Effect of pre-treatments and drying methods on the quality attributes of dehydrated pineapple slices

Purpose: Pineapple fruit is a rich source of minerals and vitamins. Its shelf life is very short due to perishability characteristic. Research Method: In this research, the effect of pre-treatments on pineapple slices for its preservation and acceptability was studied. The pineapple slices were treated with three different osmotic (table sugar) solution concentrations, temperature, and vacuum pressure levels to find the most suitable treatment in term of quality. Different parameters such as weight reduction, water loss, solid gain, nutritional quality and sensory test (texture, taste, odor, and appearance) were studied. To perform these parameters pineapple slices were immersed in sugar solution on 50, 60 ºB (degree Brix) at 30, 40 and 50 ºC followed by three vacuum pressures including 435 mmHg, 110 mmHg and atmospheric 760 mmHg pressures for up to 180 min. Findings: Results showed that water loss in pineapple slices increased with increase in vacuum level in all three sugar concentrations and degrees of temperatures in osmotic solution. Weight reduction, water loss, solid gain, water activity, total color, ascorbic acid content, whereas sugar content was found significantly affecting the process followed by temperature and levels of vacuum. Research limitations: There were no limitations to report. Originality/Value: It was found that the most affecting treatment was vacuum pressure, whereas the highest changes occurred in appearance followed by the ascorbic acid content of the samples treated with different parameters.

کلیدواژه ها:

Osmotic dehydration ، Sugar concentration ، Vacuum drying