Assessment of compositional changes during ripening of transgenic papaya modified for protection against papaya ringspot virus

Abstract

BACKGROUND: Papaya (Carica papaya L.) production is limited by over 20 viruses, the most damaging of which is papaya ringspot virus (PRSV). Owing to a lack of suitable PRSV-resistant sources in Carica germplasm, transgenic resistance using the coat protein (cp) gene of a local PRSV strain is being developed to manage the disease in Jamaica. For assurance of food safety, the nutritional and antinutritional composition of transgenic papayas during ripening was compared with that of unmodified control samples.

Effects of subchronic exposure to transgenic papayas (Carica papaya L.) on liver and kidney enzymes and lipid parameters in rats

“…41 Although significant differences (P < 0.05) in phosphorus, calcium, reducing sugar and vitamin C contents of the non-transgenic papayas were observed, the values were within the ranges reported for papaya. All other parameters (protein, fat, carbohydrate, carotenoid, iron and calcium) were found to be comparable (P < 0.05).…”

Comparative effects of dietary administered transgenic and conventional papaya on selected intestinal parameters in rat models

“…cp gene sequences by themselves in planta do not result in the formation of infectious virus particles, nor do their expression result in disease pathology. PRSV CP is heat labile and is digested by simulated gastric fluids (Fuchs and Gonsalves 2007;Roberts et al 2008). Moreover, sequence homology at the amino acid level is not demonstrated in comparisons of the cp genes of PRSV, other viruses classified in the same genus (e.g., Zucchini yellow mosaic virus, Watermelon mosaic virus, and Potato virus Y) and known allergens (Health Canada 2001).…”

Papaya Nutritional Analysis

“…The transgenic process alone (for a single gene trait) does not alter papaya nutrient quality. Genetically modifi ed (GM) papayas with resistance to PRSV had similar nutritional composition as non-GM fruit (Mutsuga et al 2001 ;Roberts et al 2008 ;Jiao et al 2010 ;Tripathi et al 2011 ).…”

“…The highest concentrations of AA were reported for Solo type varieties (Franke et al 2004 ;Melo et al 2006 ). Vitamin C content (per 100 g FW fully ripe fruit) was 142 mg for cultivar "Hawaii," 100 mg for "Golden," 47-122 mg for "Sunrise," and 47-85 mg for "Rainbow" (Bron and Jacomino 2006 ;Melo et al 2006 ;Wall 2006 ;Roberts et al 2008 ;Tripathi et al 2011 ). In contrast, cultivar "Formosa" had 64 mg AA/100 g FW (Melo et al 2006 ).…”

“…Also, analytical methods that did not separate β-carotene from β-cryptoxanthin would lead to inaccurate and overvalued measures of vitamin A because (1) β-carotene has greater provitamin A activity than β-cryptoxanthin and (2) papayas contain high amounts of the less active β-cryptoxanthin (Philip and Chen 1988 ;Granado et al 1997 ;Chandrika et al 2003 ;Wall 2006 ). Values compiled from the following references: Franke et al ( 2004 ), Hardisson et al ( 2001 ), Isabelle et al ( 2010 ), Morton ( 1987 ), Roberts et al ( 2008 ), Saxholt et al ( 2008 ), Setiawan et al ( 2001 ), Schweiggert et al ( 2011 ), Tripathi et al ( 2011), Vinci et al ( 1995), Wall ( 2006, Wall et al ( 2010 ), Wenkam ( 1990 ), and Wills et al ( 1986 ) b USDA 2009 , national nutrient database for standard reference…”