Effect of thermal pasteurization on Valencia orange juice color and pigments

Changes in carotenoid pigment content and juice color due to thermal pasteurization of Valencia orange juices were studied. Total carotenoid pigment content loss was significant (P<0.05) after thermal pasteurization at 90°C for 30s. Thermal effects on carotenoid pigment contents, especially on violaxanthin (-46.4%) and antheraxanthin (-24.8%), were clearly observed. With the loss of violaxanthin and antheraxanthin, lutein became the major carotenoid, followed by zeaxanthin, in pasteurized Valencia orange juice. There was perceptible color change after orange juice pasteurization, which led to juice color becoming lighter and more saturated. Decreases in CIE a* value and increases in CIE L*, b*, h*, and C* are the major color changes after pasteurization. Overall increases in reflected light might also influence the perception of color to a great extent in pasteurized orange juice. Total color differences (ΔE*) compared to the fresh juice was 2.92 +/- 0.97 (P < 0.05). (C) 2003 Published by Elsevier Science Ltd. on behalf of Swiss Society of Food Science and Technology.