The influenceofaddingdifferentlevelsofzincchloriderangedbetween100and500ppmandblanching time (1, 3 and 6 mins) at 85°C on the physical and structural aspects of chlorophyll pigments in peas and broccoli were investigated. It was found that when 300 and 100 ppm zinc chloride were added to the blanching water of peas and broccoli respectively to be satisfactory enough in retaining the green- colour of these vegetables.
Hunter colour “-a*" values were found to be adequately represent the colour changes. These values were used to describe the results in terms of an exponential model. Raman spectroscopy was also applied to confirmthepresenceofZn-chlorophyllcomplexeswhichprotectthechlorophyllsfromconvertingintoother derivatives.
The residual zinc chloride (ppm) in the tissues of peas and broccoli after blanching was found to be 47.55 and 10.13 ppm, respectively. Therefore, double benefitsregardingfortificationwithzincandretaining green pigments were achieved.