ABSTRACT
This study explored the active food packaging application of phycocyanin- and Spirulina extract-loaded gliadin electrospun fibers (GPhy and GSPE5%). SEM findings confirmed that the morphology of fibers was tubular, showing the GPhy and GSPE5% as the optimum fibers. The loading efficiencies of GPhy and GSPE5% were also around 90%, which proved the well-incorporated compounds within the fibers. Simulation results of α-gliadin dissolved in acetic acid illustrated the denaturation of the protein. FTIR and TGA confirmed that after electrospinning the chemical/structural changes and enhanced thermostabilities occurred, respectively. Antibacterial and antioxidant tests detected higher bactericidal and antioxidative effects of GSPE5% than GPhy. In the application part, it was found that GPhy and GSPE5% were able to decrease PV and TBA values as the indications of walnut kernels' protection from lipid oxidation. This work shows a facile and an efficient way to fabricate active food packaging materials using electrospinning and natural compounds.
ABSTRACT
In this research, phytochemical properties of lemon verbena and oxidative stability of the fat component in cookies (contain lemon verbena powder and EO) were investigated. The essential oil (EO) profile and polyphenol compounds were identified by GC/MS and HPLC, respectively. Different concentrations of lemon verbena powder and EO were added to the cookies in comparison with TBHQ. The oxidative stability of fat component in cookies (peroxide value, p-Anisidine, TOTOX value), along with the physicochemical (pH, acidity, weight loss, and moisture content) and sensory properties of the cookies were evaluated over a period of 6 months during storage at room temperature. The main constituents of EO are geranial (27.21%), neral (20.01%), spathulenol (7.28%), and limonene, while trans-Ferulic acid (6.71 mg/g), Hesperidin (1.87 mg/g), and ρ-Coumaric acid (0.04 mg/g) were measured as main phenolic compounds. The peroxide value increased in all samples for the first 2 months of storage and then decreased as hydroperoxide was converted to secondary oxidation products. The p-Anisidine value increased in all samples during storage. This parameter was lower in cookies containing lemon verbena EO and TBHQ treatments. Sensory evaluations of cookies showed that lemon verbena EO had positive effects on the aroma and taste of cookies during storage, whereas lemon verbena powder had adverse effects on mouthfeel and consumer acceptance. The results showed that lemon verbena can increase the eating quality, prolong the shelf life, and maintain the integrity of bakery products with high-fat content.