Pitaya Fruit Research Articles

Expression Profiling Analysis of the SWEET Gene Family in In Vitro Pitaya Under Low-Temperature Stress and Study of Its Cold Resistance Mechanism.

Pitaya (Hylocereus undatus) fruit is an attractive, nutrient-rich tropical fruit with commercial value. However, low-temperature stress severely affects the yield and quality of pitaya. The relevant mechanisms involved in the response of pitaya to low-temperature stress remain unclear. To study whether the SWEET gene family mediates the response of H. undatus to low-temperature stress and the related mechanisms, we performed genome-wide identification of the SWEET gene family in pitaya, and we used 'Baiyulong' tissue-cultured plantlets as material in the present study. We identified 28 members of the SWEET gene family from the H. undatus genome and divided these family members into four groups. Members of this gene family presented some differences in the sequences of introns and exons, but the gene structure, especially the motifs, presented relatively conserved characteristics. The promoter regions of most HuSWEETs have multiple stress- or hormone-related cis-elements. Three duplicated gene pairs were identified, including one tandem duplication gene and two fragment duplication gene pairs. The results revealed that the SWEET genes may regulate the transport and distribution of soluble sugars in plants; indirectly regulate the enzyme activities of CAT, POD, and T-SOD through its expression products; and are involved in the response of pitaya to low-temperature stress and play vital roles in this process. After ABA and MeJA treatment, the expression of HuSWEETs changed significantly, and the cold stress was also alleviated. This study elucidated the molecular mechanism and physiological changes in the SWEET gene in sugar metabolism and distribution of pitaya when it experiences low-temperature stress and provided a theoretical basis for cold-resistant pitaya variety breeding.

Application of hydrogen-rich water maintains red pitaya fruit quality through regulation of ROS and energy metabolism

Hydrogen-rich water (HRW) treatment has been shown to enhance the shelf life of fruit and vegetables. This study aimed to investigate the effects of HRW on improving the quality of red pitaya and its underlying regulatory mechanisms. The results revealed that applying HRW at a 70% concentration reduced decay and weight loss rates, slowed the respiratory rate, and delayed the decline in titratable acidity and total soluble solids. Additionally, HRW treatment mitigated the increase in superoxide anion production and hydrogen peroxide levels, while enhancing antioxidant enzyme activities and gene expression, including those of peroxidase, superoxide dismutase, glutathione peroxidase, catalase, ascorbate peroxidase, monodehydroascorbate reductase, and glutathione reductase. Non-enzymatic antioxidant compounds such as ascorbate and glutathione also increased. Moreover, RT-qPCR analysis showed that HRW treatment upregulated HcMYB6 and downregulated HcR2R3MYB. Dual-luciferase reporter assays indicated that HcMYB6 activated the expression of HcSOD and HcCAT, whereas HcR2R3MYB repressed their expression. These findings suggest that HcMYB6 and HcR2R3MYB may be involved in reactive oxygen species metabolism, with HcMYB6 being induced and HcR2R3MYB inhibited by HRW treatment. Furthermore, HRW treatment led to increased adenosine triphosphate and adenosine diphosphate levels, a decrease in adenosine monophosphate content, and elevated gene expression and activity of Ca2⁺-ATPase, succinate hydrogenase, H⁺-ATPase, and cytochrome C. Collectively, these results demonstrate that HRW treatment effectively reduces oxidative damage and improves energy status, thereby preserving the quality of red pitaya fruit.

The Profile of Phenolic Compounds Identified in Pitaya Fruits, Health Effects, and Food Applications: An Integrative Review.

This integrative review aimed to identify the phenolic compounds present in pitayas (dragon fruit). We employed a comprehensive search strategy, encompassing full-text articles published between 2013 and 2023 in Portuguese, English, and Spanish from databases indexed in ScienceDirect, Capes Periodics, Scielo, and PubMed. The study's selection was guided by the question, "What are the main phenolic compounds found in pitaya fruits?". After screening 601 papers, 57 met the inclusion criteria. The identified phytochemicals have been associated with a range of health benefits, including antioxidant, anti-inflammatory, and anxiolytic properties. Additionally, they exhibit promising applications in the management of cancer, diabetes, and obesity. These 57 studies encompassed various genera, including Hylocereus, Selenicereus, and Stenocereus. Notably, Hylocereus undatus and Hylocereus polyrhizus emerged as the most extensively characterized species regarding polyphenol content. Analysis revealed that flavonoids, particularly kaempferol and rutin, were the predominant phenolic class within the pulp and peel of these fruits. Additionally, hydroxycinnamic and benzoic acid derivatives, especially chlorogenic acid, caffeic, protocatechuic, synaptic, and ellagic acid, were frequently reported. Furthermore, betalains, specifically betacyanins, were identified, contributing to the characteristic purplish-red color of the pitaya peel and pulp. These betalains hold significant potential as natural colorants in the food industry. Therefore, the different pitayas have promising sources for the extraction of pigments for incorporation in the food industry. We recommend further studies investigate their potential as nutraceuticals.

Pitaya-Inspired Metal-Organic Framework Nanozyme for Multimodal Imaging-Guided Synergistic Cuproptosis, Nanocatalytic Therapy, and Photothermal Therapy.

Nature often provides invaluable insights into technological innovation and the construction of nanomaterials. Inspired by the pitaya fruit's strategy of wrapping seeds within its pulp to enhance seed survival, a unique nanocomposite based on metal-organic framework (MOF)-encapsulated CuS nanoparticles (NPs) is developed. This design effectively addresses the challenge of short retention time afforded by CuS NPs for therapeutic and imaging purposes. The MOF acts as the "pitaya pulp" protecting the internal CuS NPs ("pitaya seeds"), thereby increasing their retention time in vivo. This system exhibits triple-enzyme-mimicking activities and is proposed for application in photoacoustic and magnetic resonance imaging-guided therapies, including chemodynamic therapy, photothermal therapy, and cuproptosis-related therapy. The exceptional enzyme-mimicking activities of superoxide dismutase, catalase, and peroxidase not only produce oxygen to alleviate hypoxia but also generate a reactive oxygen species (ROS) storm for effective tumor destruction. By combining these multienzymatic properties, superior photothermal performance, and Cu-induced cuproptosis, nanozyme-treated mice exhibited an 84% inhibition of tumor growth-approximately double the effect observed in mice treated with CuS NPs alone. This study presents a smart strategy for integrating imaging with therapeutic modalities, achieving exceptional outcomes for precise imaging-guided tumor therapy.

Pitaya (Hylocereus polyrhizus) extract rich in betanin encapsulated in electrospun sweet potato starch nanofibers.

Pitaya fruit (Hylocereus spp.) is rich in bioactive compounds such as betanin. This study aimed to extract betanin-rich pitaya fruit and encapsulate it in electrospun nanofibers produced with sweet potato starch. The influence of different concentrations of this bioactive compound on the morphology, functional groups, hydrophilicity, load capacity, color, thermal properties, and contact angle of the electrospun nanofibers with water and milk was assessed. The potential antioxidant and stability of nanofibers during gastrointestinal digestion in vitro were demonstrated. The nanofibers presented average diameters ranging from 134 to 204 nm and displayed homogeneous morphology. The load capacity of the extract in the nanofibers was 43% to 83%. The encapsulation increased the thermal resistance of betanins (197-297 °C). The static contact angle with water and milk showed that these materials presented greater affinity with milk. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that the nanofibers with 5%, 25%, and 45% pitaya extract presented unique characteristics. They showed resistance in delivering betanins to the stomach, with 12% inhibition of the 2,2-diphenyl-1-picrylhydrazyl (DPPH˙) radical. However, only the 45% concentration reached the intestine with 9.83% inhibition of the DPPH˙ radical. Pattern recognition from multivariate analyses indicated that nanofibers containing 5%, 25%, and 45% of the extract presented distinct characteristics, with the ability to preserve betanins against thermal degradation and perform the controlled delivery of these bioactives in the stomach and intestine to produce antioxidant activity. © 2024 Society of Chemical Industry.

Microfiltered red-purple pitaya concentrate: A promising multifunctional food-derived colorant.

Red pitaya fruit has become a source of natural colorant, because it is rich in betalains, a pigment that imparts a red-purple color that intereststhefood and cosmetics industries. This fruit also possesses high nutritional value, with a range of bioactive compounds known to confer potential health benefits and prevent chronic diseases, such as diabetes, which makes it useful for use as pharmaceutical agents and dietary supplements. In order to improve its technological and biological effects, a concentration will be required. Thus, the microfiltration, followed by vacuum concentration, can be an interesting strategy for this purpose. This study aimed to explore tangential microfiltration to produce microfiltered material, which is an important step to obtain the microfiltered red-purple pitaya concentrate. Therefore, physicochemical and chemical characterization (including 1H NMR analysis) and biological properties (toxicity and diabetes) of this concentrate were assessed, using adult zebrafish as a model. The results show that microfiltration was carried out efficiently, with an average consumption of 95.75±3.13 and 74.12±3.58kW h m-3, varying according to the material used ("unpeeled pitaya pulp" or "pitaya pulp with peel," respectively). The in vivo tests indicated non-toxicity and hypoglycemic effect of the concentrate, since the blood glucose levels were significantly lower in the zebrafish groups treated with this concentrate in comparison with that of control group. Thus, this study suggests the potential of microfiltered red-purple pitaya concentrate as a promising multifunctional food-derived colorant, exhibiting beneficial biological effects far beyond its attractive color. PRACTICAL APPLICATION: Hylocereus polyrhizus(F.A.C. Weber) Britton & Rose has attracted attention as a potential source of natural colorants because of its red-purple skin and flesh color. In addition, this fruit has a range of bioactive compounds, which make it a valuable resource for providing potential health benefits and preventing chronic diseases such as diabetes. In this paper, the microfiltered red-purple pitaya concentrate showed beneficial biological effects far beyond its attractive color. Thus, this product can be considered a promising multifunctional food-derived colorant to use in the food, pharmaceutical, or cosmetics industries.

Characterization and Pathogenicity of Colletotrichum truncatum Causing Hylocereus undatus Anthracnose through the Changes of Cell Wall-Degrading Enzymes and Components in Fruits.

Anthracnose is one of the destructive diseases of pitaya that seriously affects the plant growth and fruit quality and causes significant yield and economic losses worldwide. However, information regarding the species of pathogens that cause anthracnose in pitaya (Hylocereus undatus) fruits in Gansu Province, China, and its pathogenic mechanism is unknown. Thus, the purposes of our present study were to identify the species of pathogens causing H. undatus fruits anthracnose based on the morphological and molecular characteristics and determine its pathogenic mechanism by physiological and biochemical methods. In our present study, forty-six isolates were isolated from the collected samples of diseased H. undatus fruits and classified as three types (named as H-1, H-2, and H-3), according to the colony and conidium morphological characteristics. The isolation frequencies of H-1, H-2, and H-3 types were 63.04%, 21.74%, and 15.22%, respectively. The representative single-spore isolate of HLGTJ-1 in H-1 type has significant pathogenicity, and finally we identified Colletotrichum truncatum as the pathogen based on the morphological characteristics as well as multi-locus sequence analysis. Moreover, the H. undatus fruits inoculated with C. truncatum had a significantly increased activity of cell wall-degrading enzymes (CWDEs) cellulase (Cx), β-glucosidase (β-Glu), polygalacturonase (PG), and pectin methylgalacturonase (PMG), while having a decreased level of cell wall components of original pectin and cellulose in comparison to control. The average increased activities of Cx, β-Glu, PG, and PMG were 30.73%, 40.40%, 51.55%, and 32.23% from day 0 to 6 after inoculation, respectively. In contrast, the average decreased contents of original pectin and cellulose were 1.82% and 16.47%, respectively, whereas the average increased soluble pectin content was 38.31% in comparison to control. Our results indicate that C. truncatum infection increased the activities of CWDEs in H. undatus fruits to disassemble their cell wall components, finally leading to the fruits' decay and deterioration. Thus, our findings will provide significant evidence in the controlling of pitaya anthracnose in the future.

GSE-YOLO: A Lightweight and High-Precision Model for Identifying the Ripeness of Pitaya (Dragon Fruit) Based on the YOLOv8n Improvement

Pitaya fruit is a significant agricultural commodity in southern China. The traditional method of determining the ripeness of pitaya by humans is inefficient, it is therefore of the utmost importance to utilize precision agriculture and smart farming technologies in order to accurately identify the ripeness of pitaya fruit. In order to achieve rapid recognition of pitaya targets in natural environments, we focus on pitaya maturity as the research object. During the growth process, pitaya undergoes changes in its shape and color, with each stage exhibiting significant characteristics. Therefore, we divided the pitaya into four stages according to different maturity levels, namely Bud, Immature, Semi-mature and Mature, and we have designed a lightweight detection and classification network for recognizing the maturity of pitaya fruit based on the YOLOv8n algorithm, namely GSE-YOLO (GhostConv SPPELAN-EMA-YOLO). The specific methods include replacing the convolutional layer of the backbone network in the YOLOv8n model, incorporating attention mechanisms, modifying the loss function, and implementing data augmentation. Our improved YOLOv8n model achieved a detection and recognition accuracy of 85.2%, a recall rate of 87.3%, an F1 score of 86.23, and an mAP50 of 90.9%, addressing the issue of false or missed detection of pitaya ripeness in intricate environments. The experimental results demonstrate that our enhanced YOLOv8n model has attained a commendable level of accuracy in discerning pitaya ripeness, which has a positive impact on the advancement of precision agriculture and smart farming technologies.

Effects of fertilization on soil ecological stoichiometry and fruit quality in Karst pitaya orchard

Pitaya (Hylocereus undulatus) is a significant cash crop in the karst region of Southwest China. Ecological stoichiometry is an essential method to research biogeochemical cycles and limiting elements. The purpose of this study was to explore the stoichiometric characteristics of C, N, and P in Karst pitaya orchards and fruit quality and to elucidate the mechanism and process of nutrient cycling. The results showed that: (1) Fruit quality was highest under the combination of chemical and organic fertilizers. Compared to the control, the contents of per-fruit weight, vitamin C, and soluble sugar increased significantly by 55.5%, 60.7%, and 23.0%, respectively, while the content of titratable acidity decreased significantly by 22.0%. (2) The content of soil nutrients under fertilization stress showed a downward trend in general, as did microbial biomass and extracellular enzyme activities. (3) Different fertilization treatments significantly affected the soil-microbial stoichiometry C:N ratio, C:P ratio, with research areas being significantly limited by C and P. (4) Spearman and PLS-SEM (partial least squares-structural equation model) analysis results showed that under the influence of fertilization, there was a significant positive effect between microorganisms and soil nutrients, but a significant negative effect between soil nutrients and quality. The results of this study offer an innovative perspective on pitaya quality research in Karst areas.

Genome-Wide Isolation of VIN Gene Family and Functional Identification of HpVIN4 in Red Pitaya (Hylocereus polyrhizus)

Soluble sugars, including glucose, fructose and sucrose, are the most important determinants that affect the flavor and quality of red pitaya (Hylocereus polyrhizus) fruit. Vacuolar invertase (VIN), which catalyzes sucrose hydrolysis into glucose and fructose, is a key type of enzyme responsible for soluble sugar metabolism in plant growth and development. Herein, we conducted genome-wide identification, gene expression analysis, subcellular localization and an enzymatic properties assay for the VIN-encoding genes from red pitaya. During red pitaya fruit development towards ripening, the enzymatic activities of VIN showed an up-regulated trend towards ripening. In total, four isoforms (HpVIN1–4) of the VIN-encoding gene were identified from the pitaya genome. Sequence alignment results revealed that the HpVIN1, HpVIN3 and HpVIN4 proteins contained essential motifs for targeting the vacuole and conserved motifs or residues responsible for sucrose binding and hydrolysis. Gene expression pattern analyses revealed that the level of HpVIN4 was obviously increasing during fruit development and acted as the most abundant VIN isoform towards ripening. Subcellular localization detection via transient expression in Arabidopsis thaliana mesophyll protoplasts revealed that the HpVIN4 protein was localized in the vacuole. Growth complementation tests of heterologous expression in the invertase-deficient baker’s yeast strain suggested that the HpVIN4 protein had a sucrose hydrolysis activity and could restore the yeast growth in vivo. The identification of enzymatic properties in vitro demonstrated that the HpVIN4 protein could degrade sucrose into glucose and fructose with an optimum pH of 4.0. Specifically, the HpVIN4 protein had an estimated Km value of 5.15 ± 1.03 mmol·L−1 for sucrose hydrolysis. Ultimately, this study provides a comprehensive understanding of the potential roles of VINs during fruit development and towards ripening and provides functional gene resources for regulating soluble sugar accumulation in red pitaya fruit.

Melatonin and methyl jasmonate inhibited the chilling injury of postharvest pitaya fruit after cold storage by regulating the antioxidant system

ABSTRACT Chilling injury (CI) is the main physiological disease caused shelf decay of pitaya fruit after low-temperature storage. To find ways to control the chilling injury of pitaya fruit, we conducted the effects of postharvest treatment with 1.0 mmol L−1 melatonin (MT) and 0.1 mmol L−1 methyl jasmonate (MeJA) on the chilling injury of pitaya vs Zihonglong at 3 days of shelf life after storage at 2 ± 0.5°C. The results showed that both MeJA and MT promote the accumulation of antioxidants and the reactive oxygen species (ROS) metabolism, and inhibit the respiration rate and ethylene release rate, thereby reducing the incidence of chilling injury after cold storage, keeping the shelf quality of pitaya fruit and prolonging the shelf life of pitaya fruit. In summary, postharvest MeJA or MT inhibited the chilling injury of pitaya fruit by regulating the antioxidant system.

HpFBH3 transactivates HpCO7 via binding to the E-boxes in the promoter and may accelerate flower formation in pitaya1

Hylocereus polyrhizus, also known as pitaya or dragon fruit, is a climbing cactus grown worldwide because of its excellent performance under drought stress and appealing red-purple fruits. In practice, accelerating flower formation and inducing more flowers usually result in higher yield. However, the genes for this purpose have not been well characterized in pitaya. Previously, FLOWERING BHLHs (FBHs) have been identified as positive regulators of flower formation. In the present work, a total of eight FBHs were identified in pitaya. This is a greater number than in beet and spinach, possibly because of the recent whole-genome duplication that occurred in the pitaya genome. The phylogenetic tree indicated that the FBHs could be divided into three groups. In TYPE II, the genes of Caryophyllales encode atypical FBHs and are generated by dispersed duplication. The Ka/Ks ratios indicated that HpFBHs are under purifying selection. Promoter and expression analysis of HpFBHs revealed that they are spatiotemporally activated in flower-related tissues and responsive to multiple abiotic stresses. These results indicated that HpFBHs are involved in the flower formation of pitaya. Therefore, typical HpFBH1/3 from TYPE III and an atypical HpFBH8 from TYPE II were selected for functional verification. HpFBH3 was found to heterodimerize with HpFBH1 in the nucleus using subcellular localization, yeast two-hybrid and luciferase complementation assays. With bioinformatic analysis, all HpFBHs were predicted to transactivate downstream genes via binding to the E-boxes, which were frequently detected in the promoters of HpCOs, HpFTs and HpSOC1s. RNA-Seq datasets showed that these flowering accelerators were expressed in coordination with HpFBH3. Yeast one-hybrid and dual-luciferase reporter assays further verified that HpFBH3 transactivated HpCO7 by selectively binding to the E-boxes in the promoter. Moreover, ectopic overexpression of HpFBH3 accelerated flower formation in Arabidopsis. In summary, this study systematically characterized the typical HpFBHs, especially HpFBH3, as positive regulators of flower formation, which could be target genes for the genetic improvement of pitaya.

Advances in the Understanding of Postharvest Physiological Changes and the Storage and Preservation of Pitaya.

Highly prized for its unique taste and appearance, pitaya is a tasty, low-calorie fruit. It has a high-water content, a high metabolism, and a high susceptibility to pathogens, resulting in an irreversible process of tissue degeneration or quality degradation and eventual loss of commercial value, leading to economic loss. High quality fruits are a key guarantee for the healthy development of economic advantages. However, the understanding of postharvest conservation technology and the regulation of maturation, and senescence of pitaya are lacking. To better understand the means of postharvest storage of pitaya, extend the shelf life of pitaya fruit and prospect the postharvest storage technology, this paper analyzes and compares the postharvest quality changes of pitaya fruit, preservation technology, and senescence regulation mechanisms. This study provides research directions for the development of postharvest storage and preservation technology.

A lightweight improved YOLOv5s model and its deployment for detecting pitaya fruits in daytime and nighttime light-supplement environments

Precise detection and low-cost deployment are the technological basis of intelligent fruit picking. This study proposes a lightweight improved YOLOv5s model to detect pitaya fruits in daytime and nighttime light-supplement environments, and make it successfully deploy in an Android device. This model first uses the module of shufflenetv2 to reconstruct the YOLOv5s backbone network. Then, the study proposes a Concentrated-Comprehensive Convolution Receptive Field Enhancement (C3RFE) module to improve the detection precision of pitaya fruits. Furthermore, a Bidirectional Feature Pyramid Network(BiFPN) feature fusion method is used to enhance the multi-scale feature fusion. Moreover, three optimized Squeeze-and-Excitation (SE) attention modules are added to make full use of the image feature information. Finally, a dynamic label allocation strategy simple Optimal Transport Assignment (simOTA) is used to optimize the YOLOv5s model original label allocation strategy. The experimental results show that the improved model achieves an average precision rate of 97.80 %, with frames per second (FPS) of 139 FPS in a GPU run environment. The model size is only 2.5 MB. Compared to the state-of-the-art SSD, Faster RCNN, YOLOv4, YOLOv4 tiny, YOLOv5s, YOLOv5Lite-s, YOLOXs, YOLOv7, YOLOv7-tiny, YOLOv8n and YOLOv8s, the improved YOLOv5s achieve preferred comprehensive performance in average precision rate, FPS and model size. When deploying this model on the Realme GT Android mobile phone by developing an application based on an NCNN framework, such an application accomplishes real-time pitaya fruit detection with an FPS exceeding 30 FPS. This study can provide technological support for a precise and effective pitaya fruit intelligent picking.

Eradication measures and products that inhibit in vitro mycelial growth of the fungus Neoscytalidium dimidiatum, the etiological agent of pitaya canker

The objective of this work was to identify the causal agent of the circular necrotic lesion present in cladodes and pitaya fruits, to test in vitro different products with potential fungicidal effect and to evaluate the effect of different eradicating products on infected pruned cladodes. Fruits and cladodes with symptoms of pitaya canker were analyzed using a magnifying glass and microscope. Isolation in PDA and inoculation was also carried out in healthy cladodes to observe symptoms. The isolated fungus was placed to grow in PDA culture medium previously mixed with the products; Castor oil, Prevam, Biometal copper, Kellus immune, Primecur, Kaumin, Bombardeiro, Serenade, Bordamil, Dithane, Bravonil, Mertin, Rovral, Sumilex, Mythos, Cantus, Fluazinam Nortox, Comet, Cercobin, Forum, Socre Flex, Cabrio Top, Orkestra, Opera, Nativo, Fusion, Tridium, Priori Xtra and Evolution. The products were applied to infected cladodes; Quaternary ammonia, Fortalece, Bordamil, Calda sulfocaucica all in concentrations of 5% and control with the objective of observing sporulation, spore germination and decomposition time. Pitaya cladodes and fruits presented stem canker caused by Neoscytalidium dimidiatum. The products; Prevam, Bordamil, Dithane, Mertin, Rovral, Sumilex, Fluazinam Nortox, Comet, Socre Flex, Cabrio Top, Orkestra, Opera, Nativo, Fusion, Tridium, Priori Xtra and Evolution at the doses tested completely inhibited the mycelial growth of the N. dimidiatum fungus. The products; Bordamil®, Sulfocaucic solution, Quaternary Ammonia and Fortalece® in concentrations of 5% accelerated the decomposition of the treated cladode and reduced the formation and germination of N. dimidiatum conidia.

Inhibitory effect and action mechanism of citral against black rot in pitaya fruit

Blackspot, caused by Alternaria alternata, is a significant postharvest disease in pitaya. Currently, there are limited effective fungicides to manage this disease. This study aimed to evaluate the antifungal activity of citral against the blackspot pathogen and to determine the protective effect of citral on pitaya. Our results demonstrated that citral effectively curtailed the mycelial growth and spore germination of Alternaria alternata, with a minimum inhibitory concentration (MIC) of 0.6 μL/mL. Observations under a light microscope revealed that citral-treated hyphae displayed characteristics such as sparseness, roughness, twisting, shriveling, and irregular internode separation, along with prominent vacuolation. Propidium iodide and 2,7-Dichlorodi-hydrofluorescein diacetate staining results revealed that the mycelia from the MIC citral-treated group emitted robust fluorescence, with the average fluorescence intensities being 4.03 and 8.09 times higher than the control group, respectively. Furthermore, citral treatment resulted in a decline in the lipid content and dry weight of the hyphae, increased nucleic acid and protein leakage, enhanced exosporial conductivity, and augmented superoxide dismutase (SOD) and catalase (CAT) enzyme activities. Additionally, it fostered the accumulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA). Fruit damage inoculation assays indicated that an appropriate concentration of citral (1/2 MIC, MIC) could notably diminish the fruit spot diameter expansion. Thus, citral shows promise as a potential alternative fungicide for managing postharvest black rot in pitaya.

HPLC-ESI/MS-MS metabolic profiling of white pitaya fruit and cytotoxic potential against cervical cancer: Comparative studies, synergistic effects, and molecular mechanistic approaches

Natural approach became a high demand for the prevention and treatment of such diseases for their proven safety and efficacy. This study is aimed to perform comparative phytochemical analysis of white pitaya (Hylocereus undatus) peel, pulp and seed extracts via determination of total flavonoid content, phenolic content, and antioxidant capacity, coupled with HPLC-ESI/MS-MS analysis. Further, we evaluated the synergistic cytotoxic potential with Cisplatin against cervical cancer cells with investigation of underlying mechanism. The highest content of phenolics and antioxidants were found in both seed and peel extracts. The HPLC-ESI/MS-MS revealed identification of flavonoids, phenolic acids, anthocyanin glycosides, lignans, stilbenes, and coumarins. The cytotoxicity effects were evaluated by MTT assay against prostate, breast and cervical (HeLa) and Vero cell lines. The seed and peel extracts showed remarkable cytotoxic effect against all tested cell lines. Moreover, the selectivity index confirmed high selectivity of pitaya extracts to cancer cells and safety on normal cells. The combined therapy with Cisplatin effectively enhanced its efficacy and optimized the treatment outcomes, through the apoptotic ability of pitaya extracts in HeLa cells, as evaluated by flow cytometry. Besides, RT-PCR and western blotting analysis showed downregulation of Bcl-2 and overexpression of P53, BAX among HeLa cells treated with pitaya extracts, which eventually activated apoptosis process. Thus, pitaya extract could be used as adjuvant therapy with cisplatin for treatment of cervical cancer. Furthermore, in-vivo extensive studies on the seed and peel extracts, and their compounds are recommended to gain more clarification about the required dose, and side effects.

Supercritical extraction of betalains from the peel of different pitaya species.

Pitaya is a fruit with high consumer acceptance and health benefits. Pitaya peel is a waste product with potential in the food industry, as an antioxidant enrichment and natural colouring. Therefore, there is an interest in recovering its constituents and searching for pitaya species with greater potential. This work aimed to obtain bioactive extracts from the dried peel of pitaya fruits of the species Selenicereus monacanthus (Lem.), S. costaricensis W. and S. undatus H. using supercritical fluids at different pressures (100, 250 and 400 bar) and ethanol-water 15% v/v or ethanol 100% as co-solvents. The extraction yield, antioxidant activity, colour and total betalain content were evaluated. The extract obtained from S. monacanthus showed the highest extraction yield (49.6 g kg-1), followed by S. costaricensis (27.5 g kg-1) and S. undatus (17.7 g kg-1) at 400 bar and 35 °C using ethanol 15%, v/v. The antioxidant capacity was strongly influenced by pressure, favouring the obtaining of betalain-rich extracts at higher pressures, especially in the species S. costaricensis (0.6 g kg-1) and S. monacanthus (0.3 g kg-1). To improve the extraction of S. undatus (the most cultivated species), the procedure of subsequential extractions was applied. This procedure considerably increased the extraction yield, antioxidant activity and total content of betalains. The use of ethanol 100% provided more bioactive fractions and achieved a good separation of betalains. The supercritical extraction method can overcome the challenge of efficiently extracting compounds from pitaya peel, due to the presence of bioactive compounds of great polarity. © 2024 Society of Chemical Industry.

Quality Analysis and Evaluation of Different Batches of Pitaya Fruit (Hylocereus) in South China

ABSTRACT Pitaya is a tropical and subtropical fruit; it can produce several batches fruit in one year. To find out the fruit quality differences between various batches in the same year in Guangzhou, South China, 11 pitaya varieties were used as the materials. Comparative analysis was performed between these varieties of each batch by 14 indexes, comprehensive evaluation and ranking were evaluated by the principal component analysis (PCA). Results showed that the red-peel and red-pulp pitaya has the longer fruit period and could obtain more batches fruits. By comparing the fruit quality of these 11 varieties in different batches: Except “Guanhuahong,” fruit weight is significant different between other 10 varieties. The edible rate of fruits from 2nd and 3rd batches is significantly higher than others. The hardness, total sugar, total acid, betalain, total phenol, and flavonoids were significant difference between batches. The PCA results indicated that in most varieties, the 1st, 8th, 9th batches are generally with heavier fruit, better color, harder and sweeter; more stable antioxidant compounds were shown in 6th, 7th, 8th, 9th batches; the 3rd, 4th, 5th, and 6th batches are smaller, softer, lower soluble sugar and higher titratable acid. Pitaya fruit quality and tastes from various batches are different in the same year, the climate may be the main factor. The fruits of 7th, 8th and 9th batches picking from Sep to Nov has better quality and higher economic value. This research has practical application value and could provide theoretical basis for the production of pitaya.

ANTI-AGING PEEL-OFF MASK OF DRAGON FRUIT PEEL EXTRACT (HYLOCEREUS POLYRHIZUS)

Antioxidants can be used to protect the skin from damage caused by oxidation to prevent premature aging. The more increasing consumption level of red dragon fruit (Hylocereus polyrhizus) affects the amount of unused remaining fruit peels. In fact, the peel of red dragon fruit is considerably potential for natural antioxidant. Pitaya or dragon fruit is reported to contain betacyanin color pigment, with antioxidant activity. The use of cosmetics containing antioxidant compounds can prevent premature aging due to free radicals. One of the interesting forms of cosmetic preparations for skin care is the peel-off gel mask. The base that can be used as a film former for peel-off gel facial masks is polyvinyl alcohol (PVA). This study aims to determine the effectiveness of red dragon fruit peel extract peel-off masks as anti-aging. Anti-aging effectiveness testing was carried out on 10 volunteers and divided into two groups, namely the blank group (F0) and the extract group (FIII) for four weeks, and anti-aging activity was measured using a skin analyzer). Based on the results and discussions in this study, it can be concluded that the application of a peel-off mask of red dragon fruit peel extract (Hylocereus polyrhizus) is effective for repairing the skin and providing an anti-aging effect.