Pitaya as a New Alternative Crop for Iberian Peninsula: Biology and Edaphoclimatic Requirements

Physical-Chemical Characterization of Fruit Harvested at Different Maturity Stages of Grafted Yellow Pitahaya (Selenicereus megalanthus Haw.)

The physicochemical properties of fruits at different maturity stages using grafting technology are of great importance since grafting can alter the nutritional and functional parameters of the fruit. In this study, grafted yellow pitahaya (Selenicereus megalanthus Haw.) fruit, grown on live tutors, was evaluated from stages 0 to 5. The following response variables were recorded: fruit weight, diameter, and length; pulp weight with seed and peel; color; firmness; total soluble solids content; titratable acidity; pH; total flavonoid content; total polyphenol content; and antioxidant activity determined using FRAP and ABTS. The results show that fruits harvested from grafted plants have better physical characteristics such as fruit weight, diameter, and length. However, the total soluble solids content and titratable acidity were similar in fruits from grafted and ungrafted plants. The highest content of total polyphenols, flavonoids, and antioxidant activity determined by ABTS and FRAP were found in fruits at maturity stage 0, and the content decreased as the fruits ripened. A positive correlation was found between the total polyphenol content, total flavonoid content, and antioxidant capacity with protein content. The S. megalanthus grafting technique is a promising technology for sustainable production because it reduces pesticide use by combatting soil pathogens and not modifying fruit quality.

Selenicereus undatus (Dragon Fruit) Phytochemicals for Managing Three Human Pathogenic Bacteria: An In Vitro and In Silico Approach

OBJECTIVES

Antibiotic-resistant bacterial infections are a growing global concern. A natural remedy for bacterial infections could be available in the Selenicereus undatus fruit, but its antibacterial and biochemical properties are not fully known.

METHODS

In this study, the biochemical composition and antibacterial, antioxidant, and cytotoxic activities of the Jindu No. 1 (JD) and Bird's Nest (YW) dragon fruit varieties and their potential effects against E. coli, Pseudomonas sp., and Staphylococcus sp. were scrutinized.

RESULTS

The JD fruit extract showed higher antibacterial activity than the YW variety against E. coli, Pseudomonas sp., and Staphylococcus sp. in vitro. Additionally, the JD variety demonstrated more significant antioxidant activity than the YW variety and showed less cytotoxic activity. The JD variety had a higher glucose content, while the YW variety had a higher fructose content, and the phytoconstituents analysis confirmed 659 metabolites in total from the two varieties. Through in silico analyses, phytoconstituents were evaluated to identify potential drug molecules against the selected bacterial strain. Moreover, the molecular docking study revealed that riboprobe and Z-Gly-Pro might be effective against E. coli, 4-hydroxy retinoic acid, and that succinyl adenosine may target Pseudomonas sp., and xanthosine and 2'-deoxyinosine-5'-monophosphate may be effective against Staphylococcus sp. These results were further validated by 100 ns Molecular Dynamics (MD) simulation, and all of the selected compounds exhibited acceptable ADMET features.

CONCLUSIONS

Therefore, phytoconstituents from S. undatus fruit varieties could be employed to fight human bacterial diseases, and future studies will support the continuation of other biological activities in medical research.

Supercritical extraction of betalains from the peel of different pitaya species

BACKGROUND

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.

RESULTS

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.

CONCLUSION

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.