Fatty acid profile and mineral composition of traditionally processed gibto (Lupinus albus L.) grown in Ethiopia

Abstract

White lupin seeds, Lupinus albus L. are known for their bitter taste due to the presence of different alkaloids and other related anti-nutritional factors which make the seeds inedible. There are reports on some of processing methods that have the potential to reduce the alkaloids and make it a safe product for consumption. However, studies on the effects of the processing techniques on other biochemical compositions of the seed are lacking. In this study, the effects of  commonly used traditional processing methods (roasting followed by soaking for five days, boiling followed by soaking for five days, germination for 48 hrs and dehulling) on the fatty acid profile and mineral composition and total alkaloid contents of L. albus seeds grown in Ethiopia are reported. The L. albus seeds were collected from two sites named Dangla and Tilili. Analysis of the seeds showed that the contents of iron, zinc, manganese and magnesium in the raw Dangla and Tilili samples were 6.01, 2.11, and 58.43, 8.93 mg/ 100 gm and 6.73, 1.81, 59.14 and 9.46 mg/ 100 gm, respectively. In raw seeds, an average value of 10 % saturated and 75 % unsaturated fatty acids were recorded. The predominant unsaturated fatty acids were C18:1 (n-9) and C18:2 (n-6), while the saturated ones contained C16:0, C18:0 and C20:0. All the traditional processing methods applied have reduced the total alkaloid contents of the raw seed from both sites significantly. Due to these treatments the content of iron in the raw seeds from both sites was reduced by (14-47) % and magnesium by only less than 10 %. Also due to these treatments no loss in the essential fatty acid contents was observed. Therefore, the minimally processed L. albus seeds using traditional methods can serve as a potential source of minerals and essential fatty acids after removing the alkaloids