Synthesis and Physicochemical Characterization of Polymer Film-Based Anthocyanin and Starch

Abstract

Colorimetric indicators, used in food intelligent packaging, have enormous promise for monitoring and detecting food quality by analyzing and interpreting the quality data of packaged food. Hence, our study developed and characterized a biopolymer film based on starch and anthocyanin for prospective meat freshness monitoring applications. The developed film was morphologically characterized using different morphology instruments to identify the interaction between anthocyanin and starch. The color differences of the proposed film in response to different pH buffers have also been investigated. The combination of anthocyanin and starch produces a smooth and homogenous surface with an intermolecular hydrogen bond that increases the biopolymer’s wavelength. The film indicated bright red at pH 2.0–6.0, bluish-grey at pH 7.0–11.0, and yellowish-green above 11.0 that the naked eye can see. The indicator film shows high sensitivity toward pH changes. The inclusion of anthocyanin increases the biopolymer film’s thickness and crystalline condition with low humidity, water solubility, and swelling values. As a result, the polymer film can be employed in the food industry as an affordable and environmentally friendly indication of meat freshness.

Polymer blends of poly(lactic acid) and starch for the production of films applied in food packaging: A brief review

“…242 The microstructure of the starch-based film is not completely homogeneous, as can be seen through the scanning electron microscopy (SEM) technique in the mentioned works. [243][244][245][246][247][248][249] The cause of the film surface heterogeneity reported in the previous paragraph may be due to the difficulty in dissolving the starch granules in water (due to hydrogen bonds and large polymer chains). The dissolution step is carried out by heating the starch dispersion under moderate shear in excess of water, characterized by: hydration, swelling, birefringence loss and crystallinity of the starch chains.…”

Optical biosensing systems for a biological living body

“…The first category not involving nanoparticles (NPs) is based on changes in external physical or chemical factors. The colorimetric biosensor of this type responds to changes in external factors such as pH values [11][12][13][14][15] and temperature [16][17][18] by changing the color of the visual readout. A momentous factor affecting the sensitivity of this sort is the type and concentration of the external indicator.…”

Recent Advances in Bio-Based Smart Active Packaging Materials

“…Most smart packaging materials are based on pH-responsive colorimetric indicators that change by visual colour, such as time–temperature indicators, freshness indicators and leak indicators [ 67 ]. The natural pigment anthocyanin is one of the most popular dyes, containing highly phenolic compounds with a wide range of pH responses [ 68 , 69 ]. The outstanding active role of natural pigment anthocyanin allows it to make some contributions in food preservation as well [ 70 ].…”