Effect of pH and Phosphate on the Interaction between Spinach Chlorophyll and Protein

• Main Authors: Liu, Cheng-ko, 劉正格
• Other Authors: James Swi-Bea Wu
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/10453632044939036405

碩士 === 國立臺灣大學 === 食品科技研究所 === 86 === The degradation of chlorophyll often results in the undesirable color change of green vegetables during processing and storage. The research in the color preservation of these vegetables concerned mainly on chlorophyll. However, chlorophyll forms a complex with protein in the plant. During thermal processing, chlorophyll pheophytinizes easily in acid condition. Therefore, elevating pH value and adding salts with buffering ability are commonly used to retain chlorophyll. The present research investigated the effect of pH elevation and phosphate addition on the chlorophyll- protein complex in spinach juice first. Then, gliadin and glutenin were added into a chlorophyll model solution in which the pH had been elevated or phosphate had been added, and the formation of chlorophyll- alien protein complexes and the effect of alien proteins on chlorophyll degradation were investigated. The results showed that high pH and phosphate addition is effective to preserve the protein and chlorophyll of the chlorophyll- protein complex in spinach juice. It needs no heating to form chlorophyll- gliadin complex in the model solution in which the pH has been adjusted or phosphate has been added. With elevating of the pH value, the amount of chlorophyll which binds to glutenin increases. Neither gliadin nor glutenin addition may improve the thermal stability of chlorophyll.