Determination of Phenolic Compounds in Three Edible Ripening Stages of Yellow Guava (Psidium cattleianum Sabine) after Acidic Hydrolysis by LC-MS/MS

Phenolic profiling and bioactivity assessment of in vitro propagated Psidium cattleianum Sabine: A promising study

Psidium cattleianum Sabine (strawberry guava) is an evergreen shrub that is grown as a fruiting hedge and has received significant consideration in the food and pharmaceutical disciplines. This study aims to set a promising protocol for in vitro propagation of P. cattleianum, along with profiling the phenolic content of the original plant (OP), induced callus (IC), and regenerated plantlets (RP) extracts, ultimately, evaluating their anti-inflammatory, antioxidant, and anticancer potential. Seeds were treated with commercial bleaching, HCl, and H2O2 to enhance the germination percentage and minimize the contamination percentage. Culturing sterilized leaf explants onto Murashige and Skoog (MS) medium supplemented with benzyl adenine (BA), 2,4-dichloro phenoxy acetic acid, and kinetin showed the best callus induction, while supplementation of MS media with BA, adenine sulfate, naphthalene acetic acid, and gibberellic acid activated regeneration. Augmentation of MS media with indol-3-butyric acid recorded the maximum rooting percentage. Finally, the obtained rooted shoots were successfully acclimatized in sand and peat moss soil. HPLC-MS/MS profiles of OP, RP, and IC showed a variety of phenolic metabolites. IC extract decreased the viability of MCF-7, HepG2, and K-562 cancer cell lines. Also, OP exhibits strong antioxidant activity. P. cattleianum and its RP are profound sources of phenolic compounds promoted for promising applications in the food and pharmaceutical industries.

Unravelling Post-harvest Ripening Metabolomics of a New White Variety Guava Fruit (Cv Arka Mridula) with Special Emphasis on Phenolics and Corresponding Antioxidants

The phenolic, antioxidant and metabolic profiling of a new white variety guava fruit Arka Mridula (AM) was performed during its storage at the room temperature (28 ± 2 °C). The comparative profiles were generated at three ripening stages (pre-ripe, ripe and over-ripe) of the fruit. Generally, a steady decrease of the phenolic and antioxidant content from the pre-ripe to the ripe stage and a subsequent increase from the ripe to over-ripe stage was observed. Further, a powerful correlation between the phenolic content and antioxidant principles was noted through the principal component analysis. We could identify 53  compounds for the hydro-methanolic fruit extract through LC and GC-MS aided metabolic analysis, and the identified compounds were dominated by phenolics (~ 44%). The statistical analysis revealed that phytochemicals catechin, myricitrin, myricetin, kaempferol glycosides and n-hexadecanoic acid contributed significantly towards the ripening process of AM, during the storage. The present study is expected to provide important insight into the ripening biochemistry of AM. Subsequently, it may help in the future development of metabolically stable guava cultivars with extended post-harvest shelf life.

Chemical Constituents and Antioxidant Potential of Red Guava (Psidium cattleianum Sabine) from Southern Brazil in Different Edible Ripening Stages

Ripening and growing location are important factors that can impact fruit quality characteristics. In this study, the influence of these factors on physicochemical characteristics, carbohydrates, aliphatic organic acids, phenolic compounds, and antioxidant capacity of red guava (Psidium cattleianum Sabine) was evaluated. Fruit ripening increased fructose and glucose (up to 22.83 and 16.42 g 100 g- 1 dry matter (DM), respectively), and decreased citric acid, the major organic acid (up to 135.35 mg g- 1 DM). Ripening and growing location also influenced the concentration of phenolic compounds and antioxidant capacity of red guava, in which a dependency between both factors was observed in most cases. Apigenin, galangin, isoquercitrin, among other phenolic compounds were quantified for the first time in red guava, in which isoquercitrin was the major (up to 13409.81 mg kg- 1 DM). The antioxidant potential of red guava was also confirmed by ferric reducing antioxidant power assay (up to 82.63 µmol Fe+ 2 g- 1 DM), Folin-Ciocalteu reducing capacity assay (up to 17.79 mg gallic acid equivalent g- 1 DM), and DPPH free radical scavenging assay (up to 25.36 mg ascorbic acid equivalent g- 1 DM). These results especially demonstrated the bioactive potential of red guava and provided knowledge regarding the influence of ripening and growing location on chemical and bioactive components encouraging its industrial exploitation.

An Integrative Review on the Main Flavonoids Found in Some Species of the Myrtaceae Family: Phytochemical Characterization, Health Benefits and Development of Products

This integrative review aims to identify the main flavonoids present in some species of the Myrtaceae family. Studies published between 2016 and 2022 were selected, specifically those which were fully available and written in Portuguese, English, or Spanish, and which were related to the fruits araçá (Psidium cattleianum), cambuí (Myrciaria floribunda), gabiroba (Campomanesia xanthocarpa), jabuticaba (Plinia cauliflora), and jambolan (Syzygium cumini). Scientific studies were gathered and selected in Google Scholar, Scielo, and Science Direct indexed databases, out of which 14 were about araçá, 7 concerned cambuí, 4 were about gabiroba, 29 were related to jabuticaba, and 33 concerned jambolan, when we observed the pre-established inclusion criteria. Results showed that the anthocyanins, such as cyanidin, petunidin, malvidin, and delphinidin, were the mostly identified class of flavonoids in plants of the Myrtaceae family, mainly relating to the purple/reddish color of the evaluated fruits. Other compounds, such as catechin, epicatechin, quercetin, and rutin were also identified in different constituent fractions, such as leaves, peel, pulp, seeds, and in developed products, such as jams, desserts, wines, teas, and other beverages. It is also worth noting the positive health effects verified in these studies, such as anti-inflammatory qualities for jambolan, antidiabetic qualities for gabiroba, antioxidant qualities for araçá, and cardioprotective actions for jabuticaba, which are related to the presence of these phytochemicals. Therefore, it is possible to point out that flavonoids are important compounds in the chemical constitution of the studied plants of the Myrtaceae family, with promising potential in the development of new products by the food, chemical, and pharmaceutical industries due to their bioactive properties.

Integrating proteomics and metabolomics approaches to elucidate the ripening process in white Psidium guajava

Psidium guajava (guava) exhibits a high content of biomolecules with nutraceutical properties. However, the biochemistry and molecular foundation of guava ripening is unknown. We performed comparative proteomics and metabolomics studies in different fruit tissues at two ripening stages to understand this process in white guava. Our results, suggest the positive contribution of ethylene and abscisic acid (ABA) signaling to the regulation of biochemical changes during guava ripening. We characterized the modulation of several metabolic pathways, including those of sugar and chlorophyll metabolism, abiotic and biotic stress responses, and biosynthesis of carotenoids and secondary metabolites, among others. In addition to ethylene and ABA, we also found a differential accumulation of other growth regulators such as brassinosteroids, cytokinin, methyl-jasmonate, gibberellins and proteins, and discuss their possible implications in the intricate biochemical network associated with guava ripening process. This integrative approach represents a global overview of the metabolic pathway dynamics during guava ripening.