Protein quality and glycemic indexes of mango drinks fortified with a soybean/maize protein isolate with three levels of urease activity fed to weanling rats

Abstract

Introduction: Public health professionals established a direct link between obesity and the rise in high caloric beverage intake. Current recommendations promote the elimination of sweet fruit drinks from the population’s diet. One way of evading this is by modifying the drink’s nutritional characteristics regarding nutrient uptake and utilization. Objectives: evaluate the protein quality of a soy/maize protein (SMP) and its physiological effects on nutrient intake and to assess glycemic indexes (GIs) of mango based drinks prepared with sucrose or stevia. Materials and methods: Mango drinks were supplemented with different sources of protein (three SMP thermally treated to contain different urease activities (UA) or whey protein concentrate (WPC)) that were sweetened with sucrose or stevia/sucralose. The protein digestibility, net protein absorption (NPA), biological value (BV), net protein utilization (NPU) value and protein efficiency ratio (PER) were assessed with weanling rats. Moreover, the GIs of the mango drinks were measured in the same animal model. Results: PER and NPA evaluated in a rat model showed that increased levels of UA decreased Biological (BV) and Net Protein Utilization (NPU) values. The GIs of the mango drinks significantly diminished with the addition of 3.5% of SMP, but unexpectedly the substitution of sucrose by stevia/sucralose did not significantly change the glycemic response. Conclusion: the SMP isolate can be used to improve the nutritional profile and lower GIs of mango drinks.

Keywords

• soy protein isolate
• glycemic index
• beverages
• mango
• protein digestibility
• urease activity
• artificial sweeteners