Effect of OHMIC heating and ultrasound on functional properties of biodegradable gelatin‐based films

Abstract

This study aimed to evaluate the effect of ohmic heating (OH) and ultrasound (US) on the functional properties of biodegradable gelatin‐based films. For OH, electric field strength (30–120 V) and exposure time (5–20 min) were evaluated; for US, intensity (50%–100%) and the exposure time (5–20 min) were investigated. Regarding OH, higher mechanical properties (tensile strength and Young's modulus) values were obtained at the lowest electric field strength applied, regardless of the exposure time. For US, tensile strength and Young's modulus values significantly increased with increasing the US intensity and exposure time. Films produced with OH and US with optimized properties were compared to a control film (produced by conventional heating). X‐ray diffraction and thermogravimetric analysis indicated that films produced by US and OH showed a more ordered structure, with a higher crystallinity index, and were more thermally stable. The most pronounced effects on mechanical properties were obtained using OH: tensile strength increased from 1.53 MPa (control) to 3.86 MPa. US application reduced film opacity, resulting in a more transparent film with a smoother surface. Both treatments also significantly decreased the water vapor permeability but did not affect film thickness, moisture content, water solubility, and biodegradability.

Morphology and functional properties of gelatin‐based films modified by UV radiation and bacterial cellulose nanofibers

“…All gelatin‐based films were prepared using a casting technique according to the methodology described by de Vargas et al (de Vargas, Flôres, et al, 2022). Air bubbles were removed from the solutions using a vacuum desiccator.…”

“…Compared to synthetic polymers, films obtained from gelatin and other proteins generally have lower mechanical strength and higher moisture sensitivity, which affect their barrier properties and limit their ability to provide desired film functions to specific applications (Murrieta‐Martínez et al, 2018). Therefore, to modify protein characteristics and improve film properties, physical (de Vargas, Flôres, et al, 2022), chemical (Shroti & Saini, 2022), and enzymatic (Dai et al, 2022) treatments have been employed. In particular, cross‐linking techniques induced by UV radiation and incorporating nanomaterials as reinforcement agents have shown promising results.…”

Ultrasound and Nanomedicine for Cancer-Targeted Drug Delivery: Screening, Cellular Mechanisms and Therapeutic Opportunities

“…The energy is converted into heat and causes tissue temperature to rise. Therefore, ultrasound can be used as a deep heat compress [16]. Under the correct operation conditions, it can cause tissue to warm up to 40-45 degrees Celsius, and the tissue will be congested, promoting circulation.…”