Effect of Lye Peeling Conditions on Sweet Potato Tissue

Heat penetration effects on sweet potato tissue resulting from three lye peeling treatments were evaluated using light and scanning electron microscopy. Heat‐mediated starch gelatinization, cell wall separation, chromoplast disruption, and enzymatic discoloration were observed in varying degrees according to the peeling treatment. Starch gelatinization, cell wall separation, and chromoplast disruption decreased in the order: 15‐min peel; 30‐min pre‐soak (water 78–83°C), followed by a 6‐min peel; 6‐min peel. Discoloration occurred in significant amounts only in the 6‐min peel because heat penetration was sufficient to disrupt lacticifer organization but insufficient to inactivate the polyphenol oxidase (PPO) enzyme. The 30‐min pre‐soak, 6‐min peel treatment provided the most attractive finished product.