The researchers wanted to see if giving rats an extract from purple sweet potato tubers could increase anthocyanin levels in their blood. They tested this on healthy rats and rats with diabetes. They found that anthocyanin levels were higher in healthy rats compared to diabetic rats. The peak levels of anthocyanin were reached after 2 hours of consuming the extract. This shows that healthy rats absorb anthocyanin better than diabetic rats from the purple sweet potato extract.