Acidity in the kitchen

In general, foods that have sour taste, such as citrus fruits, kiwi, and tomato are considered acidic. Acidity is measured with a scale called pH (potential of hydrogen) that ranges from 0 to 14. Foods with a pH value of 7 are considered neutral, lower than 7 are acidic, and above 7 are basic. Low-acidity foods have pH values higher than 4.6, while high-acidity foods have pH values equal to 4.6 or lower. Acidic foods contain increasingly higher concentrations of positively-charged hydrogen ions. Diluting with water, for example adding water into an orange juice decreases the concentration of hydrogen ion in the medium, hence the acidity. Students observe the effects of acidity on food spoilage, and sensory attributes of the foods during storage, preparation and cooking with Prof. Dr. Sibel Ozilgen as a part of the course 'Culinary Science Laboratory' at the Gastronomy and Culinary Arts Department, Yeditepe University.