Effect of High Pressure Pretreatments on Structural and Dehydration Characteristics of Aloe Vera (Aloe barbadensis Miller) Cubes

摘要

The effect of high-pressure (HP) pretreatments (300-500MPa for 5-15min) on dehydration characteristics of aloe vera cubes (AVC), dried at 50-70 degrees C and air velocity of 1-2m/s, was studied. Pretreatments resulted in higher drying rates, leading to a reduction in drying time compared to untreated ones. The drying rate and drying time were most significantly affected (p<0.05) by the drying temperature, followed by air velocity, pressure level, and dwell time. HPP enhanced the firmness of AVC with a maximum of up to 21% for the sample treated at 500MPa for 15min. Microstructural analysis using scanning electron microscopy (SEM) indicated non-uniform structures in the pretreated and dried AVC samples. Semi-quantitative elemental detection (EDS) confirmed the presence of a considerable amount (14%) of calcium in aloe vera.