Comprehensive Update on Carotenoid Colorants from Plants and Microalgae: Challenges and Advances from Research Laboratories to Industry.

The substitution of synthetic food dyes with natural colorants continues to be assiduously pursued. The current list of natural carotenoid colorants consists of plant-derived annatto (bixin and norbixin), paprika (capsanthin and capsorubin), saffron (crocin), tomato and gac fruit lycopene, marigold lutein, and red palm oil (α- and ß-carotene), along with microalgal Dunaliella ß-carotene and Haematococcus astaxanthin and fungal Blakeslea trispora ß-carotene and lycopene. Potential microalgal sources are being sought, especially in relation to lutein, for which commercial plant sources are lacking. Research efforts, manifested in numerous reviews and research papers published in the last decade, have been directed to green extraction, microencapsulation/nanoencapsulation, and valorization of processing by-products. Extraction is shifting from conventional extraction with organic solvents to supercritical CO2 extraction and different types of assisted extraction. Initially intended for the stabilization of the highly degradable carotenoids, additional benefits of encapsulation have been demonstrated, especially the improvement of carotenoid solubility and bioavailability. Instead of searching for new higher plant sources, enormous effort has been directed to the utilization of by-products of the fruit and vegetable processing industry, with the application of biorefinery and circular economy concepts. Amidst enormous research activities, however, the gap between research and industrial implementation remains wide.

Comprehensive review on carotenoid composition: Transformations during processing and storage of foods.

Stimulated by their multifaceted functions and actions, carotenoids have been among the most investigated food components, producing a voluminous, complicated, and sometimes inconsistent literature. This review puts into context developments in the last decade to have a comprehensive current knowledge on these valuable food constituents. Carotenoid analysis continues to show the wide biodiversity of carotenogenic foods and the many factors that affect the composition. Because of their instability, subject to multiple influencing factors, retention of carotenoids during processing and storage of food has been a daunting task. Since thermal processing may result in substantial carotenoid losses, thermal processes that are much faster than the conventional methods and nonthermal processing have been introduced. The processing conditions of nonthermal processing should, however, be well established so that microbial and enzymatic inactivation is achieved while maintaining nutrients and bioactive compounds. Instead of losses, higher carotenoid levels and bioaccessibility are sometimes reported for both thermal and nonthermal processing, attributed to greater extractability of carotenoids during analysis and greater release from the food matrix during digestion. Carotenoids differ markedly in their susceptibility to degradation, the epoxycarotenoids being most degradable. Results are mixed, however, in relation to the comparative stability of hydroxycarotenoids and carotenes. E-Z isomerization at sterically unhindered double bonds is now well documented. There is also more information about oxidative degradation, although more work is needed on this topic. It consists of epoxidation, cleavage to apocarotenoids and finally fragmention to low mass compounds. Enzymatic and non-enzymatic cleavage of carotenoids forms important aroma compounds but can also produce off-flavor.

Update on natural food pigments - A mini-review on carotenoids, anthocyanins, and betalains.

Extensive structure elucidation has revealed a remarkable diversity of structures for carotenoids, anthocyanins, and betalains, the major natural pigments in plant-derived foods. Composition, stability, influencing factors, processing effects have been widely investigated. Carotenoids isomerize and oxidize while anthocyanins undergo hydrolysis, nucleophilic attack of water, ring fission, and polymerization during thermal processing. Betacyanins suffer deglycosylation, isomerization, dehydrogenation, hydrolysis, and decarboxylation. Biotechnological production dominates research on carotenoids as food colorants while the search for plant sources continues with anthocyanins and betalains. Stabilization studies presently focus on microencapsulation and nanoencapsulation. For anthocyanins, co-pigmentation has also been intensely researched. Carotenoids have been the most studied in terms of health effects, involving epidemiological, cell, animal, and human intervention studies, yet some inconsistencies in the results persist. A wide range of biological activities have been attributed to anthocyanins and betalains, based mainly on cell and animal studies; human clinical studies are lacking.

Structures and Analysis of Carotenoid Molecules.

Modifications of the usual C40 linear and symmetrical carotenoid skeleton give rise to a wide array of structures of carotenes and xanthophylls in plant tissues. These include acyclic, monocyclic and dicyclic carotenoids, along with hydroxy and epoxy xanthophylls and apocarotenoids. Carotenols can be unesterified or esterified (monoester) in one or two (diester) hydroxyl groups with fatty acids. E-Z isomerization increases the array of possible plant carotenoids even further. Screening and especially quantitative analysis are being carried out worldwide. Visible absorption spectrometry and near infrared reflectance spectroscopy have been used for the initial estimation of the total carotenoid content or the principal carotenoid content when large numbers of samples needed to be analyzed within a short time, as would be the case in breeding programs. Although inherently difficult, quantitative analysis of the individual carotenoids is essential. Knowledge of the sources of errors and means to avoid them has led to a large body of reliable quantitative compositional data on carotenoids. Reverse-phase HPLC with a photodiode array detector has been the preferred analytical technique, but UHPLC is increasingly employed. HPLC-MS has been used mainly for identification and NMR has been useful in unequivocally identifying geometric isomers.

HPLC-DAD-ESI/MS identification and quantification of phenolic compounds in Ilex paraguariensis beverages and on-line evaluation of individual antioxidant activity.

"Chimarrão" and "tererê" are maté (dried, toasted and milled Ilex paraguariensis leaves and stemlets) beverages widely consumed in South America. This paper describes the application of HPLC-DAD-ESI/MS method for the identification and quantification of caffeoylquinic acids (CQA), flavonol glycosides and purine alkaloids in these beverages. The beverage samples were prepared from commercial lots of maté from Southern Brazil. The caffeoylquinic acids, 4,5-diCQA, 3-CQA, 5-CQA, and 4-CQA were the major compounds, having 238-289, 153-242, 183-263, and 123-188 µg/mL, respectively, for chimarrão and 206-265, 122-218, 164-209, 103-169 µg/mL, respectively, for tererê. Caffeine also had high amounts while glycosides of quercetin and kaempferol were found at much lower levels. The individual antioxidant activity was also determined by an on-line system that measured their ABTS•+ radical scavenging activity, showing that the antioxidant capacity was not proportional to the concentrations of the phenolic compounds. 3-CQA, quercetina-3-O-ramnosylglucoside, and quercetina-3-O-glucoside were the major contributors to the antioxidant capacity, although the quercetin glycosides had concentrations less than 10 times that of 3-CQA.

Avaliação intralaboratorial do desempenho de analistas na análise de carotenoides utilizando material de referência certificado / Intralaboratory assessment of analysts’ proficiency for carotenoidanalysis using a certified reference material

Carotenoid analysis is inherently challenging, requiring the analysts’ expertise and attention to manydetails. To guarantee the reliability of carotenoid data generated in our laboratory, aside from methoddevelopment, optimization and validation, periodic evaluation of the analysts’ performance is carried out.This paper reports the results obtained in one of our evaluations, using a certified reference material. Fiveanalysts with varying experience in carotenoid analysis participated. The same liquid chromatograph andstandard curves were used, restricting the evaluation to the analysts’ performance. The HPLC methodconsisted of extraction with acetone, partition to petroleum ether, saponification with 10 % methanolicKOH, washing with water, concentrating in a rotary evaporator, drying with nitrogen, dissolving inacetone, separation, identification and quantification. The z-score for each carotenoid was calculated.There was very good agreement in terms of the carotenes and b-cryptoxanthin for the five analysts. Forlutein and zeaxanthin, the analyst with little experience in carotenoid analysis obtained lower values,but the z-scores were still satisfactory. One analyst who had experience only with carotene analysis alsogot lower concentrations for the xanthophylls. This was due to the fact that ethyl ether was not used inpartitioning the carotenoids from the extracting solvent to petroleum ether.

Statistical optimisation of cell growth and carotenoid production by Rhodotorula mucilaginosa

Sequential statistical methods were used to maximise carotenoid production by a strain of Rhodotorula mucilaginosa, isolated from the Brazilian ecosystem. Initially, a factorial 2(5-1) experimental design was used, and the variables were pH and the levels of glucose, yeast extract, MgSO4.7H2O and KH2PO4. The nitrogen source (yeast extract) was the most important variable in enhancing carotenoid production; MgSO4.7H2O and KH2PO4 had a negative influence. The initial pH had no significant effect on carotenoid and cell productions. We further investigated the effects of glucose and yeast extract effects, using a second-order central composite design (CCD) to optimise carotenoid production, which was adequately approximated with a full quadratic equation obtained from a two-factor-2-level design. The analysis of quadratic surfaces showed that after 5 days of cultivation at 25ºC, the maximum carotenoid concentration (745 µg l-1) was obtained with 15 g l-1 of yeast extract and 20 g l-1 of glucose. The maximum carotenoid production (152 µg g-1) was obtained with 5 g l-1 yeast extract and 10 g l-1 glucose. Carotenoid formation was more sensitive to changes in yeast extract concentration than to changes in glucose concentration. Maximum cell production was achieved with 15-17 g l-1 of yeast extract and 15-20 g l-1 of glucose.

Statistical optimisation of cell growth and carotenoid production by rhodotorula mucilaginosa.

Sequential statistical methods were used to maximise carotenoid production by a strain of Rhodotorula mucilaginosa, isolated from the Brazilian ecosystem. Initially, a factorial 2(5-1) experimental design was used, and the variables were pH and the levels of glucose, yeast extract, MgSO4.7H2O and KH2PO4. The nitrogen source (yeast extract) was the most important variable in enhancing carotenoid production; MgSO4.7H2O and KH2PO4 had a negative influence. The initial pH had no significant effect on carotenoid and cell productions. We further investigated the effects of glucose and yeast extract effects, using a second-order central composite design (CCD) to optimise carotenoid production, which was adequately approximated with a full quadratic equation obtained from a two-factor-2-level design. The analysis of quadratic surfaces showed that after 5 days of cultivation at 25 °C, the maximum carotenoid concentration (745 µg l(-1)) was obtained with 15 g l(-1) of yeast extract and 20 g l(-1) of glucose. The maximum carotenoid production (152 µg g(-1)) was obtained with 5 g l(-1) yeast extract and 10 g l(-1) glucose. Carotenoid formation was more sensitive to changes in yeast extract concentration than to changes in glucose concentration. Maximum cell production was achieved with 15-17 g l(-1) of yeast extract and 15-20 g l(-1) of glucose.

Determination of catechins in green tea infusions by reduced flow micellar electrokinetic chromatography.

A sulfated-ß-cyclodextrin (s-ß-CD) modified reduced flow micellar electrokinetic chromatography (RF-MEKC) method was developed and validated for the determination of catechins in green tea. The optimal electrolyte consisted of 0.2% triethylamine, 50mmol/L SDS and 0.8% s-ß-CD (pH=2.9), allowing baseline separation of five catechins in 4min. The samples and standards were injected at 0.6psi for 5s under constant voltage of -30kV. Sample preparation simply involved extraction of 2g of tea with 200mL water at 95°C under constant stirring for 5min. The method demonstrated excellent performance, with limits of detection (LOD) and quantification (LOQ) of 0.02-0.1 and 0.1-0.5µg/mL, respectively, and recovery percentages of 94-101%. The method was applied to six samples of Brazilian green tea infusions. Epigallocatechin gallate (23.4-112.4µg/mL) was the major component, followed by epigallocatechin (18.4-78.9µg/mL), epicatechin gallate (5.6-29.6µg/mL), epicatechin (4.6-14.5µg/mL) and catechin (3.2-8.2µg/mL).

Inorganic contaminants in bee pollen from southeastern Brazil.

A set of experiments was carried out to validate a method for inorganic contaminants in honeybee-collected pollen, consisting of digestion of the samples in a closed microwave-assisted system and quantification of 10 inorganic contaminants by ICP OES. Forty-three samples of Brazilian bee pollen, collected in southeastern Brazil during one year, were analyzed. Determination of these analytes is important both as bioindicators of pollution and to verify the safety of consuming the pollen itself. The method had satisfactory performance, with good accuracy and precision. The ranges of the mean levels were 10.4-268.0 mg/kg for Al, <0.01-1.38 mg/kg for As, 2.78-17.63 mg/kg for Ba, 0.003-0.233 mg/kg for Cd, <0.01-1.11 mg/kg for Co, <0.01-2.32 mg/kg for Cr, <0.10-1.13 mg/kg for Ni, <0.01-0.44 mg/kg for Pb, <0.035-1.33 mg/kg for Sb, and <0.0004-0.0068 mg/kg for Hg. Contamination seemed to occur in the following decreasing order: Sao Paulo > Minas Gerais > Espirito Santo. Generally higher levels of all studied contaminants were observed in samples produced in an urban site, compared to those of a rural site. Al, Cd, Co, and Pb tended to have higher levels during the dry months (July-October). Ingestion estimates showed that Al and As would have the highest contributions to the adult diet, reaching 27 and 8%, respectively, of the provisional tolerable weekly intake (PTWI) values, considering a daily portion of 25 g.

Teores de carotenóides em produtos de tomate / Carotenoid contents in Brazilian tomato products

A composição dos carotenóides em produtos de tomate foi anteriormente determinada em nosso laboratório, utilizando-se cromatografia em coluna aberta. Em virtude da introdução de novas variedades de tomate, do desenvolvimento de novos produtos e dos avanços tecnológicos nas áreas de processamento e de técnicas analíticas, esses dados necessitavam ser atualizados. Neste contexto, no presente estudo determinou-se a composição de carotenóides em produtos de tomates por meio de técnica CLAE. As amostras de extrato, catchup, polpa, molho pronto e tomate seco foram adquiridas em supermercados em Campinas-SP. Para cada produto, foram adquiridos cinco lotes diferentes de cada uma das três marcas (no total de 65 amostras), em que cada lote foi composto por três embalagens coletadas ao acaso. As faixas de licopeno e de β-caroteno total (μg/g) foram, respectivamente, 188-261 e 9,3-13 para extrato, 111-203 e 5,1-7,0 para catchup, 77-117 e 4,4-73 para polpa, 93-112 e 5,1-6,4 para molho pronto e 231-471 e 7,0-25 para tomate seco. O tomate seco, que foi analisado pela primeira vez, apresentou os maiores teores de licopeno e luteína. Os teores 2 de β-caroteno do extrato e licopeno do extrato e catchup foram maiores nas amostras analisadas neste estudo, quando comparados com os resultados obtidos no trabalho anterior.

The carotenoid contents in Brazilian tomato produc0ts were previously determined at our laboratory byusing raw material. The data regarding the development of new products, the advances on processingtechnologies and analytical techniques, need to be updated. In this context, the present study was carried out in order to determine the carotenoid contents of processed tomato products by means of HPLC. Samples of ketchup, sauce, paste, pulp and dried tomato were purchased at supermarkets in Campinas, Brazil. Foreach product, five different lots from each of the three brands (a total of 65 samples) were purchased, each lot consisting of three randomly collected packages. The lycopene and β-carotene concentration ranges (μg/g) were 188-261 and 9.3-13 for paste, 111-203 and 5.1-7.0 for ketchup, 77-117 and 4.4-7.3 for pulp, 93-112 and 5.1-6.4 for sauce, 231-471 and 7.0-25 for dried tomato, respectively. Dried tomatoes, which were analyzed for the first time, showed the highest lycopene and lutein concentrations. β-carotene contents in the paste and lycopene contents in tomato paste and in ketchup samples analyzed by the present study were higher than those obtained in the previous investigation.

Multivariant optimization, validation, and application of capillary electrophoresis for simultaneous determination of polyphenols and phenolic acids in Brazilian wines.

A method for the simultaneous determination of the stilbene resveratrol, four phenolic acids (syringic, coumaric, caffeic, and gallic acids), and five flavonoids (catechin, rutin, kaempferol, myricetin, and quercetin) in wine by CE was developed and validated. The CE electrolyte composition and instrumental conditions were optimized using 2(7-3) factorial design and response surface analysis, showing sodium tetraborate, MeOH, and their interaction as the most influential variables. The optimal electrophoretic conditions, minimizing the chromatographic resolution statistic values, consisted of 17 mmol/L sodium tetraborate with 20% methanol as electrolyte, constant voltage of 25 kV, hydrodynamic injection at 50 mbar for 3 s, and temperature of 25 degrees C. The R(2) values for linearity varied from 0.994 to 0.999; LOD and LOQ were 0.1 to 0.3 mg/L and 0.4 to 0.8 mg/L, respectively. The RSDs for migration time and peak area obtained from ten consecutive injections were less than 2% and recoveries varied from 97 to 102%. The method was applied to 23 samples of inexpensive Brazilian wines, showing wide compositional variation.

Qualitative and quantitative differences in the carotenoid composition of yellow and red peppers determined by HPLC-DAD-MS.

The carotenoids of a yellow (F(1) Amanda hybrid) and a red (F(1) Magali hybrid) pepper (Capsicum annuum L.) at the ripe stage, marketed in Campinas, Brazil, were identified by the combined use of the chromatographic behavior, absorption spectra, and chemical reactions, confirmed by the mass spectra. HPLC was carried out with a Spherisorb ODS 2 (C18, monomeric, 3 microm, 4.6 x 150 mm) column and DAD and mass detector. The main carotenoids in the yellow pepper were violaxanthin (27.1-36.6 microg/g), lutein (5.3-9.3 microg/g), and beta-carotene (1.6-3.9 microg/g). Neoxanthin, (Z)-violaxanthin, (Z)-antheraxanthin, (Z)-lutein, alpha-cryptoxanthin, beta-cryptoxanthin, zeta-carotene, alpha-carotene, and phytofluene were also found as minor carotenoids. In red pepper, the major carotenoids were capsanthin (29.2-36.2 microg/g), lutein (5.8-8.7 microg/g), beta-carotene (5.1-6.8 microg/g), and violaxanthin (1.8-3.6 microg/g). Minor carotenoids were capsorubin, beta-apo-8'-carotenal, antheraxanthin, zeaxanthin, and beta-cryptoxanthin.

Lycopene epoxides and apo-lycopenals formed by chemical reactions and autoxidation in model systems and processed foods.

To gain a better understanding of the reactions and the underlying mechanisms of the oxidative degradation of lycopene, the products formed by epoxidation with m-chloroperbenzoic acid (MCPBA), oxidative cleavage with KMnO(4), and autoxidation in low-moisture and aqueous model systems, under light exposure, at ambient temperature were identified. The presence of oxidation products was also verified in processed products (tomato juice, tomato paste, tomato puree, guava juice, "goiabada"). A total of 8 lycopene epoxides and a cyclolycopene diol were formed by the reaction of lycopene with MCPBA and 6 apo-lycopenals were produced with KMnO(4). Some of these oxidation products were not detected in the model systems and in the foods analyzed, but the acid-catalyzed rearrangement product 2,6-cyclolycopene-1,5-diol and apo-12'-lycopenal were found in all model and food systems and lycopene-1,2-epoxide and 2,6-cyclolycopene-1,5-epoxide were found in the model systems and in all but 1 ("goiabada") of the 5 foods analyzed. Other epoxides and apo-lycopenals were found in some systems. The inability to detect an intermediate product could be due to a fast turn over. Increased Z-isomerization was also observed and Z-isomers of the oxidation products were detected.

Variation in the carotenoid composition of the lycopene-rich Brazilian fruit Eugenia uniflora L.

The indigenous pitanga (Eugenia uniflora L.) is now marketed and commercially processed in Brazil. In the present work, the carotenoids of the pitanga fruit from two states and at two stages of ripening, as well as of processed pitanga products (frozen pulp and juice, the brands being designated as A, B and C) commercialized in Campinas, São Paulo, were determined by HPLC. As compared to ripe pitanga from Medianeira, Paraná, those from Campinas had significantly higher (all-E)-lycopene (14.0 vs. 71.1 microg/g), (13Z)-lycopene (1.1 vs. 5.0 microg/g) and (all-E)-gamma-carotene (1.6 vs. 3.8 microg/g) levels. Significant increases in most of the carotenoids occurred from the partially ripe to the ripe fruits, with (all-E)-lycopene doubling its concentration in fruits from both states. Pitanga was found to be one of the richest fruit sources of carotenoids, particularly lycopene, but the processed products had much lower lycopene content. The mean (all-E)-lycopene concentration was 16.6 microg/g for frozen pulp brand A, 23.0 microg/g for bottled juice brand B and 25.6 microg/g for bottled juice brand C. Optimization of processing is therefore needed to guarantee better retention of this important carotenoid.

Processed and prepared corn products as sources of lutein and zeaxanthin: compositional variation in the food chain.

Widely consumed by populations of all socioeconomic classes worldwide, corn is one of the few food sources of lutein and zeaxanthin. However, data on these carotenoids in processed corn and corn as eaten are lacking. Thus, the major carotenoids in the principal brands of processed corn (canned corn, corn meal, corn flour, corn flake) and in typical corn dishes (farofa, boiled corn, pamonha, curau, fried and boiled polenta) were determined. There was marked variation between processed products and between brands of the same product, but variation between lots of the same brand was small. Canned corn had the highest zeaxanthin (11.91 to 18.06 microg/g), beta-cryptoxanthin (2.32 to 3.77 microg/g), and beta-carotene (1.79 to 2.75 microg/g) contents. The corn flake breakfast cereal had the second highest amount of zeaxanthin (9.08 to 12.77 microg/g). Corn meal had the highest lutein (4.02 to 7.62 microg/g) level and also had good zeaxanthin content (6.13 to 11.39 microg/g), but drastic reduction of all carotenoids, especially zeaxanthin, occurred when it was toasted to farofa. Boiled corn also had lower carotenoid levels compared to the raw corn. The wide variations in carotenoid concentrations appeared to be due mainly to varietal differences in the carotenoid composition of raw materials and to losses during processing and preparation for consumption.

Otimização e validação de metodologia analitica para determinação de flavonóis e flavonas por CLAE em hortaliças / Optimization and validation of HPLC methodology for determining flavonols and flavones in vegetables

O objetivo deste trabalho foi otimizar a metodologia analítica para determinação de flavonóis e flavonas em hortaliças. A hidrólise foi otimizada utilizando-se Delineamento Composto Central Rotacional (DCCR)para investigar os efeitos da concentração de HCl e do tempo de hidrólise. Essa etapa foi realizada simultaneamente com a extração por metanol aquoso 50%, em refluxo a 90ºC. Foi utilizado cromatógrafo líquido Waters com coluna Nova-Pak C18 e detector de arranjo de diodos. Os compostos estudados foram miricetina (M), quercetina (Q), kaempferol (K), luteolina (L) e apigenina (A). As condições ótimas encontradas para hidrólise de cada hortaliça foram: 1,0M HCl/6 horas para espinafre e couve, 1,6M HCl/5 horas para rúcula, 1,2M HCl/2 horas para alface, 1,7M HCl/4,3 horas para salsa e 0,8M HCl/2,5 horas para cebola. O melhor gradiente para separação (CLAE) dos flavonóides das hortaliças em estudo foi constituído de metanol:água (acidificados com 0,3% de ácido fórmico) 20:80, chegando a 45:55 em 5 minutos, 48:52 em 17 minutos e voltando a 20:80 em 20 minutos. As curvas analíticas apresentaram coeficientes de correlação maiores que 0,99. Os limites de detecção foram de 0,5, 0,4, 0,5, 0,6 e 1,0μg/mL, respectivamente, para M, Q, L, K e A.

The objective of this investigation was to optimize the analytical methodology for determining flavonols and flavones in vegetables. The hydrolysis procedure was optimized using Central Composite Rotational Design (CCRD) to investigate the effects of HCl concentration and hydrolysis time. This step was carried out simultaneously with extraction with 50% aqueous methanol, and refluxing at 90°C. A Waters liquid chromatograph, with Nova-Pak C18 column and photodiode array detector, was used. The analyzed compounds were myricetin (M), quercetin (Q), kaempferol (K), luteolin (L), and apigenin (A). The optimum conditions found for hydrolysis for each vegetable were: 1.0M HCl for 6 hours for spinach and kale, 1.6M HCl for 5 hours for roquette, 1.2M HCl for 2 hours for lettuce, 1.7M HCl for 4.3 hours for parsley, and 0.8M HCL for 2.5 hours for onion. The best gradient (HPLC) for separating flavonoids from these vegetables consisted of methanol:water (acidified with 0.03% formic acid) 20:80, changing to 45:55 in 5 minutes, 48:52 in 17 minutes, returning to 20:80 in 20 minutes. The standard curves of the flavonoids had coefficients of correlation higher than 0.99. The detection limits were 0.5, 0.4, 0.5, 0.6 and 1.0μg/mL for M, Q, L, K, and A, respectively.

Qualitative and quantitative differences in carotenoid composition among Cucurbita moschata, Cucurbita maxima, and Cucurbita pepo.

Squashes and pumpkins are important dietary sources of carotenoids worldwide. The carotenoid composition has been determined, but reported data have been highly variable, both qualitatively and quantitatively. In the present work, the carotenoid composition of squashes and pumpkins currently marketed in Campinas, Brazil, were determined by HPLC-DAD, complemented by HPLC-MS for identification. Cucurbita moschata 'Menina Brasileira' and C. moschata 'Goianinha' had similar profiles, with beta-carotene and alpha-carotene as the major carotenoids. The hybrid 'Tetsukabuto' resembled the Cucurbita pepo 'Mogango', lutein and beta-carotene being the principal carotenoids. Cucurbita maxima 'Exposição' had a different profile, with the predominance of violaxanthin, followed by beta-carotene and lutein. Combining data from the current study with those in the literature, profiles for the Cucurbita species could be observed. The principal carotenoids in C. moschata were beta-carotene and alpha-carotene, whlereas lutein and beta-carotene dominate in C. maxima and C. pepo. It appears that hydroxylation is a control point in carotenoid biosynthesis.

Selection and characterization of carotenoid-producing yeasts from Campinas region, Brazil

The objective of the present study was to select and identify yeasts from Brazil capable of producing carotenoids. Pigmented yeasts were isolated from soil, leaves, fruits, flowers and a processed product. The samples were incubated at 30°C in Erlenmeyer flasks, containing YM broth. After 48 hours, they were inoculated in Petri dishes with YM agar, and incubated at 30°C during 120 hours. The yeast colonies, which presented yellow to red coloration, were transferred to culture tubes containing YM agar, and incubated at 30°C for 72 hours. Out of 242 samples, only five had yellow to red color at high intensity. These highly pigmented yeasts were re-isolated in Petri dishes with YM agar and then transferred to tubes with GPYM agar. Identification through morphological and reproduction characteristics, along with physiological and biochemical tests, classified four strains as R. mucilaginosa and one strain as R. graminis. The main carotenoids extracted from them were identified through HPLC analysis as beta-carotene and torulene. The strains showed potential as promising microorganisms for the commercial production of carotenoids.

Este trabalho teve como objetivo selecionar e identificar leveduras encontradas no Brasil capazes de produzir carotenóides. As leveduras pigmentadas foram isoladas de amostras de solos, folhas, frutos, flores e um alimento processado. As amostras foram colocadas em frascos de erlenmeyer, contendo meio de Extrato de Malte e Levedura (YM), e incubadas a 30°C. Após 48 horas, as amostras foram inoculadas em placas de petri contendo meio YM ágar e incubadas a 30°C por 120 horas. As colônias, que apresentaram coloração entre amarelo e vermelho, foram transferidas para os tubos de culturas, contendo meio YM ágar e incubadas a 30°C por 72 horas. Das 242 amostras, somente cinco delas apresentaram coloração intensa entre amarelo e vermelho. Estas colônias de leveduras foram reisoladas, em placas de petri contendo YM ágar e, posteriormente, transferidas para tubos de ensaios contendo GPYM ágar. A identificação das leveduras, baseada nas características morfológicas, de reprodução, além dos testes fisiológicos e bioquímicos, classificou quatro linhagens como Rhodotorula mucilaginosa e uma como Rhodotorula graminis. Os principais pigmentos extraídos destas linhagens foram identificados através da análise de cromatografia de alta eficiência como beta-caroteno e toruleno. As linhagens de leveduras mostraram potencial como microrganismos promissores para a produção comercial de carotenóides por fermentação.

Avanços na pesquisa de carotenóides em alimentos: contribuições de um laboratório brasileiro / Advances in food carotenoid research: contribution of a Brazilian laboratory

Os carotenóides são pigmentos naturais, constituintes dos alimentos, sendo alguns deles precursores de vitamina A. São associados com a diminuição do risco de doenças degenerativas como câncer, doenças cardiovasculares, degeneração macular e catarata, sendo os compostos bioativos mais estudados. Os nossos estudos vêm contribuindo de maneira significativa para os avanços neste assunto em diversos aspectos. Reconhecidas internacionalmente, as nossas contribuições científicas podem ser agrupadas da seguinte forma: (a)avaliação, otimização e desenvolvimento de métodos analíticos; (b)determinação da composição de carotenóides em alimentos brasileiros, resultando em um extenso e confiável banco de dados; (c)investigação dos fatores que influenciam na composição em alimentos; (d)avaliação dos efeitos de processamento e estocagem de alimentos nos carotenóides; (e)estudo da estabilidade dos carotenóides, inclusive da cinética, dos mecanismos de degradação e do uso de microencapsulação; (f) caracterização de fontes alternativas de carotenóides como flores, leveduras e microalgas. É considerada a pesquisa mais integrada e completa nesta área, em nível mundial