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The aim of this work was to assess the chemical composition and physico-chemical, techno-functional, and in vitro antioxidant properties of flours obtained from the peel and flesh of pitahaya (Hylocereus ocamponis) to determine their potential for use as ingredients for food enrichment. The chemical composition, including total betalains, mineral content, and polyphenolic profile, was determined. The techno-functional properties (water holding, oil holding, and swelling capacities) were also evaluated. For the antioxidant capacity, four different methodologies, namely ferrous ion-chelating ability assay, ferric-reducing antioxidant power assay; 1,1-Diphenyl-2-picrylhydrazyl radical scavenging ability assay, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical assay, were used. Pitahaya-peel flour had higher values for protein (6.72 g/100 g), ash (11.63 g/100 g), and dietary fiber 56.56 g/100 g) than pitahaya-flesh flour, with values of 6.06, 3.63, and 8.22 g/100 g for protein, ash, and dietary fiber, respectively. In the same way, pitahaya peel showed a higher content of minerals, betalains, and polyphenolic compounds than pitahaya-flesh flour, with potassium (4.43 g/100 g), catechin (25.85 mg/g), quercetin-3-rhamnoside (11.66 mg/g) and myricetrin (12.10 mg/g) as principal compounds found in the peel. Again, pitahaya-peel flour showed better techno-functional and antioxidant properties than pitahaya-flesh flour. The results obtained suggest that the flours obtained from the peel and pulp of pitahaya (H. ocamponis) constitute a potential material to be utilized as an ingredient in the food industry due to the high content of bioactive compounds such as betalains, phenolic acids, and flavonoids, with notable antioxidant capacity.

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In this study, a selective and sensitive electrochemical approach for determining hydroxychloroquine (HCQ) was proposed. A novel nanocomposite based on gold nanoparticles synthesized by green synthesis in an extract of white pitaya (Hylocereus undatus) (AuNP-Ext) decorated with functionalized multi-walled carbon nanotubes (f-MWCNTs) was presented. AuNP-Ext was characterized by ultraviolet-visible spectroscopy and the f-MWCNTs/AuNP-Ext nanocomposite by transmission electron microscopy. The nanocomposite was used to modify a glassy carbon electrode (GCE). Using the f-MWCNT-AuNP-Ext/GCE sensor, an irreversible oxidation peak at +0.74 V vs. Ag/AgCl was verified by HCQ. The calibration plot was studied in two linear ranges, from 0.03 to 3.5 µmol/L and from 3.5 to 17.0 µmol/L, with a limit of detection of 0.0093 µmol/L and a limit of quantification of 0.031 µmol/L, regarding the first linear range. The proposed sensor was successfully applied to the determination of HCQ in pharmaceutical and clinical samples without any special purification, separation or pre-treatment steps. The accuracy was verified by UV-Vis spectrometry, and this revealed that the proposed method was accurate and precise, as evidenced by F- and t-tests.

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The main objective of this study was to optimize the extraction of dietary fiber (insoluble dietary fiber and soluble dietary fiber) and degree of esterification from yellow dragon fruit peels using ultrasound-assisted extraction. Additionally, the study aimed to investigate the potential application of this fiber as a fat replacement in alpaca-based sausages. The optimization process for extracting dietary fiber and degree of esterification involved considering various factors, including the liquid-to-solid ratio, pause time, and total ultrasound application time. A Box-Behnken design consisting of 15 treatments was employed to determine the optimal levels for ultrasound-assisted extraction. The optimized conditions were found to be a liquid-to-solid ratio = 30 mL/g, pause time = 1 s, and total ultrasound application time = 60 min, which resulted in the highest values of insoluble dietary fiber (61.3%), soluble dietary fiber (10.8%), and the lowest value of degree of esterification (39.7%). The predicted values were validated against experimental data and showed no significant differences (p > 0.05). Furthermore, a completely randomized design was utilized to assess the effect of dietary fiber on replacing fat content during the production of alpaca-based sausages. The findings revealed that up to 78% of the fat content could be successfully replaced by soluble dietary fiber obtained from yellow dragon fruit peels when compared to high-fat sausages. Additionally, experimental sausages using soluble dietary fiber showed similar (p > 0.05) quality characteristics, such as hardness (24.2 N), chewiness (11.8 N), springiness (0.900), cohesiveness (0.543), redness (a* = 17.4), and chroma values (20.0), as low-fat commercial sausages.

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Dragon fruit (Hylocereus genus) has the potential for the prevention of diseases associated with inflammatory and oxidative processes. We aimed to comprehensively review dragon fruit health effects, economic importance, and possible use in delivery systems. Pubmed, Embase, and Google Scholar were searched, and PRISMA (Preferred Reporting Items for a Systematic Review and Meta-Analysis) guidelines were followed. Studies have shown that pitaya can exert several benefits in conditions such as diabetes, dyslipidemia, metabolic syndrome, cardiovascular diseases, and cancer due to the presence of bioactive compounds that may include vitamins, potassium, betacyanin, p-coumaric acid, vanillic acid, and gallic acid. Moreover, pitaya has the potential to be used in food and nutraceutical products as functional ingredients, natural colorants, ecologically correct and active packaging, edible films, preparation of photoprotective products, and additives. Besides the importance of dragon fruit as a source of bioactive compounds, the bioavailability is low. The development of delivery systems such as gold nanoparticles with these compounds can be an alternative to reach target tissues.

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Dragon fruit, pitahaya or pitaya are common names for the species in the Hylocereus group of Selenicereus that produce edible fruit. These Neotropical epiphytic cacti are considered promising underutilized crops and are currently cultivated around the world. The most important species, S. undatus, has been managed in the Maya domain for centuries and is the focus of this article. Transcriptome profiles from stems of wild and cultivated plants of this species were compared. We hypothesized that differences in transcriptomic signatures could be associated with genes related to drought stress. De novo transcriptome assembly and the analysis of differentially expressed genes (DEGs) allowed us to identify a total of 9,203 DEGs in the Hunucmá cultivar relative of wild Mozomboa plants. Of these, 4,883 represent up-regulated genes and 4,320, down-regulated genes. Additionally, 6,568 DEGs were identified from a comparison between the Umán cultivar and wild plants, revealing 3,286 up-regulated and 3,282 down-regulated genes. Approximately half of the DEGs are shared by the two cultivated plants. Differences between the two cultivars that were collected in the same region could be the result of differences in management. Metabolism was the most representative functional category in both cultivars. The up-regulated genes of both cultivars formed a network related to the hormone-mediated signaling pathway that includes cellular responses to auxin stimulus and to hormone stimulus. These cellular reactions have been documented in several cultivated plants in which drought-tolerant cultivars modify auxin transport and ethylene signaling, resulting in a better redistribution of assimilates.

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Stenocereus queretaroensis (F.A.C. Weber ex Mathes.) Buxb is a cactus that has long been used as a source food in central and northern México. Its fruits, commonly called pitayas, biosynthesize high amounts of betalains. These molecules are water-soluble nitrogenous compounds; that compared to other pigments, such as anthocyanins or carotenoids, stand out for their physicochemical stability in industrial processes. Due to genetic and environmental factors involved in the biosynthesis and accumulation of secondary metabolites in plants, we tested different stress-inducing agents (elicitor, osmotic, salt, and temperature) to induce betalains accumulation in cell culture from fruits of Stenocereus queretaroensis. This work aimed to understand stress conditions that induce the metabolic pathways required for the accumulation of betalains. The results show how betacyanin concentration increases under high sugar conditions, thus affecting the expression of L-DOPA 4, 5 dioxygenase resulting in a strong dark red coloration. This suggests this enzyme is part of a rate-limiting step in betalain production. In addition, we found that betalains accumulation occurs under particular stress conditions. Cells that have a high level of betacyanins show better resistance to stress in the cell culture, as well as an overall different behavior including cell aggregation and alterations in nuclear size. Together the results shown here may provide new strategies to manipulate and mass produce the pigments from Stenocereus queretaroensis in cell culture.

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Pharmaceutical compounds are a serious problem in the environment. They cause damage to the aquatic, animal, and human organisms and soon became considered emerging pollutants where their removal is extremely urgent. Among the techniques used, adsorption has been used with success, where several adsorbent materials, including those from residual biomass, have been used to remove these pollutants. In this study, the skins of the pitaya fruit (Hylocereus undatus) productive chain were carbonized with ZnCl2 to obtain activated carbon and later used in the adsorption of the drug naproxen (NPX) in a batch system. The Freundlich model demonstrated a better adjustment for the equilibrium isotherms. A high adsorption capacity for NPX (158.81 mg g-1) was obtained at 328 K, which can be attributed to the remarkable textural properties of the adsorbent, besides certain functional groups present on its surface. Thermodynamic studies confirmed the endothermic nature of the adsorption process (∆H0 = 0.2898 kJ mol-1). The linear driving force model (LDF) presented a good statistical adjustment to the experimental kinetic data. The application of the material in the treatment of simulated wastewater composed of various pharmaceutical drugs and salts was very promising, reaching 75.7% removal. Therefore, it can be inferred that the application of activated carbon derived from pitaya bark is highly promising in removing the NPX drug and treating synthetic mixtures containing other pharmaceutical substances.

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The addition of fruit to the diet is very important, and we can use nutraceutical and functional foods for this supplement. A little-known fruit is a red pitaya (Hylocereus undatus) that has been widely reported to have a high antioxidant potential. In this study, we analyzed the in vitro and in vivo antioxidant capacity of microencapsulated pitaya extract on the behavior, antioxidant, and nervous system of the nematode Caenorhabditis elegans. The worms were treated with fruit extract before and after juglone-induced stress, to determine the protective or curative effects of pitaya. We have been evaluated cholinergic, antioxidant, and behavioral biomarkers. We have evidenced that the pulp of pitaya contains antioxidant compounds and can serve as a potential nutraceutical product. In addition, the fruit extract was effective in preventing and/or reverse the stress-induced damages, even at high levels of chemical stress at all evaluated parameters. PRACTICAL APPLICATIONS: The potential applications and uses aimed by this research are related to the supplementation of foods given the antioxidant effect. Our data suggested that the effect of the pitaya fruit microencapsulated pulp extract was effective to prevent and repair the damage caused by oxidative stress. Besides the use of this microencapsulated extract can be an auxiliary in the treatment of diseases related to oxidative damage as well as promoting senescent aging. Another important use is the application of this extract as a dietary supplement to fortify the antioxidant system.

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Abstract Endophytic bacteria from weed are emerging as valuable alternatives for biochemical pesticides in sustainable agriculture. This study aims to discover the antagonistic effects of some endophytic bacteria isolated from weed (Lactuca indica) against A. alternata, a casual of stem end rot disease of pitaya. A total of 14 endophytic bacteria were isolated and four of them presented in vitro antagonistic activity against A. alternata. Of four, strain L115 significantly inhibited the pathogenic growth with a mean inhibition diameter of 12.67 ± 0.02 mm, while the other three (strain L110, L111, and L114) showed a weak inhibition. The results indicated that strain L115 could belong to the Bacillaceae family while the other three (strain L110, L111, and L114) had characteristics of the Pseudomonadaceae family. Interestingly, strain L115 showed positive results for phosphate solubilization, indole acetic acid (IAA), and biofilm production, whereas three other strains presented weak capabilities for phosphate solubilization, biofilm production and IAA production. In addition, the filtrate of strain L115 presented antifungal activity on biocontrol tests in vitro. Especially, strain L115 significantly increased seedling biomass of pitaya and tomato compared to the control. Hence, these results suggest strain L115 has the potential to be used as biocontrol agents against A. alternata. More studies should be done in the future to evaluate their efficiency in field conditions.

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The synthesis and application of nanomaterials as antioxidants and cytotoxic agents has increased in recent years. Biological methods go beyond the chemical and physical synthesis that is expensive and not friendly to the environment. Foodborne pathogens and microorganisms causing candidiasis are responsible of 5-10% hospitalized patients. The nutritional properties of the fruit called pitaya, from the Stenocereus queretaroensis species, have been little explored. Therefore, in this study the phytochemical composition of S. queretaroensis peel was evaluated and silver nanoparticles (AgNPs) were synthesized biologically in an environmentally friendly way by S. queretaroensis peel aqueous extract that contains phytochemicals capable of reducing silver nitrate. The antimicrobial activity of the AgNPs was tested by determining the minimum inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and time-kill kinetics. AgNPs were characterized visually, by UV-visible spectroscopy and TEM. FTIR spectroscopy identified metabolites responsible for the AgNPs formation. AgNPs showed potent antimicrobial activity against gram-negative and gram-positive bacteria, against fungi, and a methicillin-resistant strain of S. aureus. MIC and MBC values were as low as 0.078 and 0.156 µg/mL using AgNPs biosynthesized by S. queretaroensis fruit peel and the time kill assay started a log reduction in CFU/mL at 1 × MIC and 2 × MIC. S. queretaroensis-mediated AgNPs could be the basis for the formulation of biofilms for packaging products or as disinfectants for use on different surfaces.

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Dragon fruit shows good sensory and nutritional attributes, but it is also highly perishable. Drying is a unitary operation that promotes the reduction of moisture content, extending the useful life of the product. In this study, the elaboration of white and red dragon fruit powder by foam mat drying was studied with optimization of the proportion of foaming agent and stirring time. The use of ethanol and air temperature were evaluated on drying kinetics, effective moisture diffusivity (Deff ), and drying rate (DR). The study was divided into two steps. In the first, density, stability, porosity and overrun foam were evaluated and the optimal condition was determined. For the white and red pulp foams, the optimal conditions were, respectively, 26.88 min and 4.12 kg 100 kg-1 and 23.5 min and 3.44 kg 100 kg-1 . In the second step, the foam was subjected to ethanol pretreatment and convective drying (50 or 70 °C). The best condition involved pretreatment and the highest tested temperature, with the shortest drying time and the highest Deff and DR. PRACTICAL APPLICATION: Foam mat drying is a suitable method for drying perishable fruits, such as dragon fruit. The foam properties need to be optimized to ensure the success of the drying process. The ethanol pretreatment and the drying air temperature influence the drying kinetics. Therefore, determining the optimal process conditions is very important.

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Physicochemical properties of a blend of 10% Aloe vera gel with 5% pitaya juice subjected to UV-C doses of 16.5, 27.7, and 40 mJ/cm2 were evaluated at pH 3.5 and 5.5. Unprocessed treatments were used as the control. The a* color parameter decreased and luminosity increased at pH 3.5. The decrease in the reddish color was consistent with the decrease in total betalains content and stabilized at pH 5.5. The NMR analyses of UV-C treatments showed changes in betalains signal patterns. Polyphenolics content was significantly reduced in the UV-C treatments at pH 5.5. UV-C processing decreased the antioxidant activity 1.25 times compared to unprocessed treatments. Total sugar content was reduced as the UV-C dose increased. Doses above 16.5 mJ/cm2 resulted in a higher simple sugar content at a pH 3.5. The UV-C continuous flow technology can be applied to stabilize betalains in Aloe vera-pitaya blends at a UV-C dose of 16.5 mJ/cm2 and pH 5.5.

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Stenocereus thurberi is an endemic species in northwestern Mexico. It produces colorful fruits called pitayas that have an edible pulp. They have phytochemical compounds associated with biological activities. Ultrafiltration is a widely used method for the clarification of fruit juices and the recovery of phytochemicals. However, its effect has not been extensively studied in extracts. Therefore, the objective of this work is to study the effect of the ultrafiltration of pitaya extract (Stenocereus thurberi) on its phytochemical content, antioxidant capacity, and identification of phenolic compounds by UPLC-DAD-MS, providing greater knowledge about the pitaya. In this study, two extracts were analyzed, the unclarified extract (UE) and the clarified extract (CE). The antioxidant capacity was higher in the CE with 15.93 ± 0.42 mM TE/g, DPPH and 18.37 ± 0.016 mM TE/g, ABTS. The UPLC-MS analysis indicated the decrease in phenolic compounds in the CE and the presence of gallic acid and resorcinol, compounds that had not been identified in other species of Stenocereus spp. The correlation analysis indicated that all the phytochemicals present in the pitaya contribute significantly to the antioxidant capacity. The ultrafiltration process could be a viable option to improve the biological activity of the natural extracts.

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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.

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This study presents unpublished data on the chlorogenic acid and caffeic acid content in fruits. Sixty-four fruits consumed in Brazil, most of which were produced domestically, were evaluated based on their levels of 3-caffeoylquinic acid, 4-caffeoylquinic acid, 5-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid and caffeic acid. The study investigated 15 fruits that have not been reported in the literature in relation to these compounds, including several native species. The highest concentration of mono-caffeoylquinic acid was observed in strawberry, cherry, bilberry, quince and mulberry, while the dicaffeoylquinic acid was present with highest concentration in kumquat, passion fruit and sweet granadilla. Regarding caffeic acid, the highest content was found in bilberry and yellow pitaya. Considering the sum of the concentrations of these compounds, quince, cherry, bilberry, mulberry and sweet granadilla were exceptional, with concentrations between 200.0 and 569.7 mg kg-1.

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A pitaia é uma frutífera tropical, pertencente à família Cactaceae, com elevado potencial produtivo, nutritivo, econômico e social para a agricultura familiar, sendo uma cultura ainda pouco conhecida e com escassas informações sobre as condições que afetam a germinação das diferentes espécies de pitaia. Assim, o trabalho teve como objetivo avaliar a influência da temperatura e da luminosidade na germinação de sementes de três genótipos de pitaia. Para avaliar o efeito da temperatura na qualidade fisiológica das sementes foram utilizadas as espécies Selenicereus setaceus (pitaia-do-cerrado), Hylocereus undatus (casca vermelha e polpa branca) e Hylocereus polyrhizus (casca vermelha rosada e polpa vermelha) submetidas à germinação em sete temperaturas (15 °C, 20 °C, 25 °C, 30 °C e 35 °C, e em temperaturas alternadas: 15-25 ºC e 20-30 ºC, todas com fotoperíodo de 12 horas). As avaliações realizadas foram: porcentagem de germinação, índice de velocidade de germinação e tempo para ocorrência de 50% de germinação. Para a avaliação da influência da luminosidade, as sementes foram acondicionadas em frasco envolto por papel alumínio, a fim de proteger as sementes de qualquer contato com luminosidade, e armazenadas em refrigerador em temperatura de 10 ± 2 °C por 365 dias. Após, foram submetidas ao tratamento com e sem luz e mantidas em BOD por 11 dias, quando se realizou a contagem das plântulas normais. As temperaturas para o máximo desempenho fisiológico das sementes das três espécies de pitaia foram de 25 °C e 20-30 ºC. Por outro lado, a temperatura mais desfavorável foi de 35 °C. A espécie Selenicereus setaceus apresentou maior percentual de germinação e vigor em todas as temperaturas avaliadas. As espécies avaliadas demonstraram ser fotoblásticas positivas.(AU)

Pitaya is a tropical fruit belonging to the Cactaceae family. With high productive, nutritive, economic and social potential for family farming, it is a still little known culture with scarce information on the conditions affecting the germination of its different species. Thus, this study aimed to evaluate the influence of temperature and luminosity on seed germination of three genotypes of pitaya. To evaluate the effect of temperature on the physiological quality of the seeds, the Selenicereus setaceus, Hylocereus undatus (red peel and white pulp) and Hylocereus polyrhizus were used and (pink red peel and red pulp) submitted to seven germination temperatures (15 °C, 20 °C, 25 °C, 30 °C, and 35 °C, and in alternating temperatures: 15-25 ºC and 20-30 ºC, all in a photoperiod of 12 hours). The evaluations were: percentage of germination, germination speed index, and time for occurrence of 50% of germination. For the evaluation of the influence of the luminosity, the seeds were conditioned in bottle wrapped in aluminum foil to protect the seeds from contact with the luminosity and stored in refrigerator at 10 ± 2 °C for 365 days. They were then submitted to the treatment with and without light and kept in BOD for eleven days, when the normal seedling were counted. The temperatures for the maximum physiological performance of the seeds of three species of pitaya were 25 ºC and the alternating 20-30 °C. On the other hand, the unfavorable temperature was 35 °C. The Selenicereus setaceus showed a higher percentage of germination and vigor in all temperatures evaluated. The species evaluated demonstrated to be positive photoblastic.(AU)

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A pitaia é uma frutífera tropical, pertencente à família Cactaceae, com elevado potencial produtivo, nutritivo, econômico e social para a agricultura familiar, sendo uma cultura ainda pouco conhecida e com escassas informações sobre as condições que afetam a germinação das diferentes espécies de pitaia. Assim, o trabalho teve como objetivo avaliar a influência da temperatura e da luminosidade na germinação de sementes de três genótipos de pitaia. Para avaliar o efeito da temperatura na qualidade fisiológica das sementes foram utilizadas as espécies Selenicereus setaceus (pitaia-do-cerrado), Hylocereus undatus (casca vermelha e polpa branca) e Hylocereus polyrhizus (casca vermelha rosada e polpa vermelha) submetidas à germinação em sete temperaturas (15 °C, 20 °C, 25 °C, 30 °C e 35 °C, e em temperaturas alternadas: 15-25 ºC e 20-30 ºC, todas com fotoperíodo de 12 horas). As avaliações realizadas foram: porcentagem de germinação, índice de velocidade de germinação e tempo para ocorrência de 50% de germinação. Para a avaliação da influência da luminosidade, as sementes foram acondicionadas em frasco envolto por papel alumínio, a fim de proteger as sementes de qualquer contato com luminosidade, e armazenadas em refrigerador em temperatura de 10 ± 2 °C por 365 dias. Após, foram submetidas ao tratamento com e sem luz e mantidas em BOD por 11 dias, quando se realizou a contagem das plântulas normais. As temperaturas para o máximo desempenho fisiológico das sementes das três espécies de pitaia foram de 25 °C e 20-30 ºC. Por outro lado, a temperatura mais desfavorável foi de 35 °C. A espécie Selenicereus setaceus apresentou maior percentual de germinação e vigor em todas as temperaturas avaliadas. As espécies avaliadas demonstraram ser fotoblásticas positivas.

Pitaya is a tropical fruit belonging to the Cactaceae family. With high productive, nutritive, economic and social potential for family farming, it is a still little known culture with scarce information on the conditions affecting the germination of its different species. Thus, this study aimed to evaluate the influence of temperature and luminosity on seed germination of three genotypes of pitaya. To evaluate the effect of temperature on the physiological quality of the seeds, the Selenicereus setaceus, Hylocereus undatus (red peel and white pulp) and Hylocereus polyrhizus were used and (pink red peel and red pulp) submitted to seven germination temperatures (15 °C, 20 °C, 25 °C, 30 °C, and 35 °C, and in alternating temperatures: 15-25 ºC and 20-30 ºC, all in a photoperiod of 12 hours). The evaluations were: percentage of germination, germination speed index, and time for occurrence of 50% of germination. For the evaluation of the influence of the luminosity, the seeds were conditioned in bottle wrapped in aluminum foil to protect the seeds from contact with the luminosity and stored in refrigerator at 10 ± 2 °C for 365 days. They were then submitted to the treatment with and without light and kept in BOD for eleven days, when the normal seedling were counted. The temperatures for the maximum physiological performance of the seeds of three species of pitaya were 25 ºC and the alternating 20-30 °C. On the other hand, the unfavorable temperature was 35 °C. The Selenicereus setaceus showed a higher percentage of germination and vigor in all temperatures evaluated. The species evaluated demonstrated to be positive photoblastic.

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The persistence of traditional cultures and modes of land use within rapidly changing, globalized societies is a central issue in understanding ecological and cultural change in the Anthropocene. Located in the heart of the Green Revolution, the Yoreme (Mayo) people of the Mayo Valley in Mexico still obtain a significant proportion of their sustenance from wild ecosystems in the midst of this intensive technological and agricultural development. They live in and around the thornscrub dominated by pitaya (Stenocereus thurberi (Engelm.) Buxb.). In this study, we hypothesize that pitaya supports Yoreme heritage and sustenance amidst anthropogenic changes to the landscape, and we asked three specific questions: What is the land-use status of the S. thurberi habitat? What are its potential uses? Does S. thurberi provide economic value? To address these questions, we conducted interviews, vegetation surveys, and land-use analysis based on geographic information systems. We found that (a) land conversion of the pitaya-rich thornscrub is occurring at a precipitous rate, (b) local producers preserve and adapt their traditions, and (c) S. thurberi supports Yoreme heritage while providing economic benefit. The resulting land-use projections along with the cultural value of pitaya products shows the importance of conserving land and promoting sustainable projects instead of clearing land for other uses. If habitat shrinking continues at the current rate, it is likely that both Yoreme livelihoods and continued cultural practices will suffer.

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The effects of different pHs (4, 5 and 6), temperatures (4, 20 and 80 °C) and storage (up to 12 days) on differential tristimulus colorimetry and betalain content related to the colour of yellow pitaya (Selenicereus megalanthus) have been investigated. The peel of the yellow pitaya was extracted with different solvents to see its colorant capacity. Highly-acidic extracts (pH 4) showed the lowest betalain content, chroma (C* ab = 60 against 70) and the yellow component of the colour (b*). Storage temperature manifested a great influence on CIELAB parameters when yellow pitaya peel was added to highly-acidic foodstuffs, with a tendency towards red hues (h ab , from 100° to 85°) and remarkable changes on lightness (L*, from 90 to 75) as temperature increased. However, low-acidic extracts (pH 5 and 6) were superior from a colour stability standpoint, not being influential the temperature of storage. All colour changes according to pH and temperature were visually appreciable by human eyes (∆E* ab  > 3). New opportunities for diversification of colorant market could be possible by employing yellow pitaya peel as natural resource.

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Una de las mayores causas de pérdidas poscosecha de frutos de pitaya amarilla es su ablandamiento excesivo, el cual ha sido documentado previamente cuando la fruta es almacenada a temperaturas de cosecha o después de refrigeración. Además, tratamientos de choque térmico antes del almacenamiento refrigerado ofrecen control en el ablandamiento de estos frutos. Diferentes experimentos fueron llevados a cabo para evaluar el papel de algunas enzimas degradadoras de pared celular en el ablandamiento de frutos de pitaya amarilla: almacenamiento a 18 °C (TA) y refrigeración con choque térmico previo (ChT-R). Se incluyó también un tratamiento refrigerado control, sin choque térmico (control-R). Si midió el color de la corteza, la firmeza y las actividades de poligalacturonasa (PG), celulasa (CEL) y xilanasa (XIL). La evaluación del color indicó que los frutos almacenados a TA alcanzaron su madurez comercial luego de seis días. Luego de 12 días de almacenamiento a TA el pardeamiento y ablandamiento excesivo afectaron negativamente la calidad de los frutos. El pardeamiento y ablandamiento excesivo fueron detectados también en los frutos control-R cuando se movieron de 2 a 18 °C. Un ligero pardeamieno fue observado en los frutos ChT-R. Estos frutos alcanzaron su madurez comercial luego de 24 días de almacenamiento (nueve días luego de terminado el almacenamiento refrigerado). La actividad de XIL se asoció al ablandamiento en los frutos almacenados a TA y ChT-R. No se observó una clara correlación entre las actividades de PG y el ablandamiento, como tampoco entre CEL y el ablandamiento.

One of the major causes of yellow pitaya fruit loss during its marketing is its excessive softening, which has been previously documented when the fruit is stored at harvest temperature or after refrigeration. Furthermore, its excessive softening has been controlled by the application of heat shock treatments before refrigeration. Different experiments were carried out to evaluate the role of cell wall degrading enzymes on yellow pitaya fruit softening: storage at 18 °C (RT) as well as refrigeration with previous heat shock treatment (HS-R). A refrigerated control, without heat shock, was included (control-R). Peel color, firmness, poligalacturonase (PG), celulase (CEL) and xilanase (XIL) activities were measured. RT fruits reached the commercial ripeness after six days, as indicated by the color evaluation. After 12 days of storage at RT browning and excessive softening negatively affected the fruit quality. Browning and excessive softening were also detected in the control-R fruit when moving from 2 to 18°C. Minor browning was found in the HS- R fruit. HS-R fruit was full ripe 24 days of storage (nine days after finishing the refrigerated storage). XIL activity was associated to the softening in the RT and HS-R fruits. No clear correlation was observed between PG and softening neither between CEL and softening.