Protein quality comparison of a new isolated soy protein and milk in chilean preschool children (original) (raw)

The protein quality of a newly developed soybean protein isolate (SPF-200) and milk were compared using apparent N digestibility (AND), N balance (ANB) and serum biochemical response to graded levels of N intake (NI). Seven healthy well nourished children aged 35 to 62 months, were given for 8 day periods 1.5, 1.25, 1.0 and 0.75 g protein/kg/day of SPF and milk in decreasing order at a constant energy intake of 100 Kcal/kg/day and a vitamin mineral supplement. AND for SPF ranged from 86 to 70% and for milk 83 to 75%, corresponding to highest and lowest NI, ANB for SPF ranged from 63 to 0 mg/kg/day and for milk from 90 to 28 mg/kg/day. Mean individual regressions of daily ANB and NI were ANB = 0.49 NI-54 for SPF and ANB = 0.51NI-34 milk. The slopes were not significantly different. Non significant decreases in serum albumin and urea were observed. A significant increase in transaminases was noted at the lowest NI for both proteins. Daily protein allowances to retain 39 mg N/kg/day were 1.27 and 0.91 g protein/kg/day for SPF a~d milk respectively.