High Levels Of Β-carotene Research Articles

Body Weight, Cholesterol Changes and Sub-Chronic Toxicity of Mice Treated with An Emulsion Product Rich in b-Carotene

Background: One of the conditions for releasing standardized herbal medicines is the presence of pre-clinical testing that can be conducted with mice. Emulsion products with the main composition of pumpkin, red palm oil, and dragon fruit have high levels of β-carotene. The purpose of this study was to observe changes in weight, cholesterol, and sub-chronic toxicity from mice treated with emulsion products.Materials and Methods: Mice observed consisted of 6 groups: (1) untreated control (given standard ration); (2) negative control (given standard ration and 2.8% (v/b) egg yolk); (3) positive control (given standard ration and 0.4% (v/b) β-carotene); (4) standard ration, 0.4% (v/b) β-carotene and 2.8% (v/b) egg yolk; (5) given a standard ration and 2% (v/b) emulsion products; and (6) given a standard ration, 2% (v/b) emulsion products and 2.8% (v/b) egg yolk. Observations of sub-chronic toxicity were done by measuring creatinine levels, kidney weight, and visual observation of kidney swelling.Results: The use of β-carotene-rich emulsions does not cause a decrease in the average weight of mice. In general, β-carotene and emulsion can overcome cholesterol increases on the 7th day, but not for the 15th day as a result of standard food intake. The increase in creatinine levels only occurs in mice treated with egg yolk control. The additional treatment of β-carotene and emulsion successfully prevents the increase in creatinine levels.Conclusion: Emulsion products did not cause changes in weight, were able to reduce cholesterol levels in a limited manner and were not toxic to mice.Keywords: cholesterol changes, sub-chronic toxicity, b-carotene, emulsion

Comparing carotene, anthocyanins, and terpenoid concentrations in selected carrot lines of different colors

Plant pigments such as anthocyanins and carotenoids have been shown to be beneficial to human health. Therefore, carrot lines of different colors have been recently developed. This study aimed to characterize terpenoid, carotene, anthocyanin, and soluble solids content and antioxidant activity levels in orange, yellow, black, and purple carrots to develop new color carrot cultivars with more nutrients, health benefits, and consumer acceptance. Both individual and total terpenoid content greatly varied among breeding lines. Each line had a unique composition, and there was no general pattern between color and terpenoid content. Orange carrot roots had high levels of α-carotene, β-carotene, and total carotenoids compared with yellow. Red carrots were characterized by high lycopene content, and black carrots exhibited identical levels of lycopene content to yellow carrots. Leaf tissues contained lutein as the main carotenoid followed by β-carotene. There was no clear relationship between leaf and root carotene profiles and content. Black and purple root colors were determined by composition and amount of anthocyanin compounds, and about five major compounds were detected in this study. Total anthocyanin content was high in solid black carrots and decreased as the interior root color contained more yellow, with low and trace levels in purple and orange carrots, respectively. Soluble solid content ranged between 4.0 and 9.5 °Brix among lines. Anthocyanin content was highly correlated with antioxidant activity. Each color of carrot contained different levels of the tested compounds and may require extensive breeding to obtain desired levels.

Differential role of the two ζ-carotene desaturase paralogs in carrot (Daucus carota): ZDS1 is a functional gene essential for plant development and carotenoid synthesis

Daucus carota is a biennale crop that develops an edible storage root. Orange carrots, the most consumed cultivar worldwide, accumulate high levels of β-carotene and α-carotene in the storage root during secondary growth. Genes involved in β-carotene synthesis have been identified in carrots and unlike most species, D. carota has two ζ-carotene desaturase genes, named ZDS1 and ZDS2, that share 91.3 % identity in their coding regions. ZDS1 expression falls during leaf, but not root development, while ZDS2 is induced in leaves and storage roots of a mature plant. In this work, by means of post-transcriptional gene silencing, we determined that ZDS1 is essential for initial carrot development. The suppression of the expression of this gene by RNAi triggered a reduction in the transcript levels of ZDS2 and PSY2 genes, with a concomitant decrease in the carotenoid content in both, leaves and storage roots. On the contrary, transgenic lines with reduced ZDS2 transcript abundance maintain the same levels of expression of endogenous ZDS1 and PSY2 and carotenoid profile as wild-type plants. The simultaneous silencing of ZDS1 and ZDS2 resulted in lines with a negligible leaf and root development, as well as significantly lower endogenous PSY2 expression. Further functional analyses, such as a plastidial subcellular localization of ZDS1:GFP and the increment in carotenoid content in transgenic tobacco plants overexpressing the carrot ZDS1, confirmed that ZDS1 codifies for a functional enzyme. Overall, these results lead us to propose that the main ζ-carotene desaturase activity in carrot is encoded by the ZDS1 gene and ZDS2 gene has a complementary and non essential role.

Poultry diets containing (keto)carotenoid-enriched maize improve egg yolk color and maintain quality

The raw materials used in poultry feed do not provide sufficient carotenoids to achieve the yolk pigmentation demanded by consumers, so color additives are included usually in the form of carotenoid-rich dried plant extracts. We fed thirty-two laying hens (ISA Brown) on diets supplemented with two genetically engineered maize lines (enriched in carotenoids or ketocarotenoids) to assess egg productivity and quality traits. Four different maize-supplemented diets were compared based on two genetically engineered maize lines (Ph3 and BKT), the white near isogenic wild-type line (M37W) and a commercial feed based on standard commercial (SC) yellow maize. Line M37W-Ph3 (Ph3) accumulates high levels of β-carotene, zeaxanthin and lutein, whereas line NSL76*BKT (BKT) is rich in astaxanthin and other ketocarotenoids. There were no significant differences among the diet groups in terms of egg weight, breaking strength, albumen height, Haugh units, or shell thickness, but there were significant differences in DSM scale values for yolk pigmentation (P < 0.001) that were higher in the Ph3 (10.08) and BKT (11.38) groups than the SC (4.22) and M37W (≤1) groups. At the end of the trial, the total yolk carotenoid content was highest in the Ph3 diet group, followed by BKT, SC and M37W diet groups (56.5, 26.18, 11.54 and 1.81 μg/g freeze-dried yolk, respectively). The Ph3 yolks were enriched in β-carotene and β-cryptoxanthin (pro-vitamin A carotenoids) whereas the BKT yolks accumulated astaxanthin and other ketocarotenoids. The diets had no detrimental effects on the health of the hens. We conclude that (keto)carotenoid-enriched maize enhances the (keto)carotenoid content and color of yolks and can replace the color additives used routinely in poultry feed formulations.

A single amino acid change at position 96 (Arg to His) of the sweetpotato Orange protein leads to carotenoid overaccumulation.

IbOr-R96H resulted in carotenoid overaccumulation and enhanced abiotic stress tolerance in transgenic sweetpotato calli. The Orange (Or) protein is involved in the regulation of carotenoid accumulation and tolerance to various environmental stresses. Sweetpotato IbOr, with strong holdase chaperone activity, protects a key enzyme, phytoene synthase (PSY), in the carotenoid biosynthetic pathway and stabilizes a photosynthetic component, oxygen-evolving enhancer protein 2-1 (PsbP), under heat and oxidative stresses in plants. Previous studies of various plant species demonstrated that a single-nucleotide polymorphism (SNP) from Arg to His in Or protein promote a high level of carotenoid accumulation. Here, we showed that the substitution of a single amino acid at position 96 (Arg to His) of wild-type IbOr (referred to as IbOr-R96H) dramatically increases carotenoid accumulation. Sweetpotato calli overexpressing IbOr-WT or IbOr-Ins exhibited 1.8- or 4.3-fold higher carotenoid contents than those of the white-fleshed sweetpotato Yulmi (Ym) calli, and IbOr-R96H overexpression substantially increased carotenoid accumulation by up to 23-fold in sweetpotato calli. In particular, IbOr-R96H transgenic calli contained 88.4-fold higher levels of β-carotene than those in Ym calli. Expression levels of carotenogenesis-related genes were significantly increased in IbOr-R96H transgenic calli. Interestingly, transgenic calli overexpressing IbOr-R96H showed increased tolerance to salt and heat stresses, with similar levels of malondialdehyde to those in calli expressing IbOr-WT or IbOr-Ins. These results suggested that IbOr-R96H is a useful target for the generation of efficient industrial plants, including sweetpotato, to cope with growing food demand and climate change by enabling sustainable agriculture on marginal lands.

Phytochemical Profiling of Fruit Powders of Twenty Sorbus L. Cultivars.

Rowanberries have been traditionally used in various processed foods. Scientific research demonstrates the pharmacological effects of Sorbus L. fruits are determined by their unique composition of biologically active compounds. The aim of this study was to determine the composition of flavonoids, phenolic acids, anthocyanins, carotenoids, organic acids and sugars as well as the total antioxidant activity in fruit powders of 20 Sorbus cultivars. Chemical profiles of rowanberry fruit powders vary significantly. Cultivars ‘Burka’, ‘Likernaja’, ‘Dodong’, and ‘Fructo Lutea’ distinguish themselves with exclusive phytochemical composition and high antioxidant activity. Fruit powders from ‘Burka’, ‘Likernaja’ contain the highest contents of anthocyanins while fruit powder samples from ‘Fructo Lutea’ and ‘Dodong’ contain the highest levels of phenolic acids, ascorbic acid and the lowest levels of fructose. Fruit powder samples from ‘Dodong’ also contain the highest levels of β-carotene and sorbitol and the lowest levels of malic acid. Cultivars ‘Burka’, ‘Likernaja’, ‘Dodong’, and ‘Fructo Lutea’ could be selected as eligible raw materials for the preparation of rowanberry fruit powders.

Drying kinetic of tucum fruits (Astrocaryum aculeatum Meyer): physicochemical and functional properties characterization.

The aim of the present study was to assess the drying kinetic of tucum fruits (epicarp and mesocarp) Astrocaryum aculeatum Meyer at three different temperatures (50, 60, and 70°C). The physicochemical characterization, water activity, moisture content, including β-carotene and vitamin C content in-natura and dried fruits were analyzed. The fruit fractions presented high β-carotene, protein and lipid levels. Fatty acid profile showed oleic acid as the major fatty acid. Different mathematical models were computed to assess the drying process. The Page model was observed to be the best to describe the drying kinetic with the highest correlation coefficient (R2) 0.99 and the least Chi squared (χ2) close to 105 at the studied temperatures. The drying process reduced water activity to desirable levels in all trials and β-carotene retentions after drying remained at satisfactory levels, fact that resulted in minimum value of 63% and approximately 94% in some cases. Vitamin C retention was comparatively more around 20-40% compared to control.

Physical Properties, Carotenoids and Antioxidant Capacity of Carrot (Daucus carota L.) Peel as Influenced by Different Drying Treatments

Abstract Carrot peel generated from the juice factories is considered as waste and it can be potential for further recovery of carotenoids. Drying treatment is essential to minimise degradation of carotenoids and ease transportation as well as storage of the peel for further processing. This study aimed to determine the impact of different drying conditions on its physicochemical and antioxidant properties to propose the most suitable conditions for drying carrot peel for further recovery of carotenoids. Drying conditions were found to significantly affect retention of total carotenoids, β-carotene, lutein and lycopene as well as antioxidant capacity in carrot peel. Optimal conditions for hot-air drying were at 40 °C for 3.5 h; vacuum drying were at 60 °C, −60 kPa for 4 h; dehumidification drying was at 50 °C for 2.5 h with relative humidity (RH) of 16–21 %; and microwave drying was at 600 W for 7 min. In comparison with freeze drying (control) and other three different drying methods at each optimal conditions, dehumidification drying at 50 °C with RH of 16–21 % was the most effective method as it retained high levels of total carotenoids (2.75 mg/g DW), β-carotene (1.57 mg/g DW), lutein (0.17 mg/g DW) and lycopene (0.78 mg/g DW). Dried carrot peel also had potent antioxidant properties (ABTS: 4.71 and CUPRAC: 19 mM TE/g DW). Therefore, these conditions are recommended for drying carrot peel for further recovery of carotenoids.

Analysis of functional components and radical scavenging activity of 21 algae species collected from the Japanese coast

The functional chemical substances and the antioxidant activity of lipids in 21 marine algae along the Japanese coast were investigated. Principal component analysis was performed to detect any correlation between the chemical substances and algae phylum. Chlorophyta contained a high level of β-carotene. Rhodophyta contained high amounts of cholesterol, β-sitosterol, and saturated fatty acids. Phaeophyta were rich in fucosterol, α-tocopherol, fucoxanthin, and polyphenol. Phaeophyta algae also showed the highest antioxidant activity compared with other phylum. This suggests that Phaeophyta has the greatest potential to be used as a functional food. Consumption of the beneficial Phaeophyta species, such as Eisenia arborea Areschoug and Ecklonia cava Kjellman should be encouraged as not only as food products but also as nutraceuticals and dietary supplements. These beneficial ingredients should be encouraged to be studied in depth with the possibility to develop specific formulated products target to special consumer’s population with added nutritional value.

Establishment of an Arabidopsis callus system to study the interrelations of biosynthesis, degradation and accumulation of carotenoids.

The net amounts of carotenoids accumulating in plant tissues are determined by the rates of biosynthesis and degradation. While biosynthesis is rate-limited by the activity of PHYTOENE SYNTHASE (PSY), carotenoid losses are caused by catabolic enzymatic and non-enzymatic degradation. We established a system based on non-green Arabidopsis callus which allowed investigating major determinants for high steady-state levels of β-carotene. Wild-type callus development was characterized by strong carotenoid degradation which was only marginally caused by the activity of carotenoid cleavage oxygenases. In contrast, carotenoid degradation occurred mostly non-enzymatically and selectively affected carotenoids in a molecule-dependent manner. Using carotenogenic pathway mutants, we found that linear carotenes such as phytoene, phytofluene and pro-lycopene resisted degradation and accumulated while β-carotene was highly susceptible towards degradation. Moderately increased pathway activity through PSY overexpression was compensated by degradation revealing no net increase in β-carotene. However, higher pathway activities outcompeted carotenoid degradation and efficiently increased steady-state β-carotene amounts to up to 500 μg g-1 dry mass. Furthermore, we identified oxidative β-carotene degradation products which correlated with pathway activities, yielding β-apocarotenals of different chain length and various apocarotene-dialdehydes. The latter included methylglyoxal and glyoxal as putative oxidative end products suggesting a potential recovery of carotenoid-derived carbon for primary metabolic pathways. Moreover, we investigated the site of β-carotene sequestration by co-localization experiments which revealed that β-carotene accumulated as intra-plastid crystals which was confirmed by electron microscopy with carotenoid-accumulating roots. The results are discussed in the context of using the non-green calli carotenoid assay system for approaches targeting high steady-state β-carotene levels prior to their application in crops.

Suppression of the β-carotene hydroxylase gene increases β-carotene content and tolerance to abiotic stress in transgenic sweetpotato plants

β-carotene, a carotenoid that plays a key photo-protective role in plants is converted into zeaxanthin by β-carotene hydroxylase (CHY-β). Previous work showed that down-regulation of IbCHY-β by RNA interference (RNAi) results in higher levels of β-carotene and total carotenoids, as well as salt stress tolerance, in cultured transgenic sweetpotato cells. In this study, we introduced the RNAi-IbCHY-β construct into a white-fleshed sweetpotato cultivar (cv. Yulmi) by Agrobacterium-mediated transformation. Among the 13 resultant transgenic sweetpotato plants (referred to as RC plants), three lines were selected for further characterization on the basis of IbCHY-β transcript levels. The RC plants had orange flesh, total carotenoid and β-carotene contents in storage roots were 2-fold and 16-fold higher, respectively, than those of non-transgenic (NT) plants. Unlike storage roots, total carotenoid and β-carotene levels in the leaves of RC plants were slightly increased compared to NT plants. The leaves of RC plants also exhibited tolerance to methyl viologen (MV)-mediated oxidative stress, which was associated with higher 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical-scavenging activity. In addition, RC plants maintained higher levels of chlorophyll and higher photosystem II efficiency than NT plants after 250 mM NaCl stress. Yield of storage roots did not differ significantly between RC and NT plants. These observations suggest that RC plants might be useful as a nutritious and environmental stress-tolerant crop on marginal lands around the world.

Novel 9-cis/all-trans β-carotene isomerases from plastidic oil bodies in Dunaliella bardawil catalyze the conversion of all-trans to 9-cis β-carotene.

We identified and demonstrated the function of 9-cis/all-trans β-carotene isomerases in plastidic globules of Dunaliella bardawil, the species accumulating the highest levels of 9-cis β-carotene that is essential for humans. The halotolerant alga Dunaliella bardawil is unique in that it accumulates under light stress high levels of β-carotene in plastidic lipid globules. The pigment is composed of two major isomers: all-trans β-carotene, the common natural form of this pigment, and 9-cis β-carotene. The biosynthetic pathway of β-carotene is known, but it is not clear how the 9-cis isomer is formed. We identified in plastidic lipid globules that were isolated from D. bardawil two proteins with high sequence homology to the D27 protein-a 9-cis/all-trans β-carotene isomerase from rice (Alder et al. Science 335:1348-1351, 2012). The proteins are enriched in the oil globules by 6- to 17-fold compared to chloroplast proteins. The expression of the corresponding genes, 9-cis-βC-iso1 and 9-cis-βC-iso2, is enhanced under light stress. The synthetic proteins catalyze in vitro conversion of all-trans to 9-cis β-carotene. Expression of the 9-cis-βC-iso1 or of 9-cis-βC-iso2 genes in an E. coli mutant line that harbors β-carotene biosynthesis genes enhanced the conversion of all-trans into 9-cis β-carotene. These results suggest that 9-cis-βC-ISO1 and 9-cis-βC-ISO2 proteins are responsible for the formation of 9-cis β-carotene in D. bardawil under stress conditions.

The effect of enhanced carotenoid content of transgenic maize grain on fungal colonization and mycotoxin content.

Novel strategies that address vitamin A deficiency have been developed, such as high-carotenoid maize, a biofortified transgenic maize line rich in carotenoids generated by genetic transformation. The South African white maize inbred (M37W), which is devoid of carotenoids, was engineered to accumulate high levels of β-carotene (provitamin A), lutein, and zeaxanthin. Maize seeds contaminated with fumonisins and other mycotoxins pose a serious threat to both humans and livestock. During three consecutive harvests, the fungal incidence and the fumonisin and aflatoxin content of maize seeds grown in an experimental field in Catalonia (Northeastern Spain) were evaluated. Fungal infection was similar in high-carotenoid maize and its isogenic line, with Fusarium verticillioides being the most prevalent fungus in all the harvests. Neither Aspergillus spp. nor aflatoxin contamination was found. Fumonisin levels were lower in high carotenoid than in its isogenic line, but this reduction was statistically significant in only 2 of the 3years of study. Our results suggest that high carotenoid content reduces fumonisin levels in maize grains.

Seasonal, Sex- and Plant Size-Related Effects on Photoinhibition and Photoprotection in the Dioecious Mediterranean Dwarf Palm, Chamaerops humilis.

In Mediterranean-type ecosystems plants are exposed to several adverse environmental conditions throughout the year, ranging from drought stress during the warm and dry summers to chilling stress due to the typical drop in temperatures during winters. Here we evaluated the ecophysiological response, in terms of photoinhibition and photoprotection, of the dioecious Mediterranean palm, Chamaerops humilis to seasonal variations in environmental conditions. Furthermore, we considered as well the influence of plant size, maturity, and sexual dimorphism. Results showed evidence of winter photoinhibition, with a marked decrease of the Fv/Fm ratio below 0.7 between January and March, which was coincident with the lowest temperatures. During this period, the de-epoxidation state of the xanthophyll cycle and zeaxanthin levels increased, which might serve as a photoprotection mechanism, owing the full recovery from winter photoinhibition during spring. Furthermore, mature plants showed lower chlorophyll levels and higher β-carotene levels per unit of chlorophyll than juvenile plants, and females displayed lower leaf water contents and higher photoinhibition than males during summer, probably due to increased reproductive effort of females. However, neither low temperatures during winter nor reproductive events in females during the summer led to irreversible damage to the photosynthetic apparatus. We conclude that (i) the Mediterranean dwarf palm, C. humilis, suffers from photoinhibition during winter, but this is transient and does not lead to irreversible damage, and (ii) females from this plant species are more sensitive than males to photoinhibition during reproductive events.

Secondary metabolite diversity in taro, Colocasia esculenta (L.) Schott, corms

Taro, Colocasia esculenta (L.) Schott, is one of the oldest major staple food crops of tropical regions. This study represents one the first in-depth surveys of taro biodiversity based on corms flesh secondary metabolites fingerprints. Out of the 167 analyzed cultivars, 70 UV-absorbing substances were annotated according to their retention time, UV/vis absorption spectrum, high resolution mass (by HRMS) and fragmentation pattern (tandem MS-MS). They included 6 carotenoids, 35 flavones/flavonols, 6 flavanones, 2 flavanols and 1 indol. Twenty flavones that were glycosylated forms of apigenin, luteolin and chrysoeriol conferred to the corms a yellow color and defined a low abundance (ca. 10% of cultivars) chemotype. Their accumulation negatively correlated with flavanones which were annotated for the first time in taro. Orange flesh corms were characterized by high levels of β-carotene. Secondary metabolite-based chemotypes displayed no geographical distribution pattern.

Adaptive changes in pigment complex of Pinus sylvestris needles upon cold acclimation

We studied seasonal changes in the content and ratio between photosynthetic pigments in one-yearold needles of Scotch pine (Pinus sylvestris L.) growing in Central Yakutia. Maximum accumulation of chlorophylls in developed young needles occurred in July when light and temperature conditions were favorable. In this period, the needles were notable for a relatively high level of β-carotene and neoxanthin and a reduced content of lutein and the pigments of violaxanthin cycle (VXC). In the course of autumn hardening, the content of chlorophylls decreased two times. Total content of carotenoids remained the same, but pigment composition considerably changed when plants progressed from a vegetating to frost-resistant state. We revealed time and temperature ranges of variation for individual carotenoids. In the beginning of hardening at reduced and low abovezero temperatures, the content of β-carotene in the needles decreased, the pigment-protein complexes (PPC) became enriched in lutein, the pigment pool of VXC gradually increased, and the content of neoxanthin transiently rose. When average daily air temperature further decreased to near- zero values, the content of zeaxanthin sharply rose. In winter, high levels of lutein and zeaxanthin were maintained. Main changes in pigment complex of the needles of P. sylvestris were completed before the coming of steady below-zero temperatures. The obtained data suggested that, upon seasonal decrease in temperature in early stages of hardening, a decrease in the level of chlorophyll promotes a reduction in the quantity of absorbed radiant energy. Apparently, this is accompanied by activation of the role of lutein and neoxanthin that perform specific photoprotective functions in antenna PPC associated with a gradual decrease in plants’ ability to quench singlet energy of excited chlorophyll. Accumulation of zeaxanthin as a result of inhibition of back reaction of epoxidation at near-zero temperatures creates necessary prerequisites for turning on the mechanisms of steady dissipation of absorbed light energy, which do not depend on transmembrane proton gradient of thylakoids. At the same time, zeaxanthin can perform antioxidant functions both in PPC and in the lipid phase of thylakoid membranes. The obtained data point to an adaptive nature of the observed reactions and a specific role of individual pigments in structural and functional reorganization of photosynthetic machinery in the course of development of frost-resistance in the needles.

Genetics of carotenoids for provitamin A biofortification in tropical-adapted maize

Yellow maize contains high levels of β-carotene (βC), making it an important crop for combating vitamin A deficiency through biofortification. In this study, nine maize inbred lines were selected at random from 31 provitamin A (PVA) maize inbred lines and crossed in a partial diallel mating design to develop 36 crosses. The crosses were evaluated in the field in two locations (Samaru and Kerawa) and their seed carotenoid content were determined by high-performance liquid chromatography. The modes of gene action, heritability, and correlations between agronomic traits and carotenoid content were estimated. Additive genetic variances (σ2a) were lower than non-additive genetic variances (σ2d) for all the carotenoids, plant height (PH), and grain yield (GY), suggesting a preponderance of non-additive gene action. Broad-sense heritability (H2) was high (H2>60%) for zeaxanthin, days to anthesis, and PH, moderate (30%<H2<60%) for lutein and GY, and low (H2<30%) for alpha carotene, beta cryptoxanthin, βC, and PVA. Genetic advance as a percentage of mean, considered with H2, also suggests a preponderance of non-additive gene action for PVA carotenoids. Hybrid variety development is thus an appropriate approach to improving grain yield and PVA. GY showed no significant genotypic correlations with carotenoid content, suggesting that these traits can be improved concurrently. Thus, there is ample scope for improvement of PVA and GY in the sample of tropical-adapted maize.

Evaluation of Porridge Made from Composite Flour of Orange-Fleshed Sweet Potato and Enset (Bulla) Flours

Bulla is the water insoluble starchy product which is separated from Kocho during the decortications process of Enset. However, this extract lacks pro-vitamin A. This study enriched the Bulla with Orange-fleshed Sweet Potato (OFSP) a plant with high levels of β-carotene that can be useful for combating vitamin A deficiency. The porridge was made of composite flours of bulla blended with 30, 35, 40 and 45% OFSP flours were investigated for proximate composition, β-carotene, functional property and sensory acceptability of products using standard methods. The data were analyzed using SAS 1.9 Software. The composite flours percentage moisture, crude (fiber, protein, fat), ash, carbohydrate, gross energy, β-carotene, pH, bulk density and water absorption capacity were found to be in the range of 29.54 to 40.25, (1.66 to 2.05, 2.11 to 2.55, 0.55 to 0.71), 1.76 to 2.11, 53.86 to 63.31, 227.49 to 268.11 Kcal/100 g, 386.68 to 558.05 μg/100 g, 4.46 to 5.71, 0.58 to 0.80 and 1.70 to 4.87 ml/g, respectively. While, the composite flours porridge percentage moisture, crude fiber, ash, crude protein, crude fat, carbohydrate, gross energy, β-carotene, pH and viscosity content found to be in the range from 43.42 to 58.03, 1.32 to 1.79, 2.39 to 2.78, 2.01 to 2.31, 0.71 to 0.82, 35.21 to 48.63, 155 to 211.11 Kcal/100 g, 201.46 to 301.50 μg/100 g, 5.71 to 5.82 and 515 to 728 cps, respectively. The porridge OB4PM2 (45% OFSP and 55% Bulla) was most preferred due to its color, odor, flavor and overall acceptability with panelist scored value of 4.28, 4.33, 4.39 and 4.45, respectively. Moreover, OB4PM2 porridge was found to be good source of ash, energy and β-carotene content.

A new regulatory mechanism controlling carotenogenesis in the fungus Mucor circinelloides as a target to generate β-carotene over-producing strains by genetic engineering.

BackgroundCarotenoids are natural pigments with antioxidant properties that have important functions in human physiology and must be supplied through the diet. They also have important industrial applications as food colourants, animal feed additives and nutraceuticals. Some of them, such as β-carotene, are produced on an industrial scale with the use of microorganisms, including fungi. The mucoral Blakeslea trispora is used by the industry to produce β-carotene, although optimisation of production by molecular genetic engineering is unfeasible. However, the phylogenetically closely related Mucor circinelloides, which is also able to accumulate β-carotene, possesses a vast collection of genetic tools with which to manipulate its genome.ResultsThis work combines classical forward and modern reverse genetic techniques to deepen the regulation of carotenoid synthesis and generate candidate strains for biotechnological production of β-carotene. Mutagenesis followed by screening for mutants with altered colour in the dark and/or in light led to the isolation of 26 mutants that, together with eight previously isolated mutants, have been analysed in this work. Although most of the mutants harboured mutations in known structural and regulatory carotenogenic genes, eight of them lacked mutations in those genes. Whole-genome sequencing of six of these strains revealed the presence of many mutations throughout their genomes, which makes identification of the mutation that produced the phenotype difficult. However, deletion of the crgA gene, a well-known repressor of carotenoid biosynthesis in M. circinelloides, in two mutants (MU206 and MU218) with high levels of β-carotene resulted in a further increase in β-carotene content to differing extents with respect to the crgA single-null strain; in particular, one strain derived from MU218 was able to accumulate up to 4 mg/g of β-carotene. The additive effect of crgA deletion and the mutations present in MU218 suggests the existence of a previously unknown regulatory mechanism that represses carotenoid biosynthesis independently and in parallel to crgA.ConclusionsThe use of a mucoral model such as M. circinelloides can allow the identification of the regulatory mechanisms that control carotenoid biosynthesis, which can then be manipulated to generate tailored strains of biotechnological interest. Mutants in the repressor crgA and in the newly identified regulatory mechanism generated in this work accumulate high levels of β-carotene and are candidates for further improvements in biotechnological β-carotene production.Electronic supplementary materialThe online version of this article (doi:10.1186/s12934-016-0493-8) contains supplementary material, which is available to authorized users.

The Potential for Engineering Enhanced Functional-Feed Soybeans for Sustainable Aquaculture Feed.

Aquaculture is the most rapidly growing segment of global animal production that now surpasses wild-capture fisheries production and is continuing to grow 10% annually. Sustainable aquaculture needs to diminish, and progressively eliminate, its dependence on fishmeal-sourced feed from over-harvested fisheries. Sustainable aquafeed sources will need to be primarily of plant-origin. Soybean is currently the primary global vegetable-origin protein source for aquaculture. Direct exchange of soybean meal for fishmeal in aquafeed has resulted in reduced growth rates due in part to soybean’s anti-nutritional proteins. To produce soybeans for use in aquaculture feeds a new conventional line has been bred termed Triple Null by stacking null alleles for the feed-relevant proteins Kunitz Trypsin Inhibitor, lectin, and P34 allergen. Triple Null is now being further enhanced as a platform to build additional transgene traits for vaccines, altered protein composition, and to produce high levels of β-carotene an intrinsic orange-colored aquafeed marker to distinguish the seeds from commodity beans and as the metabolic feedstock precursor of highly valued astaxanthin.