Abstract:
thickness on drying time, non-enzymatic browning, brightness, the ratio of redness to yellowness, ascorbic acid content, and
lycopene content of the dried tomato slices was investigated. Three levels of distance (38 to 50 cm), sample thickness (7 to 11
mm) were used for the experiment. The desirability index technique was used to determine the ideal drying conditions that yield
minimum drying time and non-enzymatic browning and maximum brightness color, redness to yellowness ratio, lycopene content,
and ascorbic acid of drying of tomato slices. At the best conditions of 40.29 cm distance and 9.04 mm sample thickness, the
drying time was 108 ± 4 minutes; the non-enzymatic browning index was 0.338 ± 0.12 Abs unit; the brightness was 40.43 ± 2.29;
the ratio of redness to yellowness was 0.92 ± 0.13; the ascorbic acid content was 3.76 ± 0.27 mg/g dry matter; and the lycopene
content was 72.34 ± 19.87 mg/100 g dry matter. These results demonstrate that FIR should be considered as an efficient drying
method for tomato with respect to colour and ascorbic acid preservation, minimization of brown pigment formation and increment
in lycopene content
