Abstract:
This study was conducted to investigate the effect of lupine flour on physico-chemical composition and sensory acceptability of tef-lupine blended injera. The effect of two factors, blending ratio and lupine varieties (Australian sweet lupine and Dibettered lupine seed) were studied. There were 23 experimental formulations generated from mixture design software. Lupine variety and blending proportion had significant (P<0.05) effect on proximate, mineral, anti-nutritional compositions and sensory properties of blended injera. The nutritional compositions of formulated injera ranged from 60.37 to 66.97%, 1.76 to 2.05 %, 11.78 to 18.84 %, 2.53 to 4.01 %, 2.83 to 3.16%, 72.55 to 81.32% and 393.19 to 400.91 kcal/100g for moisture content, total ash, crude protein, crude fat, crude fiber, utilizable carbohydrate and gross energy, respectively. The result showed that the crude protein content highly increased as the proportion of lupines increased. Crude protein and crude fat contents were higher for injera blended with DLS variety and crude fiber content was higher for those blended with ASL variety. Mineral content of composite injeras varied from 12.26 to 14.98 mg/100g, 2.39 to 2.83 mg/100g, and 145.31 to 163.96 mg/100g for iron, zinc and calcium contents respectively. All three mineral contents were higher in tef blended with DLS variety. The Tannin and phytic acid contents ranged from 9.59 to 11.95mg/100g and 98.91 to 120.64 mg/100g, respectively. The sensory scores for colour, taste, texture, number of eyes, eye size, eye distribution, top and bottom surface, aroma, rollability and overall acceptability were 5.64 to 6.18, 3.82 to 6.14, 3.50 to 6.00, 3.27 to 6.25, 3.23 to 6.08, 3.23 to 6.23, 4.01 to 6.17, 5.09 to 6.22, 3.82 to 6.09 and 4.20 to 6.18, respectively. Sensory acceptability of blended injera were reduced after when both lupine ratio were increased above 10% but with up to 15% being found acceptable by consumers with scores greater than 5 in 7 point hedonic scales. Rollability and eye distribution were higher for composite injeras from DLS variety and eye size were higher for ASL. The L* value and number of eye by injera eye software were 72.77 to 79.84 and 14220.43 to 18929.33, respectively. The L values of blended injera increased as lupine proportion were increased, but the number of injeras eyes decreased. Therefore, the findings of this study were found to be very significant and it is believed that this study could give insights for use of lupine flour mixed with tef flour in home and industry level for making injera.
