Multiple forms of pectinmethylesterase from citrus peel and their effects on juice cloud stability

It has been possible to show the occurrence of four types of pectinmethylesterase (PME) activity in citrus peel dialysis supernatant (DS) fraction through a combination of anion exchange and affinity chromatography. Of these types, only one was a thermally stable PME, while three of the four destabilized orange juice cloud within 10 days at 30 degrees C. Peel DS extract produced the most rapid cloud destabilization and peel DS contains both a thermally labile- and a thermally stable-PME able to quickly clarify citrus juice. It may therefore be beneficial in citrus juice processing to reduce the amount of peel PMEs in products.