Storage of pitaya (dragon fruit) powder produced by lyophilization

Abstract

This study evaluated the stability of integral pitaya pulp powder produced by lyophilization and packed in flexible, heat-sealed, aluminum-laminated packages. The pitaya pulp samples were formulated with 35% maltodextrin (DE = 10) and dehydrated using a lyophilizer. The resulting powders were stored in laminated packages for 60 days under controlled conditions of temperature (30 and 40 °C) and relative humidity (83%). Throughout the storage period, several parameters were assessed at 10-day intervals, including water content, water activity, titratable total acidity, ascorbic acid content, solubility, and color. The laminated packages proved inefficient in preventing water absorption and darkening reactions. Significant changes were observed during the storage tests, including decreases in titratable total acidity, luminosity (L*), red intensity (+a*), ascorbic acid, and solubility. Conversely, there were increases in water content, water activity, yellow intensity (b*), hue angle (h*), and chroma (C*). These findings suggest that the laminated packages were not adequate for maintaining the stability of lyophilized pitaya pulp powder under the tested conditions. The observed changes indicate a decline in the quality of the powder, likely due to moisture absorption and subsequent chemical reactions affecting the color and nutritional content. Further research is needed to identify more effective packaging solutions to enhance the storage stability of lyophilized fruit powders.