An intelligent pH indicator film based on cassava starch/polyvinyl alcohol incorporating anthocyanin extracts for monitoring pork freshness

Abstract

Non-biodegradable synthetic polymer-based packaging has caused serious environmental problems (Choi et al., 2017). Therefore, the development of natural and biopolymer packaging has become a global hot spot in recent years. Biopolymers have the advantages of reproducibility, biodegradability, and safety (Rawdkuen et al., 2020;Zhang et al., 2019). Among them, cassava starch film is considered to be a promising substitute due to its odorless, tasteless, colorless, inert, and non-toxic properties. However, pure starch film is highly hydrophilic and has poor mechanical properties, which limits its application in food packaging. Mixing starch with other polymers is an effective way to improve the physical properties of starch films. Polyvinyl alcohol (PVA) is a water-soluble polymer material. Because of its advantages such as biodegradability, film formation, and good mechanical properties, it has been widely used in packaging materials. Mix PVA and starch to make a film with good mechanical properties (Kurek et al., 2018;

Overview of plant extracts as natural preservatives in meat

“…Intelligent pH indicators are prepared by using plant extracts that provide useful information about the spoilage and freshness by altering the visible color of the strips based on pH changes during storage; thus, depicting degradative changes based on pH changes. Zhu et al (2021) developed an intelligent pH indicator film based on cassava starch and polyvinyl alcohol by infusing anthocyanin extracts obtained from grape skin and mangosteen rind. Grape seed extract‐infused film showed color variation from pink, blue, purple to yellow, whereas mangosteen rind extract‐infused film showed color variation from yellow to bright yellow and green to dark green; and proved a good indicator in monitoring the freshness of pork (Zhu et al, 2021).…”

“…Zhu et al (2021) developed an intelligent pH indicator film based on cassava starch and polyvinyl alcohol by infusing anthocyanin extracts obtained from grape skin and mangosteen rind. Grape seed extract‐infused film showed color variation from pink, blue, purple to yellow, whereas mangosteen rind extract‐infused film showed color variation from yellow to bright yellow and green to dark green; and proved a good indicator in monitoring the freshness of pork (Zhu et al, 2021). Biodegradable films prepared with red cabbage extract (5%–15%) and natural polymers (such as gelatin, green banana starch, and alginate) were observed to help in monitoring the quality of sheep meat (do Nascimento Alves et al, 2021).…”

“…Sanhueza et al (2017) observed a synergistic effect against S. aureus and E. coli strains and a nontoxic effect on HeLa cell lines by applying combinations of grape pomace alcohol by infusing anthocyanin extracts obtained from grape skin and mangosteen rind. Grape seed extract-infused film showed color variation from pink, blue, purple to yellow, whereas mangosteen rind extract-infused film showed color variation from yellow to bright yellow and green to dark green; and proved a good indicator in monitoring the freshness of pork(Zhu et al, 2021). Biodegradable films Abbreviations: BHT, butylated hydroxy toulene; GAE, gallic acid equivalent; PV, peroxide value; TBARS, thiobarbituric acid reactive substances; UAE, ultrasound-assisted extraction.TA B L E 4 (Continued) TA B L E 5…”

Colorimetric Indicators Based on Anthocyanin Polymer Composites: A Review

“…Moreover, although the majority of the studies prove that the developed colorimetric indicators change color in the presence of spoiled food, only few correlate the color change to the production of TVB-N [ 78 , 79 , 88 , 128 , 137 , 141 , 167 , 191 , 197 ] and total mesophil counts (TMC) [ 126 , 165 ] during spoilage, using standard food quality evaluation in order to better understand the sensibility of the developed material. As demonstrated in such studies, the film-based colorimetric indicators were not indicating the real condition of the foodstuff due to their insufficient detection limit (i.e., the lowest concentration of a substance that an indicator can trace) [ 98 , 120 , 182 , 195 , 198 , 199 ].…”

Fabrication of antimicrobial colorimetric pad for meat packaging based on polyvinyl alcohol aerogel with the incorporation of anthocyanins and silver nanoparticles

“…Freshness indicator packaging is a kind of intelligent packaging that is used to monitor the quality change of fresh food during storage 4 . For fresh meat, volatile nitrogen compounds are released due to protein degradation during the meat spoilage process, resulting in an increase in pH within the package 5 . Therefore, pH colorimetric indicators are used to effectively monitor the decline in meat quality by showing visual colour changes during meat storage 6 .…”