Caracterização físico-química e desenvolvimento de métodos analíticos para a manteiga de tucumã (Astrocaryum aculeatum)

Abstract

The Amazon tucumã (Astrocaryum aculeatum) is a typical oil of the region and its almond butter presents great potential for the pharmaceutical industry, behaving as an excellent moisturizer, anti-wrinkle cream, shampoo, conditioner and body oils. The objective of the present work was to characterize physicochemically the tucumã almond butter and to propose analytical methods for the determination of this raw material. The tucumã was purchased at the free trade fairs in the municipality of Itacoatiara, metropolitan region of Manaus - AM in the months of May 2016 and 2017, processed at the ICET / UFAM pharmacy laboratory. The extraction of almond butter was performed by the Soxhlet method, with the physico-chemical characterization by the tests of mass and relative density, refractive index, acidity, saponification, peroxide, moisture content, melting range, viscosity and absorption spectrophotometry in the region of the IV, fatty acids assay, studies of thermal analysis and photostability, antioxidant potential, total carotenoids and evaluation of the antimicrobial activity. The results presented a slightly yellowish butter of solid consistency at room temperature and mass density of 0.9012 - Lot 1 and 0.9011 - Lot 2; relative density of 0.9032 - Lot 1 and 0.9030 - Lot 2; refractive index was 1.457 ± 0.0005 for the two batches; viscosity of 64.71 Lot 1 and 33.05 - Lot 2; humidity of 0,55 ± 0,160 - Lot 1 and 0,88 ± 0,681 - Lot 2; melting range of 28ºC - 29ºC - Lot 1 and 29ºC - 30ºC - Lot 2; acid value of 0.120 ± 0.016 NaOH / g - Lot 1 and 0.074 ± 0.016 NaOH / g - Lot 2; saponification index of 195.47 ± 0.60 KOH / g - Lot 1 and 206.04 ± 2.49 KOH / g - Lot 2 and peroxide index of 8.318 ± 0.226 mEq / kg - Lot 1 and 10.521 ± 0.156 mEq / kg - Batch 2. The butter presented an average of 90% of saturated fatty acids and 7% of unsaturated fatty acids. The lauric acid showed to be the majority in the butter, representing an average value of 55.8% in both lots. It was thermally stable up to 259.17 ° C with melting peak at 31.03 ° C. The carotenoid values found were 280.163ppm ± 7.95 for both batches. Infrared spectroscopy of the lots showed stretches at 2954, 2915 and 2849 cm -1 suggesting the presence of alkanes only; two intense bands (1736 and 1729 cm -1) and characteristics in the region of carbonyl absorption; an intense stretching relative to the C-O bond (1175 cm -1) suggesting the ester bond present in the general structure of a triacylglycerol; a low intensity angular strain band of the CH groups of aliphatic at 1471 cm -1 relative to alkanes; an angular deformation of CH2 in 717 cm -1 and characteristic bands of vegetable oils in the fingerprint region (1300-900 cm -1). After the photodegradation test, the batches presented a loss of less than 10% in the fatty acid content and showed no change in the infrared spectrum, suggesting that the butter is photo-stable. We concluded that the technique used in the extraction of almond butter did not alter its physicochemical characteristics, maintaining a low acidity index and without degradation, with a concentration of 90% of saturated fatty acids. The butter was thermally stable and with more than 50% antioxidant activity, besides having ample antibacterial activity.