cushcush tubers treated against mealy bugs and P. oxalicum has 

 been widely tried in Guadeloupe. Even without the malathion treat- 

 ment, good keeping for as long as 1 year has been observed, and 

 acceptable culinary performance in this case has been verified. 



CULINARY CHARACTERISTICS 



The tubers of D. trifida are of convenient size for home use. 

 They may be baked whole or peeled and cut into convenient pieces 

 for boiling. The variety INRA 40' can be successfully peeled by 

 machine. The cooked flesh is smooth in texture, attractive even 

 when colored with anthocyanin, and of an unusual rich flavor that 

 is readily appreciated and is sufficiently moist in the mouth. 

 Fibrous and pasty textures are observed in varieties from Guyana, 

 when cooked. 



COMPOSITION 



Apparently, few analyses have been made of D. trifida tubers. 

 The starch percentage is high (38 percent) ; free carbohydrates 

 and fat are low. Starch granules are large (10 to 65 micrometers 

 in length). The ascorbic acid content of 5.5 milligrams per 100 

 grams could be significant in some diets. This vitamin is reported 

 to be lost rapidly during storage. 



The protein content was measured in a few cases by the senior 

 author and was found to be from 6.7 to 7.6 percent (dry-weight 

 basis), somewhat low for yams in general. But, these cases may 

 not represent the best potential of D. trifida, because the plants 

 were infected by a virus. The protein content of the variety *INRA 

 25' was observed to be 7-6 percent. The amino acid composition of 

 one variety in Puerto Rico is given in table 5, compared to that of 

 several other yams and the Food and Agriculture Organization 

 (FAO) reference protein. Important deficiencies are seen in the 

 case of the sulfur-containing amino acids, and with respect to 

 tryptophan. Breeding and selection should result in better protein 

 contents and more balanced amino acid distribution. 



POTENTIAL USE 



Because of its sexual fertility, D. trifida seems to hav6 the 

 potential for improvement. Breeding work, already begun in 

 Guadeloupe, shows that it should be possible to obtain hybrids of 

 this species with high yields, acceptable tuber shape, good quality, 

 virus tolerant, and with the capacity to produce without the need 

 for staking. Some of these characteristics are already incorporated 

 into selected varieties. 



On the other hand, the relatively small size of the individual 



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