Development of tea extracts and chitosan composite films for active packaging materials

Preparation and characterization of chitosan film incorporated with thinned young apple polyphenols as an active packaging material

“…The effects of YAP on the thickness, density, water content, swelling degree and solubility of films are shown in Table 1. The thickness and density of films increased significantly (p<0.05) with the YAP concentration increasing, in agreement with one previous study in which chitosan film was incorporated with tea polyphenols (Peng, Wu, & Li, 2013). With the increase in polyphenols concentration, the interactions between polyphenols and chitosan (including hydrogen bonding and hydrophobic force) increased, causing tighter binding of polyphenols and chitosan (Zhang, Yang, Tang, Hu, & Zou, 2008).…”

“…After the addition of 0.75% YAP and 1.0% YAP, the water content of YAP-chitosan films decreased by 19.45% and 42.73%, respectively. The declining tendency for water content of chitosan films after incorporation of YAP is in accordance with one previous observation, in which addition of tea polyphenols also caused a decrease in this parameter (Peng, Wu, & Li, 2013). Polyphenols may establish the interactions with chitosan molecules through the potential hydrogen bonding, which may limit the interactions between hydrophilic groups of chitosan and water molecules due to the A B C competitive binding effect (Siripatrawan, & Harte, 2010;Sascha, Rawel, & Jürgen, 2004).…”

“…It was observed that the broad peak at 3259 cm -1 became more flattened with the YAP concentration increasing, indicating the decreased stretching of free -OH and/or -NH due to the binding interactions between polyphenols and chitosan. It has been reported that the hydrogen bonds between -OH groups of polyphenols with -OH or -NH groups of chitosan contribute to the interactions between the two compounds (Peng, Wu, & Li, 2013). The hydrogen bonds affect the electron distributions in -OH and -NH, inducing the weakened internal stretching of bonds between oxygen and hydrogen atoms and that between nitrogen and hydrogen atoms in the corresponding groups (Nakamoto, Margoshes, & Rundle, 1955).…”

“…The hydrogen bonds affect the electron distributions in -OH and -NH, inducing the weakened internal stretching of bonds between oxygen and hydrogen atoms and that between nitrogen and hydrogen atoms in the corresponding groups (Nakamoto, Margoshes, & Rundle, 1955). Similarly, due to the interactions between polyphenols and chitosan, including hydrogen bonding and hydrophobic force (Peng, Wu, & Li, 2013), the changes of internal bonds between atoms occurred in certain functional groups, which induced the peaks located at 2941 cm -1 , 2885 cm -1 , 1650 cm -1 becoming less discernible.…”

Rapid assessment of the effectiveness of antioxidant active packaging—Study with grape pomace and olive leaf extracts

“…Some articles have evaluated the release kinetics of active compounds from functional packaging (Zhong, & Li, 2011;Flores, Conte, Campos, Gerschenson, & Del Nobile, 2007;Licciardello, Muratore, Mercea, Tosa, & Nerín, 2013;Peng, Wu, & Li, 2013;Colín-Chávez et al, 2014;Marcos et al, 2014), this approach takes into account the effect of the matrix and the partition coefficients of the compounds between the matrix and the contact phase. However, in the case of antioxidant packaging, a simple method for the assessment of the effectiveness should focus on the effect produced (i.e., the total antioxidant capacity) rather than on the amounts of compound released, especially in the case of mixtures of compounds, such as natural extracts.…”