Potassium analysis in various roasted coffees using atomic absorption spectroscopy

Abstract

Potassium is an important molecule needed for many bodily functions. Potassium is needed for muscle contraction, cardiovascular activity, digestive regulation and lowering blood pressure (Ehrlich). Low potassium levels can lead to fatigue and muscle cramps. On the contrary to this, people with chronic kidney disease (CKD) need to limit their potassium intake. Therefore, the measuring of potassium content in processed foods is important. Coffee is a source of potassium in the diet, but it is also known as a source to cause hypokalemia, an increased loss of potassium due to the diuretic action of caffeine. The purpose of the experiment was to determine the potassium contents of different roasted coffee. Three different coffees, light roasted, dark roasted, and instant coffees (Folger’s Coffee) were used as samples. Our test was done in triplicate using atomic absorption (AA) spectroscopy and a potassium standard curve (R² value=0.9952) was used to convert the potassium contents of the coffee sample. ANOVA single-factor test showed that the results were not significant, with p-value of 0.444. Literature shows that Folger’s does not have to include nutrition facts on their coffee as the nutrient values are less than 1.0mg (USDA). Daily value needs of potassium are 3,500mg, and so for those with CKD, this is a low-potassium food that they can consume (FDA). In conclusion, there was no significant difference between the three different roasting types of coffee for potassium concentration. Even though the roasting and processing are different, all of the coffees had similar amounts of potassium, so these processes did not have an effect on potassium concentration. Because coffee has a low amount of potassium, those with CKD can consume any coffee of their choosing. Further analysis would be comparing other brands of coffee to see their potassium concentrations.