Artículos de revistas
Assessment Of The Saponification Step In The Quantitative Determination Of Carotenoids And Provitamins A
Food Chemistry. , v. 35, n. 3, p. 187 - 195, 1990.
The saponification step in the determination of carotenoids was reassessed. Synthetic carotenoids (β-apo-8′-carotenal, β-carotene) and food samples (tomato, kale, papaya) were used and different procedures were evaluated. Hot saponification resulted in greater losses and cis- and epoxycarotenoids were formed. The degradation was aggravated by a more direct contact between the carotenoids and the alkali. The AOAC procedure, performed in the presence of acetone, led to complete transformation of β-apo-8′-carotenal to citranaxanthin. Saponification was unnecessary for kale and tomato but was needed for good separation of papaya carotenoids which included carotenol esters. Saponification of the carotenoids dissolved overnight at room temperature in petroleum ether, with equal volume of 10% methanolic KOH, retained β-, γ-carotene, β-apo-8′-carotenal and lycopene and completely hydrolysed the carotenol esters. However, even with this mild saponification, lutein, zeaxanthin and violaxanthin degraded significantly. These losses could be reduced to insignificant levels by using an atmosphere of nitrogen or antioxidant. © 1990.353187195AOAC, (1984) Official Methods of Analysis, pp. 834-835. , 14th edn, Association of Official Analytical Chemists, Arlington, USABaranyai, Matus, Szabolcs, Determination, by HPLC, of carotenoids in paprika products (1982) Acta Alimentaria, 11, pp. 309-323Beecher, Vanderslice, Determination of nutrients in foods: Factors that must be considered (1984) Modern Methods of Food Analysis, pp. 29-54. , K.K. Stewart, J.R. Whitaker, AVI, Westport, USABrubacher, Muller-Mulot, Southgate, (1985) Methods for the Determination of Vitamins in Food, pp. 33-50. , Elsevier Applied Science Publishers, London and New YorkBushway, Wilson, Determination of α-and β-carotene in fruit and vegetable by high performance liquid chromatography (1982) Canadian Institute of Food Science and Technology Journal, 15, pp. 165-169Davies, Carotenoids (1976) Chemistry and Biochemistry of Plant Pigments, 2, pp. 38-165. , 2nd edn, T.W. Goodwin, Academic Press, LondonKhacik, Beecher, Witaker, Separation identification and quantification of the major carotenoid and chlorophyll constitutents in extracts of several green vegetables by liquid chromatography (1986) Journal of Agricultural and Food Chemistry, 34, pp. 603-616Liaaen-Jensen, Isolation, reactions (1971) Carotenoids, pp. 61-188. , O. Isler, Berkauser Verlag, Basel, SwitzerlandParrish, Determination of vitamin A in foods—A review (1977) C R C Critical Reviews in Food Science and Nutrition, 9, pp. 375-394Parrish, Recent developments in chromatography of vitamins in foods and feeds (1984) Food Constituents and Food Residues: Their Chromatographic Determination, pp. 125-158. , J.F. Lawrence, Marcel Dekker, New York and BaselQuackenbush, Use of heat to saponify xanthophyll esters and speed analysis for carotenoids in feed materials Collaborative study (1973) J Assoc Off Anal Chem, 56, pp. 748-753Rodriguez, Raymundo, Lee, Simpson, Chichester, Carotenoid pigment changes in ripening Momordica charantia fruits (1976) Ann. Bot., 40, pp. 615-624Rodriguez-Amaya, Kimura, Godoy, Arima, Assessment of provitamin A determination by open column chromatography-visible absorption spectrophotometry (1988) Journal of Chromatographic Science, 26, pp. 624-629Schmidt, Francis, Liaaen-Jensen, Bacterial carotenoids. XXXVI: Remarkable C43-carotenoids artefacts of crossconjugated carotenals and new carotenoid glucosides from Athiorhodaceae spp (1971) Acta Chemica Scandinavica, 25, pp. 2476-2486Stewart, Wheaton, Conversion of β-citraurin to reticulaxanthin and β-apo-8′-carotenal to citraxanthin during the isolation of carotenoids from citrus (1973) Phytochemistry, 12, pp. 2947-2951Thompson, Problem of official methods and new techniques for analysis of foods and feeds for vitamin A (1986) J Assoc Off Anal Chem, 69, pp. 727-738Van Niekerk, Determination of vitamins (1982) HPLC in Food Analysis, pp. 187-225. , R. Macrae, Academic Press, London