Spray drying of pure kiwiberry pulp in dehumidified air

Abstract

Food producers are interested in products with “clean” composition and natural origin. Thus, the elimination of the carriers additions perfectly fits this trend. The aim of the work was to spray dry pure kiwiberry pulp at low drying air temperature (100 °C and 120 °C), possible by the application of dehumidified air. An additional goal was to compare the effect of the kiwiberry variety (Weiki, Geneva and Bingo) and temperature on powder recovery and physicochemical properties of powders. The powder recovery was up to 93%. Kiwiberry powders were characterized by low hygroscopicity and water activity and high total polyphenolics content. Based on hierarchical cluster analysis method, it was found that the kiwiberry variety had a greater impact on the properties of powders than drying temperature: Weiki powders were characterized by the lowest polyphenolics content and the lowest antioxidant activity, while Weiki and Bingo powders had the highest content of aromatic compounds. Powders obtained at lower temperature were characterized by higher water content and activity, lower hygroscopicity, higher apparent density, smaller particle size and wider particle size distribution. The results are of high practical potential, because powders did not contain any carrier material and were characterized by low hygroscopicity. The most recommended is to use Bingo variety and drying temperature 120 °C.