• K. A. Maigalura
  • J. Suleiman
Keywords: Awara, sorption isotherm, BET and GAB models, water activity


Moisture sorption and storage stability of Awara were evaluated using gravimetric method. Guggenhein-Anderson-de boer (GAB) and Brunauer Emmett and Teller (BET) were used in evaluating sorption and desorption isotherm at temperature range of 30, 40 and 50oc in the range of water activity (0.1-0.9).Sigmoid moisture isotherm shapes were obtained at various temperatures. Lowest level EMC was obtained at highest temperature (500c).A non-linear regression analysis was used to fit both BET and GAB. GAB was found to generate higher coefficient of determination R2 (0.9986, 0.9959 and 0.9933) and lowest mean of relative percentage p% (0.231, 0.0061 and 0.0017) at temperature range (30, 40 and 500c) respectively. Safe % water and storage stability were all predicted from adsorption isotherm curve. 3.14, 3.19 and 3.10 were found to be the safe % water which corresponds to the 3.8aw for GAB adsorption graphs at 30, 40 and 500c temperatures respectively. This safe % water will be useful in packaging and determination of shelf- life of Awara.


Ajibola, O.O, Aviara, N.A, and Abodunrim,V.K (2004). Sorption Equilibrium and thermodynamic properties of palm Kernel. Journal of Food Technology2(1) 18-27.

Alkali, J.S and Satimehin, A.A, (2009). Moisture Adsorption characteristics of ginger (Zingiberofficinale) Powder.CIGR Journal 1286 XI

Aviara, N.A, Ajibola, O.O, Aregbesola, O.A, Adedeji, M.A (2006).”Moisture sorption isotherms of sorghum malt at 40 and 50o c”. Journal of stored products research, 42,290-301.

AOAC. 2000. Official method of analysis. 17th ed. Horwitz, USA.

Brunauer, S., Emmett, P.H. and Teller, E. 1938. Adsorption of gases in multimolecular layer. Journal of American Chemists Society 60: 309-319.

Boquet, R., Chirife, J., and Iglesias, H, A. (1978). ‘Equations for fitting water sorption isotherms of foods’. II. Evaluation of various Two parameter models. Journal of food Technology,13, 139-327.

ChrispeelsM.J and savada D.E (1994).”Plants genes and Agriculture” Jones and Bartlett publishers, Canada P. 143.

Decagon devices, Inc., (2009). “Moisture sorption heats of sorption for potatoes” J. Food engineering, isotherm generator: Pullman, Washington, USA: operator’s manual. Version 3.0.35(3):261-280.

FabraMJ, Talens P, Moraga G, Martínez-Navarrete N. (2009) ‘Sorption isotherm and state diagram of grapefruit as a tool to improve product processing and stability’. J Food Eng. 2009 Jul; 93 (1): 52-58.

Fellow, P. (2003).’ Food processing technology, principles and practice.2nd edition wood sponge-cake as related to porous structure evaluation and moisture content’. Journal of food science 68, 555-562.

Fen-Jin He, Jin-Qiang Chen (2013). Consumption of soybean, soy foods, soy isoflavones and breast cancer incidence: Differences between Chinese women and women in Western countries and possible mechanisms. Food science and human wellness. 2 (2013) 146-161.

Figen, K.E and Atil G. (2003). ‘Sorption Isotherms and isosteric heat sorption for grapes apricots, apples and potatoes’ Journals of swiss society of food science and technology, lebensm-wiss.u.-Technol. 37 (2004) 429-438.

Iglelsias, H. A., and chirife, J., (1976). ‘Isosteric heat of water vapour sorption and dehydrated food’. Part II hysteresis and heat of sorption comparison with BET theory. Lebesmittel-wissenschaft und Techology, 9, 123-127.

GazorH.R (2010). ‘Moisture isotherms and heat of desorption of canola’. Agricultural Engineering international the CIGR E journal, Manuscript 1440 vol XII. May 2010.

Greenspan, L (1977). ‘Humidity fixed points of binary saturated aqueous solution’. Journa. Res. Nat’l Bureau of standards-Section A. Physics and chemistry, 81(1) 89-96.

Labuza,T. P. (1984). ‘Moisture sorption: practical aspect of isotherm measurement and use’. St. Paul, MN: American association of cereal chemists.

LabuzaT.P., A. Kaanane and Y. Chen, (1985). ‘Effect of temperature on moisture sorption isotherm and water activity shift of two dehydrated food’. Journal of food science, 50, 385-391

Liu, K. (1997).”Soyabeans”, chemistry, technology and utilization. Springer.Pp. 532.

Lomauro, C. J., BakshiA.S., and Labuza T.P (1985) Evaluation of food moisture sorption isotherm equation. Part I. Fruit vegetable and meat products. Lebensmittel-wissenschaft and tecnoloie, 111-117

Mekov, N.D., Durakova,A.G. and Krastera, A. (2005). Moisture Sorption Isotherms of common Beans Flour at several temperature. Electronic Journalof environment, Agriculture and food chemistry 4(2), 892-992.

Mujumdar AS (Ed.). (1980) ‘Advances in Drying’, Vol. 1. Washington, USA: Hemisphere Publishing Corporation; 1980. Fortes M, OkosMR. Drying theories: Their bases and limitations as applied to foods and grains; 301 p.

Palou, E. Lopes-malo, A. And Angaiz, A. (1997). Effect of temperature on Moisture Sorption of some Cookies and Snacks. Journal of food Engineering,31,85-93.

Raji AO, Ojediran JO. (2011). ‘Moisture sorption isotherms of two varieties of millet’. Food Bioprod Process. 2011 Jul; 89 (3): 178-184.

Sahin S, Gülüm S. Physical Properties of Foods. New York, United States: Springer; 2006. 205, 218 p.

Salunkhe , D. K., chavan, J.C., Adsule, R.N. and kadam, S.S. (1992). ‘World Oil Seed’, Chemistry, Technology and Utilization. Van Nostrand Reinhold, New York.

Timmermann, E. O. (2003). Multilayer sorption parameters: BET or GAB values? Colloids and surfaces A: Physicochemical and Engineering Aspects 220: 235-260.

Timmermann, E. O., Chirife, J. and Iglesias, H.A. (2001). Water sorption isotherms of foods and foodstuffs: BET or GAB parameters? Journal of Food Engineering 48:19-31.
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