Thermal and Textural Changes of Turkish Delight with Storage Relative Humidity

Abstract

Lokum (Turkish delight) is a high sugar and starch containing food. Since the major deterioration factor affecting the storability of lokum is moisture gain or loss, the effect of the possible ambient conditions (32%, 53%, 75% RH and 15, 25, 35 °C) on weight change and firmness of lokum was determined to estimate its structural changes. The variations in thermal properties of lokum samples stored at different RH (32, 53, 65, 75, and 85% RH) were also determined. Increasing RH decreased glass transition of lokum samples, and two glass transitions (T g) were observed at 75 and 85% RH. The presence of the second T g could be related with phase separation which was increased with increasing moisture content and RH. Lokum should be kept at around 50% RH and 15 °C, higher storage RH's and temperatures will cause the product to become unacceptable by the consumer within 20 days.