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Effective Diffusivity Coefficients for Degradation of Pectin in Guava (Psidium guajava L.) Pulps Using Immobilized Pectinase

Medala Mukunda Vani, Dubasi Govardhana Rao





Background and objective: Recently, use of immobilization technology through cell entrapment to entrap biocatalysts has been shown as an economical method since it offers several advantages over suspension cultures such as reusability, high cell concentrations over a period of time, elimination of costly processes of cell recovery and cell recycling and simplifying the downstream processing. Understanding diffusion and permeability coefficients is necessary for the creation of optimized encapsulation systems. The major objectives of the present study included degradation studies on pectin using batch systems using soluble and immobilized pectinase enzymes.

Materials and methods: Commercial pectinase enzymes were immobilized using entrapment method for liquefaction of Guava (Psidium guajava L.) pulps with a wide range of applications in food industries. Guava fruit pulps were liquefied using free and immobilized pectinase enzymes to assess the intraparticle mass transfer resistance.

Results and conclusion: In the current study, effects of mass transfer on liquefaction process were revealed. Effectiveness factors for the various sizes of immobilized beads included less than 1.0, which indicated that the pectin degradation was a diffusion-controlled process. Effectiveness factors included 0.520 and 0.268 for beads having smallest and largest diameters, respectively. Intra-particle mass transfer resistance was assessed by calculating Thiele modulus (ф) using effectiveness factors calculated for various bead sizes. These results were further used to calculate the effective diffusivity coefficients (De) of guava pulps into the pores. Thiele modulus values (ф) were much higher than 1, which showed that the reaction was very fast and the system was mass transfer controlled. Beads with lower diameters included higher diffusivity coefficients showing a better rate of diffusion of substrates from bulk solutions.

Conflict of interest: The authors declare no conflict of interest.


▪ Diffusion-controlled biochemical process ▪ Diffusivity coefficients ▪ Effectiveness factors ▪ Pectinase ▪ Pectin degradation ▪ Thiele modulus


Kaur S, Sarkar BC, Sharma HK, Singh C. Optimization of enzymatic hydrolysis pretreatment conditions for enhanced juice recovery from guava fruit using response surface methodology. Food and Bioprocess Technology. 2009 Mar 1;2(1):96-100.

Mantovani CF, Geimba MP, Brandelli A. Enzymatic clarification of fruit juices by fungal pectin lyase. Food Biotechnology. 2005 Sep 1;19(3):173-81.

Rao DG. Introduction to Bio Chemical Engineering. 2nd Ed. Tata Mc Graw-Hill company. 2010 86:87.

Lee JM. Biochemical Engineering. Prentice Hall International series in the Physical and Chemical Sciences. 1992 32:60.

Handriková G, Štefuca V, Polakovič M, Báleš V. Determination of effective diffusion coefficient of substrate in gel particles with immobilized biocatalyst. Enzyme and Microbial Technology. 1996 Jun 1;18(8):581-4.

Aksu Z, Bülbül G. Determination of the effective diffusion coefficient of phenol in Ca-alginate-immobilized P. putida beads. Enzyme and microbial technology. 1999 Aug 1;25(3-5):344-8.

Chen KC, Wu JY, Yang WB, Hwang SC. Evaluation of effective diffusion coefficient and intrinsic kinetic parameters on azo dye biodegradation using PVA‐immobilized cell beads. Biotechnology and bioengineering. 2003 Sep 30;83(7):821-32.

Idris A, Zain NA, Suhaimi MS. Immobilization of Baker's yeast invertase in PVA–alginate matrix using innovative immobilization technique. Process Biochemistry. 2008 Apr 1;43(4):331-8.

Bailey JE, Ollis DF. Biochemical engineering fundamentals. Chemical Engineering Education. 1976 2nd ed 210:14

Levenspiel O. Chemical Reaction Engineering, John Wiley, New York, 3rd Ed. 1999 384:385.

Kertesz ZI. Methods in Enzymology. New York: Interscience Publishers Inc. 1955 Vol. 1 162:164.

Li T, Wang N, Li S, Zhao Q, Guo M, Zhang C. Optimization of covalent immobilization of pectinase on sodium alginate support. Biotechnology letters. 2007 Sep 1;29(9):1413-6.

Ranganna S. Analysis of Fruits and Vegetable products. Tata Mc Graw-Hill Company, 1977 40:42.

DOI: https://doi.org/10.22037/afb.v6i2.23307


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