Effect of heat and frozen storage on degradation of peroxidase and pigments in yellow crookneck squash

Early yellow crookneck squash (Cucurbita pepo L.) was heated in water at different temperatures and lengths of time, packaged in polyethylene bags, and frozen for further storage. Peroxidase activity, pigment concentration and color values were determined and compared. The beta carotene and chlorophyll contents in the rind and placenta tissue of squash were determined to indicate the effect of blanching and frozen storage on pigment retention. The blanching treatment did not prevent pigment degradation, but reduced the relative rate of pigment loss. Each different treatment of squash was measured on Hunter Color Difference Meter. The correlation coefficients between the color values and the amount of pigment content were calculated. The correlation between Hunter L, a, and b values and beta carotene content found in the squash rind tissue were significant at 0.01 level of probability. The estimate of beta carotene content could be predicted in 70.17 per cent, 90.25 per cent, 72.25 per cent of probability for raw, under blanched, and blanched squash, respectively. There was no significant correlation between Hunter L, a, b values and pigment content found in the squash placenta tissue.