Development and characterization of a novel multifunctional film based on wheat filter flour incorporated with carvacrol: Antibacterial, antifungal, and insecticidal potentials.

Wheat filter flour is a by-product derived from the modern wheat milling process. In this study, the influence of plasticizer type (glycerol (G) and sorbitol (S)) and content (25, 35, and 45 g/100 g polymer) on the wheat filter flour-based film was evaluated. Regardless of plasticizer type, increasing the plasticizer content enhanced moisture content, water solubility, and water vapor permeability of film samples. The S-plasticized films presented the greatest tensile strength and the lowest EAB%. The scanning electron microscope observations confirmed the uniform structure of G-plasticized film. Moreover, antimicrobial and physico-mechanical properties of G-plasticized (25%) film were evaluated at the presence of carvacrol (5 and 10 g/100 g polymer). The considerable improvement was achieved in water affinity (14.2%) and flexibility (8.6%) by incorporating 10% carvacrol in G-plasticized films. The greatest inhibitory properties of active wheat filter flour films were observed against Aspergillus niger. By increasing the carvacrol concentration in film-forming solution, the inhibitory activity against Listeria monocytogenes and Escherichia coli in the liquid food model system was increased by 90.3% and 66.95%, respectively. Moreover, the active wheat filter flour-based film released a considerable insecticidal activity against Sitophilus granarius and Tribolium confusum. This work offers a novel utilization of wheat filter flour as an inexpensive blend polymer to manufacture multifunctional active film, which provides a promising approach for pest management besides enhancing the safety of products.

Development of casein-based nanoencapsulation systems for delivery of epigallocatechin gallate and folic acid.

In this work, binding characteristics of two hydrophilic nutraceutical models, namely epigallocatechin gallate (EGCG) and folic acid (FA), to sodium caseinate were studied by fluorimetry technique. EGCG-loaded casein molecules were then converted to either re-combined casein micelles (r-CMs) or casein nanoparticles (CNPs). Binding stoichiometry of EGCG and FA was 0.81 and 1.02, respectively. As determined by DLS technique, the average particle size of r-CMs prepared at 0.5% concentration was 66.2 nm. Thermal treatment (74°C, 20 s) had significant (p < 0.05) influence on the particle size of nanocarriers, but not nutraceutical loading. The average size of CNPs was larger than that of r-CMs. The encapsulation efficiency (EE) of EGCG was 85%, and its ejection from the nanocarrier was less than 3% over 21 days. Alkaline conditions resulted in higher release of EGCG than acidic conditions. r-CMs were more effective than CNPs during the protection of EGCG against heat-induced degradation. TEM micrographs confirmed the formation of r-CMs.