CHANGES IN FATTY ACID COMPOSITION IN THE SKIN OF NETTED MELON FRUIT IN RELATION TO EXPANSION OF THE NET AREA AND MOISTURE LOSS
The shelf life of fruits is affected by moisture loss during storage after harvest. In netted melon fruit, wounding of the cuticle occurs naturally, and moisture loss from such wounds was much greater than that from the cuticle in the early stage of fruit growth. During the fruit growth, the wounds were filled with a net containing suberized wax, and the water-proofing ability of this net was as high as that of the cuticle after the completion of net tissues. In this study, using three cultivars of netted melon fruits (Life, Andesu, and Gurandoru), skin tissues (cuticle with net) were isolated from hypodermal cell layers by pectinase treatment. The skin weight per unit area of Life was lower than that of the other two cultivars. The net area increased rapidly during fruit growth, with a simultaneous decrease in moisture loss. However, moisture loss did not differ among cultivars after the completion of net tissues. Fatty acid compositions were analyzed after methylation of the dried skin powder, and each fatty acid was identified using a GC-MS system throughout fruit growth. In the skin of the non-netting stages, palmitic acid was the most abundant fatty acid, and it decreased with expansion of net area. In the skin during netting stages, behenic acid accounted for over 30% of the skin area, and it increased with expansion of net area, regardless of the cultivar. Comparing cultivars, the changes in the relative amount of behenic acid showed similar tendencies to the changes in the net area. Although no apparent difference was recognized in moisture loss after the completion of net tissues among the cultivars, the relative amount of behenic acid was the lowest in Gurandoru. These results suggest that the deposition of behenic acid in the inner surface of cell walls of net tissues acts, to a certain extent, as an effective barrier to moisture loss.
Motomura, Y., Sugawara, J., Nishizawa, T., Takahashi, K., Sugawara, M. and Aikawa, T. (2015). CHANGES IN FATTY ACID COMPOSITION IN THE SKIN OF NETTED MELON FRUIT IN RELATION TO EXPANSION OF THE NET AREA AND MOISTURE LOSS. Acta Hortic. 1088, 85-90
cuticle, net, relative net area, palmitic acid, behenic acid