The Effect of Ultrasonic Waves on Sugar Extraction and Mechanical Properties of Sugar Beet

Sugar، which can be extracted from sugar cane and sugar beet، is one of the most important ingredients of food. Conducting more research to increase the extraction efficiency of sugar is necessary due to high production of sugar beet and its numerous processing units in northern Khorasan province. In this research، the effect of temperature، time and the frequency of ultrasonic waves on mechanical properties of sugar beet and its extraction rate of sugar in moisture content of 75% were studied. In this regard، an ultrasonic bath in laboratory scale was used. The studied parameters and their levels were frequency in three levels (zero، 25 and 45 KHz)، temperature in three levels (25، 50 and 70 ° C) and the imposed time of ultrasonic waves in three levels (10، 20 and 30 min). Samples were prepared using planned experiments and the results were compared with control sugar beet samples. A Saccharimeter was used to measure the concenteration of sugar in samples. Two different types of probe including semi-spherical end and the other one with sharpened edges were used to measure mechanical properties. The studied parameters of frequency، temperature and time showed significant effect on sugar extraction and their resulted effect in optimized levels revealed up to 56% increase in sugar extraction compared with control samples. The obtained values of elastic modulus and shear modulus showed a decreasing trend. The obtained values of total energy of rupture، the total energy of shear، the maximum force of rupture، and the yield point of rupture showed an increasing trend. The frequency had no significant effect on the yield point of rupture and shear force.