OLIVEIRA, Fernando da Silva.
Résumé:
The umbuzeiro (Spondias tuberosa Arr. Cam.) is a species native to the Brazilian semi-arid region, being one of the great economic importance of the family Anacardiaceae Lindl. The umbu is widely used for the production of jams and jellies, which indicates the presence of pectin (structural polysaccharides) which are extracted with abundance of most citrus fruit mesocarp. Pectic substances occur without exception in the primary cell wall and the Middle lamella of plant cells in association with cellulose and hemicelluloses. The importance of pectin is linked to its function of giving firmness, retaining flavor and aroma to foods, with the formation of the main functional characteristic gel; it is also employed as a soluble dietary fibre by offering beneficial physiological effects to the human body. The aim of this study was to develop a protocol for the extraction of pectin from the flour of peel of umbu, in different physiological stages of maturation and concentration of citric acid. Initially, the fruits were collected, cleaned and hulled, bark, dried and milled to flour, which were submitted to chemical analysis, followed by two distinct methodologies: a) extraction of pectin from umbu peel (Spondias tuberosa Arr. Cam.) under different physiological stages of maturation ("de vez" and mature) and citric acid (5.0% 6.0% 7.0%); and, b) extraction of pectin from umbu mature (Spondias tuberosa Arr. Cam.) workups and pretreatment with acids. In the first methodology adopted, the average yield of pectin extracted from the flour of umbu Peel ripe ranged from 53.7% to 77.6%. While the performance of pectins umbu bark "de vez" ranged between 72.5 and 84.5%. However, these figures were above average, suggesting that not only pectins are extracted from the peel of the umbu, but also hemicelluloses. The second methodology, the ethanol was used as pre-treatment for extraction of pectin, extracting the soluble sugars that could influence the final weight of pectins. The average yield of the extracted pectin in aqueous medium ranged from 20.8% and 21.1%, while the average yield of pectin extracted with citric acid ranged between 15.9% and 26.3%. We observe that the highest yield of umbu pectin was obtained in extractions using citric acid concentration 7.0% in both methodologies. Therefore, the acid extraction offered greater yields of pectins with results above 15%. The results show differences between the amounts of pectin extracted from ripe fruits and "de vez" of umbu.
