preview

Lab Report On Ultrasound Treatment

Decent Essays

Ultrasound treatment was done according to method by [21] with some modifications. Ultrasonic probe (JY92-IIN, Ningbo Scientz Biotechnology Co. Ltd, Ningbo, China) was used, with maximum power 1000Watt, frequency 25 kHz and probe diameter of 13mm. Pectin solutions were treated at 60% duty cycles, sonication times was fixed at 20 minutes, sonication power (200 and 400 watts). Effect of acidity on sonication was determined at pH 2, 4 and 6, by adjusting solution pH using acetic acid. Native pectin 0.25g was put in 250ml beaker suspended in 100ml deionized water to achieve low viscosity, it was stirred on a magnetic stirrer for 30 minutes, and sonic treatment was done by immersing sonic probe up to 1cm deep in the solution. After treatment, the suspension was precipitated with equal volume of 95%v/v ethanol to precipitate pectin. The content was centrifuged at 7500xg and filtrate removed. the precipitate was left in fume cupboard to remove ethanol traces then re-dissolved in deionized water and frozen at -45ᴼC and eventually freeze dried for further analysis. Ultrasound intensity was predicted according to the following equation
I=P/(πr^2 )
Where I= intensity, r =radius of the sonic probe and P= ultrasonic power. 4.2.5. Molecular weight determination
The effect of sonication on pectin molecular weight was evaluated on HPSEC according to the method described by [36,37]. The analysis was carried out on a HPSEC system equipped with a Light scattering instrument (DAWN Heleos,

Get Access