PLA-cassava flour/pulp based biocomposite sheet as a food container | |
| Author | Panitthida Ruchutrakool |
| Call Number | AIT Thesis no.FB-12-17 |
| Subject(s) | Cassava flour Lactic acid |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-12-17 |
| Abstract | The biocomposite was produced from varied cassava flour: pulp in ratios (100:0, 75:25, 50:50, 25:75 , 0:100). Cassava flour composed of 61.13% of starch which was used as matrix in biocomposite. For cassava pulp, there was 35.38% of fiber that could improve mechanical properties in biocomposite as a reinforcement material. The baking technique was used in the process of molding the biocomposite. To get the optimum situation of cassava flour and pulp for developing the biocomposite, the conditions used were solid content (30, 50, 70%), baking temperature ( 150, 170, 190 o C) and the baking time (3 - 10 min.). The optimum condition for solid content was found with 50% of cassava flour and 30% of pulp. The optimum baking temperature was at 170 o C for 7 min. The best ratio between cassava flour and pulp was at 50: 50 , which yield highe r values in most of the mechanical properties. In the same ratio of 50:50, the tensile strength and modulus were 0.73 MPa and 31.00 MPa respectively; the flexural properties were 0.86 MPa for strength and 39.42 MPa for modulus ; and the impact strength was 1.187 J/m 2 . Moreover, the water absorption property was increased up to 184.97 % as compared to the original weight. Through the Scanning Electron Microscope, the sample contained some opening in the surface of the cell and lots of bubbles inside the cell. Poly (lactic acid) ( PLA ) was added to cassava flour/pulp biocomposite to improve the mechanical properties and to reduce the water absorption capacity. Amongst the six levels of PLA contents (0%, 5%, 7.5%, 10%, 12.5% and 15% PLA), the 10% PLA showed the significant improvements in tensile properties for strength and modulus with 0. 2 3 MPa and 39. 54 MPa respectively. Flexural properties were also increased which strength and mouduls were 0.95 MPa and 60.48 MPa, respectively but the result of impact strength (0.587 J/m 2 ) was decreased when PLA content was increased to 10%. In the case of water absorption, the 10 % PLA biocomposite was significantly more water resistant (170.46%) than the non - adding PLA biocomposites. The Scanning Electron Microscope showed better appearance both in the surface and cross - sectional sides. The application of the biocomposite was to make storage sheet for tomato. The biocomposite was stored in two conditions: ambient condition (35 o C, 65%RH) and refrigerator (5 o C, 50%RH) for 11 days. The sample was then separated into three groups which were; the sheet without wrap plastic film, the sheet with wrap plastic film and the sheet containing tomato with wrap plastic film. The flexural strength of the sheet was decreased due to the influence of moisture content from environment and tomato respiration. The quality of the color and texture of tomato was lost with the storage time. The PLA - cassava flour/pulp biocomposite can be used to as a storage sheet for tomato not more than 3 days in ambient condition and not more than 7 days in refrigerator |
| Year | 2012 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-12-17 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm; |
| Examination Committee(s) | Rakshit, Sudip Kumar;Anal, Anil Kumar;Vilai Rungsardthong; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2012 |