A novel colorimetric indicator film based on watermelon peel pectin and anthocyanins from purple cabbage for monitoring mutton freshness.

Novel films based on watermelon peel pectin (WMP) incorporated with purple cabbage extract (PCE) were developed for monitoring the freshness of mutton. The FTIR result showed that WMP and PCE interacted through hydrogen bonds. Low PCE content (≤1.5%) could be well dispersed in the film matrix, resulting in an enhancement in light transmittance, mechanical properties, barrier properties, and thermal stability. Excessive addition of PCE destroyed the compact structure of the film and decreased the comprehensive properties. The antioxidant and antimicrobial activity of WMP/PCE films were proportional to the amount of incorporated PCE. Moreover, the color of the film deepened as the PCE content increased. The film had excellent color stability and pH response properties. The WMP/PCE1.5 film color varied from mauve to baby blue according to the quality of mutton (fresh to spoiled). Our results suggested that the WMP/PCE film might have great potential for monitoring the freshness of mutton.

Dielectric barrier discharge plasma: A green method to change structure of potato starch and improve physicochemical properties of potato starch films.

The effects of dielectric barrier discharge (DBD) plasma treatment on the physicochemical properties of potato starch and its films were studied. The results showed that the plasma species caused etching lead to small cracks and pores in potato starch particles and that oxidation, de-polymerization, and crosslinking were the main mechanisms underlying the effects of DBD plasma treatment. As the treatment time extended, starch hydrolysis, turbidity, syneresis, and gelatinization temperatures increased first and then decreased, whereas the solubility, swelling power, and water absorption significantly increased (P < 0.05). There was a decrease in the retrogradation tendency of the starch gels. The surfaces of the DBD plasma-modified potato starch-based films were relatively flat. After a 9-min treatment, the films exhibited the lowest water vapor permeability and highest tensile strength. In conclusion, the use of DBD plasma is a simple and green method to enhance the properties of potato starch and its film.

Changes in chilled beef packaged in starch film containing sea buckthorn pomace extract and quality changes in the film during super-chilled storage.

This study aimed to evaluate the effects of super-chilled storage (-1.3 °C) combined with starch film packaging containing different contents of sea buckthorn pomace extract (SSF, 0, 1, 2, and 3%, w/w) on the quality of chilled beef. The release kinetics, microstructure, and mechanical properties of the film were also measured to investigate its suitability for super-chilled storage. The results of the meat quality assessment showed that the L*, a*, and sensory evaluation values of the SSF-3% samples were significantly higher (P < 0.05), and the pH, b*, thiobarbituric acid reactive substance (TBARS), total volatile basic nitrogen (TVB-N), and total viable count (TCA) were significantly lower (P < 0.05) than the SSF-0%. The release of SBP from the SSF film was controlled by diffusion. Furthermore, SSF-3% was found to have a compact microstructure and good mechanical properties at the end of the super-chilled storage. The results demonstrated that SSF is an effective packaging material for beef at super-chilling temperatures.