Changes in soluble sugars of two pineapple fruit cultivars during frozen storage

Sugar changes taking place during freezing and frozen storage of two pineapple fruit cultivars, Smooth Cayenne and Red Spanish, were studied. Pineapple fruit was frozen as slices in a cold room at −18 °C and stored at this temperature for a 12-month period. The sugar content was measured by high-performance liquid chromatography (HPLC) and compared to the total soluble solids determined by refractive index. Both were linearly related. HPLC identified the major components as fructose, glucose and sucrose. A high correlation was observed between the different sugars in the two cultivars during frozen storage. Freezing preservation of pineapple fruit slices led to minimal changes in soluble solids and sugar content (fructose, glucose and sucrose) after 1 year of frozen storage.