Compositional Analysis of Transgenic Papaya with Delayed Ripening Trait

摘要

To address concerns on food safety of genetically modified (GM) foods due to unintended effects, we subjected fruit samples of transgenic papaya with delayed ripening trait and non-transgenic samples to comparative analyses of proximate composition, vitamin C or ascorbic acid, beta-carotene and benzyl isothiocyanate (BITC). Three lines of transgenic Solo papaya fruits were analyzed at green mature, 10% yellow and 100% yellow. At the three stages, some of the chemical constituents had differences which were statistically significant but all values obtained for the three different lines were quite close (maximum of 12% difference from the control) and within the values in the literature. Beta-carotene and ascorbic acid ranged from 490-769 ug (100 g)~(-1) and 41-80 mg (100 g)~(-1), respectively. BITC contents decreased ten-fold as papaya ripened for both control and transgenic papayas. For all the analyses, the values for the transgenic papayas were similar to those of the control and were within therange of values reported in the literature. The results indicate the compositional similarity of the transgenic papayas with delayed ripening trait with the non-transgenic control papayas. Fruit characteristics such as days to maturity, fruit weight andtotal soluble sugars were similar for both transgenic and control papaya trees. However, transgenic papayas ripened 3.6-6.7 d from full yellow compared with 2 d for the control.