Estudo químico e avaliação dos potenciais antioxidante e nutricional de frutos de araçá-pera (Psidium acutangulum DC)

Abstract

The araza is a variation of guava, fruit species belonging to the family Myrtaceae. It comprises of about 150 species, most of them are popularly known for the use of their leaves in preparation of teas for treating digestive problems. Its fruits, which have pleasant taste, are very exploited by the food industry. Many fruits have not been studied from the chemical and nutritional point of view. Accordingly, the aim of work is to study the chemical and nutritional composition from fruits of Psidium acutangulum DC (araçá-pera), as well as to evaluate the antioxidant potentials. These fruits were collected, segregated (peel, endocarp, whole fruit, and residues of seeds) and parts were lyophilized. An amount whole fruit of G3 was kept in natura (PA), whose content of L-(+)-ascorbic acid was determined by HPLC-MS as being 74.32±1.23mg/100g of fresh fruit. The lyophilized plant materials were subjected to extraction with ethanol, whose potential antioxidant against free radical DPPH• was peel: 191.98±3.20, endocarp: 406.52±26.42, entire fruit: 332.17±36.30, and residues of fruits): 41.29±1.72 g of fresh fruit/gDPPH•. These results were inversely proportional to the phenolic levels (peel: 603.61±11,77, endocarp: 315.13± 68.49, entire fruit: 481.77±22.60, and residues of seeds: 785.68±86.63 mg of GAE/100g of fruit) and total flavonoids (peel: 46.1±3.4, endocarp: 17.1±2.6, entire fruit: 25.7±4.2, and residues of seeds 82.7±3.7 mg/100g). The extract entire fruit have shown a potential antioxidant against free radicals (ABTS•+ and DPPH• 7.32±0.36 and 34.50±0.12 mg/mL, respectively). The results of ABTS•+ and DPPH• of in natura fruits were represented by VCEAC (Vitamin C Equivalent Antioxidant Capacity). The centesimal analysis of peel, endocarp, entire fruit and residues of seeds has shown different levels of protein, carbohydrates, and calories for the fruit of P. acutangulum. The total fiber content in extract of entire lyophilized fruit (PA) has been 4.17g/100g, a value content was according with that found in P. guajava (var. mifera, Lin.) and P. cattleyanum, while the protein content in entire fruit (2.36g/100g) has been higher than the one determined in the red and white guava. As for the values of the minerals to this matrix, it was observed that iron, copper, and magnesium have been found in amounts similar to other fruits of Psidium ssp.. The potassium content in entire lyophilized fruit has been 1.67±0,02g/100g fruit, higher than the one found in fruits known for their richness in this nutrient such as plantain banana (Musa acuminata Colla) and Brazil nut (Berthlletia excelsa HBK). The Mass Spectrometry and NMR analyses of ethanolic extract (PA) and its fractions have suggested the presence of the glycosides (sucrose, glucose and fructose), organic acids (citric, and malic).