Effects of addition of condensed tannin on the structure and properties of silk fibroin film

Abstract

Condensed tannin is a polymeric polyphenol compound, which has considerable protein‐binding ability and a variety of bioactivities, such as anti‐inflammatory, antithrombotic and antimicrobial activities. In this study, silk fibroin film was modified by adding condensed tannin. It was found that strong intermolecular interactions occurred between silk fibroin and tannin, and incorporation of 1–10% (w/w) tannin in the blend films resulted in more compact, stiffer but less elastic films. Swelling and dissolution trials showed that the addition of tannin significantly reduced the swelling and solubility of the films. The mechanical properties, swelling and solubility of the blend films varied as a function of tannin concentration, showing optimum values when containing 10% (w/w) tannin. The silk fibroin–tannin films all showed significant antioxidant activity and antibacterial activity against Gram‐positive bacteria, and the activities were positively related to the concentration of tannin. The results emphasized that the addition of condensed tannin could simultaneously improve the structural stability of silk fibroin film and impart functional properties. © 2016 Society of Chemical Industry

Silk Fibroin and Pomegranate By-Products to Develop Sustainable Active Pad for Food Packaging Applications

“…In the last few years, several natural antioxidants, such as quercetin, grape seed extract, vitamin C, tannins, oleuropein and rutin, have been incorporated or absorbed into silk fibroin in order to obtain innovative bio-based materials for biomedical applications [ 44 , 45 , 46 ]. However, only few reports concern the potential application of these SF-antioxidant-based materials as food packaging [ 47 ]. Pomegranate peel is characterized by hydrolysable tannins (punicalagin, punicalin, ellagic acid and gallic acid) that are known antioxidants effective in removing radicals [ 48 ].…”

Silk fibroin‐based films in food packaging applications: A review

“…SF is widely used in medical, optical, and electronic applications (Fan et al., 2019). Nevertheless, the drawbacks of pure SF films include low flexibility, high solubility in water, and also easily contaminated by microorganisms (M. Ma et al., 2017; Z. Wang et al., 2019; H. Zhou et al., 2019).…”

“…A few authors fabricated SF‐based films through various methods such as solution casting, coating, and electrospinning. These SF‐based films are colorless, transparent, and water soluble (M. Ma et al., 2017). Recent studies on the application of SF in the food industry included the use of SF as coating for packaging fruits (Marelli et al., 2016) and the encapsulation of SF films with active compounds for meat wrapping (Lin et al., 2019).…”

Development and Performance of Bioactive Compounds-Loaded Cellulose/Collagen/Polyurethane Materials

“…The LIP material exhibited scavenging activity of DPPH radical (83.18%) lower than free lipoic acid (87.05%), probably due to the interactions between the components of the material. scavenge free radicals [63]. This can be explained by the hydrogen-donating phenolic hydroxyl groups attached to the aromatic and heterocyclic rings, which impart good antioxidant activity to the TAN film [59].…”

“…It also suggests that the compatibility and interfacial strength between the filler particles and cellulose-collagen-polyurethane matrix is improved. scavenge free radicals [63]. This can be explained by the hydrogen-donating phenolic hydroxyl groups attached to the aromatic and heterocyclic rings, which impart good antioxidant activity to the TAN film [59].…”