Tomato pulp as source for the production of lycopene powder containing high proportion of cis-isomers

Cis-isomers of lycopene has been demonstrated to possess higher biological activity than its all-trans form. The objectives of this study were to compare the extraction efficiency and degree of isomerization of lycopene by employing supercritical carbon dioxide (SCD) and solvents, as well as process the lycopene extract into powder containing high proportion of cis-isomers from tomato pulp as source. Results showed that a high yield of lycopene was achieved by SCD at 350 bar and 70 °C, with cis-isomers making up 41.4% of total lycopene. However, with temperature at 80 and 90 °C, the maximum isomerization was accomplished, and cis-lycopene constituted 51.0 and 53.8% of total lycopene, respectively. For solvent extraction, the highest yield of all-trans-lycopene was attained by ethanol–hexane (4/3 v/v) at 25 and 50 °C, whereas the maximum isomerization (47.0% cis-lycopene) occurred at 75 °C. A powder product containing 34.5% cis-isomers of lycopene was obtained by spray-drying, and the total amount of lycopene in spray-dried powder was much greater than that in freeze-dried powder. The maximum yield of lycopene in the powder product could be obtained through processing by adding sodium alginate to the eluate directly after SCD extraction and open-column chromatography with formation of 41.4% cis-lycopene. The method developed in this study may be used for possible commercial production of highly active lycopene powder.     

Recovery of lycopene from industrially derived tomato processing by-products by pulsed electric fields-assisted extraction

The influence of pulsed electric fields (PEF) pre-treatment at different field strength (E = 1–5 kV/cm) and energy input (W_T = 5–10 kJ/kg) on the recovery yield of lycopene in either acetone or ethyl lactate from industrial tomato peels residues, was investigated. The rate of lycopene extraction in both solvents decreased with time and was predicted rather satisfactorily (R² = 0.96–0.99) by the Peleg's model. Micrograph of tomato peels showed that PEF induced size reduction and separation between the plant cells likely due to pore formation and leakage of intracellular matter. Coherently, PEF treatment (5 kV/cm, 5 kJ/kg) significantly enhanced the extraction rate (27–37%), the lycopene yields (12–18%) and the antioxidant power (18.0–18.2%) in either acetone and ethyl lactate extracts, as compared with untreated samples. However, acetone gave the highest lycopene yield. HPLC analyses revealed that all-trans lycopene was the main carotenoid extracted and no degradation/isomerization phenomena occurred. The results obtained in this work suggest that the application of PEF prior to solid-liquid extraction with environmentally friendly solvents could represent a sustainable approach for the valorization of industrial tomato peels residues.Industrial relevanceIndustrial processing of tomatoes generates large amount of by-products, mainly peels, which represent a cheap and abundant source of natural carotenoids, especially lycopene. The recovery lycopene from tomato peels residues is a crucial step for use in a wide range of industrial applications in food, cosmetic and pharmaceutical sectors as natural pigment and antioxidant. PEF pre-treatment allows to intensify the extractability of lycopene from of tomato processing by-products using environmentally friendly solvents, thus adding new value to the tomato processing chain, improving economic performances and decreasing waste problems.     

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.     

Process optimisation for recovery of carotenoids from tomato waste

Carotenoids constitute an important component of waste originating from tomato processing plants. Studies were carried out to assess the extraction yield of tomato waste carotenoids in different solvents and solvent mixtures and to optimise the extraction conditions for maximum recovery. A mixture of ethyl acetate and hexane gave the highest carotenoid extraction yield among the others examined. Extraction conditions, such as percentage of hexane in the solvent mixture of ethyl acetate and hexane, ratio of solvent to waste and particle size were optimised using a statistically designed experiment. A regression equation for predicting the carotenoid yield as a function of three extraction variables was derived by statistical analysis and a model with predictive ability of 0.97 was obtained. The optimised conditions for maximum carotenoid yield (37.5 mg kg⁻¹ dry waste) were 45% hexane in solvent mixture, solvent mixture to waste ratio of 9.1:1 (v/w) and particle size 0.56 mm.     

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.     

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.     

A Systematic Study on Extraction of Lipase Obtained by Solid-State Fermentation of Soybean Meal by a Newly Isolated Strain of <Emphasis Type="Italic">Penicillium</Emphasis> sp

This work aimed to assess the effect of some variables on the lipase extraction from the fermented medium in order to establish the experimental conditions that maximize the yield of the enzyme obtained from solid-state fermentation of soybean meal and a newly isolated strain of Penicillium sp. The experimental design technique was used to investigate the effect of relevant variables on lipase activity. The factors investigated were solvent pH (5.5–8.5), stirring rate (50–150 rpm), temperature (25–49 °C) and solid/liquid ratio (1:20–5:20). The effect of time of contact was evaluated in a kinetic study. Higher lipase activities in the extraction study were obtained using phosphate buffer 100 mM pH 8.5, at 25 °C, 150 rpm, and solid/liquid ratio of 1:20. Extraction studies showed that maximum activity (186 U/g) was obtained in 15 min of extraction.     

Supercritical Carbon Dioxide Extraction of Valuable Compounds from Citrus junos Seed

Extraction of Citrus junos seed was carried out at temperatures of 40–70 °C, pressures of 20–50 MPa, and CO₂ flow rate of 3 ml/min with supercritical carbon dioxide to obtain the valuable compounds. Seed oil was also extracted by using Soxhlet extraction with hexane as the solvent during 360 min for comparison with the efficiency of supercritical carbon dioxide extraction. Gas chromatography–mass spectrometry (GC–MS) was used to analyze the components present in the seed oil and Gas chromatography-flame ionization detector (GC-FID) was used to quantify their amounts. Among the conditions studied, the highest extraction yield was obtained at higher pressure and temperature (50 MPa and 70 °C). The extraction yield was about 29.5% of the seed, which was almost comparable to that of hexane Soxhlet extraction (33.8%). The results of the GC–MS analyses showed that the seed oil extracted contained N-methylanthranyl acid methyl, fatty acids (such as palmitic, stearic, oleic, linoleic, and linolenic acid), and physiologically active substances of β-sitosterol and squalene.     

Application of a UV–vis detection-HPLC method for a rapid determination of lycopene and β-carotene in vegetables

The purpose of this paper is to optimize an HPLC method for the determination of lycopene and β-carotene in vegetables and compare it with a spectrophotometric standard method. Among the different conditions studied the most suitable ones for our samples were: extraction with hexane/acetone/ethanol (50:25:25 v/v/v), evaporation of the hexane layer, dissolution of the dry extract in THF/ACN/methanol (15:30:55 v/v/v) and injection on a C18 column with methanol/ACN (90:10 v/v) + TEA 9 μM as mobile phase (Φ = 0.9 ml/min) and λ_detection = 475 nm. Samples considered for analysis were: tomato, carrot, pepper, watermelon, persimmon and medlar. The HPLC method proposed showed adequate reproducibility (RSD < 10.5%), accuracy (100–109% recovery) and sensitive detection limits (0.6 μM for lycopene; 0.3 μM for β-carotene), with a simple preparation of the samples (one step direct extraction) and short run times (10 min) for the quantification of lycopene and β-carotene.     

Combined thermal and high pressure inactivation kinetics of tomato lipoxygenase

The combined isothermal (10–60 °C) and isobaric (0.1–650 MPa) inactivation kinetics of lipoxygenase (LOX) extracted from tomatoes and reconstituted in a tomato purée were studied. Thermal inactivation of LOX at atmospheric pressure proceeded in the temperature range of 45–65 °C. LOX inactivation did not follow first order kinetics; the data could be fitted assuming that the two isoforms of LOX with different thermostability were present. Combined thermal and high pressure inactivation occurs at pressures in the range of 100–650 MPa combined with temperatures from 10–60 °C, and followed first-order kinetics. In the high-temperature/low-pressure range, (T≥50 °C and P≤300 MPa) an antagonistic effect is observed, therefore, the Arrhenius and Eyring equation cannot be used over the entire temperature and pressure range. Small temperature dependence is found in the low-temperature/high pressure range. A third degree polynomial model was successfully applied to describe the temperature–pressure dependence of the inactivation rate constants, which can be useful to predict inactivation rate constants of tomato LOX reconstituted in tomato purée in the temperature–pressure range studied.     

Lycopene and beta carotene concentration in aril oil of gac (Momordica cochinchinensis Spreng) as influenced by aril-drying process and solvents extraction

The purpose of this study was to evaluate the lycopene and beta carotene concentration in aril oil of gac as influenced by extracting solvents and drying methods. The solvent extractions namely chloroform:methanol (2:1 v/v), petroleum ether and hexane were evaluated for optimal extracting solvent of each carotenoid. Three different drying methods were used including hot-air (HA), low relative humidity air drying (LRH) and far-infrared radiation (FIR). The extracts of different solvents were exhibited to have different levels of lycopene and beta-carotene. Chloroform:methanol (2:1 v/v) showed higher lycopene and beta-carotene content in aril oil (0.49 and 1.18 mg/g) than that of fresh aril (0.045 and 0.009 mg/g). Among the different drying methods, HA was found to provide the highest amount of lycopene (0.82 mg/g DW) in the aril oil, followed by FIR (0.67 mg/g DW) and LRH (0.56 mg/g DW). Interestingly, HA dried aril oil had higher content of lycopene than that of control (fresh). However, processing methods are known to have variable effects on bioactive compounds of plant samples. Effects could vary from little or no change to significant losses, or even enhancement in antioxidant properties.     

Enzyme-Assisted Production of Tomato Seed Oil Enriched with Lycopene from Tomato Pomace

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.     

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.     

Tomato peel drying and carotenoids stability of the extracts

Tomato peels were firstly dried by different methods (hot air, freeze‐drying, and fluidized bed drying) to evaluate the recovery of lycopene, β‐carotene and DPPH radical scavenging activity. Comparison of the results showed that hot air drying at 50 °C was a suitable method and alternative to freeze‐drying to preserve carotenoids compounds and antioxidant activity in tomato peels. Then, ethanol/ethyl acetate (1:1) extracts from tomato peel, previously dried at 50 °C by hot air, were submitted to heat (100 °C) and light treatment (1000 lumen) to evaluate their stability as natural food dyes. Heating of the extracts caused a progressive reduction of total carotenoids, up to about 30% after 250 min of treatment, whereas the colour at the end of heat treatment showed small changes, with an overall colour difference (?E) equal to 7. Fluorescent lighting treatment showed an almost total degradation of carotenoids in the extracts after 48 h combined with a fading colour.     

Degradation kinetics of ergosterol in tomato paste serum

Thermal degradation of ergosterol in tomato paste serum was studied at different pH (4.5, 4.3, 3.9, 3.7 and 3.5,) and heating periods (0, 10, 20, 30 and 50 min) over the temperature range of 70 to 95 °C. Analysis of kinetic data suggested a first-order reaction for the degradation of ergosterol with the half-lives of 301.4–36.7, 239.0–33.7, 203.9–29.6, 113.6–29.8 and 83.5–23.7 min for 4.5, 4.3, 3.9, 3.7 and 3.5 pH samples, respectively, between 70 and 95 °C. Temperature dependence of reaction was described by the Arrhenius relationship. Activation energies for 4.5, 4.3, 3.9, 3.7 and 3.5 pH samples were found 20.57, 19.62, 19.07, 12.41 and 11.08 kcal mol⁻¹, respectively, between 70 and 95 °C.     

Thermal Stability and Isomerization of Lycopene in Tomato Oleoresins from Different Varieties

ABSTRACT: Lycopene, a tomato carotenoid, has been associated with the inhibition of certain chronic diseases including prostate cancer. Tomato oleoresin is a lipid-rich material resulting from successive solvent extraction of the tomato fruit. Thermal stability and isomerization of lycopene in oleoresins prepared from 3 different tomato varieties, Roma, High Lycopene, and Tangerine, and tomato peel waste, were studied at 25 °C, 50 °C, 75 °C, and 100 °C in the dark. Thermally degraded lycopene compounds and isomers of lycopene were analyzed by a combination of C₃₀ reversed-phase high-performance liquid chromatograph with a photodiode array detector, UV-visible spectrometer, or mass spectrometer. Effects of antioxidants on lycopene were also studied at 50 °C. As the storage temperature increased from 25 °C to 100 °C, the degradation of total lycopene in oleoresin from all samples increased significantly ( P <0.05). Lycopene at 25 °C and 50 °C may degrade mainly through oxidation without isomerization. Isomerization of lycopene in tomato oleoresins increased at 75 °C and 100 °C. Tetra- cis lycopene in Tangerine tomato varieties followed different degradation and isomerization pathways compared with all -trans lycopene in other tomato varieties. Addition of α-tocopherol or butylated hydroxytoluene slowed the rate of degradation of lycopene in oleoresin.     

Evaluation of pectolytic activities of enological interest in industrial enzyme preparations

 The purpose of this research was to determine the activity of several pectolytic enzymes, such as pectin methyl esterase, endopolymethylgalacturonase, endopolygalacturonase, exopolymethylgalacturonase, endopolygalacturonase, pectin transeliminase and pectic acid transeliminase, from within preparations that are available on the Portuguese market. The selected preparations were as follows: 15 pectolytic enzyme preparations, one hemicellulolytic preparation and one glucanase preparation. The measurements of enzyme activity were carried out using model solutions with 50 mg·l^–1 SO₂, pH 3.2, 25°C, with and without 12% ethanol (v/v), and a 24-h incubation period. Quantitatively, the results proved to be heterogeneous, significantly varying from preparation to preparation: all pectolytic enzyme activities in the 17 preparations analysed in this study were significantly different. The presence of ethanol reduced the enzymatic activity, apart from that of endopolymethylgalacturonase, and, in general, an increase of enzyme concentration raised the pectolytic enzyme activity. Received: 17 March 1997 / Revised version: 11 June 1997     

Evaluation of pectolytic activities of enological interest in industrial enzyme preparations

 The purpose of this research was to determine the activity of several pectolytic enzymes, such as pectin methyl esterase, endopolymethylgalacturonase, endopolygalacturonase, exopolymethylgalacturonase, endopolygalacturonase, pectin transeliminase and pectic acid transeliminase, from within preparations that are available on the Portuguese market. The selected preparations were as follows: 15 pectolytic enzyme preparations, one hemicellulolytic preparation and one glucanase preparation. The measurements of enzyme activity were carried out using model solutions with 50 mg·l^–1 SO₂, pH 3.2, 25°C, with and without 12% ethanol (v/v), and a 24-h incubation period. Quantitatively, the results proved to be heterogeneous, significantly varying from preparation to preparation: all pectolytic enzyme activities in the 17 preparations analysed in this study were significantly different. The presence of ethanol reduced the enzymatic activity, apart from that of endopolymethylgalacturonase, and, in general, an increase of enzyme concentration raised the pectolytic enzyme activity. Received: 17 March 1997 / Revised version: 11 June 1997     

Optimization of Enzymatic Hydrolysis Pretreatment Conditions for Enhanced Juice Recovery from Guava Fruit Using Response Surface Methodology

The effect of enzyme concentration (0.16–0.84 mg/100 g guava pulp), incubation temperature (36.6–53.4 °C), and incubation time (0.95–11 h) on juice yield was studied. A central composite rotatable design was used to establish the optimum conditions for enzymatic hydrolysis of guava to obtain maximum juice yield. Significant regression model describing the changes of juice yield with respect to hydrolysis parameters were established with the coefficient of determination, R ² = 0.85. Enzyme concentration was the most significant variable affecting the juice yield. The recommended enzymatic treatment condition from the study was at the enzyme concentration 0.70 mg/100 g guava pulp, incubation time 7.27 h, and incubation temperature 43.3 °C.     

纤维素酶和果胶酶对番茄红素提取的影响

以番茄组织为材料,用含体积分数2%二氯甲烷的石油醚为提取溶剂,研究添加果胶酶和纤维素酶提取番茄红素的实验。结果表明,果胶酶和纤维素酶混合使用比单一酶的提取效率高,且果胶酶的提取效果比纤维素酶要好。在果胶酶和纤维素酶混合质量比为2:1时,提取番茄红素的最佳条件为A3B2C2D4,即混合酶用量0.6g/100g、酶解温度35℃、pH5.0、酶解时间5h,然后2%二氯甲烷的石油醚提取20min,4000r/min离心10min。因此,添加果胶酶和纤维素酶,用2%二氯甲烷的石油醚提取,可以提高番茄红素的提取率。