Characterization of carotenoids and color in temperate Asimina triloba and comparison to other tropical Annonaceae fruits

Aim: Fruits from the tropical Annona genus of family Annonaceae have long been cultivated in tropical Latin America, Africa, and southeastern Asia. Asimina triloba is a temperate fruit from Annonaceae, but few comparisons between Annonaceae fruits exist. The objective was to determine how 21 days of refrigerated storage affected the carotenoids and color in ripe and overripe A. triloba. A comparison to tropical Annonaceae fruits is provided. Methods: Pawpaw pulp was stored refrigerated for 21 days. Total carotenoids and β-carotene were determined spectrophotometrically and by HPLC, respectively. C.I.E. L*, a*, and b* values were used to calculate hue angle, chroma, total color change (ΔE), browning index, which have been reported in A. triloba previously, and color index, whiteness index, yellowness index, the ratio of a*/b*, and percent change in L*, which are reported herein for the first time. Results: Overripe pulp contains 5-fold more carotenoids than ripe pulp. A significant decline in total carotenoids was observed during refrigerated storage in the overripe pulp, but not in fresh pulp. At the onset of refrigerated storage, ripe pulp was significantly less brown than overripe pulp, but became more brown during refrigerated storage. No further change in browning was observed during storage of overripe pulp. Conclusions: Using established conversion factors and the values generated in this study, preliminary indications are that ripe A. triloba pulp provides 4.0% (males) and 5.1% (females) of the U.S. Recommended Dietary Allowance (USRDA) of vitamin A for individuals 14 years or older, and overripe provides 3.5% and 4.6%. Carotenoids are well-characterized for Annona muricata (A. muricata), Annona reticulata (A. reticulata), and Annona squamosa (A. squamosa), but these provide less than 1% of the USRDA of vitamin A. A comparison revealed that Annonaceae fruit are nutrient-dense, provide fiber and potassium, are low in fat and protein, and have comparable calcium, iron, magnesium, potassium, and sodium levels. Understanding Annonaceae fruits nutritional value may facilitate increased economic potential.