Red Pitaya Research Articles

Physico-chemical characteristics, and bioactive compounds of red fruits of sweet pitaya (Stenocereus thurberi)

The objective of this study was to determine the physical and chemical characteristics and the content of bioactive compounds of ripe fruits of red sweet pitaya (Stenocereus thurberi). Sweet pitaya fruits are spherical, with a high moisture content (85.8%), a pulp percentage of 71.6%, soft texture (3.4 N), low acidity (0.18%), a total soluble solids content of 12.83 °Brix, with glucose and fructose being the main sugars with a content of 35.65 and 17.48 g 100 g-1 dry weight, respectively. The fruit has a low protein content (0.86% fresh weight) with tyrosine, glutamate, and methionine are the main essential amino acids. The pitaya flesh showed traces of carotenes, low content of L-ascorbic acid (12.45 mg 100 g-1 fresh weight), a content per gram of dry weight of total phenols of 11.31 mg gallic acid equivalents (GAE), total flavonoids of 13.70 mg quercetin equivalent (QE) and total betalains of 2.43 mg. The peel had a higher content of phenols and total flavonoids (5.5 and 4.3 times higher, respectively) than the flesh, which could be considered a potential source of these compounds. The red fruits of sweet pitaya can be considered a source of phenolic compounds and betalains with potential benefits to human health.

Optimization of Antioxidant Extraction in Hylocereus polyrhizus Seed using Response Surface Methodology

Seeds of red pitaya fruit (Hylocereus polyrhizus) are commonly left underutilized in the food industry. Thus, the objective of this present study was to optimize the extraction condition for the maximum DPPH radical scavenging activity of red pitaya fruit seed extract using response surface methodology (RSM). A Central Composite design was employed to determine the effects of the selected variables, comprising extraction time (30-90 min), extraction temperature (40-80 ℃) and ethanol concentration (60-80 %) on the DPPH scavenging activities. Data were analyzed by using Design Expert (version 10.0.1, Stat-Ease, Inc., Minneapolis, MN, USA) statistical analysis software. The optimal extraction conditions for the highest antioxidant capacity were derived at 45 mins of extraction time, 70℃ extraction temperature and 80% ethanol concentration that resulted in 92.89 % of scavenging activity. The optimized model developed was verified by comparing the predicted and experimental value of response. The result of measured response agreed well with the predicted values, demonstrating that the model can be used for optimizing the conditions of RSP extract that ensure high recovery of DPPH radical scavenging activity.

Effect of blue light on primary metabolite and volatile compound profiling in the peel of red pitaya

Blue light treatment can effectively delay the decay of many fruits during postharvest storage. However, little is known about the blue light-induced metabolites. In this study, pitaya fruit was treated with 300 lx blue light for 2 h. Result showed that the decay of pitaya fruit was significantly delayed after blue light treatment, and the change tendency of many physiological characters of pitaya fruit was also significantly weakened. Blue light treatment significantly reduced the increasing tendencies of respiratory rate, titrable acid (TA), H2O2 content, as well as the decreasing tendencies of total soluble solids (TSS), TSS-TA ratio, DPPH radical-scavenging activity, reducing power. To excavate the details of the change in pitaya peel, the primary metabolites and volatile compounds were determined by using gas chromatography coupled to mass spectrometry (GC–MS). A total of 84 metabolites changed significantly after blue light treatment, including 45 primary metabolites and 39 volatile compounds. Most of primary metabolites increased their levels at 1 d after blue light treatment, mainly including soluble sugars, amino acids, fatty acids, organic acids and alcohols. The increase of those metabolites might play a vital role in blue light-delayed the decay of pitaya fruit. After blue light treatment, the contents of most of volatile compounds and some primary metabolites significantly decreased at later stage of storage, mainly including cell wall monosaccharides, aldehydes, esters, ketones, alkanes and volatile alcohols, which might be related to the delay of fruit senescence by blue light treatment.

Development of active and intelligent packaging by incorporating betalains from red pitaya (Hylocereus polyrhizus) peel into starch/polyvinyl alcohol films

This study aims to develop active and intelligent packaging films based on starch/polyvinyl alcohol incorporated with betalains-rich red pitaya (Hylocereus polyrhizus) peel extract. The microstructure, physical and functional properties of the films with different contents of the extract (0.25, 0.50 and 1.00 wt% on starch basis) were measured. Results showed betacyanins were the main components in the extract, which presented significant color changes under alkaline conditions. Scanning electron microscopy observation revealed the compactness of the films was improved by the extract addition. Fourier transform infrared spectroscopy revealed that betacyanins in the extract could interact with starch, polyvinyl alcohol and glycerol through hydrogen bonds. The incorporation of the extract enhanced the water vapor barrier and ultraviolet–visible light barrier ability, and mechanical, antioxidant and antimicrobial potential of the films. The film containing 1.00 wt% of the extract was more sensitive to ammonia than other films. When applied to monitor the freshness of shrimp, the film containing 1.00 wt% of the extract presented visible color changes due to the accumulated volatile nitrogen compounds during the spoiling process of shrimp. Our results suggest the film containing 1.00 wt% of the extract can be used as active and intelligent packaging in food industry.

Simple and robust speckle detection method for fire and heat detection in harsh environments.

Standard laser-based fire detection systems are often based on measuring the variation of optical signal amplitude. However, mechanical noise interference and loss from dust and steam can obscure the detection signal, resulting in faulty results or the inability to detect a potential fire. The presented fire detection technology will allow the detection of fire in harsh and dusty areas, which are prone to fires, where current systems show limited performance or are unable to operate. It is not the amount of light or its wavelength that is used for detecting fire, but how the refractive index randomly fluctuates due to heat convection from the fire. In practical terms, this means that light obstruction from ambient dust particles will not be a problem as long as a small fraction of the light is detected and that fires without visible flames can still be detected. The standalone laser system consists of a Linux-based Red Pitaya system, a cheap 650nm laser diode, and a positive-intrinsic-negative photo-detector. Laser light propagates through the monitored area and reflects off a retroreflector generating a speckle pattern. Every 3s, time traces and frequency noise spectra are measured, and eight descriptors are deduced to identify a potential fire. Both laboratory and factory acceptance tests have been performed with success.

Effects of probiotics on the content and bioaccessibility of phenolic compounds in red pitaya pulp.

This study assessed the effects of the incorporation of Lactobacillus acidophilus LA-05 or Bifidobacterium animalis ssp. lactis BB-12 in the content and bioaccessibility of phenolics in red pitaya pulp. The oxygen radical absorbance capacity (ORAC) of the dialyzed (bioaccessible) fraction of red pitaya pulp fermented by these probiotics was also assessed. After 48 h of cultivation in red pitaya pulp, the pH and sugar contents decreased, while organic acids and viable counts of the tested probiotics increased (p < 0.05). After exposure to simulated gastrointestinal conditions the viable counts of L. acidophilus LA-05 and B. lactis BB-12 in fermented red pitaya pulp were close to 8 and 7 log CFU/mL, respectively. Fermentation with probiotics decreased (p < 0.05) the contents of phenolic acids and flavonoids in red pitaya pulp. Both, L. acidophilus LA-05 and B. lactis BB-12 increased the presence of phenolics in the non dialyzed fraction of the red pitaya pulp. The bioaccessibility of catechin, epigallocatechin gallate, and procyanidin B2 increased (p < 0.05) in red pitaya pulp fermented by L. acidophilus LA-05 or B. lactis BB-12. The bioaccessible fraction of red pitaya pulp fermented by L. acidophilus LA-05 or B. lactis BB-12 showed higher antioxidant activity than that of the non-fermented red pitaya pulp. These findings indicate the fermentation of red pitaya by probiotics as an alternative to increase the bioaccessibility of specific phenolics, as well as the antioxidant activity in this fruit.

Application of Gelatin Incorporated with Red Pitaya Peel Methanol Extract as Edible Coating for Quality Enhancement of Crayfish (Procambarus clarkii) during Refrigerated Storage

China is one of the largest producers of red pitaya in the world and responsible for disposal of the huge amount of peel generated as a waste. The objective of this research was to evaluate the effect of the addition of red pitaya peel extract (RPPE, 1.0%, 2.0%, or 3.0% (w/v)) and 0.1% ε-polylysine (ε-PL) to a fish gelatin edible coating on the preservation of deshelled crayfish (Procambarus clarkii) during refrigerated storage. The physicochemical and water migration of the samples were determined during 8-day storage. Deshelled crayfish packaged in edible coatings exhibited significantly (p&lt;0.05) lower values for total volatile basic nitrogen (TVB-N), K value maintenance, and free amino acids (FAAs). This study shows that application of an edible coating incorporated with RPPE and ε-PL is an effective strategy in retarding the quality deterioration in deshelled crayfish during storage.

The digital mirror Langmuir probe: Field programmable gate array implementation of real-time Langmuir probe biasing.

High bandwidth, high spatial resolution measurements of electron temperature, density, and plasma potential are valuable for resolving turbulence in the boundary plasma of tokamaks. While conventional Langmuir probes can provide such measurements, either their temporal or spatial resolution is limited: the former by the sweep rate necessary for obtaining I-V characteristics and the latter by the need to use multiple electrodes, as is the case in triple and double probe configurations. The Mirror Langmuir Probe (MLP) bias technique overcomes these limitations by rapidly switching the voltage on a single electrode cycling between three bias states, each dynamically optimized for the local plasma conditions. The MLP system on Alcator C-Mod used analog circuitry to perform this function, measuring Te, VF, and Isat at 1.1 MSPS. Recently, a new prototype digital MLP controller has been implemented on a Red Pitaya Field Programmable Gate Array (FPGA) board which reproduces the functionality of the original controller and performs all data acquisition. There is also the potential to provide the plasma parameters externally for use with feedback control systems. The use of FPGA technology means the system is readily customizable at a fraction of the development time and implementation cost. A second Red Pitaya was used to test the MLP by simulating the current response of a physical probe using C-Mod experimental measurements. This project is available as a git repository to facilitate extensibility (e.g., real-time control outputs and more voltage states) and scalability through collaboration.

Postharvest dipping treatment with BABA induced resistance against rot caused by Gilbertella persicaria in red pitaya fruit

β-Aminobutyric acid (BABA) is an elicitor that is capable of inducing disease resistance in many plants. The effect of postharvest BABA treatment on rot caused by Gilbertella persicaria and the underlying mechanisms of action of BABA in pitaya fruit (Hylocereus undatus cv. Zihonglong) were investigated. Fruits were dipped in 10 mM BABA for 15 min and then stored at ambient temperature (25 ± 2 °C, RH 70˜75%). The results showed that 10 mM BABA had no obvious inhibitory effects on G. persicaria in vitro. However, BABA significantly reduced lesion diameter in pitaya inoculated with G. persicaria relative to the control. Furthermore, BABA increased the activities of phenylalanine ammonia lyase (PAL), 4-coumarate/coenzyme A ligase (4CL), peroxidase (POD) and polyphenol oxidase (PPO) and promoted the accumulation of lignin, flavonoids and phenolic compounds in the fruit. These results suggested that postharvest application of BABA via immersion induced resistance in pitaya fruit by activating defense-related enzymes, and BABA treatment may be an alternative method for the control of postharvest diseases in fruits.

An Automated Scanning System for the Acquisition of Nonuniform Time-Varying Magnetic Fields

This paper presents an automatic scanning solution for measuring nonuniform magnetic fields captured by a tri-axial sensor connected to a time-domain acquisition system over a robotic arm. The sensor has been realized and calibrated through a canonical configuration consisting of Helmholtz coils. The acquisition system is instead executed by a Red Pitaya, which is an FPGA-based board with high performance and reliability regarding the sampling rate of the input signal. A LabVIEW software has then been developed for the acquisition of the sampled signal over time, the calculation and post-processing of the magnetic field, and the data saving. Finally, an Arduino-based robotic arm has been employed to make the acquisition system fully automated. This is particularly useful for the compliance assessment against electromagnetic field exposures at workplaces.

The Effect of Red Pitaya Peel (Hylocereus polyrhizus Extract) on Malondialdehida Levels and Histopathology Profile in Diazinon Induced Rat (Rattus norvegicus)

Diazinon, an organophosphate insecticide is widely used in agricultural sectors. The metabolic products of this organophosphate compound can increase Reactive Oxygen Species (ROS) in the body. It causes complications to the various organs, one of which is gastric. Red pitaya peel extract (Hylocereus polyrhizus) has high antioxidant activity in lowering ROS, in cases of diazinon poisoning. This study aims to determine the effectiveness of redpitaya peel extract in reducing the levels of Malondialdehyde (MDA) and repairing histopathological damage of rats induced by diazinon. This study used 20 tails of male white Wistar rats (Rattus norvegicus) from 8-12 weeks of age with the average weight of 150 grams . The subject was divided into 5 groups, which were negative control (-), positive control (+), treatment 1 (P1), treatment 2 (P2), and treatment 3 (P3). A dose of 40 mg/kg BW of Diazinon was given orally every day through feeding tube (sonde) for 5 consecutive days. Red pitaya peel extract was given to test groups with a dose of 150 mg/150 g BW, 200 mg/150 g BW and 250 mg/150 g BW, for 14 days. MDA levels were measured using the Thiobarbituric acid (TBA) test. Gastric histopathology features were stained with Hematoxylin-Eosin (HE) after 14 days. The MDA levels were analyzed quantitatively by ANOVA using SPSS version 22 for Windows and continued with honestly significant difference (HSD) test (α = 5%) and gastric histopathology were analyzed descriptively. The results showed that the extract of red pitaya peel with dose of 150 mg/150 g BW significantly (p&lt;0.01) reduces MDA level in gastric dan improves the histopathology of the gastric. Red pitaya peel extract at a dose of 150 mg/150 g BW was able to significantly decrease MDA levels and improve the histopathology feature of the gastric in white rats induced by diazinon. So this can be summarised that giving red pitaya extract in rats have a very significant effect on the level of malondialdehyde production and it could repair rats stomach tissue that induced by diazinon.Keywords: diazinon, histopathology, MDA, red pitaya peel

Effect of Ripening Stages on Shelf Life and Quality of Pitaya Fruits during Storage

Aims: The study objective was to determine the harvest point of red pitaya produced in the north of Minas Gerais, Brazil, according to physical and chemical changes during refrigerated storage.&#x0D; Study Design: The experiment was conducted through a completely randomized design in a 3 x 5 factorial scheme composed of three treatments (ripening stages) and five post-harvest assessment days (0, 5, 10, 15 and 20), with four repeats of four fruits per experimental unit.&#x0D; Study Place and Duration: The experiment was conducted in a cold chamber at the State University of Montes Claros, Brazil, between July and August 2018.&#x0D; Methodology: The following quality parameters were assessed: fruit fresh mass, length and diameter at harvest point, color, firmness, soluble solid content, titratable acidity, total sugars, reducing and non-reducing, pH and amide, during storage.&#x0D; Results: There was no significant difference for fresh mass, length and diameter as a function of ripening stages. Ripening stages 2 and 3 presented higher soluble solid content means.&#x0D; Conclusion: Considering the conditions of northern Minas Gerais, harvest should happen at stages 2 or 3, when fruits have a brighter red hue, that is, are more attractive and of easier identification by producers. In addition, pitayas at these stages have higher soluble solid contents and reduced pulp acidity during storage in relation to fruits harvested at S1.

RNA-Seq De Novo Assembly of Red Pitaya (Hylocereus polyrhizus) Roots and Differential Transcriptome Analysis in Response to Salt Stress

Pitaya (Hylocereus polyrhizus) is a highly valued functional food that is widely planted in Southeast Asia. However, with increased soil salinization in cultivation areas, a better understanding of the molecular mechanisms associated with salt stress responses in red pitaya is necessary. Herein, RNA-Seq was used to de novo assemble and characterize the transcriptomic profiles of red pitaya roots in response to salt stress. A total of 73,589 transcripts were obtained and the average sequence length was 1308 bp. From these transcripts, 26,878 unique transcripts were successfully matched to 13,519 Swiss-prot proteins. Gene ontology (GO) annotations showed that within the categories of molecular function, biological function, and cell component, catalytic activity (GO:0003824), metabolic process (GO:0008152), and cell part (GO:0044464) were the most enriched, respectively. 2624 transcripts were significantly differentially expressed among three time points (3 h, 7 h, and 30 h) following exposure to 450 mM NaCl. Furthermore, 261 genes were up-regulated and 61 down-regulated in all three of the time points. Glycolysis/gluconeogenesis was one of the most significantly modulated pathways. The findings presented herein provide further insight into salt stress responses in pitaya and will provide a valuable resource for future functional studies examining salt adaptations.

Synergistic effect of 1-methylcyclopropene and carvacrol on preservation of red pitaya (Hylocereus polyrhizus)

Pitaya fruit is susceptible to fungal attack and shrivelling during storage. This study investigated the individual and combined effect of 1-methylcyclopropene (1-MCP) and carvacrol (CVR) on red pitaya. Fruits were treated with 1 µL L−1 1-MCP, 20 µL L−1 CVR or their combination (1-MCP + CVR), and then storage at 7 °C for 30 days. 1-MCP + CVR was more effective in suppressing decay and maintaining quality during storage than individual treatment of 1-MCP or CVR. In addition, 1-MCP + CVR treatment led to decreased levels of O2−, H2O2, and lipid peroxidation, concomitant with increased activities of superoxide dismutase, catalase, and ascorbate peroxidase, and elevated total phenolic content, as compared to the individual application. Moreover, transmission electron microscopy observation showed that the combined treatment protected cell ultrastructure from oxidative damage. This study suggests 1-MCP combined with CVR may be a useful method for the preservation of pitaya fruit.

Comparative Study on Cold Resistance Physiology of Red Pulp Pitaya and White Pulp Pitaya

The red pulp pitaya variety ’Taiwan No. 2’ and the white pulp pitaya variety ’white crystal’ were used as experimental materials, which were cold stressed at low temperature of 3 °C for 48h, 96h, and recovering at room temperature after 96h cold stress for control. The relative conductivity (REC), malondialdehyde content (MDA), soluble sugar content (SS), soluble protein content (SP), free proline content (Pro), activity of superoxide dismutase (SOD), and catalase (CAT) were determined and the cold resistance were analyzed. The results showed that, after cold stress, the SP, Pro content and SOD and CAT activities of ’White Crystal’ pitaya were higher than that of ’Taiwan No. 2’ pitaya. It showed that the cold resistance of ’White Crystal’ white pulp pitaya was stronger than that of ’Taiwan No. 2’ red pulp pitaya.

Lipase-catalyzed synthesis of red pitaya (Hylocereus polyrhizus) seed oil esters for cosmeceutical applications: process optimization using response surface methodology.

Esters were synthesized via the alcoholysis of red pitaya seed oil with oleyl alcohol catalyzed by immobilized lipase, Lipozyme RM IM. The effects of synthesis parameters, including temperature, time, substrate molar ratio and enzyme loading, on the yield and productivity of esters were assessed using a central composite response surface design. The optimum yield and productivity were predicted to be about 80.00% and 0.58 mmol h−1, respectively, at a synthesis temperature of 50.5 °C, time of 4 h, substrate molar ratio of 3.4 : 1 and with 0.17 g of enzyme. Esters were synthesized under the optimum synthesis conditions; it was found that the average yield and productivity were 82.48 ± 4.57% and 0.62 ± 0.04 mmol h−1, respectively, revealing good correspondence with the predicted values. The main esters were oleyl linoleate, oleyl oleate, oleyl palmitate and oleyl stearate. The synthesized esters exhibited no irritancy effects and their physicochemical properties showed their suitability for use as cosmeceutical ingredients.

Growth and nutrient accumulation in the aerial part of red Pitaya (Hylocereus sp.)

Abstract Knowledge on the amounts of nutrients accumulated by pitaya in its different development stages allows defining the periods in which the essential elements are most required, thus contributing to the elaboration of rational fertilization programs for the crop, reducing production costs. This study aimed to evaluate the growth and nutritional requirement of red pitaya, estimating the accumulation of macro and micronutrients by the plants and determining the periods in which the greatest accumulations occur, as well as the relative growth rate and the relative nutrient absorption rate. Pitaya seedlings were planted in pots containing Argissolo Vermelho-Amarelo Eutrófico (Ultisol) and grown in the open air. The experimental design was randomized blocks, with four replicates and seven sampling times: 0, 60, 120, 180, 240, 300 and 360 DAP (days after planting). At each sampling time, length of cladodes, dry matter of the aerial part and nutrient accumulation in the aerial part were evaluated. Red pitaya plants showed a low growth rate until 60 days and, from this period, its growth increased significantly. Nutrient accumulation occurred in the following descending order: K &gt; Ca &gt; N &gt; Mg = P &gt; S &gt; Na element &gt; Zn &gt; Mn &gt; Fe &gt; B &gt; Cu. K and Zn were, respectively, the most exported macro and micronutrient by pitaya fruits.

Effects of Different Compound Treatments on Cold Resistance of Pitaya Plants

In this study, using red pulp pitaya plants variety ’Taiwan No. 6’ as experiment material, 2, 4-epitheloside (BR), betaine (GB), calcium chloride (CaCl2) and salicylic acid (SA) were selected as experimental factors which were set at three levels. The effects of different treatments on the cell membrane stability and osmotic adjustment substances of pitaya plants were studied by orthogonal design. The results showed that salicylic acid was the main factor affecting the relative conductivity and soluble sugar content. 2, 4-epibrassinolide was the main factor affecting the content of malondialdehyde and free proline. CaCl2 was the main factor affecting the soluble protein content. The best concentration combination for improving the cold resistance of pitaya plants was as follows: BR 1 μg/L, GB 2.5 mmol/L, CaCl2 250 mg/L, and GA 0.5 mmol/L.

Activity of red dragon fruit (Hylocereus polyrhizus) juices on doxorubicin-induced nephropathy in rats

Nephropathy is a common side effects following treatment by an antineoplastic drug, doxorubicin. Dragon fruitis rich in antioxidants which are also beneficial for supporting effective tissue regeneration and reduce detrimental sequelae of chemotherapy. The aim of this study was to determine attenuation capacities of red dragon fruit juice in doxorubicin (DOX)-induced renal damages, based on histopathological findings. Male Sprague-dawley rats, consist of 18 rats were divided into three groups. Group I was given NaCl 0.9% (saline) at the dose of 0.4 ml/rat intraperitoneally (IP) weekly for 4 weeks. Group II was given DOX to induce nephropathy at the dose 4 mg/kg body weight (BW) IP weekly for 4 weeks. Group III was given DOX at the dose 4 mg. kg BW IP weekly for 4 weeks and red pitaya juice at dose 4 ml/kg perorally (PO) three times daily for 5 weeks. Nephrotoxicity was assessed by counting total glomerular that have protein deposisition and tubular cells necrosis. Treatment in group III significantly (p<0.05) decreased the numbers of glomerular that have protein deposition and tubular necrotic cells as compared with group II. These results suggest that red dragon fruit juice has the potential nephroprotective activities in doxorubicin-induced nepropathy.

Development of a Portable Electrical Impedance Tomography System for Biomedical Applications

A portable electrical impedance tomography (EIT) system has been developed with Red Pitaya STEMlab for biomedical applications. The Red Pitaya STEMlab is a portable device to realize voltage generation and data acquisition for the EIT system. The EIT system includes a modified howland circuit as a voltage-controlled current source, a high-speed analogy multiplexer module, an 8-electrode array, and a personal computer. The generalized vector sampled pattern matching algorithm and the Tikhonov regularization algorithm are used to reconstruct the image generated by the EIT system. The reconstructed images by using Red Pitaya STEMlab are compared with a commercial impedance analyzer IM3570 within the frequencies of $f = 100$ KHz. The results show that the maximum difference of the image correlation between Red Pitaya STEMlab and IM3570 is 5.36%. Finally, the EIT system is used to image the conductivity of eggs during heating process. These results verified that the developed portable EIT system with Red Pitaya STEMlab could measure the biological tissue in a high accuracy at low cost.