CALCULATION OF WATER ACTIVITY AND ACTIVITY COEFFICIENT OF SUGAR SOLUTIONS AND SOME LIQUID FOODS.

Type of article: Article

Summary

RAOULT'S LAW OF WATER ACTIVITY AND THE MODIFIED EQUATION OF SCHWARTZBERG WERE APPLIED TO STUDY THE WATER ACTIVITY OF SUGAR SOLUTIONS, SKIM MILK, COFFEE AND FRUIT JUICE CONCENTRATES. THE DEVIATION FROM IDEALITY IS ATTRIBUTED TO THE SOLVATION OF WATER MOLECULES BY THE SOLUTES AND IS CHARACTERIZED BY ACTIVITY COEFFICIENT C WHICH DECREASES WITH INCREASING CONCENTRATIO THE VALUE OF C IS CLOSE TO UNITY FOR MOST SUGAR SOLUTIONS UP TO 40% BY WEIGHT. EQUATIONS FOR CALCULATING WATER ACTIVITY ARE PRESENTED. THE VALUES CALCULATED USING THE EFFECTIVE MOLECULAR WEIGHT ESTIMATED BY THE FREEZING-POINT DEPRESSION METHOD, AGREE WITH THE CORRESPONDING DATA MEASURED BY ELECTRIC HYGROMETERS.

Details

Original title: CALCULATION OF WATER ACTIVITY AND ACTIVITY COEFFICIENT OF SUGAR SOLUTIONS AND SOME LIQUID FOODS.
Record ID : 1988-0128
Languages: English
Source: Lebensm.-Wiss. Technol. - vol. 20 - n. 2
Publication date: 1987

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Indexing

Themes: Food engineering;
Chilling of foodstuffs
Keywords: Coffee; Calculation; Milk; Sugar; Solution; Fruit juice; Water; Water activity