Chemical constituents determination of açaí fruits (Euterpe oleracea Mart.)using high and low field NMR

Abstract

The açaí palm (Euterpe oleracea Mart.) Is a plant of the family Arecaceae, whose fruits show two distinct colors. Black açaí, with ripe fruit in dark purple color, and white açaí, whose ripe fruits have actually a bright green color. The fruit pulp called "wine" or refreshment of açaí is a very important food product consumed in the north region of Brazil and more recently also in the south, southeast and exported to USA and Europe. It is rich in lipids, proteins, fibers, a-tocopherol, anthocyanins, and minerals. For this reason it is a food source and a major income for poor communities. The two biggest problems with their marketing is the easy degradation, mainly because it is very susceptible to oxidation and, the little knowledge about organic compounds present on it making difficult his quality control and traceability, since the commercialized fruits came from different regions, different seasons (crop and intercrop), different types of cultivation (plants in dry areas and wetlands) and different cultivars. The problems relating to microbiological contamination can be solved with good hygiene practices during the production chain.Therefore, this project aims is to answer four basic questions. The first question is an overview of the chemical constituents present in the açaí pulp to evaluate the influences of seasonality, ragionality, different types of cultivation and the use of different cultivars. To this will be use the 1H NMR of the methanol pulp extract (fingerprint) combined with chemometric tools (PCA, HCA, SIMCA and PLS-DA), using fruits growing under controlled conditions, collected in experimental plantations of Embrapa Amazônia Oriental and samples collected in the local marked.The second aspect involves the identification of the chemicals compounds (majority and minority) using 1D, 2D NMR and also hyphenation techniques (HPLC-UV-SPE-NMR and HPLC-UV-NMR) in either on flow and stopped flow mode. Whit this probably it will be possible to identify new compounds which can add business value mainly those related to nutraceutical properties.The third point involves low-field NMR to analyze water and fatty acids (saturated an unsaturated) content, using intact seeds and compare its results with the data obtained via conventional oil analysis. It is also important to identify the majority and minority compounds present in the oil using 1D, 2D high field liquid state NMR and hyphenated techniques. Finally, to establish correlations of spectroscopic data and the physical chemical properties: pH, titratable acidity, total soluble solids (oBrix), humidity and total solids, total contents of lipids, proteins, ash, anthocyanins and phenolic compounds, obtained for the same samples using statistical tools with the propose to find less expensive way to get information about product quality and traceability. (AU)