16.49 Loss of vitamin C in bread.
Does bread lose its vitamins when stored? Here are data on the vitamin C content (milligrams per 100 grams of flour) in bread baked from the same recipe and stored for one, three, five, or seven days. The 10 observations are from 10 different loaves of bread.16
bread
Condition | Vitamin C (mg/100 g) | |
Immediately after baking | 47.62 | 49.79 |
One day after baking | 40.45 | 43.46 |
Three days after baking | 21.25 | 22.34 |
Five days after baking | 13.18 | 11.65 |
Seven days after baking | 8.51 | 8.13 |
The loss of vitamin C over time is clear, but with only two loaves of bread for each storage time, we wonder if the differences among the groups are significant.
16.49
H0: Vitamin C values have the same distribution in all groups. Ha: Vitamin C values are systematically higher in some groups than in others. , . The data do not show differences in vitamin C across different conditions. Although the test is not significant, looking at the data suggests that there is vitamin C lost over time. (b) With the new P-value from SAS, we would reject the null hypothesis and conclude there are systematically higher vitamin C values in some groups than in others, showing the loss of vitamin C over time.