|Perkins Veazie, Penelope|
Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 12/17/2003
Publication Date: 10/1/2003
Citation: Perkins Veazie, P.M., Collins, J.K. 2003. Watermelon lycopene degrades after low temperature storage [Abstract]. HortScience. 38:817.
Technical Abstract: Lycopene, a carotenoid pigment that imparts the red color to red-fleshed watermelons, has antioxidant properties and a high dietary lycopene intake is associated with a reduced incidence of some cancers. Watermelons are chilling sensitive, developing rind pitting, brown staining, and loss of internal color when whole fruit are held for more than 7 days below 7 C. Conversely, flesh color has been reported to become more red in melons held above 20 C. This experiment was done to determine if lycopene content was correlated to a loss or gain in flesh color. Ten to 20 watermelons each of the cultivars 'Black Diamond' (light red, seeded heirloom), 'Summer Flavor 800' (bright red, seeded hybrid), and 'Sugar Shack' (bright red, seedless triploid) were obtained from local growers and stored for 0 and 12-14 days at 5, 13, and 21 C. Melons were rated for symptoms of chilling injury and internal flesh color (L*, a*, b*, hue, chroma) was measured by Minolta CR200. Soluble solids content (SSC), pH, and lycopene content were determined on 40 g of pureed sample. The average lycopene contents were 34, 57, and 58 ug/g for 'Black Diamond', 'Summer Flavor 800', and 'Sugar Shack' melons, respectively. The lycopene content of all melons stored at 13 C was similar to that of fresh melons. Lycopene content was 12-24% lower in melons held at 5 C and 12-24% higher in those held at 21 C, compared to fresh watermelons. Puree pH increased with increasing storage temperature while SSC showed no consistent change with storage. Color, as a* values, best paralleled lycopene content. Color was less red and lycopene content was lower in watermelons held at 5 C, and higher in those held at 21 C, and the degree of loss was similar for all types of melons. These results indicate that lycopene content in stored uncut watermelons can be significantly affected by storage temperature.