Classical Food Quality Attributes and the Metabolic Profile of Cambuci, a Native Brazilian Atlantic Rainforest Fruit

NMR Fingerprinting of Conventional and Genetically Modified Soybean Plants with AtAREB1 Transcription Factors

Drought stress impacts soybean yields and physiological processes. However, the insertion of the activated form of the AtAREB1 gene in the soybean cultivar BR16, which is sensitive to water deficit, improved the drought response of the genetically modified plants. Thus, in this study, we used 1H NMR in solution and solid-state NMR to investigate the response of genetically modified soybean overexpressing AtAREB1 under water deficiency conditions. We achieved that drought-tolerant soybean yields high content of amino acids isoleucine, leucine, threonine, valine, proline, glutamate, aspartate, asparagine, tyrosine, and phenylalanine after 12 days of drought stress conditions, as compared to drought-sensitive soybean under the same conditions. Specific target compounds, including sugars, organic acids, and phenolic compounds, were identified as involved in controlling sensitive soybean during the vegetative stage. Solid-state NMR was used to study the impact of drought stress on starch and cellulose contents in different soybean genotypes. The findings provide insights into the metabolic adjustments of soybean overexpressing AREB transcription factors in adapting to dry climates. This study presents NMR techniques for investigating the metabolome of transgenic soybean plants in response to the water deficit. The approach allowed for the identification of physiological and morphological changes in drought-resistant and drought-tolerant soybean tissues. The findings indicate that drought stress significantly alters micro- and macromolecular metabolism in soybean plants. Differential responses were observed among roots and leaves as well as drought-tolerant and drought-sensitive cultivars, highlighting the complex interplay between overexpressed transcription factors and drought stress in soybean plants.

Quality Attributes and Metabolic Profiles of Uvaia (Eugenia pyriformis), a Native Brazilian Atlantic Forest Fruit

The uvaia is a native Brazilian Atlantic Forest Myrtaceae fruit with a soft pulp, ranging from yellow to orange, with a sweet acidic flavor and sweet fruity aroma. Uvaias present consumption potential, but their physicochemical characteristics are still understudied. In this context, we describe herein the metabolites of uvaia that have been determined by nuclear magnetic resonance spectroscopy. We screened 41 accessions and selected 10 accessions based on their diversity of physicochemical attributes, i.e., their fresh mass, height, diameter, yield, seed mass, total soluble solids, and titratable acidity. Twenty-six metabolites were identified, including sugars, acids, and amino acids. The results of this study comprise the most complete report on sugars and acids in uvaias. The relevant metabolites in terms of abundance were the reducing sugars glucose and fructose, as well as malic and citric acids. Furthermore, this study represents the first description of the uvaia amino acid profile and an outline of its metabolic pathways. Uvaia quality attributes differ among accessions, demonstrating high variability, diversity, and several possibilities in different economic areas. Our findings may help in future breeding programs in the selection of plant material for industries such as food and pharmaceuticals.

Bioactive Compounds and In Vitro Antioxidant Capacity of Cambuci and Uvaia: An Extensive Description of Little-Known Fruits from the Myrtaceae Family with High Consumption Potential

Cambuci (Campomanesia phaea O. Berg Landrum) and uvaia (Eugenia pyriformis Cambess), both native Atlantic Rainforest fruits, are noteworthy for being rich in bioactive compounds and their significant antioxidant capacity. Despite the numerous known edible fruits in the world, consumption by humans is most often restricted to a few dozen of them. Such behavior occurs, among other reasons, due to the lack of knowledge about fruits not yet commercialized on a large scale. This study quantified the bioactive compound content (total phenolic compounds and ascorbic acid in cambucis and uvaias; proanthocyanidins in cambucis, and total carotenoid profile and individual carotenoids for grapes) and antioxidant capacity of the edible parts (peel and pulp) of cambuci and uvaia accessions, using three methods (ABTS•+, ROO• radical scavenging and HOCl elimination). Cambuci contained higher phenolic compound levels and displayed higher antioxidant capacity determined by the ABTS•+ and ROO• radical scavenging methods than uvaia (139 and 119 mg 100 g⁻¹ of GAE, 10.5 and 7.73 μmol g⁻¹ of TE; 9.17 and 5.92 μmol g⁻¹ of TE, respectively). Vitamin C content and the antioxidant capacity determined by the HOCl elimination method were about 1.5- and 6-fold higher in uvaia compared to cambuci, with the latter being a first-time report for uvaia. Both fruits contained higher levels of bioactive compounds and antioxidant capacity than other commonly consumed fruits.