Moisture Sorption Isotherms of Whey Powder Spray in the 10

Abstract

The results of water sorption tests on whey powder spray carried out under laboratory conditions were presented together with mathematical analyses of the sorption isotherms. Moisture equilibrium data were investigated at air temperatures over the temperature range 10–40°C and water activity ranging from 0.3 to 0.99. The experimental procedure used was a gravimetric dynamic method with continuous registration of sample weight changes. A special laboratory drying device was developed for the purpose.

The sorption capacity decreased as the temperature increased. Re-hydration of the dried material resulted in hysteresis but this phenomenon was limited. Four models of equilibrium moisture content/water activity (Chung-Pfost, Halsey, Henderson and Oswin) were evaluated for their ability to fit the data for the samples tested. The Henderson equation provided a good model for moisture adsorption and desorption by whey powder spray.

References

Audu

T.O.K.

Loncin

and Weisser

(1978) Lebensm.-Wiss.+ Technol. 11, 31.

Banaszek

M.M.

and Siebenmorgen

T.J.

(1990) Trans. Agric. 33, 247.

Beuchat

(1981) Cereal Foods World 26, 345.

Chen

C.C.

and Morey

R.V.

(1989a) Trans. ASAE 32, 983.

Chen

C.C.

and Morey

R.V.

(1989b) Trans. ASAE 32, 999.

Chirife

and Karel

(1974) J. Food Technol. 9, 13.

Draper

N.R.

and Smith

(1981) Applied Regression Analysis, 1st Edn, John Wiley & Sons, New York, pp. 181–198.

Gal

(1975) “Recent Advances in Techniques for the Determination of Sorption Isotherms”, in Water Relations of Food, Duckworth

R.B.

, Ed, Academic Press, New York, pp. 139–152.

Hall

C.W.

(1957) Drying Farm Crops, AVI Publishing Co., Westport, CT, USA, p. 53.

10.

Hall

C.W.

(1979) “Moisture Content”, in Dictionary of Drying, 1st Edn, Marcel Dekker, New York, pp. 208–209.

11.

Kapsalis

J.G.

(1975) “The Influence of Water on Textual Parameters in Foods at Intermediate Moisture Levels”, in Water Relations in Foods, Duckworth

R.B.

, Ed, Academic Press, New York, pp. 627–639.

12.

Kelly

F.H.C.

Mak

F.K.

and Shah

(1995) Int. Sugar J. 97, 361.

13.

Madamba

P.S.

Driscoll

R.H.

and Buckle

K.A.

(1994) Drying Technol. 12, 669.

14.

Mazza

and Jayas

D.S.

(1991) Trans. ASAE 34, 534.

15.

Osborn

G.S.

White

G.M.

Sulaiman

A.H.

and Walton

L.R.

(1989) Trans. ASAE 32, 2109.

16.

Potthast

Acker

and Hamm

(1977) Z. Lebensm.-Unters.-Forsch. 16, 18.

17.

Rao

M.A.

and Rizvi

S.S.H.

(1995) “Chemical Potential and Phase Equilibria”, in Engineering Properties of Foods, Marcel Dekker, New York, pp. 230–248.

18.

Rockland

N.B.

and Nishi

S.K.

(1980) Food Technol. 34, 42.

19.

Rotz

C.A.

and Sprott

D.J.

(1984) Trans. ASAE 27, 715.

20.

Schuchmann

Roy

and Peleg

(1990) J. Food Sci. 55, 759.

21.

Stencl

Homola

and Gotthardova

(1996) “Experimantal Drying Device and Temperature Optimisation for Drying Food Components”, Prepr. 13th World Congr. IFAC, Vol. B, Pergamon Press, San Francisco, CA, USA, pp. 465–469.

22.

Van den Berg

and Bruin

(1978) “The Water Activity of Foods”, Proc. Int. Congr. Food Eng., Boston, MA, USA, 9–13 August, pp. 9–20.

23.

Veltchev

Z.N.

and Menkov

N.D.

(2000) Drying Technol. 18, 1127.

24.

UNISTAT (1995) UNISTAT Users Guide, Unistat Ltd., London.

Moisture Sorption Isotherms of Whey Powder Spray in the 10–40°C Temperature Range

Abstract

References