The microstructure of the starch from the underutilized seed of jaboticaba (Plinia cauliflora)

Abstract

This work presents a starch extracted from jaboticaba seeds. The extraction yielded 22.65 ± 0.63% of a slightly beige powder (a* 1.92 ± 0.03, b* 10.82 ± 0.17 and L* 92.27 ± 0.24). The starch presented low protein content (1.19% ± 0.11) and phenolic compounds (0.58 ± 0.02 GAE. g) as contaminants. The starch granules showed small, smooth, irregular shapes and sizes between 6.1 and 9.6 µm. The starch presented a high content of amylose (34.50%±0.90) and a predominance of intermediate chain length (B1-chains 51%), followed by A-chains (26%) in the amylopectin. The SEC-MALS-DRI showed the starch had a low molecular weight (5.3·106 g·mol−1) and amylose/amylopectin content compatible with a Cc-type starch, confirmed in the X-ray diffractogram. Thermal studies showed a low onset temperature (T0 = 66.4 ± 0.46 °C) and gelatinization enthalpy (ΔH = 9.1 ± 1.19 J g−1) but a high-temperature range (ΔT = 14.1 ± 0.52 °C). The jaboticaba starch proved to be a promising material for food and non-food applications.