Evaluation of Moisture Sorption Isotherms and Storage Stability of Agglomerated Boza Powder

Abstract

This study evaluated moisture sorption properties and storage stability of agglomerated boza powders as a cereal-based potential probiotic instant product. Moisture adsorption isotherms of powders were determined at 10°C, 25°C, and 40°C, and the obtained curves were characterized by Type III isotherms. Of the four models, GAB was found to be the most suitable for describing the sorption of powders over the entire range of water activity. The differential entropy values of boza powder were calculated as 16.23 and 2.68 j/mol K at 1% and 20% moisture content, respectively. As observed in isosteric sorption heat values, the differential entropy of boza powder tended to decrease with increasing equilibrium moisture content. Changes in some agglomerated boza powder quality characteristics were determined during 6-month storage at room temperature using glass and aluminum-laminated polyethylene (ALPE) packaging materials. Based on the kind of material utilized for packaging, LAB cell survival and some quality parameters, including moisture content, water activity, pH and titratable acidity, ΔE value, particle density, porosity, loose and tapped bulk density, wettability, solubility, flowability, cake strength, cohesion index, and thermal property of the powder changed to varying degrees while being stored. The results showed that glass packaging provides the best protection and is used for long-term storage of agglomerated boza powder.