Question

The nitrogen content of purified bubbanut protein in a food is known to be 17.6%. If 8.5g of dried bubbanuts are found to contain 0.35 g of nitrogen, what is the percent crude protein in this sample, on a dry matter basis? Show your work as you progress through the calculation. (2 marks)

Answer 1

To calculate the percent crude protein in a sample of dried bubbanuts, multiply the nitrogen content percentage (0.35g nitrogen in 8.5g bubbanuts) by the factor 6.25; the sample contains approximately 25.74% crude protein.

Step-by-step explanation:

The student has asked how to calculate the percent crude protein in a sample of dried bubbanuts based on its nitrogen content. Given that 8.5g of dried bubbanuts contain 0.35g of nitrogen, and that crude protein is estimated by multiplying the nitrogen content by a factor of 6.25 (the general factor used for converting nitrogen to crude protein), we can calculate the crude protein content in the sample as follows:

1. Divide the mass of nitrogen by the mass of the bubbanuts: 0.35g ÷ 8.5g = 0.04118.
2. Multiply the result by 100 to get the percentage of nitrogen: 0.04118 × 100 = 4.118%.
3. Finally, multiply the percentage of nitrogen by 6.25 to convert to percent crude protein: 4.118% × 6.25 = 25.7375%.

Therefore, the percent crude protein on a dry matter basis in this sample of dried bubbanuts is approximately 25.74%.