Abstract
This paper reports the type analysis of foodstuffs using four parameters: (1) minimum pH, (2) the time required to reach the minimum pH, (3) the time required to return to the fasting pH, and (4) the area between Stephan curve and fasting pH level (pH changed area).
A total of 21 snacks and beverages were tested. Plaque pH was measured by the method reported in the previous paper.
The following results were obtained.
1) Four types of Stephan curve were produced by eating: an acid type (A) showed a pH decrease, a basic type (B) showed a pH increase, a mixed type (AB) initially showed pH increase and then pH decrease, and an indefinite type (C) showed no definite pH change.
2) The acid type (A) was further classified into three subtypes: a small pH-change type (A1: ex. potato chips), a rapid pH-change type (A2: ex. orange juice), and a slow pH-change type (A3: chocolate).
3) Cheese gave a typical example of the basic type (B), ice cream of the mixed type (AB), and senbei (rice crackers) of the indefinite type (C).
4) Minimum pH was correlated with the differences between individuals, and the time required to return to the fasting pH and the pH changed area were correlated with the differences between foodstuffs.
5) There was correlation between the pH changed area and the carbohydrate content in foods, and also between the sucrose content in foods and either minimum pH or the pH changed area.
6) There was correlation between the concentration of sucrose solutions and the time required to return to the fasting pH.
