Evaluation of Carotenoids Accumulation and Biosynthesis in Two Genotypes of Pomelo (Citrus maxima) during Early Fruit Development

Exploring the nutraceutical potential: Evaluating the nutritional and bioactive functions of five pomelo fruit varieties in Bangladesh

Pomelo (Citrus maxima), the largest citrus fruit, provides a variety of nutrients that have several health benefits, including antioxidant and antidiabetic functions. Antioxidants help combat oxidative stress by neutralizing reactive oxygen species (ROS) and reducing cellular damage. On the other hand, antidiabetic properties involve mechanisms such as enhancing insulin secretion, improving insulin sensitivity, inhibiting carbohydrate digestion and absorption, and regulating glucose metabolism. However, there is a lack of data on the comparative analysis of the physicochemical composition, bioactive properties, and antidiabetic effects of pomelo fruits grown in Bangladesh. To address this issue, the most common and popular high-yielding five cultivars of pomelo fruits grown in Bangladesh including LOCAL, BARI-2 (BARI: Bangladesh Agricultural Research Institute, Batabi Lebu-2), BARI-3, BARI-4, and BARI-6 were evaluated concerning proximate, minerals, and physicochemical properties with their antidiabetic and antioxidant properties. Research has revealed that all pomelo varieties contained a significant amount of proximate compositions and major minerals (Ca, Mg, K, Na, and Fe). The highest juice yield (75.37 ± 0.33 %), vitamin C content (79.56 ± 2.26 mg/100 mL of fresh juice), and carotenoid content (919.33 ± 0.62 μM β-Carotene Equivalent/g DM) were found in BARI-3 pomelo fruit and adhered to the sequence (p < 0.05): BARI-3 > LOCAL > BARI-4 > BARI-6 > BARI-2; BARI-3 > LOCAL > BARI-2 > BARI-4 > BARI-6, and BARI-3 > BARI-2 > BARI-6 > LOCAL > BARI-4, respectively. The anthocyanin content and inhibitory activity of α-glucosidase were found to be at their peak in the BARI-2 pomelo variety and the values were 50.65 ± 2.27 μg cyanidin 3-glucoside equivalents/100 g DM and 85.57 ± 0.00 μM acarbose equivalents/g DM, respectively. BARI-3 pomelo variety showed highest DPPH antioxidant capacity (170.47 ± 0.01 μM Trolox equivalents/g DM), while the BARI-6 pomelo variety exhibited the highest total phenolic content (6712.30 ± 1.84 μg gallic acid equivalents/g DM), and ferric-reducing antioxidant power activity (183.16 ± 0.01 μM Fe(II) equivalents/g DM). Therefore, this study explores the nutritional value and bioactivity of five popular pomelo varieties in Bangladesh, offering valuable insights for utilizing high-value citrus resources and understanding their health-promoting functions.

Influence of Pomelo (Citrus maxima) Pericarp Essential Oil on the Physicochemical Properties of HomChaiya Rice (Oryza sativa L. cv. HomChaiya) Flour-Derived Edible Films

The food industry is increasingly interested in using active edible packaging to address environmental problems caused by conventional synthetic polymers, such as pollution and degradation. The present study took advantage of this opportunity to develop active edible packaging using Hom-Chaiya rice flour (RF), incorporating pomelo pericarp essential oil (PEO) at varying concentrations (1-3%). Films without PEO were used as controls. Various physicochemical parameters, structural and morphological observations were examined in the tested films. Overall, the results showed that the addition of PEO at varying concentrations significantly improved the qualities of the RF edible films, particularly the film's yellowness (b*) and total color. Furthermore, RF-PEO films with increased concentrations significantly reduced the film's roughness and relative crystallinity, while increasing opacity. The total moisture content in the films did not differ, but water activity was significantly reduced in the RF-PEO films. Water vapor barrier properties also improved in the RF-PEO films. In addition, textural properties, including tensile strength and elongation at break, were better in the RF-PEO films compared with the control. Fourier-transform infrared spectroscopy (FTIR) revealed strong bonding between the PEO and RF in the film. Morphological studies showed that the addition of PEO smoothed the film's surface, and this effect increased with concentration. Overall, the biodegradability of the tested films was effective, despite variations; however, a slight advancement in degradation was found in the control film. Lastly, the antimicrobial properties of the RF-PEO films exhibited excellent inhibitory effects against various pathogens, including Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), Escherichia coli (E. coli), and Salmonella typhimurium (S. typhimurium). This study demonstrated that RF and PEO could be an effective combination for developing active edible packaging that delivers desirable functional properties and excellent biodegradability.

α-Carotene: a valuable carotenoid in biological and medical research

α-Carotene, one of the C₄₀ carotenes, is a natural lipid-soluble terpene. The chemical structure of α-carotene is based on the unsaturated polyene chain skeleton, with an ε-ring and a β-ring on each side of the skeleton. α-Carotene is widely found in dietary fruits and vegetables, and the concentration depends on the plant species. In addition, processing methods and storage conditions used in the food and medical industries can alter the concentration of α-carotene in raw materials. This review of α-carotene summarizes the major studies on chemical structure, source, extraction, detection, biosynthesis, processing effect, bioactivity, medicine, and biotechnology. Whether α-carotene supplementation or a diet rich in fruits and vegetables has a positive effect on the prevention of cancer, cardiovascular disease, and other diseases is the focus of this study. © 2022 Society of Chemical Industry.

Citrus maxima (Brum.) Merr. (Rutaceae): Bioactive Chemical Constituents and Pharmacological Activities

Citrus maxima (Burm). Merr. (family Rutaceae), commonly known as Pomelo, is an ethnomedicinally, pharmacologically, and phytochemically valued species. Various ethnomedicinal reports have revealed the use of C. maxima for cough, fever, asthma, diarrhea, ulcer, and diabetes and as a sedative. Numerous phytochemicals have been reported from C. maxima such as polyphenols, terpenoids, sterols, carotenoids, vitamins, and amino acids. The plant possesses significant bioactivities like antioxidant, antimicrobial, anti-inflammatory, analgesic, anticancer, antidiabetic, anti-Alzheimer's disease, insecticidal, anxiolytic, hepatoprotective, antimalarial, and antiobesity. Extensive research is necessary to explore the detailed mechanism of action of extracts and compounds to design effective medicines, herbal products, and functional foods.

Volatiles Accumulation during Young Pomelo (Citrus maxima (Burm.) Merr.) Fruits Development

As widely planted fruits with high nutritional and medical values, pomelos are managed systematically to achieve the largest economic benefits. But the annual shedding of young pomelos, which could be applied as feedstocks for essential oil extraction with their abundant volatiles, leads to a waste of source. The present study selected two commonly planted pomelo (Citrus maxima (Burm.) Merr.) varieties in Southern China, to investigate the volatile profiles during young pomelo fruits development. Combing transcriptomic analysis, this study aimed at identifying the prominent volatile components in young pomelo fruits in order to preferably extract profitable volatiles, as well, increasing the knowledge concerning regulatory roles of transcription factors (TFs) on volatiles accumulation in young pomelos. Totally 29 volatiles were identified, including 14 monoterpenoids and 13 sesquiterpenoids. Diprene was the principal component with the highest amount. Volatiles were generally decreased during fruits development but preferable stages were figured out for volatile collections. 12 and 17 TFs were related to developing time while ERF003 and MYC2 were highly correlated to monoterpenoids. These findings put forward the comprehensive usages of young pomelos and enriched the regulatory roles of TFs on both fruit development and volatiles metabolism.

Optimization of Extraction Conditions of Carotenoids from Dunaliella parva by Response Surface Methodology

Extraction conditions can exert a remarkable influence on extraction efficiency. The aim of this study was to improve the extraction efficiency of carotenoids from Dunaliella parva (D. parva). Dimethyl sulfoxide (DMSO) and 95% ethanol were used as the extraction solvents. The extraction time, extraction temperature and the proportions of mixed solvent were taken as influencing factors, and the experimental scheme was determined by Central Composite Design (CCD) of Design Expert 10.0.4.0 to optimize the extraction process of carotenoids from D. parva. The absorbance values of the extract at 665 nm, 649 nm and 480 nm were determined by a microplate spectrophotometer, and the extraction efficiency of carotenoids was calculated. Analyses of the model fitting degree, variance and interaction term 3D surface were performed by response surface analysis. The optimal extraction conditions were as follows: extraction time of 20 min, extraction temperature of 40 °C, and a mixed solvent ratio (DMSO: 95% ethanol) of 3.64:1. Under the optimal conditions, the actual extraction efficiency of carotenoids was 0.0464%, which was increased by 18.19% (the initial extraction efficiency of 0.03926%) with a lower extraction temperature (i.e., lower energy consumption) compared to the standard protocol.