Influence of Sulphite on the Drying Kinetics of Pumpkin Fruit Slices
Comfort Mkpentseen Bunde-Tsegba,
Charles Chukwuma Ariahu,
Bibiana Dooshima Igbabul,
Joseph Oneh Abu
Issue:
Volume 3, Issue 3, September 2019
Pages:
32-39
Received:
30 July 2019
Accepted:
26 October 2019
Published:
2 December 2019
Abstract: Drying kinetics, of pumpkin fruit slices as influenced by sulphiting, was investigated. Pumpkin fruits, were sulphited at 0, 1.0, 1.5, 2.0 and 2.5% to obtain 4 mm thick (P0, 4; P1, 4; P1.5 4; P2, 4; P2.5, 4 - and 5 mm samples (P0, 5; P1, 5; P1.5, 5; P2, 5; P2.5, 5 respectively). Samples were dried at 60, 65, 70, 75 and 80°C at an air velocity of 1.53 m/s. Drying was carried out to constant moisture. Samples were screened using descriptive sensory evaluation to obtain samples P1, 4 and P2, 5 each dried at 75°C as the best samples for 4 mm and 5 mm respectively. Drying curves, moisture diffusitivity, activation energy, drying time and rehydration capacity were determined. The drying curves obtained showed results for a short constant rate followed by a falling rate period. The effective moisture diffusivity varied from 6.235×10-11 to 12.808×10-11m2/s for the 4 mm and 9.046 x 10-11 to 21.330 x 10-11m2/s for the 5 mm samples. Activation energy obtained for P0, 4; P1, 4; P0, 5 and P2, 5 were 31.342, 32.292, 31.525 and 29.88 kJ/mol. respectively. Sulphiting reduced drying time at 1% level from 16.5 to 15.2 hours for the 4 mm sample and 17.8 to 16.9 hours at 2% level of sulphiting for the 5 mm. Sulphite treatment reduced rehydration capacity significantly at p>0.05. This study implies that the parameter which governed the internal transfer of moisture was moisture diffusion.
Abstract: Drying kinetics, of pumpkin fruit slices as influenced by sulphiting, was investigated. Pumpkin fruits, were sulphited at 0, 1.0, 1.5, 2.0 and 2.5% to obtain 4 mm thick (P0, 4; P1, 4; P1.5 4; P2, 4; P2.5, 4 - and 5 mm samples (P0, 5; P1, 5; P1.5, 5; P2, 5; P2.5, 5 respectively). Samples were dried at 60, 65, 70, 75 and 80°C at an air velocity of 1....
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