Degradation compounds of carotenoids formed during heating of a simulated cashew apple juice

The influence of organic acid and heating treatments on carotenoid degradation on a simulated cashew apple juice was assessed by high performance liquid chromatography coupled with a photodiode array and mass spectrometry detectors. A total of nineteen carotenoids were separated in unheated simulated cashew apple juice, with all-trans-β-cryptoxanthin and all-trans-β-carotene as the major ones. As a consequence of heating, five xanthophylls disappeared, whereas two new cis isomers and five epoxide or furanoid-derivatives were formed and the levels of all cis isomers increased. In addition, 12′-apo-β-carotenal was formed at 90 °C. Two oxidation compounds (12′-apo-β-carotenal and 5,6-epoxy-β-cryptoxanthin) were formed after β-cryptoxanthin heating at 90 °C in an aqueous-based system. In all systems, the amounts of total carotenoids lost were not compensated by those formed. These facts indicated that isomerisation and oxidation to both coloured and non-coloured compounds were the main reactions occurring during heating of carotenoids in aqueous-based and juice systems.     

Degradation of carotenoids in orange juice during microwave heating

Degradation of carotenoids in orange juice was monitored during microwave (MW) heating at different time/temperature conditions. Various carotenoids were identified and quantified by HPLC. Degradation rate of carotenoids was influenced by MW heating temperatures: at 60 °C and 70 °C for 10 min violaxanthin and antheraxanthin were the compounds most unstable, while lutein and provitamin A carotenoids were more stable. At 85 °C a decrease of about 50% was observed for almost all carotenoids after 1 min of MW heating. Temperature sensitivity (z value) for total carotenoids was 14.2 °C, for single compounds z values ranged between 10.9 °C for β-carotene and 16.7 °C for antheraxanthin. These results can indicate an adequate choice temperature conditions for the quality control of carotenoids and the related nutritional values during MW treatment of orange juices.     

Determination of carotenoids in Dunaliella salina cultivated in Taiwan and antioxidant capacity of the algal carotenoid extract

A simple HPLC method with good separation efficiency was developed to determine all-trans and cis forms of carotenoids in Dunaliella salina cultivated in Taiwan. The analysis used a C30 column (250 × 4.6 mm, 5 μm) and an isocratic solvent system (flow rate = 1 mL/min) mixing methanol–acetonitrile–water (84/14/2, v/v/v) and methylene chloride, (75/25, v/v). Carotenoids were detected at 450 nm. Moreover, the antioxidant capacities of the algal carotenoid extract were also evaluated with Trolox equivalent antioxidant capacity (TEAC) assay, reducing power and 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging assay. Results showed that 7 carotenoids in the algal extract could be separated simultaneously within 30 min and the total amount of them was 290.77 mg/g algae. The contents of all-trans-β-carotene and 9- or 9′-cis-β-carotene, the major carotenoids in the algae, were 138.25 and 124.65 mg/g algae, respectively. The contents of all-trans-lutein, all-trans-zeaxanthin, 13- or 13′-cis-β-carotene, all-trans-α-carotene and 9- or 9′-cis-α-carotene were 6.55, 11.27, 4.95, 2.69, and 2.41 mg/g algae, respectively. The algal carotenoid extract had significantly higher antioxidant activity than all-trans forms of α-carotene, β-carotene, lutein and zeaxanthin in all antioxidant assays. The cis forms of carotenoids, especially 9- or 9′-cis-β-carotene, might play crucial roles for the antioxidant capacities of the algal extract.     

An in vitro model to study the intestinal absorption of carotenoids

An in vitro cell culture model to assess the intestinal absorption of carotenoids is described. When supplemented with taurocholate and oleic acid, differentiated Caco-2 cells on membranes are able to produce chylomicrons. Under conditions mimicking the in vivo postprandial state, Caco-2 cells take up carotenoids and secrete them incorporated into chylomicrons; the extents of absorption of all-trans, 9-cis, 13-cis β-carotene, α-carotene, lutein, lycopene were 11%, 2%, 3%, 10%, 7%, and 3%, respectively. Saturation of β-carotene transport through Caco-2 cells occurred at concentrations (>15 μM) higher than “physiological” concentrations. Finally, retinol supplementation resulted in an 1.7-fold increase in β-carotene transport. The data suggest that (1) the intestinal absorption of carotenoids is facilitated by the participation of a specific epithelial transporter and (2) retinol promotes β-carotene incorporation into larger, retinyl ester-enriched chylomicrons. The present in vitro cell culture system is a relevant model to study the intestinal absorption of carotenoids at the molecular level.     

Pasteurization of citrus juices with ohmic heating to preserve the carotenoid profile

This study was carried out to assess, for the first time, the effect of ohmic heating on the carotenoid profile of two citrus fruit juices: grapefruit and blood orange. Two heat treatments were designed to obtain pasteurization values of 50 and 150 min (Tref = 70 °C and z-value = 10 °C) with ohmic heating as compared to conventional heating. The results showed that xanthophyll losses could reach 70% for epoxyxanthophylls (cis-violaxanthin and cis-antheraxanthin) and 40% for hydroxyxanthophylls (β-cryptoxanthin, lutein, and zeaxanthin) with conventional heating, but losses were under 30% and 20%, respectively, with ohmic heating. Carotene species (lycopene and β-carotene) were stable regardless of the treatment. No negative non-thermal effects of ohmic heating were shown on carotenoids. Loss simulations of the studied carotenoids showed that the high temperatures reached with ohmic heating during pasteurization could substantially increase the organoleptic and nutritional quality of acid carotenoid-rich juices.Industrial relevanceCitrus are the top fruit crops in terms of world trade. This craze for them -particularly orange and grapefruit- is notably due to their high content in organoleptic and nutritional compounds of interest and among them carotenoids. About 50% of the Citrus production is processed in juice. From the growing variety of products, minimal processed juices now have a significant market share. This work assessed for the first time the effect of ohmic heating, a thermal method for stabilizing juices while minimizing the impact on the juice quality, on the carotenoid profiles of blood orange and grapefruit juice. Pasteurization with ohmic heating was proven to be a very good alternative for protecting carotenoids and especially xanthophylls compared to conventional heating. These results will help in designing ohmic heating process parameters for optimizing the overall quality of carotenoid-rich fruit juices.     

Effect of heating on solid β-carotene

The effect of heating on isomerisation and stability of solid β-carotene was investigated, and the products generated by heating were analysed by a number of analytical techniques, including high-performance liquid chromatography (HPLC), UV/VIS-spectroscopy (UV) and gel permeation chromatography (GPC). For the first time, isomerisation of cis- to all-trans-isomer was demonstrated in partly melted solid β-carotene when β-carotene was heated at 90 and 140 °C. Only a few high molecular weight components were detected by GPC when β-carotene was heated in a nitrogen environment. In contrast, more high molecular weight polymers, as well as low molecular fragments, were produced when β-carotene was heated and exposed to air, suggesting that polymerisation was one of the dominant side-reactions of β-carotene change, in addition to degradation.     

Comparison of lycopene stability in water- and oil-based food model systems under thermal- and light-irradiation treatments

Lycopene can undergo degradation via isomerization and oxidation during processing and storage. These degradative reactions affect its bioactivity and health benefit functionality. Degradation kinetics and isomerization of lycopene in water- and oil-based tomato model systems were investigated as a function of thermal treatments and light irradiation. Results showed that 80 and 100 °C heating favoured the stability of lycopene in oil-based tomato products. The high heating temperatures (120 and 140 °C) increased isomerization of lycopene and resulting in degradation of total lycopene and cis-isomers in both water- and oil-based tomato products. However, the levels of degradation of total lycopene contents and cis-isomers were greater in water-based samples than in oil-based model systems under different treatments. Heat and light both promoted lycopene isomerization of the all-trans form to the cis-isomers and further oxidation of cis-isomers. The major effect of thermal degradation and photosensitized oxidation was a significant decrease in the total lycopene content, especially the content of cis-isomers. These research results could be useful in assisting industry to improve processing technology and to improve the nutritional value and health-benefits of tomato-based foods.     

Carotenoid content and antioxidant capacity of Mediterranean vegetable soup (gazpacho) treated by high-pressure/temperature during refrigerated storage

High-pressure (HP) technology is an alternative to heat preservation methods for foods; therefore, it is essential to assess the impact of this technology on bioactive compounds and their properties. Carotenoids and antioxidant activity were measured in Mediterranean vegetable soup, called gazpacho subjected to HP/temperature treatment. The stability of carotenoids and the effect on antioxidant activity was studied during 40 days of refrigerated storage at 4°C. Two treatments that combine HP with temperature were assayed: T0, freshly made vegetable soup (untreated), T1, 150 MPa/60°C/15 min, T2, 350 MPa/60°C/15 min. Fresh and treated samples were kept refrigerated (4°C) for 40 days. After application of HP and during the refrigeration period, the qualitative and quantitative determination of provitamin A carotenoids (β- and γ-carotene), lycopene and the xanthophyll lutein was achieved. In addition, the radical scavenging activity of vegetable soups was assessed. T1 HP treatment (T1, 150 MPa/60°C/15 min) preserved the carotenoid content in vegetable soups better than T2 HP treatment. Moreover, T1 HP treatment retained the antioxidant activity during storage better than T2 HP treatment.     

Thermal degradation of all-trans-β-carotene in the presence of phenylalanine

Solutions of all-trans-β-carotene in liquid paraffin were stirred under air at 210°C for 15 min in the presence and absence of various amino acids. After cooling, the absorbance values at 460 nm of model systems containing all-trans-β-carotene and phenylalanine, cysteine or tryptophan were 34–58 times higher than that obtained on heating in the absence of an amino acid. Based on absorbance values at 420 nm, 86% of the coloured material present on heating the all-trans-β-carotene-phenylalanine model system at 210°C for 15 min was retained by the liquid paraffin on methanol extraction. The liquid paraffin phase remaining after methanol extraction was analysed by reverse-phase HPLC and three major components were identified as all-trans-β-carotene and two degradation products of all-trans-β-carotene, ie 9-cis-β-carotene and a furanoid diepoxy derivative. None could be detected on heating all-trans-β-carotene alone, suggesting that its degradation was retarded on heating in the presence of phenylalanine.     

Influence of extraction with ethanol or ethyl acetate on the yield of lycopene, β-carotene,phytoene and phytofluene from tomato peel powder

This study evaluated the extraction yield of the food grade solvents ethanol and ethyl acetate by extracting lycopene, β-carotene, phytoene and phytofluene from tomato peel powder at varying heating intensities, and the influence of the solvent and heating intensity on carotenoids isomerization and degradation during extraction. The heat treatments assayed were 25, 35, 50 and 60 °C which were applied for periods of 5, 10, 20, 30 or 40 min. The carotenoid yield was higher in the extractions with ethanol than with ethyl acetate. In general, the temperature increase caused an increase in the carotenoid concentrations; however in the extractions performed with ethanol at 60 °C, the yield of (all-E)-lycopene and their (Z)-isomers was lower than at 50 °C. This could indicate that a great isomerization is produced in the high temperature extractions with ethanol but the oxidative degradation is the predominant reaction. On the contrary, the obtained results in the extractions with ethyl acetate indicate that the isomerization is the predominant reaction.     

Effects of supercritical CO2 fluid parameters on chemical composition and yield of carotenoids extracted from pumpkin

Pumpkin is a traditional food that is grown extensively worldwide and is believed to be beneficial to human health due to its high contents of carotenoids. The carotenoids in pumpkin were extracted by organic solvents and by supercritical carbon dioxide (SC-CO₂), and then they were identified, quantified, and compared. β-carotene (31 to 40 g per 100 g of total carotenoids) was the predominate carotenoid in pumpkin. Lutein and lycopene contents were much higher in SC-CO₂ extracts than those in organic solvent extract. Cis-β-carotene increased by more than two times in the SC-CO₂ extracts, even at a relatively low temperature of 40 °C, over those in the solvent extracts, indicating both enhanced solubility and isomerization from trans- to cis-β-carotene. The influences of modifier (10 mL/100 mL), temperature (40-70 °C), and pressure (25-35 MPa) of SC-CO₂ extraction on the change of carotenoid yields were also investigated. The highest yield (109.6 μg/g) was obtained at 70 °C and 35 MPa, with a 73.7% recovery. Selective extraction could be achieved by adjusting the temperature and pressure. Higher proportions of all-trans-β-carotene extracts were achieved at 40 °C under both 25 MPa and 35 MPa conditions. In order to extract more cis-isomers, a higher temperature of 70 °C was preferred.     

Analysis of carotenoids with emphasis on 9-cis β-carotene in vegetables and fruits commonly consumed in Israel

Recent epidemiological studies have directed the attention from the synthetic all-trans β-carotene to natural carotenoids predominant in fruits and vegetables as possible active ingredients for prevention of cancer and cardiovascular diseases. Seventeen fruits and 17 vegetables commonly consumed in Israel and the β-car-otene-rich alga, Dunaliella bardawil, were analysed for their content of carotenoids with emphasis on 9-cis β-carotene by reversed-phase, 3D photodiode array HPLC. Fourteen carotenoids were eluted in order of decreasing polarity, from polar oxycarotenoids to lipophilic hydrocarbons, and quantified in μg carotenoid per gram freeze-dried plant sample. The richest sources of total carotenoids (>100μg/g dry weight) in Israeli fruits were pittango, mango and papaya while, in vegetables, the predominant types were carrot, dill, parsley, tomato, lettuce, sweet potato and red pepper. Red fruits and vegetables contained mainly lycopene. Yellow and orange fruits and vegetables had high contents of hydrocarbon carotenes with substantial levels of cryptoxanthins and xanthophylls. The green vegetables had high contents of both xanthophylls and hydrocarbon carotenes. Relatively high ratios (9-cis to all-trans β-carotene) of above 0.2 g/g were noted in sweet potato, papaya, parsley, lettuce, dill, apricot, pepper, prune and pumpkin, compared to the high ratio of 9-cis to all-trans β-carotene in the alga Dunaliella (~ 1.0 g/g). The high content of 9-cis β-carotene in certain fruits and vegetables and the wide variety of carotenoids and stereoisomers of carotenoids in all plants should shift nutritional and medical attention from the synthetic all-trans β-carotene toward natural carotenoids as potential candidates for chemoprevention.     

Impact of Thermal and Pressure-Based Technologies on Carotenoid Retention and Quality Attributes in Tomato Juice

The aim of this study was to investigate the impact of thermal processing (TP) (90 °C, 90 s), high-pressure processing (HPP) (600 MPa, 46 °C, 5 min), and high-pressure homogenization (HPH) (246 MPa, 99 °C, <1 s) on product quality parameters, specifically carotenoid content, and physicochemical attributes of particle size, color, viscosity, total soluble solids, and pH in tomato juice. Unprocessed tomato juice was used as control. The four major species of carotenoids (lycopene, β-carotene, phytoene, and phytofluene) in tomato juice were analyzed by HPLC. The content of total lycopene, all-trans-lycopene, cis-lycopene isomers,  phytoene, and phytofluene, in TP-, HPP-, and HPH-treated tomato juice did not significantly differ from that in unprocessed (control) juice. Significant reduction in β-carotene content was observed after TP treatment but not after HPP and HPH treatments. HPH significantly reduced tomato juice particle volume mean diameter from ～330 μm in control, HPP-, and TP-treated tomato juices to ～17 μm. A concomitant increase in apparent viscosity was observed in HPH-treated juice versus control. HPH-treated juice had increased redness (a*) and yellowness (b*) than that in control and HPP-treated tomato juices. These results indicate that high-pressure-based technologies (HPP and HPH) can preserve carotenoids as well as improve physicochemical properties.     

Changes in carotenoids during processing and storage of pumpkin puree

Changes in the contents of carotenoids and their true retentions (% TR) during the production of puree of Cucurbita moschata ‘Menina Brasileira’ and of Cucurbita maxima ‘Exposição’ pumpkins and the stability of such compounds during 180 days of storage were monitored by liquid chromatography coupled with a photodiode array detector. Cooking caused higher losses than commercial sterilisation. High losses of xanthophylls such as lutein and violaxanthin were noted during processing and storage of pumpkin puree. Such losses show the low stability of these compounds. The major carotenoids, pro-vitamin A carotenes, namely, α-carotene and all-trans-β-carotene for C. moschata ‘Menina Brasileira’ and all-trans-β-carotene for C. maxima ‘Exposição’ obtained high retentions (>75%) after processing. A slight degree of isomerisation of β-carotene was noted in the puree samples, but with low concentrations of cis-isomers. Storage for 180 days did not significantly affect (P ? 0.05) the concentrations of these carotenoids.     

Effects of High-Pressure Processing with or without Blanching on the Antioxidant and Physicochemical Properties of Mango Pulp

The effects of high-pressure processing (HPP 300 MPa/15 min, 400 MPa/5 min, 500 MPa/2.5 min, and 600 MPa/1 min) and high-temperature/short-time processing (HTST 110 °C/8.6 s), with or without blanching, on mango pulp were comparatively evaluated in terms of the antioxidant compounds, antioxidant capacity, sugars, and color. Blanching treatment significantly increased the total phenol content and the antioxidant capacity of mango pulp, but did not change the levels of L-ascorbic acid, carotenoids, sugars, and visual color (total color difference, △E?<?2.00). Both HPP and HTST treatments significantly increased the total phenol content and antioxidant capacity of un-blanched mango pulp, but no significant changes occurred in the blanched mango pulp. HPP did not affect the levels of L-ascorbic acid, carotenoids, and sugars in mango pulp regardless of blanching. However, HTST significantly decreased the fructose and glucose levels, as well as induced the isomerization of β-carotene, with the increase in 13-cis-β-carotene accompanied by the decrease in all-trans-β-carotene. Moreover, HPP-treated mango pulp consistently showed lower △E values than those HTST-treated samples, regardless of blanching.     

Analysis of Anabaena vaginicola and Nostoc calcicola from Northern Iran,as rich sources of major carotenoids

Four major carotenoids of high nutritional significance, including β-carotene, lycopene, lutein and zeaxanthin were determined in three isolates of heterocystous cyanobacteria, belonging to the genera Anabaena and Nostoc, isolated from Iranian terrestrial and aquatic ecosystems, for the first time. The ultrasonically extracted carotenoids were identified and quantified by a rapid and sensitive isocratic HPLC method and identification was further confirmed by spiking authentic standards and the pattern of the UV–Vis spectra obtained from photo-diode array detector. The results showed that these isolates contain large amounts of four major carotenoids, especially lycopene (up to 24570 μg/g dry weight, DW) which appears to be the highest reported amount until present; and β-carotene (up to 8133 μg/g DW) which is comparable with the best natural sources of β-carotene. Meanwhile, they are rich in the cis-isomers of lycopene and β-carotene which is important in their bioavailability and health benefits.     

Effects of Heat Treatment on the Carotenoid and Tocopherol Composition of Tomato

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.     

Carotenoid and phenolic profile of tomato juices processed by high intensity pulsed electric fields compared with conventional thermal treatments

The effect of high intensity pulsed electric fields (HIPEF) processing (35 kV/cm for 1500 μs of overall treatment time with bipolar pulses of 4-μs at 100 Hz) and heat pasteurisation (90 °C for 30 s or 60 s) on carotenoids and phenolic compounds as well as on some quality attributes (pH, soluble solids and colour parameters) of tomato juice was evaluated and compared, having the untreated juice as a reference. Processing enhanced some carotenoids (lycopene, β-carotene and phytofluene) and the red colour of juices, whereas no significant changes in phenolic compounds, pH and soluble solids were observed between treated and untreated juices. A slight decrease in overall health-related compounds was observed over time, with the exception of some carotenoids (β-carotene and phytoene) and caffeic acid. However, HIPEF-processed tomato juices maintained higher content of carotenoids (lycopene, neurosporene and γ-carotene) and quercetin through the storage time than thermally and untreated juices. Hence, the application of HIPEF may be appropriate to achieve not only safe but also nutritious and fresh like tomato juice.     

Thermal Isomerization and Degradation Behaviours of Carotenoids in Simulated Sweet Corn Juice

The thermal behaviour of carotenoids may affect the nutritional value and flavour quality of sweet corn juice. In this study, carotenoid compositions and volatile components in simulated sweet corn juice at elevated temperatures from 100 to 130 °C were identified and compared by C₃₀-HPLC-DAD-APCI-MS and HS-SPME-GC-MS methods. The result showed that with the increase of temperature, concentrations of total and trans carotenoids in sweet corn juice model decreased gradually, as compared with all-trans α-carotene and all-trans β-carotene, oxy carotenoids (such as all-trans lutein, all-trans zeaxanthin and all-trans β-cryptoxanthin degraded faster), especially for carotenoid epoxides (such as neoxanthin). Meanwhile, the concentration of total cis carotenoids was related with the formation of some oxidative products and volatile compounds. Levels of major volatile components derived from carotenoids in sweet corn juice model including 4-ethyltoluene, p-cymene, 2-ethyl-1, 4-dimethylbenzene, 1, 2, 3, 4-tetramethylbenzene, dodecane, BHT, 1,7-dimethyl naphthalene, hexanal, 2-nonenal, undecanal, benzaldehyde, geranyl acetone, etc. increased with temperature. Some new volatiles such as 1, 2, 4-trimethylbenzene, naphthalene, pentadecane, acetaldehyde, β-ionone, limonene, tridecanone, etc. were also formed under higher temperatures. It is suggested that the aromatic compounds containing benzene ring and alkane are produced by degradation of carotenoids, which affect the overall flavour of sweet corn juice.     

Comparison of thermal,ultraviolet-c,and high pressure treatments on quality parameters of watermelon juice

The effect of thermal, ultraviolet-c, and high pressure treatments on colour, browning degree, dynamic viscosity, and lycopene content of watermelon juice was evaluated based on its pectin methylesterase residual level. Each treatment had a different impact on parameters studied. Ultraviolet-c treatments were rapid and effective to inactivate the pectin methylesterase of the watermelon juice compared to the thermal and high pressure treatments in the same time and temperature. High pressure treatments at 600 MPa kept the colour of the treated watermelon juice close to an untreated one, and that at 600–900 MPa held the browning degree and dynamic viscosity of the treated watermelon juice comparable to an untreated one. Moreover, the high pressure treatment had a slight impact on the all-trans-lycopene, total cis-lycopene, and total lycopene concentration of the watermelon juice compared to the other treatments. In summary, the high pressure treatment showed the lowest changes in colour, dynamic viscosity, browning degree, and lycopene content of the treated watermelon juice amongst the three treatments.