Β-carotene Content Research Articles

Genome-Wide Association Study of Sweet Potato Storage Root Traits Using GWASpoly, a Gene Dosage-Sensitive Model

Sweet potato (Ipomoea batatas) is an important food crop that plays a pivotal role in preserving worldwide food security. Due to its polyploid genome, high heterogeneity, and phenotypic plasticity, sweet potato genetic characterization and breeding is challenging. Genome-wide association studies (GWASs) can provide important resources for breeders to improve breeding efficiency and effectiveness. GWASpoly was used to identify 28 single nucleotide polymorphisms (SNPs), comprising 21 unique genetic loci, associated with sweet potato storage root traits including dry matter (4 loci), subjective flesh color (5 loci), flesh hue angle (3 loci), and subjective skin color and skin hue angle (9 loci), in 384 accessions from the USDA sweet potato germplasm collection. The I. batatas ‘Beauregard’ and I. trifida reference genomes were utilized to identify candidate genes located within 100 kb from the SNPs that may affect the storage traits of dry matter, flesh color, and skin color. These candidate genes include transcription factors (especially Myb, bHLH, and WRKY family members), metabolite transporters, and metabolic enzymes and associated proteins involved in starch, carotenoid, and anthocyanin synthesis. A greater understanding of the genetic loci underlying sweet potato storage root traits will enable marker-assisted breeding of new varieties with desired traits. This study not only reinforces previous research findings on genes associated with dry matter and β-carotene content but also introduces novel genetic loci linked to these traits as well as other root characteristics.

Effects of 910 MHz Solid-State Microwave Cooking on the Quality Properties of Broccoli (Brassica olearacea L. var. Italica Plenck), Carrots (Daucus carota subsp. Sativus), and Red Peppers (Capsicum annuum L. cv. Kapya)

Domestic microwave ovens offer rapid cooking but face challenges such as non-uniform temperature distribution and hot spots. A novel solid-state heating system, which precisely controls microwave frequency and power, provides a promising alternative to traditional microwave ovens utilizing magnetron systems. This study compared the effects of solid-state microwave cooking on the quality of broccoli, red peppers, and carrots with those of traditional microwave and conventional cooking. The traditional microwave cooking used in this study operated at 2450 MHz, while the solid-state system functioned between 902 and 928 MHz. Weight loss was highest for conventional cooking, reaching a maximum of 34%, whereas microwave cooking resulted in a maximum of 11.65% and solid-state microwave cooking in 17.04%. The total phenolic content obtained through conventional cooking ranged between 61.58 and 116.51 mg GAE (gallic acid equivalents)/100 g dry basis, while microwave cooking resulted in a range of 88.04–110.92 mg, and solid-state microwave cooking achieved values between 76.14 and 122.91 mg. Furthermore, reductions in chlorophyll content were observed to be 68.2%, 25.6%, and 35.7% for conventional, microwave, and solid-state microwave cooking, respectively. Lycopene content after conventional cooking decreased to 224.73 mg/100 g dry basis, compared to 289.55 mg after microwave cooking and 242.94 mg after solid-state microwave cooking. β-carotene content showed a decrease of 14.5% in conventional cooking, while both microwave methods showed an increase of 14.7%. These results suggest that solid-state microwave cooking may have promising positive effects on food quality.

Impact of pasture feeding cows and seasonality on the concentration of selected fat-soluble compounds in milk and their ability to be used as biomarkers of “Grass-Fed” dairy

This study investigated the impact of proportion of pasture in the cow diet on the concentration of selected fat-soluble compounds in milk including β-carotene, lutein, retinol (vitamin A), α-tocopherol (vitamin E) and zeaxanthin. Bulk tank milk samples (n = 102) were collected weekly (n = 34) across an entire lactation from three herds operating either a high (GRS), medium (PMR) or no pasture allowance (TMR) feeding system. Concentrations of β-carotene and lutein increased significantly with increasing pasture allowance, with a > 2 fold increase of β-carotene in milk, between high and no pasture allowance treatments. GRS feeding system resulted in milks with higher concentrations of retinol, α-tocopherol, and zeaxanthin, compared to both PMR and TMR systems. A biomarker model based on the fat-soluble compounds concentration in milk, demonstrated excellent differentiation of high pasture allowance derived milks from that of medium and no pasture milks, with area under the curve scores of 0.955 and 0.971 respectively. Strong correlations were observed between the concentrations of lutein and zeaxanthin in milk and the milks corresponding yellow colour, while a significant correlation was exhibited between β-carotene and b*-value. Such correlations with milk colour may have a significant impact on the consumer preference of milk and dairy products produced therefrom.

Biochemical Analysis of Different Wheat Varieties Grown under Various Zones of India

Background: The study aimed to evaluate the flour quality of different wheat varieties (Triticum durum L.) for various end-use products such as chapati, bread, biscuits and pasta. The focus was on identifying varieties with superior nutritional and processing qualities by analyzing various qualitative parameters. Methods: The study assessed multiple wheat varieties using a range of qualitative parameters, including moisture, ash, total soluble sugar, starch, protein, lysine, tryptophan, dry and wet gluten, gluten index, water binding capacity, β-carotene content, sedimentation value, thousand kernel weight and mineral content (Fe and Zn). The wheat varieties evaluated included A-206, GW-1, HI 8498 (Kota), PDW 291 (Hissar) and NIDW 295 (Pune). Result: The study identified A-206 and GW-1 as wheat varieties with superior protein content, gluten quality and water binding capacity, making them ideal for various end-use products. A-206 also had the highest lysine and tryptophan levels, while GW-1 and HI 8498 (Kota) had elevated ash content. PDW 291 (Hissar) was notable for its higher total soluble sugar and NIDW 295 (Pune) excelled in starch content, β-carotene and thousand kernel weight. Overall, NIDW 295 showed the most promise for pasta production due to its comprehensive quality traits.

Determination of global yield isotherms of macaúba (Acrocomia aculeata) extract using supercritical CO2 and its biological potential

This study investigates the effectiveness of macaúba oil extraction using supercritical carbon dioxide, focusing on determining operational parameters such as temperature and pressure that maximize the quality and yield of the extract obtained. The extraction was carried out using freeze-dried macaúba pulp, under varying conditions of pressure and temperature. The overall yield isotherms of macaúba oil obtained, the solubility of the solute, composition of fatty acids, triglycerides, phenolic compounds, in addition to the antioxidant capacity and antimicrobial activity, were evaluated, before and after extraction. The results demonstrated that, under the conditions evaluated, the extraction process achieved maximum oil yields of 24.4 %, with a predominance of unsaturated acids rich in antioxidants and high concentrations of oleic acid (64.12 %), β-carotene (80.06 mg/kg) and α-tocopherol (114.66 mg/100 g of oil). This promising method offers a sustainable alternative for the production of compounds with high nutritional value, highlighting its potential for industrial applications.

Quantifying the Impact of Nitrogen Concentration Variations on Quality Characteristics of Soilless Cultivated Cherry Tomato

Within the domain of macronutrients, nitrogen has garnered significant recognition as a pivotal element due to its profound influence on both the vegetative growth and quality attributes of a crop. An abundance of scientific research has consistently demonstrated that attaining optimal productivity necessitates the meticulous management of soil moisture availability, complemented by the timely provision of nitrogen during critical growth stage intervals. The study aimed to optimize the nitrogen concentration in a hydroponic solution by testing a range of concentrations. The objective was to systematically examine the effects of different nitrogen levels and determine the optimal concentration for the desired outcomes. The assessment was carried out in a meticulously controlled greenhouse environment from October 2019 to April 2021, with the primary objective of systematically investigating the impact on quality characteristics specific to the rosa variety of cherry tomato. To investigate the effects of different nitrogen concentrations, four distinct levels of 4 mM, 6 mM, 8 mM, and 10 mM per litre of nutrient solution were employed. The nitrogen source consisted of a combination of NO3- and NH4+, with a ratio of 40:60, respectively. The nutrient solution with an 8 mM nitrogen concentration exhibited a significantly augmented effect on increasing the equatorial and polar diameter of fruits, average fruit weight, pericarp thickness, as well as the accumulation of total chlorophyll, ascorbic acid, lycopene, β-carotene, and total soluble solids (TSS) content. These findings demonstrate the pronounced and positive influence of the 8 mM nitrogen concentration on the aforementioned quality characteristics.

Prepartum supplementation of dairy cows with inorganic selenium, organic selenium or rumen-protected choline does not affect carotenoid composition or colour characteristics of bovine colostrum or transition milk.

Minerals are supplemented routinely to dairy cows during the dry period to prevent metabolic issues postpartum. However, limited information exists on the impacts of mineral supplementation on colostrum carotenoids. This study aimed to determine the effects of prepartum supplementation with three micro-nutrients; inorganic selenium (INORG), organic selenium (ORG) or rumen-protected choline (RPC) on the carotenoid content of bovine colostrum and transition milk (TM) from pasture-based dairy cows. A total of 57 (12 primiparous and 45 multiparous) Holstein-Friesian (HF) and HF × Jersey (JEX) cows were supplemented daily for 49 ± 12.9 d before calving. Colostrum samples were collected from all cows immediately postpartum and TM one to five (TM1-TM5) were collected from a sub-set of 15 cows (five per treatment group) at each consecutive milking postpartum. Carotenoid concentration was determined using ultra-high performance liquid chromatography - diode array detection (UHPLC-DAD). With the use of transmittance, the colour index and colour parameters a*, b* and L* were used to determine colour variations over this period. Prepartum supplementation did not have a significant effect on colostrum β-carotene concentration or colour. Positive correlations between β-carotene and colour parameter b* (R2 = 0.671; P < 0.001) and β-carotene and colour index (R2 = 0.560; P < 0.001) were observed. Concentrations of β-carotene were highest in colostrum (1.34 μg/g) and decreased significantly with each milking postpartum (TM5 0.31 μg/g). Breed had a significant effect on colostrum colour with JEX animals producing a greater b* colostrum than HF animals (P = 0.030). Primiparous animals produced colostrum with the weakest colour compared to second or ≥third parity animals (P = 0.042). Despite statistical increases in the b* parameter in colostrum from JEX cows and multiparous cows, β-carotene concentrations did not significantly increase suggesting that other factors may influence colostrum colour. The b* parameter may be used as an indicator for estimating carotenoid concentrations in colostrum and TM, particularly when assessed via transmittance spectroscopy.

Analysis of the interaction between airflow and high-voltage electric fields on drying characteristics of carrots using heat pump-electrohydrodynamics combined drying

The study investigates the drying characteristics of carrots under different coupling forms of airflow and high-voltage electric fields (parallel flow, PF, and cross flow, CF) using heat pump-electrohydrodynamics (EHD) combined drying. The results show that, compared to single heat pump drying, the combined drying under PF mode reduces carrot drying time by 13.33 %–31.58 %, increases effective moisture diffusivity (Deff) by 17.80 %–32.32 %, increases specific moisture extraction rate (SMER) by 12.25 %–34.26 %. While the combined drying under CF mode reduces carrot drying time by 12.5 %–18.18 %, increases Deff by 7.27 %–13.14 %, increases SMER by 4.64 %–12.58 %. The improvements in parameters under the CF mode are weaker than those under the PF mode. Additionally, the β-carotene content under PF mode is consistently higher than under CF mode. Based on the experimental results, the Modified Page model was improved, yielding an updated model MR = aexp(-(kt)^n), with an R2 value of up to 0.9999–1, which provides theoretical guidance for optimizing the heat pump-EHD combined drying process.

Developing a novel artificial model to predict the foaming properties and β-carotene content of lucuma (Pouteria lucuma) during foam-mat drying and process optimization

Drying fruit puree by the foam drying method has become popular due to its simplicity, low cost, short drying time, and low thermal degradation. The objective of the study was to investigate the effect of foaming conditions on foam properties (foam expansion, foam density) and content of β-carotene in lucuma powder using Box-Behnken design (BBD) with 3 factors and 3 levels, including water:lucuma ratio (1:1–3:1), egg albumin concentration (EA, 5–15%), and xanthan gum (XG, 0.1–0.3%). Response surface methodology (RSM) and artificial neural network (ANN) were used for model establishment. The results showed that as the EA increased, the foam volume increased significantly, while the foam density decreased. The ANN-coupled BBD model structure of 3-10-3 demonstrated a high level of accuracy in predicting the impact of foaming formulation on responses, with a coefficient of determination exceeding 0.99. The optimal conditions by stimulation multiple-objective RSM for lucuma foam-mat drying were achieved with a water:lucuma ratio, EA, and XG of 2.53:1, 10.8%, and 0.22%, respectively. Based on these ideal conditions, the foam density, foam expansion, and β-carotene content of the dried powder were found to be 0.23±0.04 g/mL, 228±2%, and 237.1±0.1 μg/g, respectively. The obtained experimental values were very close to the model-predicted results, with very low differences identified when the validation was performed. These findings provide information for controlling the drying process using an artificial model and further applying lucuma powder in various fields in the food industry.

Evaluation of the Thermal and Light Stability of β-Carotene Extracted from Mauritia flexuosa Using Ionic Liquid

The growing concern over the adverse effects of synthetic dyes has generated interest in the use of natural pigments by the food industry. β-carotene, a carotenoid found in various plant sources, is recognized for its antioxidant properties and provitamin A activity. The fruit of the buriti palm (Mauritia flexuosa), which is particularly rich in β-carotene, serves as a significant natural source of this pigment. This study aimed to extract β-carotene from buriti fruit using ionic liquids as an alternative to conventional organic solvents like acetone. β-carotene content was determined by HPLC and showed that extraction with [C4mim] [BF4] not only improved β-carotene extraction efficiency compared to acetone (19.21 and 13.13 mg/100 g, respectively) but also provided greater pigment stability during light, thermal and color stability tests. Moreover, ionic liquids are aligned with the principles of green chemistry and offer a sustainable and safe alternative for the food industry. Its favorable characteristics not only reduce environmental impacts associated with conventional solvents, but also ensure an increase in the shelf life of natural dyes, thus promoting the safety and quality of food products.

Patterns and Determinants of Micronutrient Dietary Biomarkers and Their Associations with Dietary Intakes in Young Children

BackgroundCirculating dietary biomarkers are not direct proxies for intake, as the biomarkers reflect not only food and supplement consumption but also nutrient absorption, metabolism, and tissue distribution. Therefore, along with nutrient intake, several other upstream factors can impact dietary biomarker concentrations, including demographic, medical history, and genetic factors. ObjectivesThe aim of this study was to explore the dietary and nondietary determinants of circulating levels of vitamins A, C, D, and E among children aged 6 mo–4 y. MethodsPlasma retinol, β-carotene, ascorbic acid, 25(OH)D, α-tocopherol, and γ-tocopherol were measured in 2887 samples from 1490 children enrolled in The Environmental Determinants of Diabetes in the Young study. Dietary intake was assessed with 3-d food records. Associations of genetic and environmental factors with biomarker concentrations were examined using multivariable linear regression models with random intercepts. ResultsAll biomarkers except retinol were positively associated with intake of the same nutrient. Inverse associations were identified between recent gastrointestinal infection and β-carotene, ascorbic acid, and α-tocopherol, whereas recent respiratory infection was associated inversely with plasma retinol. Several genetic determinants of biomarker status were identified, validating previously reported findings. For some genetic and environmental exposures, we found evidence of statistical interaction with same-nutrient intake, indicating that the association between intake and biomarker concentration is dependent on the level or status of these other exposures. For example, the association between β-carotene intake and concentration is weaker among children with a recent respiratory infection. ConclusionsOur findings suggest that nondietary exposures including childhood infections can alter micronutrient metabolism. This summary of micronutrient determinants will facilitate improved design of future analyses exploring the role of diet in childhood chronic disease etiology through a better understanding of relevant potential confounders and mediators of the diet–outcome relationships.

Enhancement of ketocarotenoid production using the heterologous orange protein from Ipomoea batatas in indigenous microalga Ettlia sp.

Astaxanthin, one of the most powerful natural antioxidants, is used in high-value industries such as those of cosmetics, nutraceuticals, and food products derived from microalgae. In this study, Ettlia sp. mutants were generated by expressing two types of heterologous orange proteins, IbOr and IbOr-R96H, in which the 96th arginine of IbOr was substituted with histidine derived from Ipomoea batatas to enhance astaxanthin production. The Ett-IbOr-R96H mutant showed a 2.4-fold increase in β-carotene content compared to the wildtype (4.59 mg g−1DCW), reaching 10.82 mg g−1 under high-light conditions via two-phase cultivation. Under the stress treatment combination of high-light intensity and nitrogen deprivation, total carotenoid content increased to 17.24 mg L−1 and 21.94 mg L−1 in Ett-IbOr and Ett-IbOr-R96H, respectively. The astaxanthin and canthaxanthin contents in Ett-IbOr-R96H was 4.89 mg L−1 and 0.47 mg L−1, respectively, which were 1.8- and 1.5-fold higher, respectively, than those in Ett-IbOr. Additionally, photosynthetic efficiency (Fv/Fm) recovered in Ett-IbOr-R96H under dual-stress conditions compared to the wildtype while reactive oxygen species levels decreased throughout the cultivation period. Our findings suggest that the heterologous IbOr expression in Ettlia sp. may be an effective approach for enhancing the production of ketocarotenoids and improving stress resistance for industrial applications.

Evaluation of brinjal and tomato scions for enhancing yield and quality attributes in grafted brimato plants

To meet the growing demand for fresh produce in cities, promoting peri-urban and urban farming is essential to reduce reliance on rural areas for vegetables. One innovative approach developed at ICAR-IIVR, Varanasi (2019-2022), is the dual grafting of brinjal and tomato on a single brinjal plant, termed 'Brimato' (Brinjal + Tomato). Using the vigorous, waterlogging and salinity-tolerant brinjal rootstock IC 111056, four brinjal cultivars (Kashi Sandesh, Kashi Uttam, Kashi Manohar, Kashi Vijay) and three tomato cultivars (Kashi Aman, Kashi Chayan, Vani) were selected as scions. Over three years, experiments showed that scion cultivars significantly impacted Brimato productivity. Kashi Manohar combined with Kashi Aman or Kashi Chayan yielded the highest brinjal fruit numbers, while Kashi Aman combined with hybrid brinjal Kashi Sandesh resulted in the highest tomato fruit numbers. The highest fruit yields were observed with the Kashi Sandesh + Kashi Chayan combination, yielding 2.58 kg/plant. The Kashi Aman + Kashi Sandesh combination produced a cumulative yield of 5.98 kg/plant. Physiological traits like photosynthetic rate and chlorophyll fluorescence yield varied significantly among scion cultivars, with Kashi Manohar and Kashi Aman scions exhibiting the highest photosynthetic rates. Grafted Brimato plants showed enhanced fruit quality, particularly in vitamin C and β-carotene content. These findings highlight the potential of Brimato plants for urban agriculture, offering a viable solution for sustainable fresh produce supply.

Perubahan Komponen Kimia Fungsional pada Umbi, Tepung, dan Beras Analog Ubi Jalar Ungu

The purple sweet potato tuber, rich in functional chemical components, offers potential for development into high-value products such as flour, which can then be processed into analog rice. This research aims to evaluate the changes in functional chemical components–namely moisture, ash, protein, fat, carbohydrates, anthocyanin, and β-carotene–along with antioxidant activity during the processing of purple sweet potato tubers into flour and analog rice. The chemical composition of the tubers was found to be as follows: moisture content of 78.00% on a wet basis (wb), ash content of 9.70% on a dry basis (db), fat content of 5.47% (db), protein content of 26.93% (db), carbohydrate content of 58.41% (db), anthocyanin content of 31.79 mg/100 g (db), β-carotene content of 17.73 mg/100 g (db), and antioxidant activity of 65.70%. The composition of the resulting flour included water (6.71% wb), ash (2.40% db), fat (1.06% db), protein (3.80% db), carbohydrate (92.75% db), anthocyanin (3.47 mg/100 g db), β-carotene (1.51 mg/100 g db), and antioxidant activity (45.59%). The chemical content of the analog rice was as follows: water (8.43% wb), ash (1.78% db), fat (1.62% db), protein (4.13% db), carbohydrate (92.50% db), anthocyanin (0.71 mg/100 g db), β-carotene (1.05 mg/100 g db), and antioxidant activity (8.38%). Processing the tubers into flour resulted in a reduction of fat, protein, anthocyanins, β-carotene, and antioxidant activity, while carbohydrate content increased. Similarly, the conversion of flour into analog rice led to decreased levels of carbohydrates, anthocyanins, β-carotene, and antioxidant activity, whereas fat and protein levels increased after transfor-mation into analog rice. The processing stages that significantly contributed to these changes in chemical components included drying, formulation, and extrusion.

Optimisation of Not-from-Concentrate Goji Juice Processing Using Fuzzy Mathematics and Response Surface Methodology and Its Quality Assessment

Not-from-concentrate (NFC) juice effectively retains the original characteristics of the fruit. Despite the various health benefits of Goji berries, reports on the processing technology and quality changes of NFC goji juice are lacking. We optimised the processing technology of NFC goji juice. Employing fuzzy mathematics evaluation combined with response surface methodology based on single-factor experiments, the physicochemical, nutritional, and microbiological indicators of the juice were determined. Gas chromatography-ion mobility spectroscopy was used to analyse changes in volatile compounds before and after processing. The optimal processing parameters were: times for homogenisation, ultrasonication, and sterilisation of 2 min, 3 min, and 85 s, respectively, and sterilisation temperature of 102 °C. The resulting product had a sensory evaluation score of 85.5 and a rich, pleasant taste. The ratio of total soluble solids to titratable acidity and turbidity were 12.8 and 1420 NTU, respectively. Post-processing, the contents of β-carotene, polysaccharides, and betaine increased by 57.3%, 26.7%, and 31.5%, respectively. Microbiological indicators met Chinese national limits for food pollutants and microorganisms. The total relative content of volatile substances in NFC goji juice decreased by 19.86% after processing. This study provides a theoretical reference for the intensive processing and development of high-value goji berries.

Acai Oil-Based Organogel Containing Hyaluronic Acid for Topical Cosmetic: In Vitro and Ex Vivo Assessment.

Organogels are semi-solid pharmaceutical forms whose dispersing phase is an organic liquid, for example, an oil, such as acai oil, immobilized by a three-dimensional network formed by the gelling agent. Organogels are being highlighted as innovative release systems for cosmetic active ingredients such as hyaluronic acid for topical applications. Acai oil was evaluated for its physicochemical parameters, fatty acid composition, lipid quality index, spectroscopic pattern (Attenuated total reflectance Fourier Transform Infrared Spectroscopy), thermal behavior, total phenolic, total flavonoids, and total carotenoids and β-carotene content. The effectiveness of the organogel incorporated with hyaluronic acid (OG + HA) was evaluated through ex vivo permeation and skin retention tests, in vitro tests by Attenuated total reflectance Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry. The physicochemical analyses highlighted that the acai oil exhibited quality standards in agreement with the regulatory bodies. Acai oil also showed high antioxidant capacity, which was correlated with the identified bioactive compounds. The cytotoxicity tests demonstrated that the formulation OG + HA does not release toxic substances into the biological environment that could impede cell growth, adhesion, and efficacy. In vitro and ex vivo analyses demonstrated that after 6 h of application, OG + HA presented a high level of hydration, thermal protection and release of HA. Thus, it can be concluded that the OG + HA formulation has the potential for physical-chemical applications, antioxidant quality, and potentially promising efficacy for application in the cosmetic areas.

The Effect of Light Intensity during Cultivation and Postharvest Storage on Mustard and Kale Microgreen Quality.

Microgreens are vegetable greens that are harvested early while they are still immature and have just developed cotyledons. One of the disadvantages and a challenge in production is that they exhibit a short shelf life and may be damaged easily. In seeking to prolong the shelf life, some pre- and postharvest interventions have been investigated. Here, kale and mustard microgreens were grown in a controlled-environment walk-in chamber at +21/17 °C, with ~65% relative air humidity, while maintaining the spectral composition of deep red 61%, blue 20%, white 15%, and far red 4% (150, 200, and 250 µmol m-2 s-1 photosynthetic photon flux density (PPFD)). Both microgreens seemed to exhibit specific and species-dependent responses. Higher PPFD during growth and storage in light conditions resulted in increased contents of TPC in both microgreens on D5. Additionally, 150 and 250 PPFD irradiation affected the α-tocopherol content by increasing it during postharvest storage in kale. On D0 150 for kale and 200 PPFD for mustard microgreens, β-carotene content increased. D5 for kale showed insignificant differences, while mustard responded with the highest β-carotene content, under 150 PPFD. Our findings suggest that both microgreens show beneficial outcomes when stored in light compared to dark and that mild photostress is a promising tool for nutritional value improvement and shelf-life prolongation.

Retargeting of heterologous enzymes results in improved β-carotene synthesis in Saccharomyces cerevisiae.

Carotenoids are a class of hydrophobic substances that are important as food and feed colorants and as antioxidants. The pathway for β-carotene synthesis has been expressed in various yeast species, albeit with rather low yields and titers. The inefficient conversion of phytoene to lycopene is often regarded as a bottleneck in the pathway. In this study, we aimed at the improvement of β-carotene production in Saccharomyces cerevisiae by specifically engineering the enzymatic reactions producing and converting phytoene. We show that phytoene is stored in intracellular lipid droplets, whereas the enzyme responsible for its conversion, phytoene dehydrogenase, CrtI, is located at the endoplasmic reticulum, like the bifunctional enzyme CrtYB that catalyses the reaction before and after CrtI. To improve the accessibility of phytoene for CrtI and to delay its storage in lipid droplets, we tested the relocation of CrtI and CrtYB to mitochondria. However, only the retargeting of CrtYB resulted in an improvement of the β-carotene content, whereas the mitochondrial variant of CrtI was not functional. Surprisingly, a cytosolic variant of this enzyme, which we obtained through the elimination of its carboxy-terminal membrane anchor, caused an increase in β-carotene accumulation. Overexpression of this CrtI variant in an optimized medium resulted in a strain with a β-carotene content of 79 mg g-1 cell dry weight, corresponding to a 76-fold improvement over the starting strain. The retargeting of heterologously expressed pathway enzymes improves β-carotene production in S. cerevisiae, implicating extensive inter-organellar transport phenomena of carotenoid precursors. In addition, strong overexpression of carotenoid biosynthetic enzymes and the optimization of cultivation conditions are required for high contents.

Revealing the Antioxidant, Phenolic and Beta-Carotene Richness of Sweet Potato (Ipomoea batatas L) Leaves

The diverse nutrients found in sweet potato leaves, including vitamins, minerals, and antioxidants, offer a range of health benefits. The presence of carotenoids and polyphenols, both powerful health-promoting compounds, highlights their potential contribution to medical science. The main objective of this study was to ascertain essential functionals substances of antioxidant, phenolic compounds, and β-carotene in the leaves of 14 distinct sweet potato lines cultivated in open field. A comprehensive analysis of antioxidant capacity, phenolic content, and β-carotene was conducted using ABTS, Folin-Ciocalteu, and HPLC techniques, respectively. The study showed that the concentrations of total antioxidants, phenols, and β-carotene differed markedly among the leaf materials. Among the lines, SP-13 stands out with the highest concentration of phenols (124.64 mg/g dry weight), while SP-14 comes in at the opposite end with the lowest amount (62.97 mg/g dry weight) under field conditions. In the case of antioxidant content in line SP-3 showed the highest with 3.55 mg/g dry weight, while SP-14 brings up the lowest with 1.88 mg/g dry weight. Line SP-5 showed the most β-carotene (0.51 mg/g dry weight), while SP-11 had the least (0.05 mg/g dry weight). Therefore, it can be concluded that sweet potato leaves are a valuable dietary source of antioxidants, phenolic compounds, and β-carotene which have beneficial health elements.

Unveiling the regulatory role of DzAGL6-1 in carotenoid biosynthesis during durian (Durio zibethinus) fruit development.

Approximately 119 MADS-box genes have been identified in durian. Moreover, DzAGL6-1 primarily expressed during fruit development, activates theDzPSYpromoter. Transient expression of DzAGL6-1 in tomatoes influences carotenoid production. MADS-box transcription factors play a crucial role in regulating plant biological processes, including fruit ripening and associated events. This study aimed to comprehend the mechanisms involved in durian fruit development and ripening and carotenoid production by conducting a genome-wide analysis of MADS-box proteins in durian (Durio zibethinus L.), an economically important fruit in Southeast Asia. A total of 119 durian MADS-box proteins were identified from the genome of the 'Musang King' cultivar. Based on the phylogenetic analysis, the proteins were classified into types I and II, which exhibited similar conserved motif compositions. Notably, only 16 durian MADS-box genes exhibited fruit-specific expression patterns. Among these genes, DzAGL6-1 was predominantly expressed during fruit development, a stage at which carotenoid biosynthesis is activated. Transient expression of DzAGL6-1 in tomato fruit increased the transcript level of the carotenoid biosynthetic gene phytoene synthase (PSY) and the β-carotene content. Furthermore, DzAGL6-1 activated the promoter activity of DzPSY, as demonstrated by a dual-luciferase assay. These findings provide insights into the role of MADS-box transcription factors in regulating carotenoid biosynthesis during durian fruit development.