**8. Evaluation of the quality of extracted molecules using ultrasonic-enzymatic technique**

"Sugars content was dependent on length of enzymatic treatment time. At the shortest enzymatic time (1 h), increasing ultrasonic treatment from 0 to 45 min resulted in increasing galacturonic acid by about 17%.regarding neutral sugars, the isolated pectin samples after different ultrasonic treatment had close arabinose, rhmanose, galactose, glucose, and xylose contents at the 1-hour enzymatic treatment. At 4-hour enzymatic treatment, ultrasonic treatment time had no effect on galacturonic acid content but arabinose tended to decrease, glucose sugars tended to increase, and no significant effect on rhmanose, galactose, and xxylos was found. There was generally no significant effect for increasing the ultrasonic treatment time on protein content of extracted pectin. Regarding the degree of esterification, pectin extracted using merely enzymatic treatment for 1 h had generally higher degree of esterification than those isolated after 4 h. The effect of ultrasonic treatment time on degree of esterification was depended on enzymatic treatment duration. At 1 h enzymatic treatment, there was no effect for the ultrasonic time on the degree of esterification while in case of 4 h enzymatic treatment the ultrasonic pretreatment resulted in pectin with lower degree of esterification.

Regarding the ferulic acid content, it generally decreased with increasing the ultrasonic pretreatment time in case of the 4-hour enzymatic treatment experiments while no effect was found in case of the 1-Hour enzymatic treatment. This is in accordance with a previous study, which showed that ultrasonic treatment could promote de-esterification of ferulic acid and also methyl and acetyl groups from galacturonic acid units" [4].
