Physical and Antimicrobial Properties of Hydroxypropyl Starch Bio-plastics Incorporated with Nyamplung (Calophyllum inophyllum) Cake Extract as an Eco-Friendly Food Packaging

Abstract

Nyamplung (Calophyllum inophyllum) cake as a by-product of nyamplung oil production is still limited. This research aimed to evaluate characteristics of antimicrobial bio-plastic made from hydroxypropyl starch as a basic ingredient and Nyamplung cake extract as additive. Nyamplung cake extract addition affected bio-plastic mechanical property by reduction of tensile strength but improved physical properties by reduction of vapor and oxygen permeability, water solubility, and increased elongation. This was probably due to the extract serve as natural crosslinking. Fourier Transform Infrared Spectroscopy analysis showed no difference in five bio-plastic samples, which probably caused by low concentration of extract. Thermogravimetry analysis showed the highest weight reduction in control of 95.824% and the lowest on Ext2% of 84.471%. Morphology analysis showed agglomeration of the extract on sample surface due to uneven ingredient distribution in mixture. Bio-plastic was more sensitive against gram positive bacteria than gram negative with their respective largest inhibition zone of 30 mm (Staphylococcus aureus) and 23 mm (Escherichia coli). This was probably due to the content of the extract serve as natural crosslinking and antibacterial agent.

Calophyllum inophyllum extract as a natural enhancer for improving physical properties of bioplastics and natural antimicrobial

“…The lowest increase in σ was received at the addition of a 5% extract. These results were better than the previous study (Umiyati et al 2019), in which σ increased by about 2.38%, and ε decreased by about 3.78%.…”

“…The smallest was found in the addition of 20% NCE, namely about 19.24 ± 0.07% ( Figure 5). Compared to the previous study (Umiyati et al 2019), WS decreased as much as 23.2%. Furthermore, the addition of 5% NCE reduced WVP of bioplastics about 22.3%.…”

“…Thus the addition of NCE can reduce the concentration of hydroxyl groups in starch, which can reduce the effect of interference on starch chains to reduce the stiffness and flexibility of bioplastics (Rasheeda et al 2015). As a result, WS decreased as much as 23.2% compared to the previous study (Umiyati et al 2019). WVP decrease by about 38.4%.…”

“…The cake is the residue of seed oil extraction (Gallstedt et al 2011). Besides, NCE was used to synthesized bioplastic (Umiyati et al 2019) in our laboratory. Results showed that NCE at low concentration could inhibit the growth of Staphylococcus aureus and Escherichia coli.…”

Manifesting sustainable food packaging from biodegradable materials: A review

“…Interestingly, the yam starch‐chitosan bioplastics mixer showed a larger inhibition zone activity than the clove oil formulation against Staphylococcus aureus (Ulyarti, 2021). Nyamplung ( Calophyllum inophyllum ) cake as a by product after the removal of oil from seeds as a potential ingredient for antimicrobial packaging material (Umiyati et al., 2019). The addition of Nyamplung cake in hydroxypropyl starch (HPS) with glycerol as plasticizer showed increased physical properties by reduction of vapor and oxygen permeability, water solubility, and elongation.…”