Non enzymatic browning in air-drying of washed raisins

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1995 (EN)
Non enzymatic browning in air-drying of washed raisins (EN)

Kostaropoulos, AE (EN)
Karathanos, VT (EN)
Karanikolas, T (EN)
Saravacos, GD (EN)

N/A (EN)

Processing of sun-dried raisins may involve, among other operations, washing and air-drying before the product is packaged and stored. Airdrying of the washed raisins, particularly at high temperatures, may cause significant non enzymatic browning of the light-colored Sultana raisins. The browning of raisins may be prevented by sulfur dioxide treatment. However, since sulfur dioxide is undesirable for health reasons, alternative processes are needed. A better understanding of raisin browning during air-drying is essential in order to optimize the operating conditions of the dryer for improved product quality. Sun-dried Sultana raisins were washed with cold water for 30 to 120 min and air-dried at 70-120 °C. The color parameters (L,a,b) of the raisins were determined with a Hunterlab colorimeter at various moisture contents and temperatures. The lightness (L) of the product decreased significantly during the air-drying of the washed raisins., corresponding closely to the browning of the dried product. Higher moisture contents of the washed raisins and drying air temperatures above 80°C resulted in excessive browning. A maximum of the lightness parameter (L) was observed shortly after the start of air-drying. The results obtained in this investigation provide useful information (time/temperature data) for the optimum washing and air-dying operations with minimum browning of the dried Sultana raisins. © 1995 Elsevier B.V. All rights reserved. (EN)


High Temperature (EN)
Operant Conditioning (EN)
Sulfur Dioxide (EN)
Product Quality (EN)
Moisture Content (EN)
Air Temperature (EN)

Εθνικό Μετσόβιο Πολυτεχνείο (EL)
National Technical University of Athens (EN)

Developments in Food Science (EN)


N/A (EN)

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