherry tomato L esculentum var cerasiforme cv Gardener's Delight, which contained ～9.3 and 9.9 mg kg^?1 cis isomers respectively. Results indicate that genetics and choice of cultivation environment may have a strong influence on tomato lycopene content. Copyright © 2005 Society of Chemical Industry     

黑果枸杞中多酚的体外消化及其抗氧化性研究

以黑果枸杞为原料,研究了化学提取法和体外消化法两种不同提取方式对多酚含量的影响。同时,采用DPPH、FRAP、ABTS和ORAC四种不同方法测定了枸杞提取物的抗氧化性。结果表明,体外消化处理后的总酚和总花色苷含量低于化学提取法,而酚酸含量则高于后者;总体上,化学提取法的抗氧化性高于体外消化法;两种提取方法处理后的总酚和总花色苷与各化学抗氧化值均有较高的线性相关性(R2>0.83)。而体外消化法中,酚酸与各化学抗氧化值的相关性(R2>0.68)明显高于化学提取法(R2>0.03)。      

番茄红素脂质体生物利用率的比较研究

番茄红素的理化性质极大地限制了其生理活性功能的发挥,脂质体作为一种常见药物载体,考虑将其作为番茄红素的产品剂型,提高番茄红素的生物利用率。选取薄膜- 超声法制备番茄红素脂质体,经体外实验及体内实验研究可知：油溶番茄红素在人工胃液和无胆酸盐的人工肠液中无释放,但在添加胆酸盐的人工肠液中释放率达91%;番茄红素脂质体和番茄红素微胶囊在人工胃液中释放率低于22%,在添加胆酸盐和无胆酸盐的人工肠液中24h 释放率均达80%～90%。以油溶番茄红素为参照剂型,自制番茄红素脂质体与市售番茄红素微胶囊均具有较长的体内滞后时间和较低的清除率,延长了有效作用时间;自制番茄红素脂质体相对生物利用率为154.42%,大大优于油溶番茄红素,接近市售番茄红素微胶囊(205.03%)。     

Lycopene content and colour of ripening tomatoes as affected by environmental conditions

Tomatoes may have a great impact in the prevention of some types of cancer. This protective effect has been attributed to lycopene. The biosynthesis of lycopene is affected by environmental conditions. If the temperature of the fruits exceeds 30 °C, the synthesis of lycopene is inhibited. Strong direct radiation on fruits (～2990 µmol m^?2 s^?1 for 1.5–4 h) is harmful. In 2002, we investigated the effect of temperature and photosynthetically active radiation (PAR) on lycopene content. Fruit samples were harvested three times during the growing phase. The average lycopene content of harvested fruits, picked on 18 June 2002, reached 64.9 mg kg^?1 of fresh tomato. The fruits gathered on 25 June 2002 contained on average only 35.5 mg of lycopene per kilogram. The average lycopene content from the third harvest (on 9 July 2002) was 68.9 mg kg^?1. The values of PAR varied between 150 and 415 µmol m^?2 s^?1, so they did not exceed the critical value. The average temperature preceding the second harvest was the highest (28–32 °C) and the maximum temperature ranged between 40 and 43 °C. This prolonged, extremely high temperature may have caused the low lycopene level in the second harvest. The lycopene content of six ripeness stages, from green to deep red stage, was measured in 2002 and 2003. The accumulation of lycopene accelerates from the pink stage and there is a high correlation (R² = 0.92) between lycopene content and colour values (a*/b*). The higher the ratio of a*/b*, the higher was the lycopene content. Copyright © 2005 Society of Chemical Industry     

红小米黄酒酿造工艺研究及体外抗氧化活性评价

以南阳特色红小米为主要原料,研究红小米黄酒酿造工艺,并对其体外抗氧化活性进行评价。将单因素试验与Box-Behnken试验结合,以酒精度为评价指标,对前发酵工艺进行优化;以感官评分为评价指标,采用均匀设计试验对后发酵工艺进行优化;通过测定红小米黄酒对DPPH·、·OH的清除效果及对K3[Fe（CN）6]的还原力,评价其体外抗氧化活性。结果显示,红小米黄酒较优酿造工艺条件为：麦曲用量9%,酿酒曲用量0.48%,前发酵温度26 ℃,前发酵时间7 d,后发酵温度12 ℃,后发酵时间75 d。红小米黄酒清除DPPH·的半抑制浓度（IC50值）为0.45 mL/mL,清除·OH的IC50值为0.48 mL/mL,一定浓度范围内,其对K3[Fe（CN）6]的还原力与浓度呈线性相关,表明南阳特色红小米黄酒具有较强的体外抗氧化活性。     

固体培养粗糙脉孢菌产番茄红素及抗氧化活性研究

运用响应面法确定粗糙脉孢菌（Neurospora crassa）固体培养发酵产番茄红素的工艺参数,并对其所产的番茄红素进行抗氧化活性研究。结果表明,最佳发酵工艺条件为：发酵温度30 ℃,接种量0.95%,发酵时间95 h。在该最佳条件下,番茄红素产量为（2.45±0.16） mg/g。所得番茄红素对DPPH自由基的清除及Cu2+诱导低密度脂蛋白(LDL)氧化修饰的抑制均有明显的效果。     

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.     

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.     

不同食用油对番茄红素抗氧化活性的影响

目前市面上有多种品牌的番茄红素软胶囊,使用的食用油介质不同。为了更好地指导生产和消费,选择亚麻籽油、花生油、大豆油、玉米油和葵花籽油五种不同种类的食用油和番茄红素混合,采用五种体外抗氧化活性的测定方法来研究这几种不同的食用油对番茄红素抗氧化活性的影响。实验结果显示,几种食用油对番茄红素的抗氧化性都有很好的促进作用,其中亚麻籽油、花生油的效果最为显著,但是亚麻籽油在质量浓度高于40 μg/mL时,促进效果可能会下降。     

体外模拟消化体系中油茶多酚以及抗氧化活性的变化

为了研究油茶蒲提取物在消化过程中成分和抗氧化活性的变化,本研究以油茶蒲为原料,研究模拟人体体外消化过程中成分及其抗氧化活性的变化。结果表明,在模拟体外消化的前后油茶蒲提取物总酚含量稍有下降,而HPLC分析中多数酚类物质出现增长,其中鞣花酸增长了4.56倍。体外抗氧化体系中,DPPH?和ABTS?与总酚含量变化一致,呈下降趋势,而?OH的清除能力出现明显增长。综上,研究发现经体外消化油茶蒲提取物总酚含量会降低,而小分子酚酸增长,有利于后续的吸收,同时也,使其对?OH的清除能力增加。     

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     

Influence of in vitro gastrointestinal digestion on the bioavailability and antioxidant activity of polyphenols from Ipomoea batatas leaves

Sweet potato leaves (SPL) are natural by‐products rich in bioactive compounds, particularly polyphenols, and can be consumed as a vegetable. This work aims to investigate the influence of in vitro gastrointestinal digestion on the bioavailability and antioxidant activities of polyphenols from SPL. The phenolic compounds of sweet potato leaf extracts (SPLE) were quite stable in gastric phase. However, the amount of phenolic compounds decreased during transition from the acidic gastric environment to the alkaline intestinal environment. The bioavailability of phenolic compounds of SPLE was 13.36%. The ABTS^·+ scavenging capabilities and reducing power of SPLE were not affected during gastric digestion. Antioxidant activity increased after intestinal digestion. This research suggested that phenolic compounds of SPLE were sufficiently available for absorption. This study also provides useful information on the potential commercial value of SPL.     

热处理增加总抗氧化剂活性提高番茄营养价值

人们长久以来一直认为加工后的果蔬因Vc损失而导致其营养价值低于新鲜果蔬。而通过我们的研究发现苹果中Vc对总的抗氧化剂活性的贡献率小于0.4%,而大部分该活性来自于植物活性物质的结合,这意味着尽管有Vc损失,但加工过的果蔬还能保留其抗氧化剂活性。结果表明,尽管有Vc损失,热处理提高了总的抗氧化剂活性和番茄中生物可利用番茄红素含量,并且没有引起总酚类和总类黄酮含量的显著变化,从而提高了番茄的营养价值。     

黑果枸杞籽油品质及体外抗氧化活性北大核心CSCD

为挖掘黑果枸杞籽油的潜在开发利用价值,采用石油醚浸提法提取黑果枸杞籽油,对黑果枸杞籽油的理化性质进行测定,分析其脂肪酸组成及含量,并测定其对DPPH·、ABTS^(+)·的清除能力和总还原能力。结果表明:黑果枸杞籽油碘值(I)为(84.0±0.2) g/100 g,皂化值(KOH)为(130.1±0.3) mg/g,过氧化值为(0.42±0.03) g/100 g,酸值(KOH)为(8.4±0.2) mg/g,需进一步精炼;黑果枸杞籽油主要包括亚油酸(68.31%)、油酸(17.76%)、棕榈酸(5.37%)、γ-亚麻酸(3.73%)、硬脂酸(2.58%)等9种脂肪酸;黑果枸杞籽油对DPPH·清除率的IC_(50)为0.587 mg/mL,3.2 mg/mL黑果枸杞籽油的ABTS^(+)·清除率为57.50%,且其具备一定的Fe^(3+)还原能力。因此,黑果枸杞籽油富含不饱和脂肪酸,体外抗氧化活性良好,具有开发的价值和潜力。     

诺丽多糖的单糖组成分析及体外抗氧化活性研究

目的:不同浓度乙醇醇沉诺丽多糖,并对比分析其单糖组成及抗氧化活性的差异。方法:不同浓度乙醇醇沉超声辅助提取得到的诺丽多糖经脱色脱蛋白纯化后,利用柱前衍生化HPLC法测定其单糖组成,并采用三种抗氧化活性评价方法比较其抗氧化活性差异。结果:四个多糖样品均主要由甘露糖、鼠李糖、葡萄糖、半乳糖及阿拉伯糖组成,但摩尔百分比不同,30%（A）、50%（B）、70%（C）、90%（D）乙醇醇沉的四个多糖样品的单糖摩尔百分比依次为1.33∶4.24∶77.22∶9.83∶7.38、2.58∶2.28∶52.20∶31.40∶11.54、1.32∶6.45∶47.00∶32.91∶12.31、3.18∶3.39∶27.23∶45.50∶20.70。四个多糖样品对DPPH·和O₂^-·的清除能力大小排序相同,均为D>C>B>A;对OH·的清除能力大小排序为C>B>A>D。结论:四个多糖样品中主要单糖组成相同,但摩尔百分比不同,70%乙醇醇沉诺丽多糖的抗氧化活性最强。