Caracterização físico-química e microbiológica de sementes, farinha e óleo de gergelim (Sesamum indicum L.)

Abstract

Sesame (Sesamum indicum L.) is considered one of the major worldwide-cultivated oil seeds, a source of lipids, proteins, minerals, vitamins and important antioxidants for human health. There are few studies that analyzed the chemical characteristics of the sesame. The objective of this study was to characterize the chemical composition of different commercial brands of sesame seeds (white and black), the sesame flour, the crude sesame oil and black sesame "milk". This study was conducted in the laboratories of the Nutrition Institute and the Chemical Institute of UERJ and in Campinas, Sao Paulo. Analyzes were conducted in the flour and seeds of centesimal composition, fiber, calcium, magnesium, zinc, copper, potassium, manganese, vitamin E, beta carotene and fatty acids. In the oil and "milk", minerals were analyzed, except calcium and magnesium, vitamin E, beta carotene, fatty acids and in the oil, acid and peroxide levels. Microbiological evaluations have also been made in the white and black sesame seeds and flour. The results were submitted to analysis of variance (ANOVA) with Tukey post test to compare means between groups and the t test was used to compare the two groups. The confidence interval was 95%. The GraphPad Prism 5 software was used. Significant differences between different brands of the seeds were observed, as well as differences between the flour and the black and white sesame seeds, for the majority of the analyzes. Sesame oil showed excellent standard of identity and quality, as well as a great fatty acid profile, according to the legislation recommendations, presenting itself as the best source of vitamin E in the analyzed products. The sesame was considered rich in calcium, having the black sesame as the main source (983.25 mg / 100g) with high significant difference compared to white sesame (p <0.0001), besides being the main source of insoluble fiber (27.71%), which enables the black sesame to have functional properties. Sesame flour has been considered the main source of copper (2,18 mg / 100g) and magnesium (388,00 mg / 100 g), showing significant difference with the black seed (0<0,05). Sesame oil has been considered the main source of potassium (16%) and vitamin E (28.34 mg / 100g). In addition, it was considered a source of monounsaturated oleic fatty acid and polyunsaturated linoleic fatty acid, with 47.62% and 35.32%, respectively, with significant differences compared to the other products (p <0.0001) and low amount of omega 3. For the microbiological assessments in flour and seeds, all results showed that the products are within the microbiological criteria established by law and therefore, good for human consumption. Our study characterized the nutritional composition of different sesame products, which presented important and appropriate physical, chemical and microbiological characteristics to human health, with good amounts of calcium, magnesium, copper, dietary fiber and unsaturated fatty acids, contributing to the clinical applicability