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Abstract: Local communities in Mexico consume Jatropha platyphylla seeds after roasting. The kernels of J. platyphylla contained ca. 60% oil and were free of phorbol esters. The kernel meal of this Jatropha species contained trypsin inhibitor, lectins and phytate. However, trypsin inhibitor and lectins are heat labile so this explains why the local people can eat roasted seeds without ill effects. Heat-treated J. platyphylla kernel meal (JPKM) was free of trypsin inhibitor and lectin activities. Crude protein content of JPKM was 75%. Heated JPKM and soybean meal were included in a standard diet (crude protein 36%) for Nile tilapia (Oreochromis niloticus) to replace 50% of the fish meal protein. The growth of fish in all the three groups was statistically similar and the blood biochemical parameters that serve as biomarkers for toxicity were within the normal ranges. This is the first study that confirms the non-toxic nature of J. platyphylla. [ABSTRACT FROM AUTHOR]

Based on a producer questionnaire and interviews, twelve native forage species from northern Quintana Roo, Mexico, with foliage during the dry season were selected for determination of chemical composition and qualitative antinutritional factor content: Galactia multiflora, Psychotria nervosa, Macroptilium atropurpureum, Acalipha villosa, Cecropia obstusifolia, Piscidia piscipula, Trophis racemosa, Chaetocalyx scandens, Dalbergia glabra, Guazuma ulmifolia, Spondias mombin, and Ampelocissius erduendbergiana. Crude protein varied from 106.3 to 238.8 g kg-1 DM and true protein from 75 to 94 %. Neutral detergent fiber varied from 283.4 to 629.1 g kg-1 DM, and acid detergent fiber from 161.0 to 415.6 g kg-1 DM. Phenols were present in all the studied species, except Galactia multiflora. The studied species are potential sources of true protein for grazing ruminants in the dry season. [ABSTRACT FROM AUTHOR]

The legumes Canavalia ensiformis and Mucuna pruriens are underexploited in tropical Mexico. Their seeds have good nutritional potential, but contain antinutritional factors. Physicochemical and antinutritional properties were determined for raw flours (RF) and protein isolates (PI) produced from these legumes. Protein content in the PI was 737 g kg–1 for C. ensiformis and 666 g kg–1 for M. pruriens. Protein isolation improved in vitro digestibility, while maintaining high lysine levels and adequate sulphur amino acids content. Antinutritional factors such as cyanogenic glucosides, cyanide precursors from hydrolysis, tannins and trypsin inhibitors were lower in the PIs than in the RFs. The reduction in canavanine levels, a structural analogue of arginine, in the C. ensiformis PI was noteworthy. These PIs thus have potential applications in the development of new food ingredients in tropical regions using processes that improve nutritional value. [ABSTRACT FROM AUTHOR]

Nutrient and antinutritional/toxic factors present in some edible flowers consumed in Mexico were determined. The edible flowers were: Agave salmiana, Aloe vera, Arbutus xalapensis, Cucurbita pepo (cultivated), Erythrina americana, Erythrina caribaea, Euphorbia radians benth and Yucca filifera. The nutrient content in the flowers studied is similar to that of the edible leaves and flowers studied mainly in Africa. The moisture content of the flowers varied from 860 to 932 g kg(-1). Crude protein (CP) was between 113 to 275 g kg(-1) DM, crude fiber, 104 to 177 g kg(-1) DM and the nitrogen free extract, between 425 to 667 g kg(-1) DM. The highest chemical score (CS) was found in E. americana and A. salmiana; in five samples the limiting amino acid was lysine, and in three of them it was tryptophan. Trypsin inhibitors and hemaglutinnins had a very low concentration. Alkaloids were present in both the Erythrina species and the saponins in A. salmiana and Y. filifera. Cyanogenic glucosides were not found in the studied flowers. The traditional process of preparing these specific flowers before consumption is by cooking them and discarding the broth; in this way the toxic substances are diminished or eliminated. These edible flowers from wild plants consumed in local areas of the country play an important role in the diet of the people at least during the short time of the season where they are blooming. [ABSTRACT FROM AUTHOR]