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Effect of Lye Peeling Conditions on Phenolic Destruction, Starch Hydrolysis, and Carotene Loss in Sweet Potatoes
Paper no. 7084 of the journal series of the North Carolina Agricultural Research Service, Raleigh, NC.
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ABSTRACT
‘Jewel’ sweet potatoes were peeled in a boiling, 10% NaOH solution using the following treatments: (1) 6-min peel (6P); (2) 20-min pre-soak in water (55°C) followed by a 6-min peel (20S); (3) 30-min pre-soak in water (80°C) followed by a 6-min peel (30S); (4) 15-min peel (15P). Tissue from the heat-affected area was excised and analyzed for o-dihydroxyphenols (DP) and carotene destruction and sugar formation. The data showed that roots peeled by 6P or 20S treatments could discolor as a result of the PPO-DP reaction. Discoloration would not be found in 15P and 30S because both treatments are vigorous enough to inactivate the PPO system. Amylolytic enzymes are inactivated by all treatments except 6P. No carotenoid destruction was detected.