Nutritional and haemagglutination properties of several tropical seeds

Abstract

SUMMARYThe nutritional potential of a number of raw tropical seeds was assessed in a series of feeding trials with rats. Seed lectin reactivity was also monitored, α-amylase and trypsin inhibitory activities were determined in some of the seeds.Abelmosclius esculentus, Chenopodium quinoa, Delonix regia, Macroptilium lathyroides, Papaver sonmiferum, Parkia biglandulosa, Sesbania arabica, Terminalia catappa, Vigna subterranea, Vigna umbellata and Vigna unguiculata seeds supported moderate rat growth. The seeds contained only low levels of essentially non-toxic lectin, moderate amounts of trypsin inhibitors and negligible quantities of a-amylase inhibitors and they have great potential as dietary protein sources for man and animals.Artocarpus altilis, Canavalia ensiformis, Canavalia maritima, Dioclea grandiflora, Phaseolus acutifolius, Phaseolus coccineus and Phaseolus vulgaris cv. Processor, cv. Rosinha G2 and cv. Carioca 80 seeds were toxic. These seeds contained high levels of potentially toxic lectins. Other antinutritional factors may also have contributed to the high oral toxicity of some of these seeds.Albizia adinocephala, Albizia lebbeck, Bauhinia violacea, Cassia nodosa, Cassia tora, Dioclea sclerocarpa, Entada phaseoloides, Enterolobium cyclocarpum, Leucaena leucocephala and Moringa oleifera seeds were also highly toxic but had only low levels of essentially non-toxic lectins suggesting that the toxicity was due to other anti-nutritional factors.Bauhinia reticulata, Macrotyloma uniflorum and Tamarindus indica proteins were poorly digested and utilized. The seeds contained low levels of lectins which agglutinated only rat and cattle erythrocytes which had been pre-treated with suitable proteases. Brownea macrophylla had a similar lectin reactivity.