Pigment pattern and expression of colour in fruits from different Hylocereus sp genotypes

Pigment profiles, betalain contents, colour and pH-values were studied in fruits from five Hylocereus sp. genotypes originating from Costa Rica. Significant colour differences between fruit pulps from Nacional and San Ignacio were found for C*-values and Lisa exhibited the most reddish tint h degrees. Whereas highest betalain contents were registered in San Ignacio and Orejona, lowest values were found in Nacional. Additionally, pigment patterns of the genotypes were found to differ: While Lisa, Nacional and Orejona were characterised by a similar betalain pattern, Rosa and San Ignacio were significantly different offering a valuable tool for genotype comparison. Moreover, Rosa showed the highest betanin and isobetanin contents, whereas phyllocactin and hylocerenin were predominant in San Ignacio. Apart from the newly reported betalains neobetanin and gomphrenin 1, indicaxanthin was the first betaxanthin so far detected in pitaya fruits. (c) 2007 Elsevier Ltd. All rights reserved.