Physicochemical Analysis of Biofilms from Cocos nucifera Linn. (Coconut) Flour and Manihot esculenta Crantz (Cassava) Starch with Polyvinyl Alcohol (PVA)

The province of Northern Samar, its municipalities including Pambujan, is a place abundant of Manihot esculenta Crantz (cassava), and Cocos nucifera Linn. (coconut). However, its industry is mainly limited to food production. This study developed biofilms from cassava starch (CasS), and coconut flour (CoF) with polyvinyl alcohol (PVA). The physicochemical properties were analyzed to determine their pH, solubility, moisture content, and tensile strength. Functional groups were investigated using FTIR, and the antibacterial properties were evaluated. The results showed that both biofilms with PVA were weakly acidic and insoluble in all solvents. Meanwhile, CoF biofilm contained higher moisture content than the CasS biofilm. CoF biofilms also carried more weight and higher force than CasS biofilm. Hydroxyl, alkyl, and alkene functional groups were identified for both biofilms. Meanwhile, both biofilms showed no inhibitory effect against E. coli, and S. aureus. Therefore, the developed biofilms with PVA showed good physicochemical properties and can be used for packaging applications. The slight acidity can prolong their shelf-life. Moreover, both will not easily dissolve. CoF biofilm comprised more water than CasS but both are still suitable for packaging due to their tensile strength attributed to the presence of the functional groups. However, CasS, CoF, and PVA do not have antibacterial properties. More physicochemical tests, further characterization, and incorporation of antibacterial agents were recommended.