EVALUATION OF EXTRACTION METHOD FOR THE ANALYSIS OF CAROTENOIDS IN FRUITS AND VEGETABLES

This study evaluated a suitable extraction method for a wide range of sample matrices in carotenoid analysis. Using canned tomato juice as a representative sample, it is shown that two solvents of low biologica l hazard, ethanol and hexane are the most suitable for extracting caro tenoids from the matrix. The use of double extraction, each with 35 ml of ethanol:hexane mixture (4:3, by volume), resulted in good recoveri es of carotenoids (lycopene 96%, alpha-carotene 102% and beta-carotene 93-100%). Coefficients of variation conducted on different days were: lycopene 5% and beta-carotene 7%. An application of the established m ethod to various kinds of fruit and vegetable matrices is also shown, using carrot and spinach as representative samples of root and leafy v egetables, for determining recoveries of added carotenoids. The averag e percent recoveries of added carotenoids from canned tomato juice, ca rrot and spinach were: 101, 99.8 and 101% for alpha-carotene (12.4, 24 .8, 49.6 and 99.2 mu g/10 mi of added alpha-carotene); and 98.1, 99.7 and 96.1 percent for beta-carotene (25.5, 50.9, 101 and 201 mu g/10 mi of added beta-carotene). These similar recoveries over the explored c oncentration ranges confirm that the application of established extrac tion method is unaffected by differences in matrix composition of the samples. (C) 1998 Elsevier Science Ltd. All rights reserved.