OCCURRENCE OF SAPONINS AND SAPOGENOLS IN ANDEAN CROPS

Samples of bitter seeds of local ecotypes and cultivars of lupin (Lupi n mutabilis), white and yellow ecotypes of quinoa (Chenopodium quinoa Wild) and a local ecotype of amaranth (Amaranthus caudatus) grown in t he Peruvian highlands were analysed for total saponin content and sapo genol composition. Sweet cultivars of L albus and L luteus cultivated in mild-rainy lowlands of Chile were also analysed for comparison. Fas t atom bombardment-mass spectrometry (FAB-MS) of the saponin extracts and gas chromatography (GC) analysis of the sapogenols after acid hydr olysis of the crude extract were used for the identification and quant ification of saponins. It was found that L albus and amaranth had unde tectable levels of saponins making them attractive for human consumpti on. The cultivars and ecotypes of L mutabilis contained saponin levels in the range of 229.8-390.5 mg kg(-1). FAB-MS showed the presence of soya saponins I and II, whereas GC allowed the identification of soya sapogenols A and B. The same saponin composition was determined in L l uteus whose total content was 55.3 mg kg(-1). Saponin composition in q uinoa seeds comprised oleanolic acid and three other sapogenols identi fied as hederagenin, phytolaccagenic acid and deoxyphytolaccagenic aci d. Oleanolic acid saponins were found to be the main class of saponin in quinoa seeds sampled for this study. The yellow ecotype of quinoa p resented a significantly higher content of saponins and of oleanolic a cid as compared to white ecotypes. Since only one ecotype of amarinth was analysed, the nutritional significance of no detectable saponin ne eds further study. It was concluded that the environmental conditions in the Peruvian highlands are determinants of the amount and compositi on of saponins present in bitter lupin and quinoa.