Color variation of Ultra High Temperature (UHT) sterilized milk during storage

Abstract

The color variation of Ultra High Temperature (UHT) sterilized milk packed aseptically in glass bottles was studied using Hunter Lab Colorimeter during storage period at room temperature. Hunter color parameters (L, a, b) of stored milk samples were measured at 15 days intervals up to two months. The Chroma, Hue angle, Browning Index and Total color change were calculated from L, a, b values. The L value of raw milk was 81.35 while that of UHT sterilized milk was 78.80. The L value and Hue angle of UHT sterilized milk were found to decrease while a value, b value, chroma and Browning Index of UHT sterilized milk were found to increase with storage period due to formation of brown pigments resulting from Maillard reaction. These color attributes data could be helpful in monitoring the quality of UHT milk during storage and also useful in predicting the shelf life of UHT milk.