Development and characterization of sugar palm [Arenga pinnata (Wurmb.) Merr.] starch/nanocellulose biocomposites films incorporated with essential oils

The demand of antibacterial active packaging is escalating due to the needs of improving quality and shelf life of food. Furthermore, plastic waste is one of the world’s concern to human health. Biocomposite have attracted attentions among the researchers, due to their environmental friendliness and sustainable nature. Starch is an alternative to substitute the petroleum based plastic film. There are several limiting factors as using starch, which are fragile and brittle. Plasticizers were added to the starch film-forming solutions to help overcome the unplasticized starch films' fragile and brittle nature. Besides, cinnamon essential oil was incorporated as antibacterial agent in the biocomposite films to form antibacterial active packaging. In order to transform into high performance of the antibacterial active packaging, cinnamon essential oil incorporated sugar palm nanocellulose reinforced sugar palm starch biopolymer composites were casted by using solution-casting method to investigate the properties of biocomposite films. The characterizations of biocomposite films was performed using Field Emission Scanning Electron Microscopic (FESEM), Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopic (FTIR), density, antibacterial activity, seal and tear strength. The effect of various types of plasticizer with different concentrations (glycerol, sorbitol and (glycerol + sorbitol) at 0 - 4.5 %wt) on the mechanical, physical, water barrier and biodegradable properties were evaluated. It shows water absorption were increase respective to the plasticizer concentration. Besides, water vapour permeability (WVP) and solubility of the different concentration plasticizer used in the biopolymer shows increasing trend due to high water content. Water content for sample glycerol (Gplasticized), sorbitol (S-plasticized) and mixture of glycerol and sorbitol (GSplasticized) were shown increasing trend, which were from 14.86-30.30%, 12.36- 15.00% and 13.58-35.04% respective to their concentration. Increasing plasticizer contents resulted in increments in film thickness and moisture contents. On the contrary, the increase in plasticizer concentrations resulted in the decrease of the densities of the plasticized films. Three types of essential oil, i.e. cinnamon, eucalyptus and rosemary oils were tested for antibacterial activity, cinnamon essential oil (EO) showed the highest inhibition zone. Cinnamon EO had been chosen as antibacterial agent in the biocomposite films. The effect of various concentration of cinnamon EO (0 - 2.0 wt %) on the mechanical, morphological, flammability, thermal and antibacterial activity were evaluated. The effectiveness of antibacterial packing is determined by the diameter of the zone of inhibition; the wider the diameter, the more sensitive the bacterium to the packaging. The antibacterial test was carried out by agar disc method (ADM) to evaluate the inhibition effect of the films on the gram positive bacteria, gram negative bacteria and yeast. The result suggested that the optimum amount of EO used (2.0 wt %) for positive result of inhibition activity. Tested film incorporated with 2.0 wt % EO showed the inhibition zone for B. subtilis, S. aereus and E. coli, which were 7.85, 6.63, and 7.43 mm respectively. From scanning electron microscopy analysis, the cross-sections of the cinnamon EO-containing films showed appearance of micro-porous spots as microporous holes because of the occurrence of partial evaporation on the cryo-fractured surface as a result of the vacuum condition. Increment in cinnamon EO concentration resulted in increasing trend of the number and size of the micro-porous holes. Significant increase was observed in the thermal stability with the cinnamon EO loading. The thermal stability of the CEO/SPNCC/SPS biopolymer composites was remarkably improved with increasing CEO loadings (sample 5, Tmax=296.25°C) compared to the thermal stability of the unfilled compound (sample 1, Tmax=289.18°C). FESEM micrograph show the films was slightly yellowish and transparent films. Overall, cinnamon essential oil/sugar palm nanocellulose/starch biocomposite films have good potential for active food packaging applications.

Text MOHAMAD OMAR SYAFIQ BIN - IR.pdf Download (1MB)

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