Characterization and technological properties of peach palm (Bactris gasipaes var. gasipaes) fruit starch

Abstract

Peach palm fruit mesocarp (Bactris gasipaes var. gasipaes) is already consumed in the Northern region of Brazil, after its cooking and is known as a source of starch and carotenoids and like all fruits it has low storage stability. This work characterized the starch extracted from the mesocarp of peach palm fruit using with water in terms of its physical and chemical properties. The SEM micrographs show that starch presented bimodal distribution (size 3.9–10.4 µm), while the smaller granules had a smooth surface and an oval or conical shape, the larger granules were spherical with holes and cracks on the surface. The starch presented low amylose content (<20%) and amylopectin branch chain length distribution with the absence of a shoulder, which is suggestive of perfect crystalline structure, and a higher proportion of medium chains (DP 13–24), despite the large number of short chains (DP 6–12), and on average DP 21. X-ray diffraction showed a mixture of polymorphs A and B, which can be considered C-type crystalline pattern, which is indicative of being a slow digestible starch. Through paste viscosity results, by RVA, we can observe low values for thermal and pasting properties, suggesting greater homogeneity of crystals. Also, due to interaction with lipids originally present (2.69%), the starch showed lower retrogradation rate (22.64%), which resulted in a weak gel after 24 h of storage. As a product with greater storage stability, peach palm fruit starch, extracted for the purpose of promoting its regional use, has shown that it can be used in products where slow and smooth retrogradation is desired, such as in breads, soups, chowder and porridges, without the use of emulsifiers or fat.