Konvektivno sušenje kaše od organske kruške u tankom nepokrenom sloju

Zoran Stamenković,Ivan Pavkov,Milivoj Radojčin,Mirko Babić,Vojislava Bursić,Ana Dolovac,Krstan Kešelj

doi:10.5937/jpea1804153s

Abstract

The aim of this paper is to present the influence of convective drying of organic pear pulp and adding ascorbic acid on changes in color, the difference in vitamin C content and also show the kinetics of convective drying. It was a two-factor experiment. The first factor was the air temperature needed for drying, between 45 °C and 65 °C, with a constant speed of drying air of 1.5 m/s; the second factor of the experiment was the adding of ascorbic acid to the pear pulp in the amount of 1 % and 2 % of the full mass of the prepared pulp. The lowest change in color was achieved by adding ascorbic acid in the amount of 2 % of the full mass of the pulp and drying air temperature of 45°C (ΔE= 23.981). The highest change was accomplished at the air temperature of 65 °C and by adding ascorbic acid in the amount of 1% (ΔE= 30.039). With samples where ascorbic acid was added reduction of vitamin C was over 99 % with all samples. By examining the kinetics of convective drying based on statistical indicators R, X2, RMSE, models Page and Logarithmic are the best in representing convective drying of pear pulp at air temperatures of od 65 °C and 45 °C respectively.

Highlights

Fruit produced by organic principles and production of products based on the principles of organic production comprises a set of advantages, in health, ecological and economic terms.Fruit needs to be processed, stored in cold storage, frozen and dried right after harvest
The Page model best shows the convective drying of pear pulp in a thin layer at air temperatures of 65 °C
This paper shows the influence of convective drying of the pear pulp produced in accordance with the organic principles of the “Kieffer Seedling” (Kiferov sejanac) with the aim of producing pear leather-rolls

Summary

Introduction

Fruit produced by organic principles and production of products based on the principles of organic production comprises a set of advantages, in health, ecological and economic terms.Fruit needs to be processed, stored in cold storage, frozen and dried right after harvest. Convective drying of fruit, as the most common method of drying, effects the chemical-physical changes that occur during the process of drying, changes in the color, deconstruction of vitamin C, etc. One of the newer products that can be found on the market is fruit leather rolls. Order of processing is that fruit is first blended into a pulp and set on drying trays in fixed thin-layers, 4-5 mm thick. It is cut in ribbons that are used to form rolls. The downside of these products is a high level of oxidation and darkening during the preparation of the fruit pulp and during the process of convective drying. There is a loss in the content of vitamin C, which is especially noted with fruit that is susceptible to these changes

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