Evaluation of the Effects of Osmosis Pretreatment Assisted by Ultrasound on the Impregnation of Phenolic Compounds into Aloe vera Gel and Dry Product Qualit

In this study, the effects of combined osmosis and ultrasonic pre-treatment on the infusion of phenolic compounds extracted from grape residue into Aloe vera gel was evaluated, and the qualitative characteristics of dried Aloe vera samples were evaluated with hot air flow. For this purpose, the Aloe vera gel was prepared with agar and cut in the cylinder form (20 x 20 mm). The effects of different methods (osmotic dehydration, ultrasound prior and ultrasound assisted osmotic dehydration) on water loss, adsorption of solids, dehydration index and weight loss were measured. The samples were dried with a cabinet- dryer with a constant temperature of 60 °C and air speed of 1.5 m / s. The results showed that ultrasonic application had a significant effect on the physico-chemical properties of Aloe vera gel. The ultrasound assisted osmotic dehydration increased the amount of water loss and solids gain, comparing with other methods. The dried Aloe vera gel pre-treated with ultrasound assisted osmotic dehydration, had higher anthocyanin compounds and its color was lighter and reddened. The results of the sensory evaluation of the samples showed that this pretreatment improved the color, texture and appearance of the product.