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.     

Use of Multi-response Modelling to Investigate Mechanisms of β-Carotene Degradation in Dried Orange-Fleshed Sweet Potato During Storage: from Carotenoids to Aroma Compounds

In order to give insight into β-carotene degradation mechanism during the storage of dried orange-fleshed sweet potato, and particularly into the role of isomers and norisoprenoids formation, multi-response kinetic modelling was applied. Determination of degradation compounds were carried out by HPLD-DAD and SPME-GC-MS as a function of time between 10 and 40 °C and at four water activities from 0.13 to 0.76. Kinetic modelling was developed assuming first-order reactions and by using mass balance. Eight compounds, namely, two isomers (9-cis- and 13-cis-β-carotene), two β-carotene epoxides (β-carotene 5,6 and 5,8 epoxide) and four volatile compounds (β-cyclocitral, β-ionone, 5,6-epoxy-β-ionone and dihydroactinidiolide), were integrated into two theoretical reaction schemes. The different models were discriminated according to goodness of fit to experimental data. This work showed that: (1) the formation of cis-isomers from β-carotene preceded oxidation, (2) β-cyclocitral arose directly from β-carotene scission while the other norisoprenoids resulted from β-carotene epoxide degradation, (3) cis-isomers were high reactive compounds. Temperature had a major influence on reaction rates k while water activities only impacted k at values under 0.51. Therefore, multi-response modelling is not only a tool to predict β-carotene degradation but a interesting way to select the appropriate degradation scheme based on the different options presented in literature.     

Scaled-up production of zero-trans margarine fat using pine nut oil and palm stearin

An interesterified structured lipid was produced with a lipid mixture (600 g) of pine nut oil (PN) and palm stearin (PS) at two weight ratios (PN:PS 40:60 and 30:70) using lipase (Lipozyme TL IM, 30 wt.%) as a catalyst at 65 ^°C for 24 h. Major fatty acids in the interesterified products were palmitic (35.1–40.4%), oleic (29.5%), and pinolenic acid (cis-5, cis-9, cis-12 18:3; 4.2–5.9%). α-Tocopherol (1.1–1.3 mg/100 g) and γ-tocopherol (0.3–0.4 mg/100 g) were detected in the interesterified products. Total phytosterols (campesterol, stigmasterol, and β-sitosterol) in the interesterified products (PN:PS 40:60 and 30:70) were 63.2 and 49.6 mg/100 g, respectively. Solid fat contents at 25 ^°C were 23.6% (PN:PS 40:60) and 36.2% (PN:PS 30:70). Mostly β′ crystal form was found in the interesterified products. Zero-trans margarine fat stock with desirable properties could be successfully produced from pine nut oil and palm stearin.     

Beta-carotene isomerisation in mango puree as influenced by thermal processing and high-pressure homogenisation

The present study describes a case study on mango puree, in which focus is given to the effect of thermal processing (100–130 °C, 0–80 min) and high-pressure homogenisation (0–1300 bar) on the isomerisation of β-carotene. Both unit operations are of relevance for the production of mango puree. β-Carotene is an essential micronutrient which is present in a high amount in most mango cultivars, and it is important for human health due to its antioxidant and provitamin A capacity. It is known that these health-related properties of β-carotene are negatively affected by the conversion to cis-isomers. The results have shown that during high-pressure homogenisation of mango puree, β-carotene isomerisation was negligible. During thermal processing, on the other hand, an increase in β-carotene cis-isomer formation with increasing treatment intensity could be observed, although high temperatures and/or long treatment times were required to observe clear additional isomer formation. From a kinetic point of view, a fractional conversion model could be used to model the all-trans-β-carotene isomerisation in mango puree in the temperature and time range studied. In general, it can be concluded that a high percentage of β-carotene is present as cis-isomers in raw mango puree. Furthermore, only intense thermal processing of mango puree leads to the formation of additional cis-isomers in relevant amounts.     

Changes in β-carotene bioaccessibility and concentration during processing of carrot puree

The effect of some process and product factors (addition of olive oil, high pressure homogenisation, subsequent thermal or high pressure pasteurisation) on β-carotene bioaccessibility and isomerisation of carrot puree was investigated. High pressure homogenisation could improve β-carotene bioaccessibility by disrupting cells, but only at a pressure higher than 50 MPa. Softening of the cell walls during a subsequent thermal pasteurisation resulted in a further increase in β-carotene bioaccessibility. Unfortunately, the high temperature also induced formation of some undesirable cis-isomers. As cell walls are probably strengthened by high pressure, high pressure pasteurisation could not positively affect the amount of bioaccessible β-carotene. Moreover, the high pressure process induced β-carotene oxidation. A positive effect of olive oil on β-carotene bioaccessibility could only be noticed in combination with a thermal pasteurisation process when β-carotene was solubilised in the oil droplets. Under high pressure however, oil can be crystallised which hinders the solubilisation of β-carotene.     

Ultra-performance liquid chromatographic separation of geometric isomers of carotenoids and antioxidant activities of 20 tomato cultivars and breeding lines

All-trans-lutein, lycopene, β-carotene and their 22 cis-isomers in 20 tomato breeding were separated and identified by a rapid and sensitive UPLC method using a 1.7 μm C₁₈ column and a new gradient mobile phase based on methanol-MTBE-water in 15 min. All-trans-carotenoids were predominant, but 9-cis, 13-cis-lutein, 5-cis, 9-cis, 13-cis, 15-cis, di-cis-lycopene, 9-cis, 13-cis, 15-cis and di-cis-β-carotene were also found. The cis-isomers were identified using absorption around 330 nm and the Q-ratio. The total antioxidant activities as evaluated by PCL and DPPH assays were found to correlate well with the total carotenoid content, but not with the individual carotenoid or its different isomers. This paper provides an efficient analytical method for obtaining a complete picture of carotenoids in tomatoes. It can be a valuable tool for plant breeders, food processors and researchers in developing designer tomatoes and tomato-products with unique carotenoid compositions, and functional properties.     

On the monitoring of carotenogenesis by Blakeslea trispora using HPLC

A rapid, isocratic RP-HPLC method for the determination of the carotenoids produced by Blakeslea trispora is described. The mixture of acetone:acetonitrile, 60:40, v/v, found appropriate for the cellular triacylglycerol analysis, was also successfully used for the separation of lycopene, γ-carotene and β-carotene. The method was validated for β-carotene using an olive oil triacylglycerol fraction devoid of carotenoids. Recovery study (300 mg/kg oil) was 99%. RSDr and RSD_L were satisfactory (<4%). The limit of quantification was found to be 4.56 ng/5 μL and the system was linear in the range 2.0–30.0 ng/μL.     

Characterization of the Photodegradation of β-Carotene in Aqueous Model Systems

The photodegradation of β-carotene in model dispersions was studied to gain a better understanding of carotene stability in foods. Aqueous dispersions were exposed to 250 ft-c of light at varied times and temperatures. Analysis was by HPLC and spectrophotometry. Degradation reactions fit a first-order kinetic model. Temperature, physical state and β-carotene microenvironment had some influence on degradation rates. cis-isomers of β-carotene were present and the relative amounts of cis-isomers increased with time of exposure.     

Bioaccessibility of provitamin A carotenoids in bananas (Musa spp.) and derived dishes in African countries

Bananas and plantains (Musa spp.) constitute an important component of the diet in Africa. Substantial levels of provitamin A carotenoids (pVACs) in Musa fruit have been reported, but the bioaccessibility of these pVACs remains unknown. In this study, we used an in vitro digestion model to assess the bioaccessibility (i.e. the transfer into micelles) of pVACs from boiled bananas and derived dishes using the Eastern Democratic Republic of Congo as a study context. In particular, the effect of different food ingredients added to boiled bananas on pVAC’s bioaccessibility was studied. The bioaccessibility of all-trans β-carotene ranged from 10% to 32%, depending on the food recipes, and was modified, particularly when pVACs-rich ingredients (palm oil/amaranth) were added. Efficiency of micellarization of all-trans β-carotene was similar to that of all-trans α-carotene and depended on the cultivar (Musilongo, plantain type, 16%; Vulambya, East African cooking type, 28%), while that of the 13-cis isomer was higher (21–33.5%). Taking into account bioaccessibility, the estimated vitamin A activity was significantly different across the different Musa-based dishes tested. Results are discussed in terms of recommendations to help reduce vitamin A deficiency in Musa-dependent African communities.     

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.     

Variations in the essential oil composition in buds of six blackcurrant (Ribes nigrum L.) cultivars at various development phases

The variations in the content and the composition of dormant bud essential oil in six blackcurrant (Ribes nigrum L.) cultivars collected at various vegetation phases (from December 15, 2004 until April 19, 2005) were studied. Essential oil yield varied from 0.6% to 1.8%, except for the buds harvested in April, when the yield was considerably lower, 0.19–0.27%. Fifty volatile compounds were identified in the bud oils, hydrocarbon (38–55%) and oxygenated (on average 30%) terpenes being the major chemical constituents. Sabinene, δ-3-carene, terpinolene were dominant components, while cis- and trans-β-ocimene, α-thujene, α- and β-pinene, myrcene, α- and β-phellandrene, α- and γ-terpinene, p-cymene, cis- and trans-sabinene hydrate, terpinen-4-ol, α-terpineol, trans-piperitol, bornyl acetate, terpinyl acetate, citronellyl acetate, germacrenes D, β-caryophyllene, α-humulene, α-selinene, δ-cadinene and α-cadinol were found in reasonable amounts. Almiai may be considered as a superior cultivar, as possessing the most even content of oils ant the main constituents at all harvesting periods, except for April; however some other cultivars (Gagatai, Joniniai) accumulated higher amounts of oil at particular vegetation phases. January may be considered as a preferable harvesting time of buds; the amount of major terpenes at this phase was the highest in the all cultivars except for Joniniai. The concentration of the main oil compounds in buds harvested in April was 2–50 times lower than at other periods in the all six cultivars.     

Supercritical Carbon Dioxide Extraction Efficiency for Carotenes from Carrots by RSM

Increasing demand for β-carotene has resulted in a growing interest in its extraction from natural sources. Carotenes were extracted from carrot pulp (press cake) using SC-CO₂. Three levels of pressure (20.7, 27.6, and 34.5 MPa), temperature (40, 55, and 70°C), and ethanol co-solvent (0, 5, 10% wt) were studied. Percentages α-, β- and total carotenes extracted were determined by HPLC and spectrophotometric methods. A maximum of 99.5% of β-carotene was extracted using 10% ethanol. Concentration of ethanol and temperature were the most important factors in increasing extraction yield. A response surface model was developed from the results: %β-carotene extraction = 8.4558 + 0.8816 T– 10.7650 E + 0.1843 T*E + 1.9019 E²– 0.0261 E²*T, where T = temperature (°C), E = ethanol (%). R²= 0.973.     

Degradation and isomerization of chlorophyll a and β-carotene as affected by various heating and illumination treatments

The degradation and isomerization of β-carotene and chlorophyll a as affected by oven-heating, reflux-heating, iodine-catalysed illumination, and non-iodine-catalysed illumination, were studied. Results showed that the degradations of both total β-carotene and chlorophyll a may fit the first-order model under either heating or illumination treatment. 13-cis-β-Carotene and 13,15-di-cis-β-carotene were the major cis isomers of β-carotene formed during oven heating, while 13-cis-β-carotene was favoured during reflux heating. For illumination with or without iodine as catalyst, 13,15-di-cis-β-carotene was the major cis isomer of β-carotene formed. The formation of 13,15-di-cis-β-carotene may be due to conversion of either 13-cis- or 15-cis-β-carotene. No epimerization of chlorophyll a was observed as a result of illumination.     

Determination of thermal oxidation and oxidation products of β-carotene in corn oil triacylglycerols

A reversed phase HPLC-DAD coupled to APCI-MS method is reported for the determination of the degradation of β-carotene and characterization of the oxidation products in corn oil. Corn oil containing β-carotene was oxidized in the Rancimat at 110 °C from 1 to 14 h. A significant degradation of β-carotene was observed in corn oil during accelerated thermal oxidation. A total of eight different oxidized products of β-carotene were identified, which includes 8′-apo-β-carotenal, 6′-apo-β-carotenal, 5,6-epoxy-8′-apo-β-carotenal, β-carotene-2,2′-dione, 13-Z-5,6,5′,6′-diepoxy-β-carotene, all-E-5,8-epoxy-β-carotene, all-E-5,6-epoxy-β-carotene, and 15-Z-5,6-epoxy-β-carotene. Corn oil triacylglycerols (TAGs) oxidation products were also identified using isocratic HPLC–ESI-MS. It was found that β-carotene promoted oxidation of TAGs especially at longer exposure times. For the first time two new classes of oxidized TAGs have been identified in corn oil, which were epidioxy bis-hydroperoxides and hydroxy bis-hydroperoxides. Other oxidation products of TAGs were mono-epoxides, mono-hydroperoxides, and epoxy hydroperoxides. It was found that complementing the HPLC-DAD method for β-carotene with ESI-MS method for TAGs oxidation provides a comprehensive set of analytical tools to characterize carotenoids and triacylglycerols oxidation and degradation in edible oils.     

Adsorption of carotenes and phosphorus from palm oil onto acid activated bleaching earth: Equilibrium,kinetics and thermodynamics

In this work, the adsorption of carotenes and phosphorus from crude palm oil onto acid activated bleaching earth was investigated under bleaching conditions, i.e. high temperature (90, 105 and 115 °C) and low pressure (less than 50 mbar). Bleaching earth was added to palm oil in a range of 0.5–3.0 wt%. Results presented in this work suggest that adsorption of β-carotene increases with temperature, while phosphorus adsorption was less affected. Both the pseudo-first-order and the pseudo-second-order kinetic model describe efficiently the β-carotene experimental data. Intra-particle diffusion is involved in β-carotene adsorption mechanism, although it is not the sole rate limiting step in the adsorption onto acid activated bleaching earth. Phosphorus adsorption was too fast resulting in a lack of kinetic data. The equilibrium data were described better by Langmuir and Freundlich models, for β-carotene and phosphorus, respectively. A multi-component Freundlich type isotherm was tested. Its competition coefficients were too low, and it assumed the same form as the monocomponent Freundlich. A thermodynamic study demonstrated that β-carotene and phosphorus adsorption is spontaneous, endothermic and an entropy-driven process. Isosteric heat values suggest that the interactions between adsorbate and adsorbent are heterogeneous.     

Carotenoid Photostability in Raw Spinach and Carrots During Cold Storage

A reverse-phase gradient HPLC method was developed for separating xanthophylls, chlorophylls, carotenes and cisβ-carotene isomers from raw spinach and carrots. The effect of dark and lighted cold storage on pigment stability was studied. Light promoted pigment losses in raw spinach. Degradative losses at 8 days ranged from 60% for violaxanthin to 22% for lutein. Dark, cold storage did not affect carotenoid levels except for all-transβ-carotene which showed an 18% loss at 8 days. In raw carrots, neither lighted nor dark cold storage affected major carotenoids. In spinach, the isomeric distribution of β-carotene showed strong linear correlations between trans and cis forms.     

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.     

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.     

Analysis of α-Cryptoxanthin, β-Cryptoxanthin, α -Carotene,and β-Carotene of Pandanus Conoideus Oil by High-performance Liquid Chromatography (HPLC)

Pandanus conoideus is an endemic plant of Papua, Indonesia, reported to be very rich in carotenoids. The purpose of this study was to develop method for the determination of carotenoids (α-cryptoxanthin, β-cryptoxanthin, α-carotene and β-carotene) in P. conoideus oil (PO) by high-performance liquid chromatography (HPLC). sing the proposed method in this research, carotenoids content of nine clones of PO were analyzed which ranged from 5.4-138.5 ng/mg for α-cryptoxanthin, 3.9-29.4 ng/mg for β-cryptoxanthin, 3.5-80.0 ng/mg for α-carotene, and 10.8-118.0 ng/mg for β-carotene. Our results showed that four carotenoids content was very small as compared to total carotenoids content (3027-19959 ng/mg). This suggests that those four carotenoids were not a major component of the PO carotenoids. Using the principal component analysis, nine clones of P. conoideus can be grouped based on the proximity of its carotenoid content into group A (Monsor, Mbarugum, Himbiak, Monsrus and Memeri), group B (Menjib Rumbai), and group C (Edewewits, Hibcau and Hityom).     

Bioaccessibility of carotenes from carrots: Effect of cooking and addition of oil

Food processing and occurrence of dietary lipids are believed to be important and limiting factors for carotenoid bioavailability in humans. In the present study the isolated and combined effects of household cooking and addition of olive oil on the bioaccessibility of carotenes from carrots have been investigated. Although thermal treatment during cooking showed to have a negative impact on the carotenoid content, a positive effect on the micellarisation of carotenes and therefore on their bioaccessibility was found. Carotenes transferred to the digests were micellarised to a higher extent from cooked carrots (52%) than from crude carrots (29%). Addition of olive oil to carrot samples during cooking and before application of the in vitro digestion model had a marked positive effect on the release of carotenes, although the design of the model did not allow the correct estimation of this effect. The higher amounts of micellarised carotenes (80%) were found in the digest prepared from cooked carrots containing 10% olive oil. In general, the inclusion of olive oil during cooking increased the carotenoid extraction and micellarisation in a dose-dependent fashion. Although β-carotene and α-carotene were affected in a similar way by the cooking process, α-carotene appeared to be more efficiently incorporated into the micelles when olive oil was added to the samples. In conclusion, both processing and mainly lipid content (cooking oil in this case) significantly improve carotenoid bioaccessibility from carrots, and therefore may increase bioavailability in humans.Industrial relevanceThe consumption of carotenoid-rich foods such as fruits and vegetables has been associated with a decrease of the risk of developing certain types of degenerative and chronic diseases. Processing of food and the interaction of carotenoids with lipophilic food components or ingredients may modify the amount of the released pigment from the food matrix, and therefore potentially increase or decrease their bioavailability. For this purpose, in the present study we have investigated the effects of cooking and presence of olive oil on the release of carotenes from carrots (as a model food) and their incorporation into absorbable micelles, the bioaccessibility. From the industrial point of view, a better understanding of the factors governing the release of carotenoids and other active components from vegetable foods is of great importance with the aim of optimising the manufacturing processes.