Effect of pretreatment and drying temperatures on proximate analysis of peeled and unpeeled sweet potato flours.
Parameter Drying temperature (C)
55 60 65
PF1 PSF2 UF3 USF4 PF1 PSF2 UF3 USF4 PF1 PSF2 UF3 USF4
Moisture (%) B
8.67b B7.99ab B7.69ab A7.01a A6.98b A7.47c A6.45a A7.17ab A6.18a B7.77c A6.82b A7.14b
Ash (%) A
3.45c A3.59b A3.91a A3.61a A3.64d A3.53a A3.77c A3.57b A3.41c A3.53b A3.59a A3.55a
Protein (%) A
3.48a A3.61a A3.51a A3.51a A3.59a A3.69a A3.32a A3.28a A3.47a A3.60a A3.41a A3.50a
Fat (%) B
1.27a B0.87a B1.29a A0.95a AB0.86a AB0.74a AB0.80a A0.99a A0.59a A0.60a A0.60a A0.90b
Total sugar (g/100 g) A
3.00a A3.14a A3.26a A3.48a A3.39a A3.41a A3.29a A3.39a A3.49a A3.29a A3.57a A3.30a
Carbohydrate (%) A
83.94a A84.53a A84.88a A84.87a A85.18d A83.89a A85.90bc A84.30ab A85.82c A84.06a A84.96b A84.24ab
Total dietary fibre (%) A
5.26a A5.96b A5.60ab A6.95c A5.95a A6.97a A6.54a A7.14a AB5.38a AB6.45ab A5.57ab A6.57b
Starch content (%) A
65.31a A64.81a A64.87a A65.37a A64.81a A65.31a A65.50a A64.81a A65.31a A65.81a A65.81a A64.81a
Means followed by different lowercase letters in each row are significantly different among flour samples (p < 0.05).
Means followed by different uppercase letters in each row are significantly different among drying temperatures (p < 0.05).
All data, except ash expressed in wet weight basis.
1 PF: Flour from peeled sweet potatoes without sulphite-treatment. 2 PSF: Flour from peeled sulphite-treated sweet potatoes. 3 UF: Flour from unpeeled sweet potatoes without sulphite-treatment. 4 USF: Flour from unpeeled sulphite-treated sweet potatoes.