1 Methods for Reliable and Accurate Measures of pHpH Measurement Methods for Reliable and Accurate Measures of pH

2 Definition of pH A way to measure acids (acidic) and bases (alkalinity) in food. Expression of the concentration of hydrogen (H+) and hydroxide ions (OH-) in an aqueous solution (water-based). Uses a scale between 0 and 14 A pH Measurement

3 Measurement Method– Litmus Paper1. Used by dipping litmus paper into solution 2. Turns yellow to red in acidic solution (acid) 3. Turns green or blue in alkaline solution (base) 4. Easy method 5. Not completely accurate A pH Measurement

4 Measurement Method – Indicator StripsDip the strip into the aqueous (liquid) food being tested for a few seconds. Remove strip from test solution and compare color segments to center color printed on the strip. A pH Measurement

5 Measurement Method – Indicator DyeOrganic dyes Done with dropper Acidic (acid) -- pink or red Alkaline (base) -- green or blue Neutral solution may turn lilac Not totally accurate A pH Measurement

6 Measurement Method – pH MeterDigital reading Accurate Some units are expensive Easy and sanitary A pH Measurement

7 Measure Method – Titratable Acidity1. Add base with know pH to an acid. 2. Use burette. 3. More difficult to calculate. 4. Use if have chemistry knowledge. A pH Measurement