J.E, V.-T., V.-S. J.W, G.-R. O., L.-L. C., and A.-C. S.C. “EFFECT OF ULTRASOUND AND THERMAL TREATMENT ON PECTIN METHYLESTERASE ACTIVITY IN PAPAYA (Carica Papaya) JUICE”. Journal of Microbiology, Biotechnology and Food Sciences, vol. 5, no. 5, Apr. 2016, pp. 487-90, doi:10.15414/jmbfs.2016.5.5.487-490.