Pitaya Peel Research Articles

Synthesis of N/O Atoms Co-Doped Biochar with 3D Porous Structure for Effective Electromagnetic Wave Absorption.

Developing biochar with large specific surface area (SSA), heteroatom doping, and porous structure is attracting substantial attention to absorb electromagnetic wave (EMW) in recent. Herein, a novel method of ethanol and KOH co-treatment is used to produce the biomass carbon deriving from pitaya peels. The obtained carbon possesses the high SSA of 1580 m2/g, successful N/O atoms co-doping, and massive pores with different size. The results of EMW absorption measurement show that the prepared biochar could achieve over 99 % absorpition to EMW, which the highest reflection loss is of ca. -45.25 dB at 7.54 GHz with an effective absorption bandwidth (EAB) of ca. 4.87 GHz. The execellent microwave absorption property is caused by the surface defects, dipole and interface polarizations of the synthesized biochar owning unique microstructure and N/O atoms co-doping. Hence, this avenue provides a new reference for fabricating low-cost and eco-friendly biochar as a microwave absorber.

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.

MXene quantum dots modified pitaya peel-based composite phase change material with excellent thermal properties for building energy efficiency applications

Bio-based materials have attracted much attention because their application in the construction field is conducive to energy saving and emission reduction. In this paper, a bio-based composite phase change material (CPCM) was prepared by utilizing pitaya peel as a bio-based material, MXene quantum dots (MQDs) as a modified material, and polyethylene glycol (PEG) as a phase change medium. MXene quantum dots dispersed in the pitaya peel-based porous carbon skeleton enhanced the three-dimensional thermal conductivity network of the porous carbon skeleton somewhat improved the thermal conductivity (0.676 W/mK) of the polyethylene glycol/MXene quantum dots-modified pitaya peel-based porous carbon foam (PPF) composite phase change material (PEG/PPF@M). It is worth noting that PEG/PPF@M has excellent thermal stability and its enthalpy is basically unchanged after 100 cycles, which proves the recyclable stability of PEG/PPF@M in practical applications. PEG/PPF@M has great potential for thermal management of buildings and electronic components. Overall, a novel multifunctional CPCM was prepared in this study using a simple process method, which can not only be applied in electronic products to improve the service life of electronic components, but also in the field of construction to realize energy saving and emission reduction, as well as the recycling and reuse of waste.

Magnetized pitaya peel bio-based carbon aerogel modified with APD and KH-550 for the removal of acid chrome blue K

Magnetized pitaya peel bio-based carbon aerogel modified with APD and KH-550 for the removal of acid chrome blue K

Development and characterization of pH-sensing films based on red pitaya (Hylocereus polyrhizus) peel treated by high-pressure homogenization for monitoring fish freshness

High pressure homogenization (HPH) was used to physically modify red pitaya (Hylocereus polyrhizus) peel (RPP) dispersions to develop pH-sensing films for monitoring fish freshness. Effects of HPH treatment at various pressures of 0 (control), 10, 20, 30, 40, 60 and 80 MPa on microstructure and properties of RPP film-forming dispersions (FFDs) and their resultant films were systematically investigated. Results showed that due to the structure destructing effect of HPH, the mean particle size of RPP dispersion treated at 80 MPa decreased significantly from 129.17 to 37.41 μm and its total soluble solids content increased from 7.64 to 8.62 °Bx. Rheological analysis manifested that all FFDs exhibited a shear thinning behavior with higher apparent viscosities as well as storage modulus and loss modulus with increasing HPH pressure. Besides, the HPH treated FFDs had a higher total betacyanins content and showed an obvious color response to pH variation. Consequently, the resultant films had not only smoother surfaces and more transparent appearance, but also better water vapor barrier and mechanical properties than the control. Particularly, film obtained from RPP treated at 60 MPa showed a highest tensile strength of 21.87 MPa and elongation at break of 22.09%, together with a lowest water vapor permeability of 11.41 g⋅mm⋅m−2⋅d−1⋅kPa−1. Notably, this film also exhibited high sensitivity to volatile ammonia and showed a remarkable color variation when applied for monitoring fish spoilage at 25 °C. Thus, the pH-sensing films developed from HPH treated RPP had desirable properties to be potentially used in intelligent food packaging.

Nutrition, phytochemical profiling, in vitro biological activities, and in silico studies of South Chinese white pitaya (Hylocereus undatus)

BackgroundWhite pitaya, a popular tropical fruit, is known for its high nutritional value. It is commercially cultivated worldwide for its potential use in the food and pharmaceutical industries. This study aims to assess the nutritional and phytochemical contents and biological potential of the South Chinese White Pitaya (SCWP) peel, flesh, and seed extracts. MethodsExtract fractions with increasing polarity (ethyl acetate < acetone < ethanol < methanol < aqueous) were prepared. Antibacterial potential was tested against multidrug-resistant (MDR) bacteria, and antioxidant activity was determined using, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assays, and cytotoxic activity against human keratinocyte cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Pharmacological screening and molecular docking simulations were conducted to identify potential antibacterial compounds with druggable characteristics. Molecular dynamics simulation (MDS) was employed to validate the binding stability of the promising ligand-protein complexes. ResultsAll parts of the fruit exhibited a substantial amount of crucial nutrients (minerals, sugars, proteins, vitamins, and fatty acids). The ethanol (ET) and acetone (AC) fractions of all samples demonstrated notable inhibitory effects against tested MDR bacteria, with MIC50 ranges of 74–925 μg/mL. Both ET and AC fractions also displayed remarkable antioxidant activity, with MIC50 ranges of 3–39 μg/mL. Cytotoxicity assays on HaCaT cells revealed no adverse effects from the crude extract fractions. LC-MS/MS analyses identified a diverse array of compounds, known and unknown, with antibacterial and antioxidant activities. Molecular docking simulations and pharmacological property screening highlighted two active compounds, baicalein (BCN) and lenticin (LTN), showing strong binding affinity with selected target proteins and adhering to pharmacological parameters. MDS indicated a stable interaction between the ligands (BCN and LTN) and the receptor proteins over a 100-ns simulation period. ConclusionOur study provides essential information on the nutritional profile and pharmacological potential of the peel, flesh, and seeds of SCWP. Furthermore, our findings contribute to the identification of novel antioxidants and antibacterial agents that could be capable of overcoming the resistance barrier posed by MDR bacteria.

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.

Red-fleshed pitaya peels (Hylocereus polyrhizus) as a biosorbent for removal of hormone 17α-methyltestosterone in aqueous medium

Red-fleshed pitaya peels (Hylocereus polyrhizus) as a biosorbent for removal of hormone 17α-methyltestosterone in aqueous medium

Pitaya peel-derived carbon film through one-step carbonization as a functional interlayer for lithium sulfur battery

To address the persistent challenge of soluble lithium polysulfides (LiPSs) migration in lithium-sulfur batteries, this study introduces a functional conductive interlayer derived from a cost-effective porous carbon film, innovatively synthesized through one-step carbonization of pitaya peel waste. The porous structure and abundant oxygen-containing functional groups in the resulting film successfully restrict LiPSs diffusion and boost the redox dynamics of LiPSs. Electrochemical evaluation reveals that the sulfur cathode with the proposed interlayer outperforms a pure sulfur cathode, exhibiting superior discharge capacity and cycling stability. The research presents a simplified and economical method for interlayer fabrication, contributing to sustainable advancements in lithium-sulfur battery technology.

Enhancing corrosion protection in acidic environments through biomass-derived carbon quantum dots

In this work, an effective and eco-friendly biomass carbon quantum dots (BCQDs) inhibitors were prepared by hydrothermal method from pitaya peels. Physicochemical characterization revealed that the particle size and carbon content of BCQD changed depending on the preparation time. In hydrochloric acid solution, BCQDs with smaller particle-sized and/or higher carbon content performed a stronger corrosion inhibition effect according to electrochemical tests. An inhibition efficiency of over 95% could be achieved. Additionally, the inhibition mechanism of BCQDs was also inferred and analyzed. It is expected that this systemic study will provide guidance for the design of nanomaterial corrosion inhibitors in the future.

MXene-modified bio-based pitaya peel foam/polyethylene glycol composite phase change material with excellent photo-thermal conversion efficiency, thermal energy storage capacity and thermal conductivity

The preparation of multifunctional composite phase change materials (CPCM) for efficient conversion and storage of solar energy using green technology remains a big issue. Herein, in this research, a novel CPCM was prepared for the first time by encapsulating polyethylene glycol (PEG) into MXene-modified pitaya peel-based porous carbon using a simple vacuum impregnation method. Pitaya peel-based porous carbon was selected as the carrier to coat with MXene nanosheets to construct a continuous three-dimensional thermal conductivity network. The MXene-modified bio-based pitaya peel foam/polyethylene glycol composite phase-change material (PEG/BPC@M) exhibited high loading ratio (95.4 %) and enthalpy (154.9 J/g). Interestingly, due to the introduction of MXene nanosheets, both the photothermal conversion (θ = 92.9 %) and thermal conductivity (2.34 times that of PEG) of PEG/BPC@M were substantially increased. Significantly, PEG/BPC@M with outstanding thermal stability, wherein the PEG/BPC@M still maintained enthalpy values similar to those in non-thermal cycles after 100 cycles, further proving that PEG/BPC@M has outstanding reusability. This study provided a simple and green novel process for the preparation of multifunctional CPCM, similarly, it provided a feasible scheme for waste reuse, which has huge potentials for the field of solar energy conversion and storage.

The Improvement of Lipid Profiles and Glucose Resistance of Hypercholesterolemic Rats using Tempeh Flour Based-Yoghurt Complemented with Red Pitaya Peel Extract

Tempeh flour is potentially a substitute material in making yoghurt that provides bioactive for improving cardiovascular health. It is also suitably combined with antioxidant sources, such as red pitaya peel extract, which is well known for inhibiting metabolic inflammation. This study aims to analyze the effectiveness of tempeh flour-based yoghurt complemented with red pitaya peel extract in improving lipid profiles and glucose tolerance in hypercholesterolemic rats. A total of 36 male Wistar rats were used and divided into six different groups: regular diet (ND) and five high-fat-diet rat groups treated with no supplementation (HFD); diary-based yoghurt with lactic acid bacteria (YBAL); commercial yoghurt (YB); tempeh flour based-yoghurt with lactic acid bacteria (SY); and tempeh flour based yoghurt complemented with red pitaya peel extract (SDS). The supplementation of each treatment group was given a dose of 3.6 ml/ KgBW/ day as a single dose for 28 days. The blood sample was collected from sinus orbitalis and then used for lipid profile, glucose, liver enzyme analysis, and statistical analysis using ANOVA. The result shows that glucose levels increased significantly in all groups, except HFD groups, and there is no significant difference between normal and yoghurt treatment groups. However, yoghurt and red pitaya peel extract supplementation significantly decrease LDL-C and increase HDL-C levels while improving liver condition during hypercholesterolemia. In conclusion, tempeh flour-based yoghurt complemented with red pitaya peel extract can improve lipid profile and liver health in hypercholesterolemia rats. Therefore, further research on metabolism pathways is needed to develop potential nutraceutical products for people with hypercholesterolemia.

Sustainable aquafeed development: Incorporating select fruit wastes into Zebrafish diets using mathematical model-based approach

Expensive aquafeed is a major problem in aquaculture, creating the need for a low-cost feed that provides ideal nutritional requirement to maximize growth performances. This study aims to formulate and evaluate two new optimized Zebrafish feeds (F1 and F2) using linear programming mathematical model, one of which incorporates two pigment rich fruit wastes (Pitaya peel and Roselle calyx) in the formulation. The model represents nutritional content and cost of each ingredient into linear equations, with the goal of finding ideal combination that satisfies the specific nutrient requirements. By systematically evaluating ingredient proportions, linear programming ensures that Zebrafish receives adequate nutrients at the lowest possible cost, making the feed development process more efficient and cost-effective. The novel feed formulations derived from the mathematical model were tested on the growth and pigmentation of Zebrafish in comparison to a commercial feed (control). Feed intake of F1 and F2 were generally found to be similar to the control feed, indicating the acceptability of the formulated feeds by the Zebrafish. Body weight and length of Zebrafish fed with F1 and F2 were comparable to Zebrafish fed with control feed (p > 0.05). Similarly, Zebrafish fed with F1 and F2 showed no significant differences in pigment intensity compared to Zebrafish fed with control feed (p > 0.05). The survival rate of fishes in all feeding groups were greater than 70 % with no significant differences (p > 0.05). Results obtained in this study illustrated the potential of mathematic linear programming and effectiveness of utilising pigment-rich fruit wastes in formulating an optimized economic aquafeed.

Chemical profile, in vitro bioactivities, and antinociceptive effect of Red Pitaya extracts on zebrafish

Aqueous and ethanolic extracts of red pitaya (Hylocereus polyrhizus) peel, pulp, and seeds were evaluated for their chemical composition by UPLC-Q-TOF-MSE, antioxidant capacity (DPPH and ABTS assays), cytotoxicity and in vitro antiproliferative effect (MTT assay), antinociceptive activity and in vivo toxicity (Zebrafish model). A total of 25 compounds were identified in the extracts, mostly betacyanins, phenolic acids, flavonoids, and organic acids. The seeds extracts displayed both the highest radical scavenging activity and total phenol content. The pulp aqueous extract and ethanolic extracts exhibited some cytotoxicity against Vero cells, depending on the concentration and exposure time. These extracts were also able to inhibit S-180 cells proliferation, however only the peel ethanolic extract showed moderate to high selective indexes (SI: 4.06, 18.63), suggesting that its antiproliferative effect is not associated with the cytotoxic effect towards non-cancer cells, such as Vero cells. Regarding the antinociceptive activity, after adjusting the dose to exclude the sedation effect, the seeds ethanolic extract displayed antinociceptive activity at the inflammatory phase, similar to morphine. The extracts (1.0, 2.5 or 5.0 mg/mL) showed to be safe for zebrafish. In summary, these findings highlight the red pitaya as a promising natural source of bioactive, both in its edible and inedible parts, which can be better probed, for instance as anticancer and antinociceptive agents. In addition, the regular consumption of red pitaya can contribute to the health promotion, and the prevention of chronic diseases.

Pitaya (Hylocereus lemairei) extracts avoid mitochondrial dysfunction and NF-kβ/NLRP-3-mediated inflammation in endothelial cells under high glucose and are in vivo safe

BackgroundPitaya has gained popularity as a dietary alternative for diabetics. However, the precise molecular basis and biochemical effects are not well understood. This study aimed to evaluate pitaya influence in endothelial cells under high glucose, mimicking hyperglycemia. MethodsEA.hy926 cells were treated with 1 µg/mL of extract for 24 h with 35 mM of glucose (HG) and/or metformin (MET; 0.5 mM). It was analyzed cell viability/proliferation, apoptosis, ΔΨm, and pHi. Markers of aerobic (NADH and succinate dehydrogenase, and ATP synthase) and anaerobic (LDH) glycolysis were evaluated, as well as NO levels, NF-kβ, and NLRP3 expressions. To determine in vivo safety, acute toxicity in A. salina was conducted (0.5–65 mg/mL). Chemical characterization was performed by HPLC. ResultsHG negatively impacted cell viability and proliferation. Cells presented high levels of extracellular LDH and NO, as well as an increment on NADH, and succinate dehydrogenase activities, and ATP production. Cytometry revealed an increase in ROS levels, apoptosis, and changes in pHi and ΔΨm, accompanied by an increase in NF-kβ, and NLRP3 expressions. These alterations were partially (extract per se pulp and/or associated with MET) or totally (extract per se peel and/or MET associated) reversed. No toxicity for peel extract at concentrations until 65 mg/mL was found. HPLC revealed quercetin and kaempferol in both extracts. ConclusionData indicate that pitaya peel extract is safe and, according to a Principal Component Analysis, can be used as a co-therapeutic strategy to minimize oxidative damage and inflammation in endothelial cells under high glucose.

Film Properties of Pectin Obtained from Various Fruits’ (Lemon, Pomelo, Pitaya) Peels

Food by-products, as sources of high-value compounds, have shown great promise for formulating novel food packaging and edible films for food preservation. This work focused on extracting pectin from lemon, pomelo, and pitaya peels using an ethanol precipitation method. The degree of esterification and the monosaccharide composition of the extracted pectin were determined, and the antioxidant activity of the pectin was assessed. Subsequently, pectin-based films were prepared using the casting method, employing pectin from various sources. These films’ physical and mechanical properties (tensile strength and elongation at break) were assessed, and their microstructure and intermolecular interactions were examined using scanning electron microscopy and Fourier transform infrared spectroscopy analysis. The results of this study demonstrate variations in the degree of esterification among the three pectin samples, with pomelo peel and lemon peel pectins exhibiting higher degrees of methylation compared to pectin from pitaya peel, which had a lower degree of methylation. However, no significant differences were observed regarding the films’ moisture content and water vapor permeability. Notably, the films made from pitaya peel pectin exhibited superior tensile strength and elongation at break to those derived from pomelo peel and lemon peel pectins. The pectin recovered from these fruit peels had great film properties and thus could be utilized for food packaging and edible films.

Sustainable valorization of pitaya (Hylocereus spp.) peel in a semi-continuous high-pressure hydrothermal process to recover value-added products

This study evaluated the use of a semi-continuous high-pressure hydrothermal process for the recovery of value-added products from pitaya peel. The process was carried out at 15 MPa, a water flow rate of 2 mL/min, a solvent-to-feed ratio of 60 g water/g pitaya peel, and temperatures ranging from 40 to 210 °C. The results show that extraction temperatures (between 40 and 80 °C) promoted the recovery of betacyanin (1.52 mg/g), malic acid (25.6 mg/g), and citric acid (25.98 mg/g). The major phenolic compounds obtained were p-coumaric acid (144.63 ± 0.42 µg/g), protocatechuic acid (91.43 ± 0.32 µg/g), and piperonylic acid (74.2 ± 0.31 µg/g). The hydrolysis temperatures (between 150 and 210 °C) could produce sugars (18.09 mg/g). However, the hydrolysis process at temperatures above 180 °C generated Maillard reaction products, which increased the total phenolic compounds and antioxidant activity of the hydrolysates. Finally, the use of semi-continuous high-pressure hydrothermal process can be a sustainable and promising approach for the recovery of value-added compounds from pitaya peel, advocating a circular economy approach in the agri-food industry.

Optimisation of fish gelatin and red pitaya peel powder edible film production

SummaryGrowing awareness of the environmental devastation caused by plastic packaging, particularly in the food industry, has led to the emergence of the concept of a renewable and environmentally safe consumable film as an alternative to plastic. Red pitaya (dragon fruit) peel (RPP), which has a high pectin content, can be used as an additional ingredient or co‐biopolymer to enhance the functional properties of fish gelatin (FG) edible film. Edible films were produced using casting techniques and varying concentrations of FG (3.2%–8.8% w/v) and RPP (0.2%–1.0%) with the aid of Central Composite Design (CCD) of Response Surface Methodology (RSM) by Design Expert 13's software. The optimal formulation consisted of 5.97% (w/v) FG and 0.45% (w/v) RPP. Increasing the concentrations of RPP and FG affected the thickness (0.18–0.36 mm), water solubility (46.72%–66.78%), brightness (60.04–79.02), redness (7.08–28.36), yellowness (2.48–8.44), and opacity (0.85–2.58) of the physical properties. Mechanical testing revealed a tensile strength between 2.76 and 9.34 MPa and a break elongation between 82.78% and 153.89%. The results suggested the physical and mechanical properties of RPP‐based films were greatly affected by concentration of gelatin.

Effects of Pitaya Peel Supplementation on Nutritional Quality, Overall Sensory Acceptance, In Vitro Glycemic Index, and Antioxidant Release from Fiber-Enriched Cookies

Pitaya peel is a by-product of fruit processing. In this study, the effects of pitaya peel supplementation in the cookie recipe on the nutritional quality, in vitro glycemic index, and antioxidant release from the enriched fiber cookies were investigated. The higher the ratio of pitaya peel powder (PPP) in the recipe, the greater the dietary fiber, betacyanin and phenolic contents, and antioxidant activities of the product. Cookies supplemented with 10–25% PPP were classified as having a low glycemic index, ranging from 51.9 to 45.7 in relation to glucose reference. The release of betacyanins, phenolics, and antioxidant activities from the cookie samples was recorded at the salivary, gastric, intestinal, and colon steps during in vitro sequential digestion, and the gastric digestion showed the highest release of antioxidant content and activity. The increased PPP ratio in the cookie recipe improved the antioxidant activities of the aqueous fractions at the four digestive steps. Statement. This study has a preprint entitled “Effects of the ratio of pitaya peel powder on the product quality, predicted glycemic index, and antioxidant release during in vitro sequential digestion” (DOI: https://doi.org/10.21203/rs.3.rs-2322871/v1). This preprint was posted on the research square website on December 5th, 2022.