The Effects of Blanching Temperature and Cooking Methods on the Changes in Vitamin C of Potato

감자의 Vitamin C의 변화에 대한 Blanching 온도 및 조리 방법의 영향

  • 정현미 (고려대학교 가정교육과) ;
  • 이귀주 (고려대학교 가정교육과)
  • Published : 1989.12.01

Abstract

This study was attempted to investigate the effects of blanching temperature and cooking methods on the changes in the proportions of vitamin C of fresh potato and potatoes with different storage time. Sensory evaluation of fresh potato by different cooking methods was also conducted. The contents of residual ascorbic acid(AA) and total ascorbic acid(TAA) of fresh potato were maximum at $40^{\circ}C$ followed by rapid decrease at $50-65^{\circ}C$ while leached AA and TAA showed steady increase as the blanching temperature increased. Oxidized AA and dehydroascorbic acid(DHA) hydrolyzed increased at $50-65^{\circ}C$. From these results, it was considered that AA was lost mainly by oxidation up to $65^{\circ}C$ and leaching of AA was the major mode of loss above $65^{\circ}C$. In the case of potatoes stored for 1-4 weeks, they showed similar changes in the proportions of vitamin C as that of fresh potato. However, at $40^{\circ}C$ the content of residual TAA decreased and those of leached TAA and DHA hydrolyzed increased redundant during storage. At $65^{\circ}C$, the content of DHA hydrolyzed decreased The residual TAA of fresh potato by different cooking methods decreased in the order of pressure cooking (PC) > microwave cooking (MC)>boiling. Leached TAA were 49.5% and 36.4%, during boiling and MC, respectively. While DHA hydrolyzed were 22.3% and 4.2%, respectively Leached TAA and DHA hydrolyzed during PC were not determined. From these results, it was considered that AA was lost mainly by leaching during cooking. Residual TAA of stored potatoes by different cooking methods decreased during storage. But leached TAA and DHA hydrolyzed did not show any steady increase or decrease. Overall eating quality of fresh potato by different cooking methods decreased in the order of PC>MC>boiling(p<0.05).

Keywords

potato;proportions of vitamin C;cooking methods