Dietary fiber chemical structures and physicochemical properties of edible Pouteria glomerata fruits, native from Brazilian Pantanal.

Pouteria glomerata is a native species from the Brazilian Pantanal, whose fruit is edible and still underexploited. The objective of this study was to carried out the chemical, nutritional and antioxidant properties of this tropical fruit, as well as to isolate e characterize the chemical strucutre of their dietary fibers. DPPH and ORAC methods were used to determine the antioxidant capacity. Minerals were quantified using inductively coupled plasma optical emission spectrometry. Soluble and insoluble dietary fiber fractions were obtained by the standard enzymatic-gravimetric method and chemically characterized by monosaccharide composition, gel permeation and NMR spectroscopy. Results showed that P. glomerata fruits presented high antioxidant capacity and high levels of vitamin C, minerals, insoluble dietary fiber, and malic acid. The soluble dietary fiber was mainly composed of uronic acids, arabinose, and galactose, and NMR analysis indicated the presence of highly methylesterified homogalacturonan, arabinan and/or arabinogalactan as pectic polysaccharides. Hemicelluloses present in insoluble dietary fiber fraction were solubilized by alkaline treatment, and characterized as (1 â†’ 4)-ß-D-xylan. The results brings new chemical information about this native fruit and may open new opportunities for using it as a potential ingredient for health improvement by human comsumption.

Metabolic Study of Dioecy in Mauritia flexuosa: NMR-based and Chemometric Approaches.

INTRODUCTION: Mauritia flexuosa is a dioecious species native to the Amazon, and the gender identification can currently be determined through the differentiation between female and male flowers in the first flowering. OBJECTIVES: To identify variations in the metabolome profiles of pooled and individual samples of leaves from female and male plants of M. flexuosa in reproductive phase, and the plant in its vegetative phase, using two extraction systems. MATERIAL AND METHODS: Extractions of leaves were separately conducted using deuterated water and methanol. The extracts were evaluated by NMR spectroscopy and chemometric methods. RESULTS: Different NMR spectroscopic profiles were observed for females, males, and plants in the vegetative phase. Significant variations were found in the carbohydrate and fatty acid contents for the aqueous and methanolic extracts, respectively. Although principal component analysis (PCA) has not been efficient to distinguish the genders, orthogonal signal correction/partial least squares-discriminant analysis (OPLS-DA) was able to successfully differentiate male and female plants in the reproductive phase, independently on the sampling approach. For plants in the vegetative phase, OPLS-DA method from aqueous extracts of M. flexuosa leaves also distinguished female samples from the others and showed a small overlap between male and young plants, while the classification model was not able to be used for prediction. CONCLUSIONS: NMR spectroscopy and chemometric-based approach was demonstrated to be useful in the metabolic study of dioecy in M. flexuosa. The extracts of the leaves allowed for differentiation between male and female plants; however, for plants in the vegetative phase, the identification of the gender was not effective. Copyright © 2018 John Wiley & Sons, Ltd.