Applied Chemical Engineering (Transferred)

The accumulation of plastics in landfills and oceans has encouraged the development of biodegradable plastic products from renewable sources. Natural polymers are excellent candidates that need further modification of their functional and structural properties comparable to conventional plastics. This study aims to fabricate and optimize the formulation of bioplastic films from chitosan and mango kernel starch with glycerol as a plasticizer using response surface methodology (RSM). The chitosan-to-starch mass ratio (1:0.17 to 1:5.83) and glycerol concentration per gram of dry polymer (15.86% to 44.14%) were assigned as the independent variables to design an empirical model that describes the films’ elastic modulus as the sole response. The results yielded an optimal formulation of 1:0.17 chitosan-to-starch mass ratio (2% weight by volume chitosan solution blend) with 15.86% glycerol (per gram of dry chitosan and starch). Reproduction of the optimized film was carried out to validate the empirical model. Characterization of the films’ mechanical and barrier properties, surface morphology, and biodegradability were also investigated in this work. The results suggest that the functional properties of the bioplastic film surpass other chitosan-based bioplastic film blends and can be developed further to become a more sustainable alternative to conventional plastic packaging products.

1. Ashter SA. Introduction to Bioplastics Engineering. Elsevier Inc; 2016.

2. Chillo S, Flores S, Mastromatteo M, et al. Influence of glycerol and chitosan on tapioca starch-based edible film properties. Journal of Food Engineering 2008; 88(2): 159–168. doi: 10.1016/j.jfoodeng.2008.02.002

3. Liu H, Adhikari R, Guo Q, Adhikari B. Preparation and characterization of glycerol plasticized (high-amylose) starch–chitosan films. Journal of Food Engineering 2013; 116(2): 588–597. doi: 10.1016/j.jfoodeng.2012.12.037

4. Hamed I, Özogul F, Regenstein JM. Industrial applications of crustacean by-products (chitin, chitosan, and chitooligosaccharides): A review. Trends in Food Science & Technology 2016; 48: 40–50. doi: 10.1016/j.tifs.2015.11.007

5. Butler BL, Vergano PJ, Testin RF, et al. Mechanical and barrier properties of edible chitosan films as affected by composition and storage. Journal of Food Science 1996; 61(5): 953–956. doi: 10.1111/j.1365-2621.1996.tb10909.x

6. Wang H, Qian J, Ding F. Emerging chitosan-based films for food packaging applications. Journal of Agricultural and Food Chemistry 2018; 66(2): 395–413. doi: 10.1021/acs.jafc.7b04528

7. Basiak E, Lenart A, Debeaufort F. How glycerol and water contents affect the structural and functional properties of starch-based edible films. Polymers 2018; 10(4): 412. doi: 10.3390/polym10040412

8. Farahnaky A, Saberi B, Majzoobi M. Effect of glycerol on physical and mechanical properties of wheat starch edible films. Journal of Texture Studies 2013; 44(3): 176–186. doi: 10.1111/jtxs.12007

9. Ren L, Yan X, Zhou J, et al. Influence of chitosan concentration on mechanical and barrier properties of corn starch/chitosan films. International Journal of Biological Macromolecules 2017; 105(Part 3): 1636–1643. doi: 10.1016/j.ijbiomac.2017.02.008

10. Xu YX, Kim KM, Hanna MA, Nag D. (2004). Chitosan-starch composite film: Preparation and characterization. Industrial Crops and Products 2004; 21(2): 185–192. doi: 10.1016/j.indcrop.2004.03.002

11. Silva APM, Oliveira AV, Pontes SMA, et al. Mango kernel starch films as affected by starch nanocrystals and cellulose nanocrystals. Carbohydrate Polymers 2019; 211: 209–216. doi: 10.1016/j.carbpol.2019.02.013

12. Wuttisela K, Shobsngob S, Triampo W, Triampo D. Amylose/amylopectin simple determination in acid hydrolyzed tapioca starch. Journal of the Chilean Chemical Society 2008; 53(3): 1565–1567. doi: 10.4067/S0717-97072008000300002

13. Punia Bangar S, Kumar M, Whiteside WS. Mango seed starch: A sustainable and eco-friendly alternative to increasing industrial requirements. International Journal of Biological Macromolecules 2021; 183: 1807–1817. doi: 10.1016/j.ijbiomac.2021.05.157

14. Tesfaye T, Johakimu JK, Chavan RB, et al. Valorisation of mango seed via extraction of starch: preliminary techno-economic analysis. Clean Technologies and Environmental Policy 2018; 20(1): 81–94. doi: 10.1007/s10098-017-1457-3

15. Minitab LLC. Regression coefficients. Available online: https://support.minitab.com/en-us/minitab/20/help-and-how-to/statistical-modeling/regression/supporting-topics/regression-models/regression-coefficients/ (accessed on 19 October 2023).

16. Ferreira S, Araujo T, Souza N, et al. Physicochemical, morphological and antioxidant properties of spray-dried mango kernel starch. Journal of Agriculture and Food Research 2019; 1: 100012. doi: 10.1016/j.jafr.2019.100012

17. ASTM D6988-13. Standard guide for determination of thickness of plastic film test specimens. American Society for Testing and Materials 2004; 8(3): 1–7. doi: 10.1520/D6988-13.2

18. ASTM D882-18. Standard test method for tensile properties of thin plastic sheeting. American Society for Testing and Materials 2002; 8(1): 1–12. doi: 10.1520/D0882-18

19. ASTM E96/E96M-16. Standard test methods for water vapor transmission of materials. American Society for Testing and Materials 2018; 4(6): 1–9. doi: 10.1520/E0096-00E01

20. La Mantia FP, Ascione L, Mistretta MC, et al. Comparative investigation on the soil burial degradation behaviour of polymer films for agriculture before and after photo-oxidation. Polymers 2020; 12(4): 753. doi: 10.3390/polym12040753

21. Frost J. How to interpret adjusted R-squared and predicted R-squared in regression analysis 2017. Available online: https://statisticsbyjim.com/regression/interpret-adjusted-r-squared-predicted-r-squared-regression/ (accessed on April 27 2023).

22. Ekpenyong M, Antai S, Asitok A, Ekpo B. Response surface modeling and optimization of major medium variables for glycolipopeptide production. Biocatalysis and Agricultural Biotechnology 2017; 10: 113–121. doi: 10.1016/j.bcab.2017.02.015

23. Minitab LLC. How to interpret a regression model with low R-squared and low P values. Available online: https://blog.minitab.com/en/adventures-in-statistics-2/how-to-interpret-a-regression-model-with-low-r-squared-and-low-p-values (accessed on 12 June 2014).

24. Laluce C, Tognolli JO, de Oliveira KF, et al. Optimization of temperature, sugar concentration, and inoculum size to maximize ethanol production without significant decrease in yeast cell viability. Applied Microbiology and Biotechnology 2009; 83(4): 627–637. doi: 10.1007/s00253-009-1885-z

25. Mollah MZI, Akter N, Quader FB, et al. Biodegradable colour polymeric film (starch-chitosan) development: Characterization for packaging materials. Open Journal of Organic Polymer Materials 2016; 6(1): 11–24. doi: 10.4236/ojopm.2016.61002

26. Zhong Y, Li Y, Zhao Y. Physicochemical, microstructural, and antibacterial properties of β-chitosan and kudzu starch composite films. Journal of Food Science 2012; 77(10): E280-6. doi: 10.1111/j.1750-3841.2012.02887.x

27. Wang S, Li C, Copeland L, et al. Starch retrogradation: A comprehensive review. Comprehensive Reviews in Food Science and Food Safety 2015; 14(5): 568–585. doi: 10.1111/1541-4337.12143

28. Chin AW. (2010). Polymers for Innovative Food Packaging. Worcester Polytechnic Institute, 55.

29. Basha RK, Konno K, Kani H, Kimura T. Water vapor transmission rate of biomass based film materials. Engineering in Agriculture, Environment and Food 2011; 4(2): 37–42. doi: 10.1016/S1881-8366(11)80018-2

30. McHugh TH, Avena-Bustillos R, Krochta JM. Hydrophilic edible films: Modified procedure for water vapor permeability and explanation of thickness effects. Journal of Food Science 1993; 58(4): 899–903. doi: 10.1111/j.1365-2621.1993.tb09387

31. Wiles JL, Vergano PJ, Barron FH, et al. Water vapor transmission rates and sorption behavior of chitosan films. Journal of Food Science 2000; 65(7): 1175–1179. doi: 10.1111/j.1365-2621.2000.tb10261.x

32. Emblem A. Plastics properties for packaging materials. Packaging Technology. Woodhead Publishing; 2012. pp. 287–309.

33. Chandran KSR. Mechanical fatigue of polymers: A new approach to characterize the S N behavior on the basis of macroscopic crack growth mechanism. Polymer 2016; 91: 222–238. doi: 10.1016/j.polymer.2016.03.058

34. European Standard EN 13432:2000. (2000). Packaging - Requirements for packaging recoverable through composting and biodegradation - Test scheme and evaluation criteria for the final acceptance of packaging. In European Committee for Standardization.

35. Kochkina NE, Lukin ND. Structure and properties of biodegradable maize starch/chitosan composite films as affected by PVA additions. International Journal of Biological Macromolecules 2020; 157: 377–384. doi: 10.1016/j.ijbiomac.2020.04.154

36. Mutmainna I, Tahir D, Lobo Gareso P, Ilyas S. Synthesis composite starch-chitosan as biodegradable plastic for food packaging. Journal of Physics: Conference Series 2019; 1317(1): 1–5. doi: 10.1088/1742-6596/1317/1/012053

37. Greene J. Biodegradation of compostable plastics in green yard-waste compost environment. Journal of Polymers and the Environment 2007; 15(4): 269–273. doi: 10.1007/s10924-007-0068-1