Effect of Fluidized Bed Drying on the Physicochemical, Functional, and Morpho-Structural Properties of Starch from Avocado cv. Breda By-Product

Abstract

Fluidized bed drying has been widely applied in the food industry due to its high heat and mass transfer rates. In this study, the impact of drying temperatures (50, 60, 70 and 80 °C) in a fluidized bed on the physicochemical, functional, morpho-structural, and thermal properties of avocado seed starch was evaluated. The process yield for all temperatures ranged from 52.3 to 58.5% (p > 0.05), with a starch content of 59.20–60.9 g/100 g, amylose content of 28.85–31.84 g/100 g, and amylopectin content of 29.13–30.37 g/100 g. Additionally, all samples showed high water, milk, and oil absorption capacity (>90%), low solubility (5.22–8.35%), good flow characteristics, and swelling power greater than 50%. There was also a greater release of water (syneresis) after 168 h of storage, regardless of the drying temperature, which likewise did not influence the texture parameters. The granules had a smooth surface, without cracks or cavities, predominantly oval and partially rounded, being classified as type B. In the FT-IR analysis, no new functional groups were observed, only a reduction in peak intensity with increasing drying temperature. Finally, the thermal properties indicated high conclusion temperatures (>130 °C), with gelatinization enthalpy in the range of 14.18 to 15.49 J/g, reflecting its thermal resistance and structural integrity under heat conditions. These results demonstrated that fluidized bed drying is an alternative technique for drying avocado seed starch pastes.