EFFECTS OF STORAGE RELATIVE HUMIDITY AND TEMPERATURE ON QUALITY OF PALACE HALVA

Palace halva is a traditional flour-containing confectionery of Turkey. Primarily, physical deterioration is observed in this halva due to its brittle-fibrous structure and low aw. In this study, effects of storage relative humidity (RH) and temperature on quality of palace halva were investigated. Halva samples were stored at different RH (22-90%) at 25-35°C until equilibrium moisture content was reached. Moisture content, aw, hardness, oxidation, color and X-ray diffraction measurements were made before and after storage. Adsorption isotherms of palace halva were determined. Fresh palace halva had aw of 0.21 and glassy structure. Glassy structure of palace halva was not preserved at RH of 54% at 25°C and 32% at 35°C and crystalline structure formed because of state change. Hardness of halva increased and then decreased as RH was increased. Color change by Maillard reaction and increase in TBARS by oxidation occurred in the product as RH and temperature were increased