Ratio Of Β-carotene Research Articles

Combined Heat and Mass Transfer Associated with Kinetics Models for Analyzing Convective Stepwise Drying of Carrot Cubes.

Stepwise drying is an effective technique that promotes energy saving without additional capital cost. The stepwise drying mode was investigated for energy consumption and dried product qualities using a coupled heat and mass transfer model associated with kinetics equations of volume shrinkage and degradation of β-carotene in carrot cubes. Simulations were performed using a finite element method with extension of a chemical species transport. Validation experiments were carried out under constant drying modes at 60 °C, 70 °C and 80 °C using a lab-scale convective hot air dryer. The verified models were subsequently employed to investigate the effects of two step-up drying modes (60 to 70 °C and 60 to -80 °C). The optimal drying condition was determined using the synthetic evaluation index (SI) with criteria of high specific moisture evaporation rate (SMER), low shrinkage ratio and β-carotene degradation. Simulated results showed comparable agreement with experimental data of moisture content, shrinkage ratio and β-carotene ratio. Step-up drying of 60 to 70 °C gave the highest SMER of 0.50 × 10-3 kg of water evaporated per kWh, while the operation at constant temperature of 80 °C gave the lowest value of 0.19 × 10-3 kg of water evaporated per kWh. Model-predicted results showed less shrinkage of carrot cubes, but higher degradation of β-carotene under step-up drying compared to single-stage drying under temperature of 60 °C. Based on the highest SI value (0.36), carrot cubes were optimally dried under step-up mode of 60 to 70 °C.

Concurrent Production of α- and β-Carotenes with Different Stoichiometries Displaying Diverse Antioxidative Activities via Lycopene Cyclases-Based Rational System.

α- and β-carotenes belong to the most essential carotenoids in the human body and display remarkable pharmacological value for health due to their beneficial antioxidant activities. Distinct high α-/β-carotene stoichiometries have gained increasing attention for their effective preventions of Alzheimer's disease, cardiovascular disease, and cancer. However, it is extremely difficult to obtain α-carotene in nature, impeding the accumulations of high α-/β-carotene stoichiometries and excavation of their antioxidant activities. Herein, we developed a dynamically operable strategy based on lycopene cyclases (LCYB and LCYE) for concurrently enriching α- and β-carotenes along with high stoichiometries in E. coli. Membrane-targeted and promoter-centered approaches were firstly implemented to spatially enhance catalytic efficiency and temporally boost expression of TeLCYE to address its low competitivity at the starting stage. Dynamically temperature-dependent regulation of TeLCYE and TeLCYB was then performed to finally achieve α-/β-carotene stoichiometries of 4.71 at 37 °C, 1.65 at 30 °C, and 1.06 at 25 °C, respectively. In the meantime, these α-/β-carotene ratios were confirmed to result in diverse antioxidative activities. According to our knowledge, this is the first time that both the widest range and antioxidant activities of high α/β-carotene stoichiometries were reported in any organism. Our work provides attractive potentials for obtaining natural products with competitivity and a new insight on the protective potentials of α-/β-carotenes with high ratios for health supply.

Thermal-induced impact on physicochemical property and bioaccessibility of β-carotene in aqueous suspensions fabricated by wet-milling approach

The physicochemical properties of β-carotene in aqueous system were scarcely explored before. Herein, β-carotene aqueous suspensions were fabricated by wet-milling, and the impact of milling temperature on thermal degradation kinetics, coloring mechanism, recrystallization behavior and bioaccessibility of β-carotene in aqueous system was investigated. The thermodynamic parameters indicated that the degradation of total β-carotene and all-trans isomer in aqueous suspensions was endothermic and energetically unfavorable. The hue of aqueous suspensions was dependent on the particle size and cis isomer ratio of β-carotene (especially in the formation of 13-cis isomer). The reduced conjugation effect of CC groups was responsible to the hypochromicity and amorphization of isomerized β-carotene. The recrystallization rate of β-carotene in aqueous suspensions was decreased owing to the presence of higher magnitude of steric hindrance between the isomerized β-carotene. The bioaccessibility of β-carotene was significantly increased through the nanoencapsulation and elevating the level of cis isomers of β-carotene.

A Comparison of β-Carotene, Phytoene and Amino Acids Production in Dunaliella salina DF 15 (CCAP 19/41) and Dunaliella salina CCAP 19/30 Using Different Light Wavelengths.

Strains of Dunaliella salina microalgae are of considerable research and industrial interest because they hyper-accumulate β-carotene as well as produce high-quality protein. To explore the co-production of valuable compounds in D. salina, this study compared the production of β-carotene, phytoene and amino acids in two strains cultivated under white, red or blue light until no further nitrogen was available. D. salina DF15 (CCAP 19/41 (PLY DF15)) produced more than 12% β-carotene (ash-free dry weight (AFDW) basis), and red light triggered the production of 9-cis β-carotene at a 9-cis/all-trans β-carotene ratio of 1.5. Phytoene production was also evident in D. salina DF15 under all conditions, particularly under blue light. However, the profile of essential amino acids (EAAs) and calculation of the essential amino acid index (EAAI) was less than ideal in terms of protein quality, for both strains. Umami compounds, quantified as monosodium glutamate (MSG) equivalents, indicated a higher equivalent umami concentration (EUC) in D. salina DF15 under red light (3.2 g MSG/100 g AFDW) than in D. salina CCAP19/30. Overall, D. salina DF15 demonstrates valuable traits for further exploration and product optimisation.

Assessment of Stirred Probiotic Yogurt fortified with Husk Tomato (Physalis peruviana, L) Juice as a Healthy Dairy Product

Consumers are increasingly aware of the consumption of natural health products. Husk Tomato fruit is a remarkable fruit in a modern survey. Therefore, this study aims to produce novel stirred probiotic yogurt (SPY) fortified with Husk Tomato Juice (HTJ). Chemical, microbiological, toxins, color, and viscosity characteristics for the new product were evaluated. Vitamins A, B1, B2, C, amino acid profile, and the effect of HTJ or SPY on the growth of some pathogens were assessed. Vitamin A and β-carotene for fresh stirred probiotic yogurt were also analyzed. On the other side, the control sample (with no fortification) and four treatments of SPY were produced with different ratios of Husk Tomato Juice T1, T2, T3, and T4 with (20, 30, 40, and 50% V/V) respectively. Apparent viscosity, color parameters, and pH values of fermented beverage samples were estimated. Data revealed that the juice had a considerable vitamin C ratio, representing about 32-38% of the recommended daily use. On the same line, Lysine, Leucine, Valine, Threonine, Tryptophan, and Isoleucine were the main essential amino acids in the juice. Also, the HTJ possessed diverse degrees of inhibition opposite to grow of some pathogenic bacteria and fungi. The counts of starter cultures of yogurt and Lb. casei as the probiotic strain increased during the storage period until 10 days, especially in T1, T2, and T3. The viable counts of pathogenic strains in the contaminated treatments decreased during storage periods compared with control. Furthermore, treatment samples had significantly lower L values and higher a & b values due to the orange color of the high ratio of β-carotene in HTJ compared to control samples. A healthy probiotic fruity beverage had been successfully produced. It has appropriate amounts of important vitamins.

Examination of dissolution ratio of β-carotene in water for practical application of β-carotene amorphous solid dispersion.

β-Carotene (BC) has an antioxidant effect that removes active oxygen in vivo and can reduce the risk of developing various diseases, but it is almost insoluble in water. Therefore, to develop highly effective BC functional food products, it is essential to increase its water solubility, which in turn can improve its absolute bioavailability. Recently, a BC amorphous solid dispersion (BC-SD) prepared using hot melt extruder technology had increased water solubility and improved absorption from the gastrointestinal tract. However, only a part of the BC in BC-SD could be dissolved in water. In this study, we evaluated whether the dissolution ratio of BC in water could be improved by examining the mixing ratio of BC and base materials in BC-SD. Results showed that by reducing the mixing ratio of BC to the base materials, the dissolution ratio of BC in water increased. It was also found that when BC-SD, which has the highest dissolution ratio, was intragastrically administered to rats, its absolute bioavailability was most increased. These results are useful findings that may help in reducing the costs associated with the BC-SD manufacturing process and will be an important part of our strategy for practical use in the future.

9-cis and all-trans beta-carotene isomers of super critical CO2-extracted Dunaliella oil are absorbed and accumulated in mouse tissues

ABSTRACT Animals cannot produce β-carotene, and therefore they exclusively depend on its dietary availability. We previously showed that a 9-cis β-carotene-enriched diet, provided as Dunaliella powder, has a beneficial effect on atherosclerosis and diabetes mellitus in animal models and on lipid profiles, retinitis pigmentosa, and psoriasis in human trials. Therefore, the current study aimed to investigate the bioavailability of 9-cis β-carotene from super-critical CO2-extracted Dunaliella oil in mice. In total, ten 12-week old mice were allocated into two groups: (1) a control-received unfortified diet; (2) a Dunaliella oil diet enriched with Dunaliella oil. Four-week dietary supplementation with Dunaliella oil led to a substantial accumulation of both all-trans and 9-cis β-carotene in the plasma, liver and white adipose tissue. β-carotene was stable in oil preparation, and the 9-cis to all-trans β-carotene ratio was constant (60:40, g/g) after two years of storage at 4°C. These results suggest that supercritically extracted Dunaliella oil can potentially be used as a food supplement.

Phytoene and phytofluene overproduction by Dunaliella salina using the mitosis inhibitor chlorpropham

The halotolerant chlorophyte microalga, Dunaliella salina, is one of the richest sources of carotenoids and will accumulate up to 10% of the dry biomass as β-carotene, depending on the integrated amount of light to which the alga is exposed during a division cycle. Red light also stimulates β-carotene production, as well as increases the 9-cis β-carotene/all-trans β-carotene ratio. In this paper we investigated the effects of chlorpropham (Iso-propyl-N (3-chlorophenyl) carbamate, CIPC), with and without red light, on carotenoid accumulation. Chlorpropham is a well-known carbamate herbicide and plant growth regulator that inhibits mitosis and cell division. Chlorpropham arrested cell division and induced the massive accumulation of colourless phytoene and phytofluene carotenoids, and, to a much lesser extent, the coloured carotenoids. The chlorophyll content also increased. When phytoene per cell accumulated to approximately the same level with chlorpropham as with norflurazon, a phytoene desaturase inhibitor, coloured carotenoids and chlorophyll increased with chlorpropham but decreased with norflurazon. Cultivation with chlorpropham under red LED light for 2 days did not affect the content of β-carotene, but phytoene was 2.4-fold the amount that was obtained in cultures under white LED light and the 9-cis β-carotene/all-trans β-carotene ratio increased from 1.3 to 1.8. With norflurazon, red LED light boosted the contents of both phytoene and β-carotene, 2-fold and 1.3-fold respectively compared to those under white LED light, and the ratio of 9-cis β-carotene/all-trans β-carotene reached 3.8. The results are discussed in terms of disruption by chlorpropham of synchronised control between nuclear and chloroplast events associated with carotenoid biosynthesis. Since phytoene and phytofluene are colourless carotenoids which are sought after for the development of nutricosmetics and other health/beauty products, the results also present as a new method with low toxicity for production of colourless carotenoids based on the cultivation of D. salina.

Encapsulation of β-carotene by self-assembly of rapeseed meal-derived peptides: Factor optimization and structural characterization

Rapeseed meal rich in protein serves as one of the major agricultural processing by-products; however, it is currently used as a fertilizer or feed, which causes a great waste of protein resources. The aim of this study was to enzymatically prepare rapeseed peptides (RPs) that can be self-assembled and used as a nanocarrier for encapsulation of hydrophobic β-carotene. During this process, the effects of rapeseed protein hydrolysis time, encapsulation time, and the ratio of β-carotene to RPs on the encapsulation results were investigated. The encapsulation efficiency (EE) and drug loading amount (LA) were used as the evaluation indicators. Through optimization of conditions, the optimal parameters of encapsulation were obtained, namely enzymatic hydrolysis for 60 min, encapsulation time for 3 h, the optimal ratio of β-carotene to peptide for 3/5, the EE for >80%, and the LA for 0.55 mg/mg. In addition, the encapsulation structure of RPs and β-carotene was systematically characterized by FTIR, TEM and CLSM, suggesting that β-carotene was successfully encapsulated by RPs. The present study contributes to a deep understanding of encapsulation of β-carotene by self-assembly of RPs.

Association between serum β-carotene-to-retinol ratio and severity of hepatic steatosis in non-alcoholic fatty liver disease in Japan: A cross-sectional study.

Retinol and β-carotene have been reported to be involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, clinical studies are limited. The aim of this study was to investigate the relationship between serum the ratio of β-carotene to retinol (SC/SR) and hepatic steatosis in NAFLD diagnosed by ultrasonography. The participants were 606 Japanese adults who were enrolled in a health survey. Clinical profile, dietary nutrition intake, blood biochemistry, serum retinol, and carotenoids were analyzed. NAFLD was defined as fatty liver on ultrasonography in the absence of other causes of steatosis. Women had higher daily intake of α- and β-carotene, although there were no differences in daily retinol and carotenoid intake between participants with or without NAFLD in both men and women. Women had a higher SC/SR ratio than men regardless of the presence or absence of NAFLD, and the SC/SR ratio in women decreased with exacerbation of hepatic steatosis, whereas the SC/SR ratio in men did not change despite exacerbation of hepatic steatosis. After adjusting for confounding factors, the likelihood of NAFLD among participants in the highest quartile of SC/SR ratio decreased by two-thirds compared with participants in the lowest quartile (adjusted odds ratio, 0.64; 95% confidence interval, 0.21-1.92; P=0.041). The SC/SR ratio was positively correlated with serum high-density lipoprotein cholesterol level, and negatively correlated with serum triacylglycerol level. The SC/SR ratio was lower in NAFLD with sex differences, and was associated with the severity of hepatic steatosis and lipid profile. Future studies are needed to expand on these findings.

Specific Composition of Lipid Phases Allows Retaining an Optimal Thylakoid Membrane Fluidity in Plant Response to Low-Temperature Treatment.

Thylakoid membranes isolated from leaves of two plant species, the chilling tolerant (CT) pea and chilling sensitive (CS) runner bean, were assessed for the composition of lipids, carotenoids as well as for the arrangement of photosynthetic complexes. The response to stress conditions was investigated in dark-chilled and subsequently photo-activated detached leaves of pea and bean. Thylakoids of both species have a similar level of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), but different sulfoquinovosyldiacylglycerol to phosphatidylglycerol (PG) ratio. In pea thylakoid fraction, the MGDG, DGDG and PG, have a higher double bond index (DBI), whereas bean thylakoids contain higher levels of high melting point PG. Furthermore, the lutein to the β-carotene ratio is higher in bean thylakoids. Smaller protein/lipid ratio in pea than in bean thylakoids suggests different lipid-protein interactions in both species. The differences between species are also reflected by the course of temperature-dependent plots of chlorophyll fluorescence pointing various temperatures of the lipid phase transitions of pea and bean thylakoids. Our results showed higher fluidity of the thylakoid membrane network in pea than in bean in optimal temperature conditions. Dark-chilling decreases the photochemical activity and induces significant degradation of MGDG in bean but not in pea leaves. Similarly, substantial changes in the arrangement of photosynthetic complexes with increase in LHCII phosphorylation and disturbances of the thylakoid structure take place in bean thylakoids only. Changes in the physical properties of bean thylakoids are manifested by the conversion of a three-phase temperature-dependent plot to a one-phase plot. Subsequent photo-activation of chilled bean leaves caused a partial restoration of the photochemistry and of membrane physical properties, but not of the photosynthetic complexes arrangement nor the thylakoid network structure. Summarizing, the composition of the thylakoid lipid matrix of CT pea allows retaining the optimal fluidity of its chloroplast membranes under low temperatures. In contrast, the fluidity of CS bean thylakoids is drastically changed, leading to the reorganization of the supramolecular structure of the photosynthetic complexes and finally results in structural remodeling of the CS bean thylakoid network.

Efficiency of milk proteins in eliminating practical limitations of β-carotene in hydrated polar solution

The objective of this work was to study β-carotene functionalities (color and antioxidant activity) and practical limitations (aggregate formation, poor solubility and low stability) when included in the aqueous systems containing milk proteins. According to the results, self-association constant of β-carotene in the presence of casein is 1.7-fold of that calculated for WPI. Casein and WPI were capable of conserving β-carotene against chemical oxidation up to 15 and 12%, respectively, at 1:5M ratio of β-carotene to protein. While, WPI reduced its photodegradation quantum yield from 0.03 to 0.012 compared to 0.017 obtained for casein. A 2.7- and 3.6-fold enhancement in β-carotene solubility was observed in the presence of 1.5mg/mL of casein and WPI, respectively. The study of β-carotene interaction with proteins showed, on the one hand, a negative effect on electron transfer and, on the other hand, improved hydrogen transfer to the radical species in the solution.

One-Step Preparation of Z-Isomer-Rich β-Carotene Nanosuspensions Utilizing a Natural Catalyst, Allyl Isothiocyanate, via Supercritical CO2

This study aims to improve the production efficiency of β-carotene suspensions using a naturally occurring Z-isomerization-accelerating catalyst, allyl isothiocyanate (AITC), via supercritical CO2 (SC-CO2). Namely, utilizing solubility improvement of β-carotene with the Z-isomerization by adding AITC in the SC-CO2-used dispersion process, the encapsulation efficiency of β-carotene was enhanced. The dispersion of β-carotene was conducted by ultrasonic treatment, and there was no involvement of organic solvents in the whole process. When 100 mg of AITC was added in the dispersion process, the encapsulation efficiency (β-carotene content in resulting suspension) was approximately 3.5 times higher than that without addition of the catalyst. Moreover, the Z-isomer ratio of β-carotene in the suspensions significantly improved, that is, it was approximately 12 times higher than the raw β-carotene material. Since Z-isomers of β-carotene are known to have higher antiatherosclerotic and antiatherogenic activities compared to the all-E-isomer, this one-step method not only efficiently produces β-carotene suspensions without organic solvents but also enhances the bioactivities of them.

Enhanced production of β-carotene suspensions using supercritical CO2 via naturally occurring Z-isomerization-accelerating catalyst

β-carotene has high antioxidant activity and its adequate intake can reduce the risk of various diseases. Thus, β-carotene can be utilized as a dietary supplement and valuable natural food colorant. Z-isomerization of β-carotene can reduce the crystallinity of (all-E)-β-carotene and improve the solubility of it in solvents. Preparing nanosuspensions of Z-isomer-rich β-carotene can improve the dispersibility of β-carotene in water and bioavailability of it. In previous work, Z-isomerization and encapsulation process of β-carotene was implemented in two separated steps. In this work, organic catalyst derived from plants was utilized for Z-isomerization of β-carotene. The Z-isomerization and emulsification-evaporation process were conducted simultaneously under supercritical CO2 assisted by ultrasound. β-carotene suspension produced in this work was characterized by UV-vis, HPLC and DLS. The nanosuspensions rich in Z-isomers of β-carotene has been successfully prepared using allyl isothiocyanate (AITC) as the catalyst for Z-isomerization. When the distributed processing was performed with 50mg, 100 mg AITC, the encapsulation efficiency and Z-isomerization ratio in the suspensions were approximately 6 times and 13 times higher than those of no catalyst. Adding AITC in the emulsification-evaporation process using SC-CO2 as a Z-isomerization-accelerating catalyst improved not only the Z-isomerization ratio of βcarotene but also the encapsulated β-carotene content in suspensions.

β-Carotene solid dispersion prepared by hot-melt technology improves its solubility in water.

β-Carotene is a member of the carotenoid family and is a red-orange pigment abundantly present in many vegetables and fruits. As an antioxidant, it eliminates excessive reactive oxygen species generated in the body. Accordingly, it has potential to be used in the pharmaceutical, food, and cosmetic industries. β-Carotene has a very low water solubility and low bioavailability; thus, there is a need to develop techniques to overcome these issues. In this study, we aimed to enhance the water solubility of β-carotene by using hot-melt technology, a type of solid dispersions technology. When preparing β-carotene solid dispersion using this method, suitable conditions for the emulsifiers and mixing ratios were investigated using water solubility as an index. Setting the weight ratio of β-carotene:polyvinylpyrrolidone:sucrose fatty acid ester to 10%:70%:20% resulted in the poorly-water soluble β-carotene showing improved water solubility (120μg/mL). The physicochemical properties of the optimized β-carotene solid dispersion were analyzed using field emission scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction. The solid dispersion was found to have an amorphous structure. The improved solubility observed for β-carotene in the solid dispersions developed in this work may make these dispersions useful as additives in foods or in nutraceutical formulations.

Carrot Leaves Maintain Liver Vitamin A Concentrations in Male Mongolian Gerbils Regardless of the Ratio of α- to β-Carotene When β-Carotene Equivalents Are Equalized

Carrots are an important horticultural crop that contain provitamin A carotenoids (PACs). Orange carrots have high concentrations of α-carotene, which upon central cleavage yields 1 retinal and 1 α-retinal molecule. The leaves of carrot plants are a source of PACs when consumed. Male Mongolian gerbils aged 27-30 d were used to assess the bioefficacy of carrot leaves to maintain vitamin A (VA) status and investigate whether the ratio of α- to β-carotene (α:β-carotene) affected bioefficacy. After 3 wk depletion, baseline gerbils were killed (n=6) and the remaining gerbils (n=60) were divided into 6 groups to receive 4 VA-deficient, carrot leaf-fortified feeds (1:1.4, 1:2.5, 1:5.0, and 1:80 α:β-carotene ratio) equalized to 4.8 nmol/g β-carotene equivalents (βCEs), or VA-deficient feed with (VA+) or without (VA-) retinyl acetate supplements. Carrot-leaf powder from 4 carrot plants with differing α:β-carotene ratios was used. After 4 wk, gerbils were killed and tissues were collected and analyzed for retinoids by HPLC. VA+ had higher total liver VA (means ± SD 0.91±0.29 μmol) than all other groups (range: 0.40-0.62) (P≤0.03), and the carrot leaf treatments did not differ from baseline (0.55±0.09 μmol). VA- (0.40±0.23 μmol VA/liver) did not differ from the leaf-fed groups, but 30% became VA deficient (defined as <0.1 μmol VA/g liver). α-Retinol accumulated in livers and lungs and was correlated to total α-carotene consumption (R2=0.83 and 0.88, respectively; P<0.0001). Bioefficacy factors ranged from 4.2 to 6.2 μg βCE to 1 μg retinol. Carrot leaves maintain VA status and prevent deficiency in gerbils regardless of the α:β-carotene ratio. The bioconversion of PACs from carrot leaves to retinol is similar to what has been reported for other green leafy vegetables, making the consumption of carrot leaves a viable method to improve dietary PAC intake.

Red Light Control of β-Carotene Isomerisation to 9-cis β-Carotene and Carotenoid Accumulation in Dunaliella salina

Dunaliella salina is a rich source of 9-cis β-carotene, which has been identified as an important biomolecule in the treatment of retinal dystrophies and other diseases. We previously showed that chlorophyll absorption of red light photons in D. salina is coupled with oxygen reduction and phytoene desaturation, and that it increases the pool size of β-carotene. Here, we show for the first time that growth under red light also controls the conversion of extant all-trans β-carotene to 9-cis β-carotene by β-carotene isomerases. Cells illuminated with red light from a light emitting diode (LED) during cultivation contained a higher 9-cis β-carotene content compared to cells illuminated with white or blue LED light. The 9-cis/all-trans β-carotene ratio in red light treated cultures reached >2.5 within 48 h, and was independent of light intensity. Illumination using red light filters that eliminated blue wavelength light also increased the 9-cis/all-trans β-carotene ratio. With norflurazon, a phytoene desaturase inhibitor which blocked downstream biosynthesis of β-carotene, extant all-trans β-carotene was converted to 9-cis β-carotene during growth with red light and the 9-cis/all-trans β-carotene ratio was ~2. With blue light under the same conditions, 9-cis β-carotene was likely destroyed at a greater rate than all-trans β-carotene (9-cis/all-trans ratio 0.5). Red light perception by the red light photoreceptor, phytochrome, may increase the pool size of anti-oxidant, specifically 9-cis β-carotene, both by upregulating phytoene synthase to increase the rate of biosynthesis of β-carotene and to reduce the rate of formation of reactive oxygen species (ROS), and by upregulating β-carotene isomerases to convert extant all-trans β-carotene to 9-cis β-carotene.

Lycopene cyclases determine high α-/β-carotene ratio and increased carotenoids in bananas ripening at high temperatures

Bananas are a recommended food source to alleviate vitamin A deficiency because they contain a high ratio of provitamin A precursors. The objective of this study was to investigate carotenoid accumulation pattern in banana fruits during postharvest ripening and the mechanisms regulating this process. Ripe banana pulp had an unusually high α-/β-carotene ratio (1.05), and the carotenoid contents increased (p ≤ 0.05) under light and high temperature. We analyzed the sequences, transcript levels, and functions of genes involved in carotenoid synthesis. The high ratio of α-/β-carotene in ripe banana fruit was explained by the high flux to the α-carotene biosynthetic pathway, as reflected by high transcript levels of LCYE, and the weak flux to the β-carotene branch of the biosynthetic pathway due to inactive MaLCYB1.2. High temperature during ripening up-regulated the transcript levels of genes involved in the α- and β-carotene biosynthesis pathways and the activities of their encoded enzymes.

Optimization of the Four Most Effective Factors on β-Carotene Production by Dunaliella salina Using Response Surface Methodology.

During recent years, there was growing demand in using microalga valuable products such as β-carotene in health care. β-Carotene has anti-cancer and anti-aging properties for human. In Dunaliella salina cells, β-carotene has a major protecting role for biomolecules, when the production of reactive oxygen species is elevated. In the present study, we investigated the influence of the four most effective factors (light intensity, temperature, nitrate and salinity concentration) and their interactions on the β-carotene production and the total chlorophyll/β-carotene ratio in low light adapted D. salina cells. Box-Benken design and response surface methodology (RSM) were used for this purpose and optimization of the factor levels. Two models were developed to explain how β-carotene productivity and the total chlorophyll/β-carotene ratio may depend on the stress factors. Among the four stress variables for β-carotene production, light intensity was stronger than the others. Meanwhile, interaction between light intensity and salt concentration exhibited the most important effect on the total chlorophyll/ β-carotene ratio. The predicted optimal conditions for maximum β-carotene productivity and minimum total chlorophyll/β-carotene ratio were derived from the fitted model in 200 µmol photons m-2s-1 light intensity, 25 ºC, 0.9 mM nitrate and 3.8 M NaCl. When the predicted condition was tested experimentally, the expected results were observed. This suggests that overproduction of β-carotene in D. salina under certain conditions depends on used light intensity for preadaptation. The step-wise manner applying of stresses may act as a beneficial strategy to β-carotene overproduction.

Use of Electrosprayed Agave Fructans as Nanoencapsulating Hydrocolloids for Bioactives.

High degree of polymerization Agave fructans (HDPAF) are presented as a novel encapsulating material. Electrospraying coating (EC) was selected as the encapsulation technique and β-carotene as the model bioactive compound. For direct electrospraying, two encapsulation methodologies (solution and emulsion) were proposed to find the formulation which provided a suitable particle morphology and an adequate concentration of β-carotene encapsulated in the particles to provide a protective effect of β-carotene by the nanocapsules. Scanning electron microscopy (SEM) images showed spherical particles with sizes ranging from 440 nm to 880 nm depending on the concentration of HDPAF and processing parameters. FTIR analysis confirmed the interaction and encapsulation of β-carotene with HDPAF. The thermal stability of β-carotene encapsulated in HDPAF was evidenced by thermogravimetric analysis (TGA). The study showed that β-carotene encapsulated in HDPAF by the EC method remained stable for up to 50 h of exposure to ultraviolet (UV) light. Therefore, HDPAF is a viable option to formulate nanocapsules as a new encapsulating material. In addition, EC allowed for increases in the ratio of β-carotene:polymer, as well as its photostability.