engleski

Antibrowning effects of various pre-treatment methods on dried apple samples

The aim of this research was to find the most effective antibrowning agent for apple samples determined on the basis of colour changes, rehydration characteristics and drying kinetics under the uniform drying conditions. The colour characteristics were used as quality parameter of the dried apple samples. For this purpose, colour changes were observed using the image analysis system in RGB colour model, as well as chromameter in CIE Lab colour model. The results obtained by both methods were then compared. Florina variety apple samples were pre-treated and dried in laboratory tray drier at temperature of 60 °C. The applied chemical pre-treatments of samples were dipping in 0.5% ascorbic acid solution ; 0.3% L–cysteine solution ; 0.1% 4–hexyl resorcinol solution and 1% sodium metabisulfite solution. The drying temperature for apple samples was 60 °C at airflow velocity of 1.5 ms-1. The Page’s mathematical model was used to calculate the drying kinetic parameters. The obtained results showed a good agreement with experimental data. According to drying time, rehydration and colour characteristics the best results were achieved when samples were pre-treated with 4–hexyl resorcinol.

Pre-treatment; Apple; Drying; Colour; Image analysis; Rehydration

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