Effect of water activity on lycopene and flavonoid degradation in dehydrated tomato skins fortified with green tea extract

Tomato by-products (skins) were formulated with a green tea (GT) extract (5 mmol flavanol per mmol of lycopene) and dehydrated to obtain powders with potential added-value as food ingredients. The aims were to evaluate product stability during storage at different water activity (a_w) levels in the range 0.17–0.75, by assessing: (a) lycopene and flavonoid degradation rates, (b) the antiglycoxidative and antioxidant properties, and (c) color variations.     

Combined high-pressure and thermal treatments for processing of tomato puree: evaluation of microbial inactivation and quality parameters

The effects of combined high-pressure thermal treatments on consistency, viscosity, colour, lycopene content, enzyme activity and micro-organisms were determined, and compared to conventional pasteurisation and sterilisation processes of tomato puree. High-pressure processing at ambient temperature (HPP) improved the colour and viscosity compared to heat pasteurisation, while the water binding capacity and lycopene content were unaffected by HPP. Products treated at 700 MPa, 20 °C resulted in inactivation of the natural flora to a level below the detection limit. After pressure treatment and during chilled storage a increase in viscosity was observed. HPP caused partial inactivation of polygalacturonase (70%), but activation of pectin methylesterase. After high-pressure sterilisation treatments combined with elevated starting temperatures (≥80 °C, HPS, one or two pulses) an ambient stable product was obtained. HPS (one pulse, 700 MPa, 30 s, 90 °C) reduced B. stearothermophilus spore contamination level in inoculated meatballs in tomato puree with at least 4.5 log units. HPS resulted in more than 99% inactivation of polygalacturonase and pectin methylesterase. HPS resulted in a lower viscosity compared to conventional sterilised samples, whereas the water binding capacity was improved. Colour appreciation was improved and lycopene content was retained compared to a 40% loss after conventional sterilisation.     

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.     

Improving the stability of lycopene Z-isomers in isomerised tomato extracts

Tomato-based foods rich in Z-lycopene are potentially more bioavailable and have greater bioefficacy compared to natural tomato products which mainly contain all-E-lycopene. To prepare a stable tomato extract with a high level of Z-lycopene, geometrical isomerisation of lycopene was studied in organic solvents either alone or in the presence of a tomato extract. Interconversion between the isomers was observed in all systems with 13Z-lycopene being the least stable. Heating a tomato extract containing mainly the all-E-isomer in ethyl acetate produced successively 13Z-, 9Z- and 5Z-lycopene. An isomerised tomato oleoresin with a minimal content of the most unstable 13Z-lycopene could be obtained by refluxing tomato oleoresin in ethyl acetate for 1 week. In this isomerised tomato oleoresin, total lycopene and lycopene isomer profiles were shown to remain constant for 1 year at room temperature. Accordingly, this product is a valid source of stable and potentially highly bioavailable lycopene.     

Stability of nutritionally important compounds and shelf life prediction of tomato ketchup

Ketchup is an important source of tomato antioxidants in human nutrition, this ambient stable product is processed using several relatively important heat treatments and can be stored for one or more years at ambient temperature. Model storage experiments were carried out with two sets of commercial ketchup produced according to the Czech recipe: (a) hot-filled without subsequent pasteurization and (b) filled and pasteurized in the jar. The samples were stored at 25, 50, 75 and 90 °C, during the storage the content of total lycopene and ascorbic acid was observed as well as the colour parameters (a*, ΔE). The obtained data were processed using the pseudo first order (total lycopene, ascorbic acid and a*) and zero order kinetics (ΔE). The obtained results corresponded with the published data, but were not consistent between the both sets of the samples. The total lycopene and ascorbic acid degradation is more dependent on the conditions in the product, mainly on the previous history of heat treatment. The colour parameters, especially ΔE seemed to be more robust criterion, which could be used for the shelf life prediction estimation. The empirically set up shelf life by the producer was confirmed.     

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。     

Evaluation of processing qualities of tomato juice induced by thermal and pressure processing

Effects of processing conditions including hot-break processing (92 °C for 2 min), cold-break processing (60 °C for 2 min) and hydrostatic pressure treatments (100-500 MPa) at different temperatures (4, 25 and 50 °C) for 10 min on quality aspects of tomato juice were investigated. Both hot- and cold-break processing induced significant changes in color, viscosity and radical-scavenging capacity of tomato juice compared with control (fresh tomato juice); moreover, hot-break processing induced a specific range of reduction of pectin methylesterase (PME) and polygalacturonase (PG) activities. Pressure treatments at and below 200 MPa at 4 and 25 °C maintained the color, extractable total carotenoids and lycopene, and radical-scavenging capacity; further, those at 500 MPa at 4 and 25 °C improved all the quality attributes the most except inactivation of PME in this study. The residual activity of PME showed the lowest after treating by 200 MPa at 25 °C; however, the PME activity was enhanced by treatments at 300-500 MPa and various temperatures. The residual activity of PG decreased gradually to 72% with pressure elevated from 100 to 400 MPa at 4 and 25 °C, further, that declined quickly to 10% after 500 MPa treatments. This research clearly shows that it is possible to selectively produce good tomato juice products by high pressure processing at ambient temperature.     

乙醇酶法从番茄中提取番茄红素的研究

本研究采用乙醇酶法是从番茄中提取番茄红素，研究了酶和乙醇浸取提取方法，并对番茄红素的提取条件作了研究，确定了较佳工艺条件。     

Effect of extraction conditions on lycopene extractions from tomato processing waste skin using response surface methodology

Skin, rich in lycopene, is an important component of waste originating from tomato paste manufacturing plants. A central composite design with five independent variables, namely solvent/meal ratio (20:1, 30:1, 40:1, 50:1, and 60:1 v/w); number of extractions (1, 2, 3, 4 and 5); temperature (20, 30, 40, 50 and 60 °C); particle size (0.05, 0.15, 0.25, 0.35 and 0.43 mm); extraction time (4, 8, 12, 16 and 20 min) was used to study their effects on lycopene extraction. The experimental values of lycopene ranged between 0.639 and 1.98 mg/100 g. The second order model obtained for extracted lycopene revealed a coefficient of determination (R²) of 0.99 and a standard error of 0.03. Maximum lycopene (1.98 mg/100 g) was extracted when the solvent/meal ratio, number of extractions, temperature, particle size and extraction time were 30:1 v/w, 4, 50 °C, 0.15 mm and 8 min, respectively.     

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...     

Enzyme aided extraction of lycopene from tomato tissues

Lycopene is a natural carotenoid pigment and a high value nutraceutical having wide use. The objective of the present work was to obtain a good yield of lycopene from tomato tissues, using cellulase and pectinase enzymes. Various parameters such as concentration of enzymes and time of incubation were optimised, to improve the yield of lycopene from tomatoes. Enzyme aided extraction of lycopene from whole tomatoes under optimised conditions resulted in an increase in the lycopene yield by 132 μg/g (198%) in cellulase treated sample and 108 μg/g (224%) in case of pectinase treated sample. Extraction from tomato peel under optimised conditions showed a remarkable increase in the yield of lycopene by 429 μg/g (107%) and 1104 μg/g (206%), for cellulase and pectinase treated samples, respectively. Likewise, the enzyme aided extraction of lycopene from fruit pulper waste and industrial waste of tomatoes was done to determine the potential for recovering the natural pigment from tomato waste.     

番茄加工副产物利用研究进展

番茄是国际上广泛种植的蔬菜,可以加工成番茄酱、番茄罐头、番茄粉等产品,加工过程中产生3%~8%的副产物,这些副产物不利用会造成环境污染和资源浪费。本文主要对目前国内外有关番茄副产物的食品化利用情况进行了综述,包括作为食品配料直接添加和提取副产物中的番茄红素、膳食纤维、蛋白质、籽油等有效成分,深入分析了番茄副产物利用中面临的问题,以期为番茄加工副产物的综合利用研究提供新思路。      

Improved lycopene extraction from tomato peels using cell-wall degrading enzymes

Four commercial enzyme preparations with pectinolytic, cellulolytic and hemicellulolytic activities were tested for their ability to enhance lycopene extraction from tomato peels. Screening experiments were performed at 25 °C by subjecting the peels to a 4-h enzyme incubation followed by 1-h hexane extraction. Peclyve EP and LI were the most efficient, with an almost 20-fold increase in extraction yield. Peclyve LI was used to evaluate the influence of solvent type and enzyme incubation time on lycopene recovery. Hexane, ethyl acetate and the mixture hexane/acetone/ethanol 50:25:25 (v/v) were used as solvents. Under the best extraction conditions (1-h enzyme incubation followed by a 3-h solvent extraction at 40 °C) up to 440 mg of lycopene per 100 g of dry tomato peels were obtained. The percentage recoveries were in the range of 3–30%, for the untreated peels, and 77–98% for the enzymatically treated material.     

The physico-chemical characteristics of extruded snacks enriched with tomato lycopene

Adding tomato derivatives to traditional starchy extruded snacks can improve their nutritional properties by adding lycopene and fibre; however the physico-chemical properties of these products must also be considered. Ingredients and extrusion parameters, including temperature, alter these properties, but their effect on lycopene content is not known. In this study, crisp low density extruded snacks were manufactured from corn, wheat and rice, with or without dried tomato skin or paste powder extruded at temperatures of 140, 160 or 180 °C. Lycopene content and the physico-chemical properties (expansion, density, hardness, colour parameters and percentage of moisture loss) of the extruded products were measured. Lycopene retention was higher in products containing tomato skin powder and significantly lower when wheat flour was used to make the snacks. Increases in the processing temperature improved the physico-chemical characteristics of the snacks but had no significant effect on lycopene retention (P > 0.05).     

Lycopene extraction from tomato peel by-product containing tomato seed using supercritical carbon dioxide

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.     

Production of frankfurters with tomato powder as a natural additive

This study includes the investigation of chemical properties such as nitrosomyoglobin content, lycopene content, and the oxidation level, and the sensorial properties of frankfurters which have been produced by both reducing the nitrite level and adding tomato powder. All samples have been vacuum packed and stored at +4 °C for 60 days.The pH of the frankfurters produced with tomato powder was reduced, when compared to the samples which did not contain tomato powder. This effect was due to the acidic characteristics of tomato. As the level of nitrite was reduced, the oxidation level of the frankfurters was increased significantly. Addition of 2 g/100 g of tomato powder decreased the level of oxidation; however, 4 g/100 g of tomato powder caused a slight increase when compared to the samples which did not contain tomato powder. According to this result it can be stated that tomato powder retards the oxidation reaction. According to sensorial evaluations, tomato powder improved the consumer acceptability as well. Addition of tomato powder increased the internal and external colour scores, and frankfurters were found to be more acceptable by the panellists. Nitrosomyoglobin (NOMb) content of the samples was decreased along with the decreased level of nitrite, and this, in turn, contributed to the decreased level of redness (a*).     

Evaluation of microbial inactivation and physicochemical properties of pressurized tomato juice during refrigerated storage

Effects of high pressure processing (300-500 MPa/25 °C/10 min) on microbial inactivation and processing qualities of tomato juices during refrigerated storage at 4 °C for 28 days were investigated to compare with those of conventionally thermal processing. Conventionally, thermal processing almost inactivated all the microorganisms and pectolytic enzymes and produced microbially and consistency stable tomato juices; however, they also reduced the color, extractable carotenoids and lycopene and vitamin C compared with fresh juice. During storage, all the pressure processing could improve the extractable carotenoids and lycopene contents compared with fresh juice, and they also retained more vitamin C contents than thermal processing. Although 300- and 400-MPa processing could retain a/b values of tomato juices as fresh juice during storage for 21 and 28 days, 500-MPa processing could improve the color of juices even after storage. Syneresis occurred in the 300- and 400-MPa processing juices by storing for 7 and 14 days; however, viscosity stable juice was produced by 500-MPa processing. Moreover, 400- and 500-MPa processing significantly inactivated microorganisms and the juices were microbially stable during storage. This study demonstrated that 500-MPa processing would be an alternative for conventionally thermal processing for tomato juice with improvement of some processing quality attributes.     

番茄果实在成熟过程中类胡萝卜素含量的变化

番茄红素和其它类胡萝卜素是番茄果实中的主要色素,其含量对果实颜色的变化有显著的影响。采用C18-HPLC-PDA方法,对番茄果实在采后成熟过程中番茄红素等类胡萝卜素的积累进行了监测。结果表明:在室温、避光、通风条件下,采后的番茄果实中总类胡萝卜素(TCA)的含量在“白果”阶段后迅速增加。其中,番茄红素在TCA中的比例也随之增长。     

番茄中VC和番茄红素在煸炒过程中的变化研究——基于模糊理论的番茄煸炒烹调工艺的确定

研究了番茄中VC、番茄红素含量在煸炒过程中的变化,目的在于对番茄中的主要营养素进行较深入地研究,促进煸炒工艺标准化。利用模糊理论,科学确定煸炒番茄的最佳工艺条件。结果表明:(1)随着煸炒过程的加深,番茄中的VC含量不断减少,番茄红素不断溶出,两者呈负相关的关系;以食醋为介质,煸炒番茄的最佳工艺条件为:在食醋含量0.57%、煸炒温度120℃条件下煸炒5min。在此工艺条件下,番茄中的营养成分VC得到了有效地保护,同时,番茄的食用品质也达到了较优水平。(2)番茄中VC对总抗氧化活性的贡献率小于0.4%,意味着尽管VC损失了,煸炒处理后番茄仍能保持其总酚类含量、总类黄酮含量和总抗氧化活性,对番茄的营养价值损失不大。番茄煸炒后番茄红素的溶出使得番茄的营养价值提高了,所以在实际生活中,将番茄加热或煸炒后食用,可以提高番茄的营养价值,对人体健康更加有益。     

Effect of illumination and chlorophylls on stability of tomato carotenoids

Lipidic extract from tomato peels, or tomato peels plus stalks, dissolved in ethanol were submitted to illumination. Lycopene, β-carotene, phytoene and phytofluene isomerisation and degradation, during storage at room temperature for 28 days, were studied. Degradation of chlorophylls a and b were analysed in lipidic extracts from stalks. Total lycopene and all-E-lycopene degradation was found to fit to a first-order model. The degradation rate constant was lower in extracts from peels −0.0137 (all-E-lycopene) and −0.0737 (total lycopene), than in those from peel plus stalk −0.0415 (all-E-lycopene) and −0.0854 (total lycopene). Z-lycopene isomers showed an inconsistence change during storage, in all analysed samples. Concentration of β-carotene from extracts of tomato peels plus stalks decreased slightly during storage. Phytoene and phytofluene degradation were not significantly affected by both storage conditions and chlorophylls. The obtained results showed that some compounds from stalks, such as chlorophylls, could favour lycopene and β-carotene degradation during storage under illumination.