Nutritional composition of Rainbow papaya, the first commercialized transgenic fruit crop

Rainbow papaya (Carica papaya L.) is a genetically engineered (GE) cultivar with resistance to papaya ringspot virus (PRSV). This cultivar currently accounts for about 70% of Hawaii's papaya acreage. The nutritional composition of Rainbow papaya and a non-transgenic control were analyzed to address GE food safety concerns regarding the potential for altered nutritional composition and altered expression of inherent allergens and toxic proteins. Rainbow papaya fruit were analyzed at three ripening stages and the data compared to that of a non-transgenic papaya which shares a similar pedigree. No differences were observed between GE and non-GE papaya for 36 nutrients at any of the tested fruit ripeness stages. However, vitamin A was higher and calcium levels were lower in the GE fruit. The GE fruit showed higher levels of protein and papain at the earliest stage of ripening (color break), but in ripened fruit these differences were insignificant. Benzyl isothiocyanate (BITC) levels were very low and similar for both Rainbow and the non-transgenic control fruit at all ripeness stages. Our data show that the contents of nutrients, BITC and papain of GE Rainbow papaya are within the range of those of non-GE papaya and that the Rainbow cultivar is substantially similar to the non-GE cultivar.