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1.
Lycopene and β-carotene were extracted from freeze-dried tomatoes (skin + pulp) with pure SC CO2 and SC CO2 + 5% w/w co-solvent at 40 °C, 400 bar and flow rates of 0.5 and 1.2 L/min. The apparent solubility of lycopene and β-carotene in the multicomponent complex system was determined from dynamic extraction experiments using a laboratory-scale supercritical extraction system. Solubility of pure lycopene and β-carotene in SC CO2 (binary system) was reported in the literature to be of the order of 10−6 mole fraction. The apparent solubility of lycopene extracted from tomatoes with SC CO2 (multicomponent complex system) under the same conditions was almost one order of magnitude smaller. The apparent solubility obtained using oil as a co-solvent was higher than that obtained with ethanol as a co-solvent or pure SC CO2. The differences in solubility are mainly due to the polarity of the co-solvent and the impact of the tomato matrix in the multicomponent complex system.  相似文献   

2.
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  相似文献   

3.
Tomato waste is characterised by high amounts of bioactive compounds, such as carotenoids, polyphenols and essential fatty acids. In this work, oleoresins were produced from tomato waste (skins + seeds) and skins using carbon dioxide under liquid and supercritical conditions. The use of ethanol as a co-solvent was also evaluated. Compositions of the oleoresins were analysed and compared to oleoresin obtained by means of an organic solvent, which was used as the control. Oleoresin extraction from the waste by liquid and supercritical CO2 provided the highest yields (12.5%–12.9%). The extracts obtained from the skins with supercritical CO2 without ethanol had the highest content of α- and γ-tocopherols (80 and 575 mg/100 g oleoresin, respectively), while lycopene and β-carotene were found at 205 and 75 mg/100 g oleoresin, respectively. The highest quantity of polyphenols (9305 mg GAE/100 g oleoresin) was found in the oleoresin extracted from skin by supercritical CO2 with ethanol. All oleoresins were characterised by a high antioxidant activity, which improved with the synergy of carotenoids, tocopherols and polyphenols.  相似文献   

4.
BACKGROUND: Soluble sugars and cell wall polysaccharides are well known for contributing to a range of ‘quality’ characteristics of fresh vegetables such as flavour, texture and healthy properties. Red‐ripe berries of 14 cultivars of cherry tomatoes and four cultivars of high‐pigment tomato hybrids, cultivated in the south of Italy, were analysed for their content of these important qualitative parameters. RESULTS: Sakura appeared to be the cultivar with the highest amount of soluble sugars (53 g kg?1 fresh weight (f.w.)), mainly glucose and fructose, and, hence the ‘sweetest’ among cherry tomatoes. High‐pigment tomatoes, especially HLY02 and HLY13, showed a soluble sugar content much lower than cherry tomatoes, as expected for industrial, normal‐size tomatoes. Variations in the fructose/glucose ratio, of between 0.68 and 1.48, were evidenced among the different tomato cultivars. Cell wall polysaccharides isolated from whole fresh red‐ripe berries of each cultivar were analysed chemically. The amount of matrix polysaccharides (0.9–3.4 g kg?1 f.w.) and cellulose (0.16–1.86 g kg?1 f.w.), as well as their glycosidic composition, showed significant differences among the different cultivars. Cellulose to matrix polysaccharide ratio was highly variable and ranged between 0.06–1.44 and 0.17–0.77 in cherry and high‐pigment tomato cultivars, respectively. CONCLUSION: The differences evidenced in the total soluble sugar and cell wall polysaccharide composition, not only among different types of tomatoes but also different cultivars within the same typology, may play a fundamental role in the quality of tomatoes and deserve further investigations. Copyright © 2008 Society of Chemical Industry  相似文献   

5.
Large amounts of a waste known as tomato pomace and consisting mainly of the fruit peel and seeds are generated annually from the industrial processing of tomatoes. This material is rich in lycopene, a phytochemical with antioxidant and chemopreventive properties, and contains many valuable nutrients. In this study, we have investigated the possibility of using the whole waste to produce a lycopene-enriched seed oil. The oil was obtained by cold-pressing the seeds and was subsequently enriched in lycopene (up to 500 ppm) by incorporation of a tomato oleoresin derived from the peels. To increase lycopene recovery, the peels were pretreated with cell-wall-degrading enzymes and solvent extracted. This procedure allowed the production of about 25 kg/ton oleoresin with an average lycopene content of 6.8 wt.%. The compositional characteristics of the oil combined with the production of significant amounts of oleoresin strongly support the use of tomato pomace for producing lycopene-based functional products.  相似文献   

6.
BACKGROUND: Oil yield from avocado fruit may be influenced by fruit pre‐treatment and extraction method. Unripe and ripe avocado fruit pieces were deep‐frozen at ? 20 °C and either freeze‐dried or oven‐dried (80 °C). Oil yield from these samples was determined after extraction with hexane and supercritical carbon dioxide (SC‐CO2). The fruit samples were examined using scanning electron microscopy before and after oil extraction. RESULTS: Average oil yield from ripe fruit (freeze‐dried and oven‐dried combined) was 72 g kg?1 higher than from unripe fruit for SC‐CO2 extracts and 61 g kg?1 higher for hexane extracts. This may be due to enzymatic degradation of parenchyma cell walls during ripening, thus making the oil more available for extraction. Freeze‐dried samples had a mean oil yield 55 g kg?1 greater than oven‐dried samples for SC‐CO2 extracts and 31 g kg?1 higher for hexane extracts. However, oil yields from ripe fruit (freeze‐dried and oven‐dried) subjected to hexane extraction were not significantly different. All hexane extracts combined had a mean oil yield 93 g kg?1 higher than SC‐CO2 extracts. CONCLUSION: SC‐CO2 may be more selective and may create paths of least resistance through the plant material. Hexane, on the other hand, is less selective and permeates the whole plant material, leading to more complete extraction and higher oil yields under the experimental conditions. Copyright © 2007 Society of Chemical Industry  相似文献   

7.
皂化对番茄红素提取的影响研究   总被引:22,自引:2,他引:22  
用KOH溶液对番茄进行碱洗皂化可有效的除去番茄中的大部分脂肪酸甘油酯及各种游离脂肪酸 ,释放出其中的番茄红素。番茄皂化的最佳条件为 :KOH浓度 0 5mol/L ,温度 65℃ ,皂化时间 0 5h。皂化后的番茄经固液萃取后得到的番茄红素油树脂产品有部分晶体出现 ,色价提高到 40 2 5。  相似文献   

8.
ASSESSING LYCOPENE CONTENT IN CALIFORNIA PROCESSING TOMATOES   总被引:1,自引:0,他引:1  
Tomatoes constitute the main source of lycopene in the U.S. diet. Growing interest in the potential health‐protective role of lycopene is bringing attention to the content of lycopene in tomatoes. A wide range of lycopene content (55–181 mg/kg) was observed in juice prepared from selected cultivars of tomatoes grown in nine California counties. A comparison of cultivars H 8892, H 9665 and Halley 3155 grown in Colusa, Fresno, San Joaquin and Yolo counties during three seasons concludes that mean lycopene concentrations were significantly greater (P < 0.01) in 2000 (106 mg/kg) than in 1999 (101 mg/kg) and 2001 (88 mg/kg). An evaluation of nine processing tomato cultivars harvested in one season on four separate dates indicated that lycopene concentration of tomatoes decreases with maturation on the plant. Lycopene concentration of tomatoes is dependent on the growing season, location, cultivar and maturity.  相似文献   

9.
BACKGROUND: The feasibility of using modified atmosphere packaging (5 kPa O2 + 5 kPa CO2) to maintain the antioxidant properties of fresh‐cut tomatoes during shelf‐life was assessed through storage at different temperatures (5, 10, 15 and 20 °C). Health‐related compounds, antioxidant capacity, microbiological counts, physicochemical parameters and in‐package atmosphere of tomato slices were determined. RESULTS: Initial lycopene, vitamin C and phenolic contents and physicochemical parameters of tomato slices were well maintained for 14 days at 5 °C. Lycopene and total phenolic contents were enhanced over time in tomato slices stored at 15 and 20 °C. However, this increase in antioxidant compounds of fresh‐cut tomatoes during storage may be associated with excessive amounts of CO2 (R2 = 0.5679–0.7328) in the packages due to microbial growth. Although keeping tomato slices at temperatures above 10 °C increased their antioxidant content, the shelf‐life of the product was reduced by up 4 days. CONCLUSIONS: A storage temperature of 5 °C is appropriate for maintaining the microbiological shelf‐life of fresh‐cut tomatoes for up to 14 days and also allows the antioxidant properties of tomato slices to be retained over this period, thus reducing wounding stress and deteriorative changes. Copyright © 2008 Society of Chemical Industry  相似文献   

10.
Abstract: The chemical properties and oxidative stability of perilla oils obtained from roasted perilla seeds as affected by extraction methods (supercritical carbon dioxide [SC‐CO2], mechanical press, and solvent extraction) were studied. The SC‐CO2 extraction at 420 bar and 50 °C and hexane extraction showed significantly higher oil yield than mechanical press extraction (P < 0.05). The fatty acid compositions in the oils were virtually identical regardless of the extraction methods. The contents of tocopherol, sterol, policosanol, and phosphorus in the perilla oils greatly varied with the extraction methods. The SC‐CO2‐extracted perilla oils contained significantly higher contents of tocopherols, sterols, and policosanols than the mechanical press‐extracted and hexane‐extracted oils (P < 0.05). The SC‐CO2‐extracted oil showed the greatly lower oxidative stability than press‐extracted and hexane‐extracted oils during the storage in the oven under dark at 60 °C. However, the photooxidative stabilities of the oils were not considerably different with extraction methods.  相似文献   

11.
This work discusses the extraction of lycopene from tomato peel by-product containing tomato seed using supercritical carbon dioxide. The presence of tomato seed in the peel by-product improved the yield of extracted lycopene. Extraction was carried out at temperatures of 70-90 °C, pressures of 20-40 MPa, a particle size of 1.05 ± 0.10 mm and flow rates of 2-4 mL/min of CO2 for 180 min extraction time. Oil from tomato seed was extracted under similar operating conditions and analyzed using GC-MS and GC-FID, while carotenoids extracted were analyzed by HPLC. The optimum operating condition to extract lycopene, under which 56% of lycopene was extracted, was found to be 90 °C, 40 MPa, and a ratio of tomato peel to seed of 37/63. The presence of tomato seed oil helped to improve the recovery of lycopene from 18% to 56%. The concentration of lycopene in supercritical carbon dioxide as a function of density at various temperatures was determined.  相似文献   

12.
Abstract: The objective of this study was to determine the influence of thermal processing on the assessment of tocopherols and carotenoids, as well as their isomer formation in tomatoes. The sliced tomatoes were heated in an oven at 100, 130, and 160 °C for 5, 10, and 20 min, then freeze‐dried. Freeze‐dried samples were finely ground and the analysis was performed on lyophilized samples. The average concentrations of total lycopene, lutein, β‐carotene, α‐tocopherol, and γ‐tocopherol in fresh tomatoes (in 100 g dry weight) were 21.2, 1.1, 2.7, 8.0, and 2.5 mg, respectively. Oven baking of tomato at 160 °C for 20 min led to a significant increase in the apparent measurement of lycopene, β‐carotene, and α‐tocopherol content by 75%, 81%, and 32%, respectively. Heating induced isomerization of (all‐E) to various (Z) isomers of lycopene, and we found that the total (Z)lycopene proportion in the tomatoes increased with longer heating time. (All‐E)lycopene constituted 75.4% in fresh tomatoes and decreased to 52.5% in oven‐baked tomatoes (160 °C, 20 min), while (5Z)lycopene increased from 9.4% to 17.9% of total lycopene. However, β‐carotene release and isomerization was less influenced by the heat treatment than that of lycopene. These results suggested that thermal processes might break down cell walls and enhance the release of carotenoids and tocopherols from the matrix, as well as increase isomerization of lycopene and β‐carotene.  相似文献   

13.
BACKGROUND: Food allergies are increasing in the European population. At present the onset of symptoms can be avoided only by elimination of a particular fruit or vegetable from the diet. A new approach is to develop hypoallergenic food products. This study characterises the allergenic potential of tomatoes, considering cultivation conditions, developmental stages and genotypes, in order to identify hypoallergenic fruits. RESULTS: Patients with a history of tomato allergy were recruited for skin allergy tests. Tomatoes carrying distinct genotypes were grown under various cultivation conditions and harvested at different maturation stages. Cultivation conditions (nitrogen fertilisation, light exposure and plant nutrition) did not affect the skin reactivity in tomato‐allergic patients. However, skin reactivity was significantly lower when using green‐unripe compared with red‐ripe tomatoes and when using landrace cultivars compared with cultivars bred for use in organic horticulture. CONCLUSION: Depending on their genetic background and maturity level, some tomato cultivars elicit positive reactions in tomato‐allergic patients in the skin allergy test. This novel finding should pave the way for the development of tomatoes with reduced allergenicity to relieve sufferers of tomato allergy. Copyright © 2011 Society of Chemical Industry  相似文献   

14.
BACKGROUND: Two important quality attributes of processing tomatoes are pH and titratable acidity. These and other quality attributes can be affected by tomato fruit maturity and over‐maturity. We have determined the magnitude of these maturity effects in four processing tomato cultivars commonly grown in California. RESULTS: Allowing tomatoes to remain on the vine for up to 4 weeks after ripening resulted in an increase in fruit pH of between 0.01 and 0.02 unit per day for the four cultivars examined. The increase in pH was paralleled by a decrease in titratable acidity, due to a loss of citric acid. Glucose and fructose concentrations also declined with increasing maturity after ripening. Other quality parameters (color, lycopene, total pectin, pectin solubility, and Bostwick consistency) all showed little change. CONCLUSION: Vine holding of ripe fruit adversely affects quality, especially pH and titratable acidity. Recent problems with high tomato juice pH encountered by tomato processors in California could be the result of increased average fruit maturity at harvest. Copyright © 2011 Society of Chemical Industry  相似文献   

15.
The use of 1‐methylcyclopropene (1‐MCP) to extend the shelf life of cherry tomato (Lycopersicon esculentum var. cerasiforme) was investigated. Higher concentrations of 1‐MCP delayed the ethylene induced climacteric peaks in mature green (MG) and breaker (BR) fruits. Thirteen days after treatment, control fruits were 55% as firm as fruit treated with 0.11 μL L?1 1‐MCP. The initiation of fruit softening, chlorophyll degradation and accumulation of lycopene and carotenoids was delayed in treated fruits. Higher 1‐MCP concentrations inhibited the accumulation of lycopene and carotene such that the colour of the fruit did not reach that of control fruit. Treatment of MG cherry tomatoes with 1‐MCP enhanced shelf life optimally, while treatment of BR fruits was beneficial where full colour and high content of lycopene and carotenoids is important. Differentiation of the different stages of ripening before application of 1‐MCP is needed in order to succeed in accomplishing different postharvest objectives.  相似文献   

16.
BACKGROUND: The tomato fruit is a dietary source of carotenoids, bioactive antioxidant compounds that play an important role in the prevention of degenerative diseases. Several extraction and detection techniques regarding carotenoids in tomatoes can be found in the literature, mainly based on high‐performance liquid chromatography separation and ultraviolet‐visible detection. RESULTS: The best extraction conditions and tandem mass spectrometry (MS) analysis were evaluated: lycopene and β‐carotene were extracted in a cyclohexane/ethyl acetate mixture without the addition of antioxidants, next separated by liquid chromatography on a C18 column and then determined through electrospray tandem MS. Ionic suppression by the matrix in negative ionisation mode did not allow the analysis of extracts, hence the positive ionisation mode was chosen. Validation parameters demonstrated the suitability for purpose of the analytical method: accuracy, precision, linearity and detection limits were adequate. The method was finally applied to different tomato samples, and differences could be easily highlighted. CONCLUSION: The method was simple, fast and appropriate for the purpose of analysing lycopene and β‐carotene in tomatoes. Copyright © 2011 Society of Chemical Industry  相似文献   

17.
BACKGROUND: Marigold is a traditional medicine herb which shows good pharmacological activity in many aspects. It is very important to obtain and investigate the specific bioactive compounds from marigold. The objective of the study was to extract the oleoresin from marigold with supercritical CO2 (SC‐CO2) at different pressures and temperatures, detect the fatty acid composition by gas chromatography–mass spectrometry and investigate the antioxidative components in the extracts by combined online high‐performance liquid chromatography‐2,2‐azinobis‐(3‐ethylbenzothiazolin‐6‐sulfonic acid (HPLC‐ABTS?+) post‐column assay and HPLC‐tandem mass spectrometry. RESULTS: For the pressure range (20–40 MPa) and temperature range (30–70 °C), 30 MPa/70 °C gave the highest yield of oleoresin (58.9 g kg?1). The dominant fatty acids of marigold flower oleoresin were linoleic acid (>26.41%), palmitic acid (>24.22%) and oleinic acid (>20.12%). Significant effects of the extraction pressure and temperature on the antioxidant activity were observed (P < 0.05). Lutein esters, α‐tocopherol, β‐tocopherol, γ‐tocopherol and δ‐tocopherol were the dominant antioxidant compounds in the extracts. CONCLUSION: The study has shown that the yield and total antioxidant activity of the marigold extracts were affected by the pressure and temperature of SC‐CO2, and that online HPLC technique could be used as an efficient and rapid method for separation and identification of bioactive compounds from a complex mixture. Copyright © 2011 Society of Chemical Industry  相似文献   

18.

ABSTRACT

The effects of 1‐methylcyclopropene (1‐MCP), modified atmosphere packaging (Xtend, StePac L.A. Ltd., Tefen, Israel) and their combination were investigated on storage and quality maintenance of tomatoes cv. “Perla” harvested at two maturity stages. 1‐MCP treatment was performed in 1,000 nL/L doses for 24 h while untreated fruits were considered as control. Fruits were stored at 12C with 90% relative humidity for 21 days. Weight loss, skin color, elasticity, lycopene, ascorbic acid, soluble solid content (SSC), titratable acidity (TA) and SSC/TA were evaluated with the intervals of 7 days. MAP with and without 1‐MCP reduced weight loss and maintained to elasticity compared with control and 1‐MCP alone. Nevertheless, 1‐MCP or its combination with MAP significantly delayed changes in parameters related to fruit ripening, such as skin color, lycopene, TA and SSC/TA increase in both ripening stages. Overall results indicated that the combination of 1,000 nL/L 1‐MCP and modified atmosphere package was the most effective treatment in both ripening stages.

PRACTICAL APPLICATIONS

Tomato is a climacteric fruit and its ripening depends on ethylene production physiology. 1‐Methylcyclopropene (1‐MCP) prevents ethylene action by blocking ethylene receptors and extends the storage life of tomatoes. Modified atmosphere packaging (MAP) of fresh fruits and vegetables refers to the still evolving technique of matching the respiration of the product with the O2 and CO2 permeability of packages in order to modify the oxygen and carbon dioxide concentrations of the atmosphere to desired levels within the package. Recent studies revealed that combined applications of 1‐MCP and MAP have significant effects on maintaining storage quality of banana, litchi and plums. This study was conducted on the investigation of the effects of 1‐MCP and MAP combination on storage duration and quality of tomatoes harvested at different maturity stages.  相似文献   

19.
BACKGROUND: High‐voltage electrostatic field (HVEF), as a feasible and non‐chemical technique, applied to food preservation is a new area of study. Our previous research suggested HVEF could maintain the quality of tomato in storage. The present article intensively investigated the effect of HVEF pretreatment on antioxidant system of green mature tomato in storage. RESULTS: Green mature tomatoes were exposed to negative (or positive) HVEF for 2 h at 20 °C and then stored for 24 days at 13 ± 1 °C, 85–90% relative humidity. The results indicated HVEF significantly reduced contents of O2? and H2O2 of tomato fruits during storage compared to the control. HVEF treatment also enhanced the activities of antioxidant enzymes including catalase, superoxide dismutase, ascorbate peroxidase and peroxidase. The contents of non‐enzyme antioxidant components including reduced glutathione, phenols and ascorbic acid also were increased by HVEF treatment. However, HVEF treatment did not increase the content of lycopene in tomato fruit. CONCLUSION: HVEF treatment could promote the antioxidant capacity of tomato fruits in storage. Further research is be highly recommended to understand the mechanisms improving the antioxidant capacity of tomato fruits by HVEF. Copyright © 2011 Society of Chemical Industry  相似文献   

20.
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.  相似文献   

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