title: Pigments in avocado tissue and oil.
abstract: Pigments are important contributors to the appearance and healthful properties of both avocado fruits and the oils extracted from these fruits. This study determined carotenoid and chlorophyll pigment concentrations in the skin and three sections of the flesh (outer dark green, middle pale green, and inner yellow flesh-nearest the seed) and anthocyanin concentrations in the skin of Hass avocado during ripening at 20 degrees C. Pigments were extracted from frozen tissue with acetone and measured using high-performance liquid chromatography. Pigments were also measured in the oil extracted from freeze-dried tissue sections by an accelerated solvent extraction system using hexane. Carotenoids and chlorophylls identified in the skin, flesh, and oil were lutein, alpha-carotene, beta-carotene, neoxanthin, violaxanthin, zeaxanthin, antheraxanthin, chlorophylls a and b, and pheophytins a and b with the highest concentrations of all pigments in the skin. Chlorophyllides a and b were identified in the skin and flesh tissues only. As the fruit ripened and softened, the skin changed from green to purple/black, corresponding to changes in skin hue angle, and a concomitant increase in cyanidin 3-O-glucoside and the loss of chlorophyllide a. In flesh tissue, chroma and lightness values decreased with ripening, with no changes in hue angle. The levels of carotenoids and chlorophylls did not change significantly during ripening. As fruit ripened, the total chlorophyll level in the oil from the flesh sections remained constant but declined in the oil extracted from the skin.
authors.affiliation: Institute of Food, Nutrition & Human Health, Massey University, Private Bag 102-904, Auckland, New Zealand.
authors.forename: Ofelia B O
authors.initials: OB
authors.lastname: Ashton
authors.forename: Marie
authors.initials: M
authors.lastname: Wong
authors.forename: Tony K
authors.initials: TK
authors.lastname: McGhie
authors.forename: Rosheila
authors.initials: R
authors.lastname: Vather
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Cecilia
authors.initials: C
authors.lastname: Requejo-Jackman
authors.forename: Padmaja
authors.initials: P
authors.lastname: Ramankutty
authors.forename: Allan B
authors.initials: AB
authors.lastname: Woolf
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development; D027421:Persea / Q000737:chemistry*; D010860:Pigments, Biological / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D010860:Pigments, Biological; D010938:Plant Oils; D002734:Chlorophyll; D002338:Carotenoids