Topical Area: Global Nutrition
Objectives : Previously we found that extruded sorghum-soy blend (SSB) and corn-soy blend (CSB) fortified blended foods (FBFs) containing whey protein concentrate (WPC) were equally nutritious foods. WPC provides high-quality protein, however, it is the most expensive component of FBFs. Our primary objective was to determine if soy protein may serve as an alternative to WPC and our secondary objective was to evaluate effects of varying sugar amounts in FBFs.
Methods : Extruded SSB and CSB FBFs were developed with increased soy flour to meet protein requirements. Sugar content ranged from 0–15% in SSBs (SSB-0, SSB-5, SSB-10, SSB-15) and 0–10% in CSBs (CSB-0, CSB-5, CSB-10). Previously developed SSB and CSB FBFs with 9.5% WPC and 15% sugar served as comparison diets (SSB-WPC, CSB-WPC). Weanling, male Sprague Dawley rats were individually housed and consumed assigned diets, dry FBF or AIN-93G, for 28 days (n = 9-10). Food intake was measured every other day and body weights were measured weekly. At study conclusion, blood and livers were collected to evaluate iron outcomes and PIXImus body scans were performed to assess body composition and bone mineral density (BMD).
Results : There were no significant differences in food intake or final body weights among SSB and CSB groups. Protein efficiency was significantly higher in the WPC groups compared to the non-WPC groups. WPC groups’ caloric efficiencies were significantly higher than the non-WPC CSB groups, but not different than the non-WPC SSB groups. BMD was significantly decreased in 15% sugar diets (CSB-WPC, SSB-WPC, SSB-15) compared to AIN-93G. There were no significant differences in lean mass or hemoglobin concentrations between groups. Liver iron concentrations were significantly higher in all FBF groups compared to the AIN-93G group.
Conclusions : Protein efficiency was the most notable significant difference among the groups which may be explained by lower protein intake in the WPC groups compared to the non-WPC groups. All findings considered, our results suggest that extruded SSB and CSB FBFs with soy protein are an efficacious alternative to WPC-containing FBFs.
Funding Sources : Partially funded by the USDA Foreign Agricultural Service under the Micronutrient Fortified Food Aid Products Pilot (MFFAPP) program and the Kansas Agricultural Experiment Station.