Evaluating the buffering capacity of various soft drinks, fruit juices and tea

AIMS AND OBJECTIVE: The purpose of this study is to measure the initial pH of various commonly used beverages and to determine their ability to maintain a low pH by measuring their buffering capacities. MATERIALS AND METHODS: Twelve commercially available drinks were taken and divided into four groups (preserved fruit juices, tea, mineral water and carbonated drinks. Each group comprised of three drinks. Their initial pH were measured with pH meter and their buffering capacities were measured by adding 1M NaOH in the increments of 0.2 ml into 100 ml of each drink till the pH raised to 5.5 and 7 respectively. STATISTICAL ANALYSIS: The volume of NaOH required to raise the pH to 5.5 and 7 were recorded in all the groups. This data was subjected to statistical analysis using Mann- Whitney tests. RESULTS: Total titratable acidity measurement shows that among all the drinks, there was no significant difference between carbonated drinks and preserved fruit juices while a significant difference was present between carbonated drinks, preserved fruit juices and tea. CONCLUSION: In this in vitro study, it was found that packaged apple juice had the most buffering capacity with maximum erosive potential whereas green tea had the least.