Chitosan biobased and intelligent films: Monitoring pH variations

Development of edible films from tapioca starch and agar, enriched with red cabbage (Brassica oleracea) as a sausage deterioration bio-indicator

“…A purple quinoidal anhydrobase and a deep blue ionized anhydrobase are formed at pH > 7.0 and pH > 8.0 respectively, when the equilibrium is shifted. A yellow chalcone is generated through opening of the central pyran ring of carbinol at even higher pH [30,31,32]. Results of ΔE (Table 3) were consistent with the films' visual appearance (Figure 1).…”

Preparation of a visual pH-sensing film based on tara gum incorporating cellulose and extracts from grape skins

“…Anthocyanins are a large group of natural dyes used to monitor pH variations due to the presence of phenolic or conjugated substances. There have been several studies of anthocyanins extracted from Bauhinia blakeana Dunn and grape as pH indicator dyes [7,9]. They found that the color clearly altered from red to green in the pH range of 2-9 and that films that incorporate these compounds could be used to visually monitor the spoilage of pork.…”

An overview of smart packaging technologies for monitoring safety and quality of meat and meat products

“…Sulphmyocin, a green pigment, is formed by reacting with myoglobin, and this pigment is responsible for the development of an agarose‐immobilized myoglobin‐based freshness indicator for unmarinated broiler cuts . Yoshida et al prepared a colorimetric pH indicator based on chitosan film containing anthocyanin that has the potential to be used as metabolite indicators such as L‐lactic acid, n‐butyrate, acetic acid, and D‐lactate. Rukchon et al developed a colorimetric indicator based on pH‐sensitive dyes for real‐time monitoring of the freshness of skinless chicken breast.…”