Mixture approach for optimizing lycopene extraction from tomato and tomato products

A simple mixture process design based on the comparison of both quadratic and special cubic models and involving three mixture components (hexane/acetone/ethanol) as a solution for extracting lycopene from raw tomato, tomato sauce, and tomato paste was used to confirm the hypothesis that lycopene extraction rates are a function of the solvent used during the extraction process. Conventional criteria (p 相似文献   

Supercritical CO(2) extraction of beta-carotene and lycopene from tomato paste waste

Lycopene and beta-carotene were extracted from tomato paste waste using supercritical carbon dioxide (SC-CO(2)). To optimize supercritical fluid extraction (SFE) results for the isolation of lycopene and beta-carotene, a factorial designed experiment was conducted. The factors assessed were the temperature of the extractor (35, 45, 55, and 65 degrees C), the pressure of the extraction fluid (200, 250, and 300 bar), addition of cosolvent (5, 10, and 15% ethanol), extraction time (1, 2, and 3 h), and CO(2) flow rate (2, 4, and 8 kg/h). The total amounts of lycopene and beta-carotene in the tomato paste waste, extracts, and residues were determined by HPLC. A maximum of 53.93% of lycopene was extracted by SC-CO(2) in 2 h (CO(2) flow rate = 4 kg/h) at 55 degrees C and 300 bar, with the addition of 5% ethanol as a cosolvent. Half of the initially present beta-carotene was extracted in 2 h (flow rate = 4 kg/h), at 65 degrees C and 300 bar, also with the addition of 5% ethanol.     

Optimization of lycopene extraction from tomato cell suspension culture by response surface methodology

Radioisotope-labeled lycopene is an important tool for biomedical research but currently is not commercially available. A tomato cell suspension culture system for the production of radioisotope-labeled lycopene was previously developed in our laboratory. In the current study, the goal was to optimize the lycopene extraction efficiency from tomato cell cultures for preparatory high-performance liquid chromatography (HPLC) separation. We employed response surface methodology (RSM), which combines fractional factorial design and a second-degree polynomial model. Tomato cells were homogenized with ethanol, saponified by KOH, and extracted with hexane, and the lycopene content was analyzed by HPLC-PDA. We varied five factors at five levels: ethanol volume (1.33-4 mL/g); homogenization period (0-40 s/g); saturated KOH solution volume (0-0.67 mL/g); hexane volume (1.67-3 mL/g); and vortex period (5-25 s/g). Ridge analysis by SAS suggested that the optimal extraction procedure to extract 1 g of tomato cells was at 1.56 mL of ethanol, 28 s homogenization, 0.29 mL of KOH, 2.49 mL of hexane, and 17.5 s vortex. These optimal conditions predicted by RSM were confirmed to enhance lycopene yield from standardized tomato cell cultures by more than 3-fold.     

Supercritical fluid extraction of lycopene from tomato processing byproducts

Tomato seeds and skins acquired from the byproduct of a local tomato processing facility were studied for supercritical fluid extraction (SFE) of phytochemicals. The extracts were analyzed for lycopene, beta-carotene, alpha-carotene, alpha-tocopherol, gamma-tocopherol, and delta-tocopherol content using high-performance liquid chromatography-electrochemical detection and compared to a chemically extracted control. SFEs were carried out using CO(2) at seven temperatures (32-86 degrees C) and six pressures (13.78-48.26 MPa). The effect of CO(2) flow rate and volume also was investigated. The results indicated that the percentage of lycopene extracted increased with elevated temperature and pressure until a maximum recovery of 38.8% was reached at 86 degrees C and 34.47 MPa, after which the amount of lycopene extracted decreased. Conditions for the optimum extraction of lycopene from 3 g of raw material were determined to be 86 degrees C, 34.47 MPa, and 500 mL of CO(2) at a flow rate of 2.5 mL/min. These conditions resulted in the extraction of 61.0% of the lycopene (7.19 microg lycopene/g).     

Extraction of lycopene from tomato skin with supercritical carbon dioxide: effect of operating conditions and solubility analysis

Supercritical carbon dioxide (SCCO2) extraction of lycopene from waste tomato skins was investigated. The experiments were carried out at pressures and temperatures ranging from 20 to 50 MPa and 313 to 373 K, respectively, without any modifiers. The flow rate of CO2 was maintained at 2.5 mL/min for 330 min extraction time. Solvent flow rate effect was examined for CO2 flow rates from 1.5 to 4.5 mL/min. The extracts were analyzed by high-performance liquid chromatography and UV-visible spectroscopy. The results showed that with optimized operating conditions, the maximum yield of lycopene (1.18 mg of lycopene/g of sample) was obtained at 40 MPa, 373 K, and 2.5 mL of CO2/min. Chromatographic analysis indicated that lycopene was extracted from tomato skin with negligible degradation at the optimum conditions and the amount extracted represented more than 94% of the total carotenoid content of the sample. The solubility of lycopene was modeled by use of the Chrastil equation.     

Combined pressure-temperature effects on carotenoid retention and bioaccessibility in tomato juice

This study highlights the changes in lycopene and β-carotene retention in tomato juice subjected to combined pressure-temperature (P-T) treatments ((high-pressure processing (HPP; 500-700 MPa, 30 °C), pressure-assisted thermal processing (PATP; 500-700 MPa, 100 °C), and thermal processing (TP; 0.1 MPa, 100 °C)) for up to 10 min. Processing treatments utilized raw (untreated) and hot break (～93 °C, 60 s) tomato juice as controls. Changes in bioaccessibility of these carotenoids as a result of processing were also studied. Microscopy was applied to better understand processing-induced microscopic changes. TP did not alter the lycopene content of the tomato juice. HPP and PATP treatments resulted in up to 12% increases in lycopene extractability. all-trans-β-Carotene showed significant degradation (p < 0.05) as a function of pressure, temperature, and time. Its retention in processed samples varied between 60 and 95% of levels originally present in the control. Regardless of the processing conditions used, <0.5% lycopene appeared in the form of micelles (<0.5% bioaccessibility). Electron microscopy images showed more prominent lycopene crystals in HPP and PATP processed juice than in thermally processed juice. However, lycopene crystals did appear to be enveloped regardless of the processing conditions used. The processed juice (HPP, PATP, TP) showed significantly higher (p < 0.05) all-trans-β-carotene micellarization as compared to the raw unprocessed juice (control). Interestingly, hot break juice subjected to combined P-T treatments showed 15-30% more all-trans-β-carotene micellarization than the raw juice subjected to combined P-T treatments. This study demonstrates that combined pressure-heat treatments increase lycopene extractability. However, the in vitro bioaccessibility of carotenoids was not significantly different among the treatments (TP, PATP, HPP) investigated.     

Processing effects on lycopene content and antioxidant activity of tomatoes

Consumption of tomato products has been associated with decreased risk of some cancer types, and the tomato antioxidant, lycopene, is thought to play an important role in the observed health effects. In this study, four carotenoids, trans-lycopene, phytofluene, phytoene, and zeta-carotene, were quantified in tomato products. Samples of raw tomatoes, tomato juice after hot break scalder, and final paste were obtained from two different processing plants over two years. Comparison of carotenoid levels throughout processing indicated that lycopene losses during processing of tomatoes into final paste (25-30 degrees Brix) ranged from 9 to 28%. The initial Brix level of the raw tomatoes appeared to influence the amount of lycopene loss that occurred, possibly due to the differences in processing time required to achieve the final desired Brix level of the paste. In general, no consistent changes in the other carotenoids were observed as a function of processing. The antioxidant activity of fresh tomatoes, tomato paste, and three fractions obtained from these products (i.e., aqueous, methanol, and hexane fractions) was also determined. In both a free radical quenching assay and a singlet oxygen quenching assay, significant antioxidant activity was found in both the hexane fraction (containing lycopene) and the methanol fraction, which contained the phenolic antioxidants caffeic and chlorogenic acid. The results suggest that in addition to lycopene, polyphenols in tomatoes may also be important in conferring protective antioxidative effects.     

Carotenoid absorption in humans consuming tomato sauces obtained from tangerine or high-beta-carotene varieties of tomatoes

Tomato sauces were produced from unique tomato varieties to study carotenoid absorption in humans. Tangerine tomatoes, high in cis-lycopene, especially prolycopene (7Z,9Z,7'Z,9'Z), and high-beta-carotene tomatoes as an alternative dietary source of beta-carotene were grown and processed. Sauces were served after 2 week washout periods and overnight fasting for breakfast to healthy subjects (n = 12, 6M/6F) in a randomized crossover design. The serving size was 150 g (containing 15 g of corn oil), tangerine sauce containing 13 mg of lycopene (97.0% as cis-isomers) and high-beta-carotene sauce containing 17 mg of total beta-carotene (1.6% as the 9-cis-isomer) and 4 mg of lycopene. Blood samples were collected 0, 2, 3, 4, 5, 6, 8, and 9.5 h following test meal consumption and carotenoids determined in the plasma triacylglycerol-rich lipoprotein fraction by HPLC-electrochemical detection. Baseline-corrected areas under the concentration vs time curves (AUC) were used as a measure of absorption. AUC0-9.5h values for total lycopene in the tangerine sauce group were 870 +/- 187 (nmol.h)/L (mean +/- SEM) with >99% as cis-isomers (59% as the tetra-cis-isomer). The AUC0-9.5h values for total beta-carotene and lycopene after consumption of the high-beta-carotene sauce were 304 +/- 54 (4% as 9-cis-carotene) and 118 +/- 24 (nmol.h)/L, respectively. Lycopene dose-adjusted triacylglycerol-rich lipoprotein AUC responses in the tangerine sauce group were relatively high when compared to those in the literature and the high-beta-carotene group. The results support the hypothesis that lycopene cis-isomers are highly bioavailable and suggest that special tomato varieties can be utilized to increase both the intake and bioavailability of health-beneficial carotenoids.     

Lycopene bioaccessibility and starch digestibility for extruded snacks enriched with tomato derivatives

To improve the nutritional value of energy-dense extruded snacks, corn grits were replaced with tomato paste and/or tomato skin powder at ratios of 5, 10, and 20% and extruded to make expanded snack foodlike products. Using a model digestion system, lycopene bioaccessibility and uptake from the snacks into Caco-2 cells were determined. The digestibility of the starch, the main nutrient component of the snacks, was also investigated. While extrusion cooking reduced the lycopene content of the snacks, the proportion of bioaccessible lycopene increased. Lycopene uptake by the Caco-2 cells from the extruded snacks exceeded that of the control in which the lycopene was not extruded, by 5% (p < 0.05). The digestibility of starch in the snacks varied depending on the type of tomato derivative and its concentration. Optimization of the extrusion cooking process and the ingredients can yield functional extruded snack products that contain bioavailable lycopene.     

Characterization of high purity lycopene from tomato wastes using a new pressurized extraction approach

In this paper, a method for the extraction of high purity lycopene from tomato wastes is presented. The method is based on a pressurized extraction that uses the Extractor Naviglio, and it is performed in the 0.7-0.9 MPa range. Tomato skin, the byproduct deriving from manufacturing of tomato, in a water dispersion, are used as starting material. Lycopene is transferred, for the effect of the high pressure used, in the form of molecular aggregates into the water as a dispersion, while apolar compounds remain in the matrix. The aggregates are easily purified in a single subsequent step by using methanol, thus, obtaining lycopene at 98% chromatographic purity or higher. A new stationary phase, phenyl-hexyl silicone, and a simple water/acetonitrile gradient were used for HPLC analysis of lycopene. The extract was characterized by UV-Vis spectrophotometry, (1)H NMR, (13)C NMR, and electrospray ionization mass spectrometry. An average recovery of 2.8 mg lycopene/kg tomato waste can be obtained after 4 hours of extraction and using tap water as the extracting liquid. The recovery percentage was of about 10%. The exhausted tomato byproduct can be easily dried and used in agriculture or as feeding for animals.     

Liquid chromatography-mass spectrometry of cis- and all-trans-lycopene in human serum and prostate tissue after dietary supplementation with tomato sauce

Several epidemiological studies suggest a lower incidence of prostate cancer in men who routinely consume tomato products. Tomatoes are the primary dietary source of lycopene, which is among the most potent antioxidants of the carotenoids. Men with clinical stage T1 or T2 prostate adenocarcinoma were recruited (n = 32) and consumed tomato sauce based pasta dishes for 3 weeks (equivalent to 30 mg of lycopene per day) before radical prostectomy. Prostate tissue from needle biopsy just before intervention and prostectomy after supplementation from a subset of 11 subjects was evaluated for both total lycopene and lycopene geometrical isomer ratios. A gradient HPLC system using a C(18) column with UV-vis absorbance detection was used to measure total lycopene. Because the absorbance detector was insufficiently sensitive, HPLC with a C(30) column and positive ion atmospheric pressure chemical ionization mass spectrometric (LC-MS) detection was developed as a new assay to measure the ratio of lycopene cis/trans isomers in these samples. The limit of detection of the LC-MS method was determined to be 0.93 pmol of lycopene on-column, and a linear response was obtained over 3 orders of magnitude. Total lycopene in serum increased 2.0-fold from 35.6 to 69.9 microg/dL (from 0.664 to 1.30 microM) as a result of dietary supplementation with tomato sauce, whereas total lycopene in prostate tissue increased 3.0-fold from 0.196 to 0.582 ng/mg of tissue (from 0.365 to 1.09 pmol/mg). all-trans-Lycopene and at least 14 cis-isomer peaks were detected in prostate tissue and serum. The mean proportion of all-trans-lycopene in prostate tissue was approximately 12.4% of total lycopene before supplementation but increased to 22.7% after dietary intervention with tomato sauce. In serum there was only a 2.8% but statistically significant increase in the proportion of all-trans-lycopene after intervention. These results indicate that short-term supplementation with tomato sauce containing primarily all-trans-lycopene (83% of total lycopene) results in substantial increases in total lycopene in serum and prostate and a substantial increase in all-trans-lycopene in prostate but relatively less in serum.     

Hydroxymethylfurfural and furosine reaction kinetics in tomato products

The reaction kinetics of two heat damage indices, HMF and furosine, were examined in four tomato products with different dry matter contents (10.2, 25.5, 28.6, and 34.5%) over a temperature-time range of 80-120 degrees C and 0-255 min. The reactions followed pseudo-zero order kinetics. E(a) and z-value were, respectively, 139. 9 kJ/mol and 19.2 degrees C for HMF, and 93.9 kJ/mol and 28.4 degrees C for furosine. The analyses of both indices in several samples of commercial and industrial tomato products showed very low levels of HMF (from 1 to 42 ppm) and a lack of correlation between HMF and furosine mainly because of the different evolution of the two indices during storage. The HMF level of a tomato paste sample stored at 25 degrees C decreased from 609 to 17 ppm after 98 days, while furosine increased from 458 to 550 mg/100 g of protein.     

Thermal processing enhances the nutritional value of tomatoes by increasing total antioxidant activity

Processed fruits and vegetables have been long considered to have lower nutritional value than their fresh commodities due to the loss of vitamin C during processing. This research group found vitamin C in apples contributed < 0.4% of total antioxidant activity, indicating most of the activity comes from the natural combination of phytochemicals. This suggests that processed fruits and vegetables may retain their antioxidant activity despite the loss of vitamin C. Here it is shown that thermal processing elevated total antioxidant activity and bioaccessible lycopene content in tomatoes and produced no significant changes in the total phenolics and total flavonoids content, although loss of vitamin C was observed. The raw tomato had 0.76 +/- 0.03 micromol of vitamin C/g of tomato. After 2, 15, and 30 min of heating at 88 degrees C, the vitamin C content significantly dropped to 0.68 +/- 0.02, 0.64 +/- 0.01, and 0.54 +/- 0.02 micromol of vitamin C/g of tomato, respectively (p < 0.01). The raw tomato had 2.01 +/- 0.04 mg of trans-lycopene/g of tomato. After 2, 15, and 30 min of heating at 88 degrees C, the trans-lycopene content had increased to 3.11+/- 0.04, 5.45 +/- 0.02, and 5.32 +/- 0.05 mg of trans-lycopene/g of tomato (p < 0.01). The antioxidant activity of raw tomatoes was 4.13 +/- 0.36 micromol of vitamin C equiv/g of tomato. With heat treatment at 88 degrees C for 2, 15, and 30 min, the total antioxidant activity significantly increased to 5.29 +/- 0.26, 5.53 +/- 0.24, and 6.70 +/- 0.25 micromol of vitamin C equiv/g of tomato, respectively (p < 0.01). There were no significant changes in either total phenolics or total flavonoids. These findings indicate thermal processing enhanced the nutritional value of tomatoes by increasing the bioaccessible lycopene content and total antioxidant activity and are against the notion that processed fruits and vegetables have lower nutritional value than fresh produce. This information may have a significant impact on consumers' food selection by increasing their consumption of fruits and vegetables to reduce the risks of chronic diseases.     

Change in carotenoids and antioxidant vitamins in tomato as a function of varietal and technological factors

The change in the carotenoid and bioantioxidant content of tomato as a function of varietal and technological factors was investigated in the present work. No great differences were found between cultivars for fresh consumption (salad tomatoes) and those for processing in ascorbic acid content. The concentration of ascorbic acid ranged between 14.6 and 21.7 mg/100 g fresh weight of ripe tomato fruit. Processing cultivars contained higher amounts of tocopherols, particularly alpha-tocopherol than tomatoes for fresh consumption. Significant differences could be obtained between the examined varieties with regard to carotenoid concentration. The different tomatoes varied not only in the total carotenoid content but also in the qualitative distribution of some pigments such as lycopene, beta-carotene and lutein. During heat-based processing, ascorbic acid, tocopherols, and carotenoids showed different role and response. Ascorbic acid, alpha-tocopherol quinone, and beta-carotene were the most susceptible components toward thermal degradation.     

Contribution of tomato phenolics to antioxidation and down-regulation of blood lipids

This study was performed to understand the characteristics and biological activities of phenolics in tomatoes and to examine the effect of tomato on the regulation of blood lipids. Tomatoes of both big and small sizes were used fresh, after blanching, or after blanching and heating. Moreover, a human clinical trial was conducted to examine plasma antioxidation, status of blood lipids, and phenolic responses after ingestion of fresh tomato, tomato juice, and a lycopene drink. The contents of tomato phenolics were increased by 34% for small tomato and by 23% for big tomato after treatment by blanching and heating at 100 degrees C for 30 min. Tomato phenolics showed fair antioxidant activity (57-71%) and also synergistically promoted the antioxidation (81-100%) of tomato carotenoids. In the human clinical study, total antioxidant capacity and phenolic contents in plasma were increased after administration of fresh tomato and tomato juice, but no significant difference was found for lycopene drink consumption. Triglyceride levels and low-density lipoprotein cholesterol were decreased after administration of fresh tomato and tomato juice, and high-density lipoprotein cholesterol was increased.     

Isoprenoid, lipid, and protein contents in intact plastids isolated from mesocarp cells of traditional and high-pigment tomato cultivars at different ripening stages

This study reports quali-quantitative analyses on isoprenoids, phospholipids, neutral lipids, phytosterols, and proteins in purified plastids isolated from fresh fruits of traditional (Donald and Incas) and high-pigment (Kalvert and HLY-18) tomato cultivars at four ripening stages. In all of the investigated cultivars, lycopene, β-catotene, lutein, and total carotenoids varied significantly during ripening. Chromoplasts of red-ripe tomato fruits of high-pigment cultivars accumulated twice as much as lycopene (307.6 and 319.2 μg/mg of plastid proteins in Kalvert and HLY-18, respectively) than ordinary cultivars (178.6 and 151.7 μg/mg of plastid proteins in Donald and Incas, respectively); differences in chlorophyll and α-tocopherol contents were also evidenced. Phospholipids and phytosterols increased during ripening, whereas triglycerides showed a general decrease. Regardless of the stage of ripening, palmitic acid was the major fatty acid in all cultivars (ranging from 35 to 52% of the total fatty acids), followed by stearic, oleic, linoleic, linolenic, and myristic acids, but their relative percentage was affected by ripening. Most of the bands detected on the SDS-PAGEs of plastid proteins were constantly present during chloroplast-to-chromoplast conversion, some others disappeared, and only one, with a molecular weight of ~41.6 kDa, was found to increase in intensity.     

Nondestructive measurement of fresh tomato lycopene content and other physicochemical characteristics using visible-NIR spectroscopy

Measurement of fresh tomato fruit overall quality, and particularly lycopene content, is challenging in the context of high-volume production. An experiment was conducted to simultaneously measure various quality parameters of tomato in a nondestructive manner using vis-NIR reflectance spectroscopy and chemometrics. The sampling set included different cultivars that are obtainable from both retailers' shelves and two greenhouse producers. Results indicate that lycopene content was accurately predicted [r(2) = 0.98; root mean square error of cross-validation (RMSECV) = 3.15 mg/kg], along with color variables such as Hunter a (r(2) = 0.98), L, and b (r(2) = 0.92). Tomato color index (TCI) was better predicted (r(2) = 0.96) than the a/ b ratio (r(2) = 0.89). Firmness prediction, with an r(2) of 0.75, is comparable to what is reported in the literature for other fruits and may have a practical interest. Prediction of internal quality such as pH, soluble solids, titratable acidity, and electrical conductivity was less accurate, partly due to a low variability of these parameters among samples. Predictions were robust with regard to cultivars, except for pink variety tomato. The 400-1000 nm range gave results almost as accurate as the 400-1500 nm range.     

Uracil as an index of lactic acid bacteria contamination of tomato products

The aim of this research was to evaluate the suitability of uracil as an hygienic quality index of tomato products. Whereas uridine was naturally present throughout tomato fruits' ripening, uracil appeared only after microbial contamination. In tomato pulp inoculated with nine different microbial strains, all five lactic acid bacteria (LAB) studied released relevant quantities of uracil (150-1040 mg/kg of dm), with a correlated partial or total decrease of uridine. Uracil production by yeasts and molds was very low or nonexistent; the starting uridine concentration (approximately 960 mg/kg of dm) remained constant or increased. Uracil thermostability was also verified. Twenty-six samples of tomato paste (30 degrees Brix) were collected from bag-in-drums produced in an industrial processing plant, some with evident swelling symptoms. All of the samples with high microbial count presented uracil. Uracil was also present in samples with microbial contamination under the detection limit and Howard mold count below legislation limits, implying the reprocessing, at least partial, of altered tomato product. The results indicate that uracil presence in tomato products is an index of LAB contamination that has occurred before heat treatment.     

基质栽培番茄营养液中氮、钾最佳浓度研究

【目的】合理的氮、钾养分供给是提高番茄生长及果实品质的重要措施，本文研究了滴灌营养液中不同的氮、钾养分供给水平对基质栽培番茄生长及果实品质的影响，为优化基质栽培番茄的营养液配方，确定最佳的氮、钾养分浓度，实现养分供给的精量化管理提供科学依据。【方法】以沙∶珍珠岩比例为1∶2配置栽培基质，用于温室中番茄栽培，以番茄‘A20’为试材，进行了水培试验。采用2因素 (氮、钾) 5水平响应面中心复合设计，滴灌营养液中氮浓度的基础值为244 mg/L，试验设计步长为120 mg/L；钾浓度的基础值为313 mg/L，试验设计步长为150 mg/L。调查了番茄叶片叶绿素含量、净光合速率、单株产量、果实可溶性糖含量、可滴定酸含量、糖酸比、维生素C含量和番茄红素含量。【结果】随着滴管液中氮浓度从74 mg/L增加到414 mg/L，番茄产量、叶片叶绿素含量、叶片净光合速率、果实可溶性糖含量、糖酸比、番茄红素含量和果实维生素C含量均呈先增后减的趋势。随着营养液中钾浓度从101 mg/L增加到525 mg/L，果实可溶性糖含量、糖酸比和维生素C含量持续增加，番茄产量、叶绿素含量、净光合速率、番茄红素含量均先增后减。此外，通过建立各指标与氮钾二因子的二次回归方程发现，氮素是叶绿素含量、净光合速率和单株产量的主要影响因子，钾素是果实可溶性糖、可滴定酸、糖酸比、维生素C和番茄红素含量的主要影响因子。氮、钾互作显著影响番茄产量和叶片叶绿素含量；充足的钾营养供给可以促进植株对氮素的吸收与同化，提高叶片叶绿素含量，利于产量提高；适量的氮素供应有利于钾素的吸收与利用，促进产量的进一步提高。采用主成分分析方法对8种配施方案下番茄产量和品质的综合性能进行评价，结果显示营养液中氮、钾浓度分别为N 378 mg/L、K 391 mg/L时为最优配方方案，且番茄叶片净光合速率达到最大值。【结论】在沙子和珍珠岩1∶2 (v∶v) 为基质的番茄无土栽培条件下，滴灌营养液中氮、钾浓度分别为N 378 mg/L和K 391 mg/L时，番茄产量和品质的综合性能达到最优，该方案可在生产实践中为基质栽培番茄营养液精确管理提供一定的借鉴意义。     

Effect of dietary dried tomato pulp on oxidative stability of Japanese quail meat

Ninety, 21-day-old, Japanese quail (Coturnix coturnix japonica) divided into three groups with five subgroups each were fed a basal diet that served as control or a basal diet containing 5 or 10% of dried tomato pulp (DTP), a byproduct of the tomato-processing industry. The DTP contained lycopene and beta-carotene at 281 and 24.3 mg kg(-)(1) of dry weight, respectively. On day 42 of age, birds were slaughtered, and carcasses were trimmed for breast meat. To assess the effect of dietary treatment on the oxidative stability of raw and cooked meat, raw meat was subjected to iron-induced lipid oxidation, whereas both raw and cooked meats were subjected to refrigerated storage at 4 degrees C. The extent of lipid oxidation was determined on the basis of the malondialdehyde (MDA) formed through the use of third-order derivative spectrophotometry. Results showed that after 6 and 9 days of refrigerated storage, MDA values in raw meat were increased. The increase was higher (P < 0.05) for the 10% DTP group and lower (P < 0.05) for the 5% DTP group, compared to control. An analogous oxidation profile was observed for cooked meat at 3, 6, and 9 days of storage. Iron-induced lipid oxidation of raw meat showed that the 10% DTP group as well as the control group exhibited MDA values that did not differ (P > 0.05) from each other at all time points, whereas the 5% DTP group presented MDA values that, although not differing from those of the other groups at 0 and 50 min, were significantly (P < 0.05) lower than those of the other groups at 100 and 150 min of iron-induced lipid oxidation. These results suggested that inclusion of dried tomato pulp in feed at a level of 5% exerted an antioxidant effect, whereas addition at level of 10% exerted a prooxidant effect. Mean alpha-tocopherol levels in the control, 5% DTP, and 10% DTP groups were 2.2, 2.1, and 1.4 mg kg(-)(1) of meat, respectively. Fatty acid analysis showed that the 10% DTP group had a higher (P < 0.05) content of total polyunsaturated fatty acids and a greater (P < 0.05) unsaturated/saturated fatty acid ratio compared to control. There might be an interaction between DTP and alpha-tocopherol that is of importance for the balance between pro- and antioxidative activities. Future experiments should be designed to explore the interaction between individual carotenoids and tocopherols in order to better elucidate their role in oxidative changes.