The Enhanced Moisture Absorption and Tensile Strength of PVA/Uncaria gambir Extract by Boric Acid as a Highly Moisture-Resistant, Anti-UV, and Strong Film for Food Packaging Applications

Abstract

There is an increasing demand for food packaging materials that are safe for the environment and human health. Pure polyvinyl alcohol (PVA) film is non-toxic and transparent but has poor UV-light shielding, thermal and moisture resistance, and antibacterial activity. Our previous work prepared and characterized a biofilm derived from PVA and edible Uncaria gambir extract (UG). The film has antibacterial properties and is anti-UV and flexible. However, UG is hydrophilic, making this film have low moisture absorption. To improve these properties, we trialed adding boric acid (BA) and UG into the PVA. This present study aims to characterize pure PVA film and blend films resulting from mixing PVA (10%), BA (0.5%), and UG (1%). It was found that the PVA/UG/BA film presented the best performance in terms of UV light absorption, tensile properties, thermal and moisture resistance, and antibacterial activity. This blend sample absorbs about 98% of the UV light at 400 nm wavelength without significantly sacrificing transparency. These findings indicate that UG and BA could be advantageous in the preparation of moisture and thermal-resistant UV shielding films with low toxicity and high antibacterial properties based on PVA. They were also found to be strong enough for food packaging applications.

Effect of sonication to the stability properties of carboxymethyl cellulose/uncaria gambir extract water-based lubricant

“…After adding UG, the sample remained stable at all temperatures. This is because Gambir is hydrophilic and can dissolve in water [19]. In this previous study, samples were sonicated for 30 minutes, and samples with 2wt% gambier underwent sedimentation [11].…”

“…It can be seen that all sample is well-dispersed without any sedimentation or agglomeration found. CMC is hydrophilic in nature with high solubility in water [19]. The addition of UG causes a color change in the solution.…”

Plant-based cellulose fiber as biomaterials for biomedical application: A Short Review

“…In the final stage, water is removed from the cellulose fibrils' suspension through several methods, including four methods (1) oven drying, (2) freeze drying, (3) supercritical drying (SCD), and (4) spray-drying (SD) as shown in Figure 2 [23]. The dried cellulose fibrils will be used for characterization such as Scanning Electron Microscopy (SEM), Fourier transform infrared (FTIR), and Raman spectroscopy for physiochemical assessment [24]- [26], further modification such as antimicrobial agent treatment [27], and possible application such as NCC based-composite [28].…”

“…The PC can serve as an antimicrobial biomaterial [46]. Some studies show that the incorporation of PC with other substances can provide anti-microbial materials such as Uncaria gambir -polyvinyl alcohol (PVA) composite [28] and nano cellulose conjugated lysozyme and allicin [27].…”

Influence of kepok banana bunch as new cellulose source on thermal, mechanical, and biodegradability properties of Thai cassava starch/polyvinyl alcohol hybrid‐based bioplastic

“…Stage I (27-174 C) shows a decrease in mass due to the water evaporation. [33] Evaporation at this stage means losing water content, glycerol, and volatile extractive substances when the bioplastic film is heated at low temperatures. [34] The percentage reduction in mass in this temperature range for S1-S5 bioplastic films was 10.7%, 10.7%, 8.9%, 8.7%, and 10.8%.…”