Effect of predehydration chemical treatment on enzymic discolouration and rehydration of solar dehydrated potato slices and cubes

Predehydration treatments with 0.5% sodium metabisulphite, 2% sodium hydroxide, 2% acetic acid and 2% ethanol were tried to reduce enzymic discolouration and to improve rehydration of solar dehydrated potato slices and cubes of variety Kufri Jyoti. Predehydration treatment with 0.5% sodium metabisulphite eliminated discolouration of the products. Sodium hydroxide and acetic acid also reduced discolouration but to a lesser extent, while ethanol treatment resulted in dark colour products. Predehydration treatment with 0.5% sodium metabisulphite and 2% sodium hydroxide improved the rehydration of 2 mm thick dehydrated potato slices considerably (453 and 405%, respectively) with no adverse effect on texture and mashability. Predehydration treatment with acetic acid and ethanol did not improve rehydration and adversely affected the texture of rehydrated, cooked slices. Rehydration of 1 cm potato cubes was not satisfactory and predehydration chemical treatment had little effect.