Protective effect of provitamin A dietary carotenoid intake on overweight/obesity and their relation to inflammatory and oxidative stress biomarkers - a case-control study.

This investigation assessed associations between dietary carotenoid intake and the odds of overweight/obesity, as well as inflammatory/oxidative stress biomarkers, in 851 participants with overweight/obesity (BMI ≥25 kg m-2) and 754 normal-weight controls. A 124-item food-frequency-questionnaire (FFQ) and food composition databases were employed to estimate carotenoid intake. Binary logistic regressions assessed the association of carotenoid intake with the odds of overweight/obesity, adjusting for several potential confounders. Multiple linear regression models revealed associations between carotenoid intake and biomarkers (anthropometrics, blood lipids, inflammation, antioxidant status). Logistic regression models adjusted for various confounders and fruits and vegetables showed protective associations for provitamin A carotenoids (i.e., ß-carotene + α-carotene + ß-cryptoxanthin; odds ratio (OR): 0.655, p = 0.041) and astaxanthin (OR: 0.859, p = 0.017). Similarly adjusted multiple linear regressions revealed significant associations between several carotenoids and lower levels of interleukin (IL)-6, IL-1ß, and TNF-α and increased IL-10 and total antioxidant capacity. Further analysis revealed that lycopene was significantly associated with increased odds of overweight/obesity (OR: 1.595, p = 0.032) in a model adjusted for various confounders and vegetables (i.e., unadjusted for fruits). A protective association between the sum of provitamin A carotenoid and astaxanthin dietary intake and the odds of having overweight/obesity was found. The findings that carotenoids other than lycopene were not or inversely associated with the odds of overweight/obesity may point toward differentiating effects of various carotenoids or their associations with different food groups. Provitamin A rich food items including fruits and vegetables appear to be a prudent strategy to reduce inflammation and the odds of having overweight/obesity.

ß-Carotene production from sugarcane molasses by a newly isolated Rhodotorula toruloides L/24-26-1.

Production of carotenoids by yeast fermentation is an advantaged technology due to its easy scaling and safety. Nevertheless, carotenoid production needs an economic culture medium and other efficient yeast stains. The study aims to isolate and identify a yeast strain capable of producing carotenoids using a cost-effective substrate. A new strain was identified as Rhodotorula toruloides L/24-26-1, which can produce carotenoids at different pretreated and unpretreated sugarcane molasses concentrations (40 and 80 g/L). The highest biomass concentration (18.6 ± 0.6 g/L) was reached in the culture using 80 g/L of hydrolyzed molasses. On the other hand, the carotenoid accumulation reached the maximum value using pretreated molasses at 40 g/L (715.4 ± 15.1 µg/g d.w). In this case, the ß-carotene was 1.5 times higher than that on the control medium. The yeast growth in molasses was not correlated with carotenoid production. The most outstanding production of The DPPH, ABTS, and FRAP tests demonstrated the antioxidant activity of the obtained carotenogenic extracts. This research demonstrated the R. toruloides L/24-26-1 strain biotechnological potential for carotenoid compounds. The yeast produces carotenoids with antioxidant activity in an inexpensive medium, such as sulfuric acid pretreated and unpretreated molasses.

Effects of supplementation of different selenium sources on lipid profile, selenium, and vitamin E concentration of yolk.

Egg preference as a source of protein also provides beneficial fatty acids, vital for human consumption. However, rich in lipid products are prone to oxidative damage. The study aims to determine the effect of supplementing biogenic selenium (Se) from Stenotrophomonas maltophilia, ADS18 (ADS18) in laying hens' diet on yolk lipid oxidation status (MDA), beta-carotene (ß-carotene) content, cholesterol, fatty acids, Se, and vitamin E (VE) level. A total of one hundred and twenty (120) laying hens of Lohmann Brown strains aged 50 weeks, weighing 1500 to 2000 g were reared individually in A-shape two-tier stainless-steel cages sized 30 cm x 50 cm x 40 cm (width, depth height). The hens were randomly allotted into four treatments with six replications in a complete randomised design for the period of 12 weeks. The basal diet contains 100 mg/kg VE. Treatment diets consist of basal diet as control, SS containing 0.3 mg/kg sodium selenite, Se-yeast containing 0.3 mg/kg selenised yeast, and VADS18 containing 0.3 mg/kg of ADS18. Forty-eight eggs were collected and freeze-dried biweekly for analysis. The results of the present study showed that hens supplemented ADS18 had significantly (P < 0.05) lower MDA and cholesterol levels while their egg yolks had higher levels of Se and mono-unsaturated fatty acids (MUFA). The control group had significantly (P < 0.05) higher saturated fatty acid (SFA) contents than the VE and dietary Se-supplemented groups, while the ADS18 group had the lowest SFA contents. Conversely, in comparison to the inorganic and control groups, the VE content of the egg yolk was significantly (P < 0.05) higher in organic Se-supplemented (Se-yeast and VADS18) groups. Hens with SS supplementation had significantly (P < 0.05) higher egg yolk ß-carotene content. When compared to other treatment groups, the control group had higher (P < 0.05) polyunsaturated fatty acids (PUFA) content. The ADS18 is therefore deemed comparable to other Se sources. To prevent Se toxicity, however, a better understanding of the levels of ADS18 incorporation in poultry diets is required.

Association between carotenoid intake and periodontitis in diabetic patients.

This study aimed to evaluate the association between dietary carotenoid intake and periodontitis in diabetic patients. Data on diabetic patients were collected from the National Health and Nutrition Examination Survey (NHANES) 2009-2014 for this cross-sectional study. Dietary intake of carotenoids was assessed through the first 24-hour dietary recall interview. Full-mouth periodontal examinations were conducted by trained dental examiners. Subgroup analysis was conducted in terms of age, gender, the number of missing teeth, cardiovascular disease, smoking, and anti-diabetic drugs. Totally 1914 diabetic patients were included, with 1281 (66.93%) in the periodontitis group. After adjusting for age, gender, race, education, smoking, dental implants, hepatitis, and the number of missing teeth, α-carotene intake ≥55.82 mcg was associated with lower odds of periodontitis than α-carotene intake <55.82 mcg [OR = 0.70, 95% CI: 0.53-0.91, P = 0.010]; lutein and zeaxanthin intake ≥795.95 mcg was associated with decreased odds of periodontitis than lutein and zeaxanthin intake <795.95 mcg (OR = 0.75, 95%CI: 0.57-0.98, P = 0.039). The association between carotenoid intake and periodontitis varied across different subpopulations. In diabetes, dietary intake of α-carotene and lutein and zeaxanthin was inversely associated with the odds of periodontitis, which may facilitate clinical periodontitis management.

Enhancing astaxanthin biosynthesis and pathway expansion towards glycosylated C40 carotenoids by Corynebacterium glutamicum.

Astaxanthin, a versatile C40 carotenoid prized for its applications in food, cosmetics, and health, is a bright red pigment with powerful antioxidant properties. To enhance astaxanthin production in Corynebacterium glutamicum, we employed rational pathway engineering strategies, focused on improving precursor availability and optimizing terminal oxy-functionalized C40 carotenoid biosynthesis. Our efforts resulted in an increased astaxanthin precursor supply with 1.5-fold higher ß-carotene production with strain BETA6 (18 mg g-1 CDW). Further advancements in astaxanthin production were made by fine-tuning the expression of the ß-carotene hydroxylase gene crtZ and ß-carotene ketolase gene crtW, yielding a nearly fivefold increase in astaxanthin (strain ASTA**), with astaxanthin constituting 72% of total carotenoids. ASTA** was successfully transferred to a 2 L fed-batch fermentation with an enhanced titer of 103 mg L-1 astaxanthin with a volumetric productivity of 1.5 mg L-1 h-1. Based on this strain a pathway expansion was achieved towards glycosylated C40 carotenoids under heterologous expression of the glycosyltransferase gene crtX. To the best of our knowledge, this is the first time astaxanthin-ß-D-diglucoside was produced with C. glutamicum achieving high titers of microbial C40 glucosides of 39 mg L-1. This study showcases the potential of pathway engineering to unlock novel C40 carotenoid variants for diverse industrial applications.

Metabolic Pathway Coupled with Fermentation Process Optimization for High-Level Production of Retinol in Yarrowia lipolytica.

Retinol is a lipid-soluble form of vitamin A that is crucial for human visual and immune functions. The production of retinol through microbial fermentation has been the focus of recent exploration. However, the obtained titer remains limited and the product is often a mixture of retinal, retinol, and retinoic acid, necessitating purification. To achieve efficient biosynthesis of retinol in Yarrowia lipolytica, we improved the metabolic flux of ß-carotene to provide sufficient precursors for retinol in this study. Coupled with the optimization of the expression level of ß-carotene 15,15'-dioxygenase, de novo production of retinol was achieved. Furthermore, Tween 80 was used as an extractant and butylated hydroxytoluene as an antioxidant to extract intracellular retinol and prevent retinol oxidation, respectively. This strategy significantly increased the level of retinol production. By optimizing the enzymes converting retinal to retinol, the proportion of extracellular retinol in the produced retinoids reached 100%, totaling 1042.3 mg/L. Finally, total retinol production reached 5.4 g/L through fed-batch fermentation in a 5 L bioreactor, comprising 4.2 g/L extracellular retinol and 1.2 g/L intracellular retinol. This achievement represents the highest reported titer so far and advances the industrial production of retinol.

Insights into the molecular mechanism of yellow cuticle coloration by a chitin-binding carotenoprotein in gregarious locusts.

Carotenoids are hydrophobic pigments binding to diverse carotenoproteins, many of which remain unexplored. Focusing on yellow gregarious locusts accumulating cuticular carotenoids, here we use engineered Escherichia coli cells to reconstitute a functional water-soluble ß-carotene-binding protein, BBP. HPLC and Raman spectroscopy confirmed that recombinant BBP avidly binds ß-carotene, inducing the unusual vibronic structure of its absorbance spectrum, just like native BBP extracted from the locust cuticles. Bound to recombinant BBP, ß-carotene exhibits pronounced circular dichroism and allows BBP to withstand heating (T0.5 = 68 °C), detergents and pH variations. Using bacteria producing distinct xanthophylls we demonstrate that, while ß-carotene is the preferred carotenoid, BBP can also extract from membranes ketocarotenoids and, very poorly, hydroxycarotenoids. We show that BBP-carotenoid complex reversibly binds to chitin, but not to chitosan, implying the role for chitin acetyl groups in cuticular BBP deposition. Reconstructing such locust coloration mechanism in vitro paves the way for structural studies and BBP applications.

The Potential of Natural Carotenoids-Containing Sericin of the Domestic Silkworm Bombyx mori.

Sericin derived from the white cocoon of Bombyx mori has been attracting more attention for its utilization in food, cosmetics, and biomedicine. The potential health benefits of natural carotenoids for humans have also been well-established. Some rare strains of Bombyx mori (B. mori) produce yellow-red cocoons, which endow a potential of natural carotenoid-containing sericin. We hypothesized that natural carotenoid-containing sericin from yellow-red cocoons would exhibit better properties compared with white cocoon sericin. To investigate the physicochemical attributes of natural carotenoid-containing sericin, we bred two silkworm strains from one common ancestor, namely XS7 and XS8, which exhibited different cocoon colors as a result of the inconsistent distribution of lutein and ß-carotene. Compared with white cocoon sericin, the interaction between carotenoids and sericin molecules in carotenoid-containing sericin resulted in a unique fluorescence emission at 530, 564 nm. The incorporation of carotenoids enhanced the antibacterial effect, anti-cancer ability, cytocompatibility, and antioxidant of sericin, suggesting potential wide-ranging applications of natural carotenoid-containing sericin as a biomass material. We also found differences in fluorescence characteristics, antimicrobial effects, anti-cancer ability, and antioxidants between XS7 and XS8 sericin. Our work for the first time suggested a better application potential of natural carotenoid-containing sericin as a biomass material than frequently used white cocoon sericin.

The assessment of dietary carotenoid intake of the Cardio-Med FFQ using food records and biomarkers in an Australian cardiology cohort: a pilot validation.

Dietary carotenoids are associated with lower risk of CHD. Assessment of dietary carotenoid intake using questionnaires can be susceptible to measurement error. Consequently, there is a need to validate data collected from FFQs which measure carotenoid intake. This study aimed to assess the performance of the Cardio-Med Survey Tool (CMST)-FFQ-version 2 (v2) as a measure of dietary carotenoid intake over 12-months against plasma carotenoids biomarkers and 7-Day Food Records (7DFR) in an Australian cardiology cohort. Dietary carotenoid intakes (ß- and α-carotene, lycopene, ß-cryptoxanthin and lutein/zeaxanthin) were assessed using the 105-item CMST-FFQ-v2 and compared to intakes measured by 7DFR and plasma carotenoid concentrations. Correlation coefficients were calculated between each dietary method, and validity coefficients (VCs) were calculated between each dietary method and theoretical true intake using the 'methods of triads'. Thirty-nine participants aged 37-77 years with CHD participated in the cross-sectional study. The correlation between FFQ and plasma carotenoids were largest and significant for ß-carotene (0.39, p=0.01), total carotenoids (0.37, p=0.02) and ß-cryptoxanthin (0.33, p=0.04), with weakest correlations observed for α-carotene (0.21, p=0.21) and lycopene (0.21, p=0.21). The FFQ VCs were moderate (0.3-0.6) or larger for all measured carotenoids. The strongest were observed for total carotenoids (0.61) and ß-carotene (0.59), while the weakest were observed for α-carotene (0.33) and lycopene (0.37). In conclusion, the CMST-FFQ-v2 measured dietary carotenoids intakes with moderate confidence for most carotenoids, however, there was less confidence in ability to measure α-carotene and lycopene intake, thus further research is warranted using a larger sample.

Distinct growth patterns in seedling and tillering wheat plants suggests a developmentally restricted role of HYD2 in salt-stress response.

KEY MESSAGE: Mutants lacking functional HYD2 homoeologs showed improved seedling growth, but comparable or increased susceptibility to salt stress in tillering plants, suggesting a developmentally restricted role of HYD2 in salt response. Salinity stress threatens global food security by reducing the yield of staple crops such as wheat (Triticum ssp.). Understanding how wheat responds to salinity stress is crucial for developing climate resilient varieties. In this study, we examined the interplay between carotenoid metabolism and the response to salt (NaCl) stress, a specific form of salinity stress, in tetraploid wheat plants with mutations in carotenoid ß-hydroxylase 1 (HYD1) and HYD2. Our investigation encompassed both the vulnerable seedling stage and the more developed tillering stage of wheat plant growth. Mutant combinations lacking functional HYD2 homoeologs, including hyd-A2 hyd-B2, hyd-A1 hyd-A2 hyd-B2, hyd-B1 hyd-A2 hyd-B2, and hyd-A1 hyd-B1 hyd-A2 hyd-B2, had longer first true leaves and slightly enhanced root growth during germination under salt stress compared to the segregate wild-type (control) plants. Interestingly, these mutant seedlings also showed decreased levels of neoxanthin and violaxanthin (xanthophylls derived from ß-carotene) and an increase in ß-carotene in roots. However, tillering hyd mutant and segregate wild-type plants generally did not differ in their height, tiller count, and biomass production under acute or prolonged salt stress, except for decreases in these parameters observed in the hyd-A1 hyd-B1 hyd-A2 hyd-B2 mutant that indicate its heightened susceptibility to salt stress. Taken together, these findings suggest a significant, yet developmentally restricted role of HYD2 homoeologs in salt-stress response in tetraploid wheat. They also show that hyd-A2 hyd-B2 mutant plants, previously demonstrated for possessing enriched nutritional (ß-carotene) content, maintain an unimpaired ability to withstand salt stress.

Spray-drying and rehydration on ß-carotene encapsulated Pickering emulsion with chitosan and seaweed polyphenol.

The spray-drying process to generate microcapsules from Pickering emulsions needs high temperatures, leading to instability of emulsions and degradation of encapsulated thermosensitive compounds (ß-carotene). However, these effects may be attenuated by the introduction of seaweed polyphenols into the emulsion interfacial layers, although the effects underlying this protective mechanism have not been explored. This study evaluates the effects of spray-drying/rehydration on the morphology, encapsulation efficiency, redispersibility, and stability of ß-carotene loaded Pickering emulsions stabilized by chitosan (PESC) and Pickering emulsions stabilized by chitosan/seaweed polyphenols (PESCSP). The encapsulation efficiency of ß-carotene in PESCSP microcapsules (61.13 %) was higher than PESC (53.91 %). Rehydrated PESCSP exhibited more regular droplet size distribution, higher stability, stronger 3D network morphology, and lower redispersibility index (1.5) compared to rehydrated PESC. Analyses of interfacial layers of emulsions revealed that chitosan covalently bound fatty acids at their hydrophobic side. Polyphenols were linked to chitosan at the hydrophilic side of emulsions through hydrogen bonds, providing 3D network between droplets and antioxidant activities to inhibit the degradation of ß-carotene. This study emphasized the role of polyphenols in the interfacial layers of Pickering emulsions for the development of efficient delivery systems and protection of ß-carotene and other thermosensitive bioactive compounds during spray-drying and rehydration.

Strategies for the efficient biosynthesis of ß-carotene through microbial fermentation.

ß-Carotene is an orange fat-soluble compound, which has been widely used in fields such as food, medicine and cosmetics owing to its anticancer, antioxidant and cardiovascular disease prevention properties. Currently, natural ß-carotene is mainly extracted from plants and algae, which cannot meet the growing market demand, while chemical synthesis of ß-carotene cannot satisfy the pursuit for natural products of consumers. The ß-carotene production through microbial fermentation has become a promising alternative owing to its high efficiency and environmental friendliness. With the rapid development of synthetic biology and in-depth study on the synthesis pathway of ß-carotene, microbial fermentation has shown promising applications in the ß-carotene synthesis. Accordingly, this review aims to summarize the research progress and strategies of natural carotenoid producing strain and metabolic engineering strategies in the heterologous synthesis of ß-carotene by engineered microorganisms. Moreover, it also summarizes the adoption of inexpensive carbon sources to synthesize ß-carotene as well as proposes new strategies that can further improve the ß-carotene production.

Effect of the Drying Method and Storage Conditions on the Quality and Content of Selected Bioactive Compounds of Green Legume Vegetables.

This study aimed to determine the effect of the drying method (freeze-drying, air-drying), storage period (12 months), and storage conditions (2-4 °C, 18-22 °C) applied to two legume species: green beans and green peas. The raw and dried materials were determined for selected physical parameters typical of dried vegetables, contents of bioactive components (vitamin C and E, total chlorophyll, total carotenoids, ß-carotene, and total polyphenols), antioxidative activity against the DPPH radical, and sensory attributes (overall quality and profiles of color, texture, and palatability). Green beans had a significantly higher content of bioactive components compared to peas. Freeze-drying and cold storage conditions facilitated better retention of these compounds, i.e., by 9-39% and 3-11%, respectively. After 12 months of storage, higher retention of bioactive components, except for total chlorophyll, was determined in peas regardless of the drying method, i.e., by 38-75% in the freeze-dried product and 30-77% in the air-dried product, compared to the raw material.

Synergistic stabilization of high internal phase Pickering emulsions by peanut isolate proteins and cellulose nanocrystals for ß-carotene encapsulation.

In this study, high internal phase Pickering emulsions (HIPPEs) were stabilized by the complexes of peanut protein isolate (PPI) and cellulose nanocrystals (CNCs) for encapsulation ß-carotene to retard its degradation during processing and storage. CNCs were prepared by H2SO4 hydrolysis (HCNCs), APS oxidation (ACNCs) and TEMPO oxidation (TCNCs), exhibiting needle-like or rod-like structures with nanoscale size and uniformly distributed around the spherical PPI particle, which enhanced the emulsifying capability of PPI. Results of optical micrographs and droplet size measurement showed that Pickering emulsions stabilized by PPI/ACNCs complexes exhibited the most excellent stability after 30 days of storage, which indicated that ACNCs had the most obvious effect to improve emulsifying capability of PPI. HIPPEs encapsulated ß-carotene (ßc-HIPPEs) were stabilized by PPI/ACNCs complexes and showed excellent inverted storage stability. Moreover, ßc-HIPPEs exhibited typical shear thinning behavior investigated by rheological properties analysis. During thermal treatment, ultraviolet radiation and oxidation, the retentions of ß-carotene encapsulated in HIPPEs were improved significantly. This research holds promise in expanding Pickering emulsions stabilized by proteins-polysaccharide particles to delivery systems for hydrophobic bioactive compounds.

Functional Analysis of ß-Carotene Oxygenase 2 (BCO2) Gene in Yesso Scallop (Patinopecten yessoensis).

Carotenoids are essential nutrients for humans and animals, and carotenoid coloration represents an important meat quality parameter for many farmed animals. Increasingly, studies have demonstrated that vertebrate carotenoid cleavage oxygenases (CCOs) are essential enzymes in carotenoid metabolism and are therefore potential candidate genes for improving carotenoid deposition. However, our understanding of carotenoid bioavailability and CCOs functions in invertebrates, particularly marine species, is currently quite limited. We previously identified that a CCO homolog, PyBCO-like 1, was the causal gene for carotenoid coloration in the 'Haida golden scallop', a variety of Yesso scallop (Patinopecten yessoensis) characterized by carotenoid enrichment. Here, we found that another CCO-encoding gene named PyBCO2 (ß-carotene oxygenase 2) was widely expressed in P. yessoensis organs/tissues, with the highest expression in striated muscle. Inhibiting BCO2 expression in P. yessoensis through RNA interference led to increased carotenoid (pectenolone and pectenoxanthin) deposition in the striated muscle, and the color of the striated muscle changed from white to light orange. Our results indicate that PyBCO2 might be a candidate gene used for improving carotenoid content in normal Yesso scallops, and also in 'Haida golden scallops'.

Enhanced high ß-carotene yeast cell production by Rhodotorula paludigena CM33 and in vitro digestibility in aquatic animals.

This study assessed Rhodotorula paludigena CM33's growth and ß-carotene production in a 22-L bioreactor for potential use as an aquatic animal feed supplement. Optimizing the feed medium's micronutrient concentration for high-cell-density fed-batch cultivation using glucose as the carbon source yielded biomass of 89.84 g/L and ß-carotene concentration of 251.64 mg/L. Notably, using sucrose as the carbon source in feed medium outperforms glucose feeds, resulting in a ß-carotene concentration of 285.00 mg/L with a similar biomass of 87.78 g/L. In the fed-batch fermentation using Sucrose Feed Medium, R. paludigena CM33 exhibited high biomass production rates (Qx) of 0.91 g/L.h and remarkable ß-carotene production rates (Qp) of 2.97 mg/L.h. In vitro digestibility assays showed that R. paludigena CM33, especially when cultivated using sucrose, enhances protein digestibility affirming its suitability as an aquatic feed supplement. Furthermore, R. paludigena CM33's nutrient-rich profile and probiotic potential make it an attractive option for aquatic nutrition. This research highlights the importance of cost-effective carbon sources in large-scale ß-carotene production for aquatic animal nutrition.

Exocyclic DNA adducts and oxidative stress parameters: useful tools for biomonitoring exposure to aldehydes in smokers.

CONTEXT: Exocyclic DNA adducts have been shown to be potential biomarkers of cancer risk related to oxidative stress and exposure to aldehydes in smokers. In fact, aldehydes potentially arise from tobacco combustion directly and endogenously through lipid peroxidation. OBJECTIVE: This study aims to investigate the relationship between a profile of nine aldehydes-induced DNA adducts and antioxidant activities, in order to evaluate new biomarkers of systemic exposure to aldehydes. METHODS: Using our previously published UPLC-MS/MS method, adducts levels were quantified in the blood DNA of 34 active smokers. The levels of antioxidant vitamins (A, C and E), coenzyme Q10, ß-carotene, superoxide dismutase (SOD) and autoantibodies against oxidized low-density lipoprotein were measured. RESULTS: Adducts induced by tobacco smoking-related aldehydes were quantified at levels reflecting an oxidative production from lipid peroxidation. A significant correlation between SOD and crotonaldehyde-induced adducts (p = 0.0251) was also observed. ß-Carotene was negatively correlated with the adducts of formaldehyde (p = 0.0351) and acetaldehyde (p = 0.0413). Vitamin C tended to inversely correlate with acetaldehyde-induced adducts (p = 0.0584). CONCLUSION: These results are promising, and the study is now being conducted on a larger cohort with the aim of evaluating the impact of smoking cessation programs on the evolution of adducts profile and antioxidants activities.

Diversity, distribution, and bioprospecting potentials of carotenogenic yeast from mangrove ecosystem.

Microbial production of carotenoids has gained significant interest for its cost-effectiveness and sustainable nature. This study focuses on 47 red-pigmented yeasts isolated from sediments and plant parts of 13 species of mangrove trees. The relative abundance and distribution of these yeasts varied with plant species and plant parts. The highest number of red yeasts was associated with the mangrove plant Avicennia officinalis (32%). Notably, the leaves harbored the highest percentage (45%) of carotenogenic yeasts, and definite compartmentalization of these yeast species was noticed in mangrove plant parts. All the isolates were molecularly identified and they belonged to the genera of Rhodotorula, Rhodosporidiobolus, and Cryptococcus. The diversity of the pigmented yeasts isolated from A. officinalis was found to be the greatest. Among these strains, Rhodotorula mucilaginosa PV 8 was identified as the most potent producer of carotenoid pigment. Under optimized conditions of physical parameters - 28 °C, pH 5, and 15% salinity led to biomass production of 9.2 ± 0.12 g/L DCW and a pigment yield of 194.78 µg/g. The pigment produced by PV 8 was identified as ß-carotene by thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FT-IR). This ß-carotene demonstrated strong antioxidant activity. Moreover, the carotenoid displayed promising antibacterial activity against multidrug-resistant organisms, including Aeromonas sp. and Vibrio sp. In vitro studies revealed the probiotic traits of PV 8. The cytotoxicity of R. mucilaginosa PV 8 was assessed in the invertebrate model Artemia salina and the survival rate showed that it was non-toxic. Furthermore, the ß-carotene from PV 8 demonstrated the ability to transfer its vibrant color to various food products, maintaining color stability even under varied conditions. This research underscores the potential of R. mucilaginosa PV 8, as a versatile and valuable resource for the production of carotenoids.

Dunaliella ß-Carotene Productivity Comparison Under In Vitro Conditions.

Some species of Dunaliella produce high levels of ß-carotene, which is the largest natural Vitamin A source. ß-carotene production in Dunaliella is expensive due to low yields obtained under culture conditions used. Since three decades ago synthetic ß-carotene has dominated 98% of world market, even when synthetic is less bioactive than Dunaliella ß-carotene molecule. In vitro experiments have been performed to increase ß-carotene productivity in Dunaliella and some useful results have been obtained. In this review, culture conditions used in those experiments were compared to identify parameters that improved ß-carotene productivity in Dunaliella. Comparison results show that ß-carotene in vitro production can be increased regulating some specific culture conditions.

Vitamins C, E, and ß-Carotene and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis.

A systematic review and meta-analysis was conducted to assess the relationship between the common dietary antioxidants vitamin C, vitamin E, and ß-carotene and type 2 diabetes (T2D) and related traits. MEDLINE, Embase, and the Cochrane Library were searched for relevant publications up until May 2023. Studies were eligible if they had a cohort, case-control, or randomized controlled trial (RCT) design and examined dietary intake, supplementation, or circulating levels of these antioxidants as exposure, and insulin resistance, ß-cell function, or T2D incidence as outcomes. Summary relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI) were estimated using random-effects models. The certainty of the evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluations framework. Among 6190 screened records, 25 prospective observational studies and 15 RCTs were eligible. Inverse associations were found between dietary and circulating antioxidants and T2D (observational studies). The lowest risk was seen at intakes of 70 mg/d of vitamin C (RR: 0.76; CI: 0.61, 0.95), 12 mg/d of vitamin E (RR: 0.72; CI: 0.61, 0.86), and 4 mg/d of ß-carotene (RR: 0.78; CI: 0.65, 0.94). Supplementation with vitamin E (RR: 1.01; CI: 0.93, 1.10) or ß-carotene (RR: 0.98; CI: 0.90, 1.07) did not have a protective effect on T2D (RCTs), and data on vitamin C supplementation was limited. Regarding insulin resistance, higher dietary vitamin C (RR: 0.85; CI: 0.74, 0.98) and vitamin E supplementation (MD: -0.35; CI: -0.65, -0.06) were associated with a reduced risk. The certainty of evidence was high for the associations between T2D and dietary vitamin E and ß-carotene, and low to moderate for other associations. In conclusion, moderate intakes of vitamins C, E, and ß-carotene may lower risk of T2D by reducing insulin resistance. Lack of protection with supplementation in RCTs suggests that adequate rather than high intakes may play a role in T2D prevention. This systematic review and meta-analysis was registered in PROSPERO with registration number CRD42022343482.