Determination of sucrose and sucrose gain
The samples will be analysed of sucrose content in order to calculate the sucrose gain during the osmotic dehydration process by following the method of Finley and Fellers (1973). Weigh 1 g of sample and add into a 100 ml volumetric flask. Add 50 ml of 80% ethanol and gently boil for 15 min. Concurrently, run a reagent blank and a standard which is 1 ml of a 15% w/v. sucrose solution. Then, the samples will be cooled down to room temperature and dilute to 100 ml with 80% ethanol and then filter through Whatman No. 1 filter paper. Then, add 1 ml of filtrate to 9ml of Fehling solution in a test tube and heat in boiling water bath for 15 min and cool down to 20ºC. To 1 ml of this solution in a clean test tube, rapidly add 10 ml of anthrone reagent and keep them at 40ºC in 30 min. After that, read absorbance at 610 nm against a reagent blank.