Prevention of Protein Oxidation in Chicken Meat during Chilled Storage Using Chitosan Gelatin Films with Green Tea Extracts

In present study, the usability of chitosan and gelatin (1:1) films incorporated with green tea extract (GTE) to improve the shelf life of the chicken meat stored in chilled condition was evaluated. The extract of green tea was evaluated for its phenolic content, antioxidant activity and ferric ion chealating ability. The ChGel films possessed antimicrobial activity and inactivated approximately 3 log cfu/ ml of K. pneumoniae, S. typhi var. Weltevreden, S. typhi var. Oslo, Y. enterocolitica, E. feacalis, B. cereus, E. coli and S. aureus in 3 hours. Incorporation of GTE influenced the optical and mechanical properties of the films. Chicken samples without films were observed to be microbiologically safe for not more than 6 days, while ChGel and ChGel-GTE films improved the microbial safety of chicken samples till day 13. ChGel-GTE films also prevented lipid peroxidation in samples as evident by TBARS value (day 10: control: 1.14; ChGel-GTE: 0.21 mg MDA eq/kg). Protein oxidation during chilled storage of chicken was also prevented by ChGel-GTE by inhibiting protein carbonylation, loss of free thiols groups in protein and lowering the number of disulphde bonds. This study supports use of ChGel films with GTE for enhancing the safety of stored chicken meat not only by maintaining the microbial quality of the samples but also preventing oxidative changes which can hamper the functional, nutritional and sensorial properties.

Effectiveness of Goji Berries (Lycium barbarum) Extract and Some Nanoparticles Loaded on Gelatin Film on Microbial Content of Labneh

This study was conducted to evaluate the effect of Lycium barbarum extract, Chitosan nanoparticles (ChNPs) and Nanotitanium dioxide (TiO2 NPs) loaded on Gelatin films on the microbial content of labneh during different storage periods. The samples were divided into seven treatments which included (T1) non-coated labneh, (T2) labneh coated with gelatin membranes, (T3) labneh coated with gelatin membranes and Lycium barbarum extract, (T4) labneh coated with gelatin films and ChNPs, (T5) labneh coated with gelatin films treated TiO2NPs, (T6) Labneh coated with gelatin films, Lycium barbarum and ChNPs, (T7) Labneh coated with gelatin films, Lycium barbarum and TiO2 NPs. The total number of bacteria decreased after loading with the membranes for each specific period of time, and the treatment with T7 was the best, as the total number of bacteria decreased to 9.93 log/gm compared to the two controls (T1, T2), which amounted to (15.58, 13.47 log/gm) after 14 days of storage, respectively. While the numbers of Lipolytic and Proteolytic bacteria, yeasts and molds did not show any growth at the time of one day, with the prolonged storage period, the gradual increase in the total count of bacteria occurred for all treatments, it reached the highest numbers at the time of 14 days. Treatment T7 was the best in reducing the numbers of both lipolytic and proteinolytic bacteria, as well as yeasts and molds.

Effect of Goji Berries (Lycium Barbarum) Extract and Some Nanoparticles Loaded on Gelatin Film in Chemical Properties of Labneh

This study is conducted to evaluate the effect of Lycium barbarum extract (Goji berries), Chitosan nanoparticle (ChNPs), titanium dioxide nanoparticle (TiO2 NPs) loaded on Gelatin films in terms of the chemical composition of labneh during different storage periods. The samples were divided into seven treatment procedures, include (T1) non-coated labneh, (T2) labneh coated with Gelatin membranes, (T3) labneh coated with Gelatin membranes and Lycium barbarum extract, (T4) labneh coated with Gelatin films and ChNPs, (T5) labneh coated with Gelatin films treated TiO2 NPs, (T6) Labneh coated with Gelatin films, Lycium barbarum, ChNPs, (T7) Labneh coated with Gelatin films, Lycium barbarum, TiO2 NPs. The results showed that the moisture percentage decreased significantly (p <0.05) untilthe end of the storage period, and treatment T6 was less in the rate of moisture loss (72.35%). It was also found that the ratios of protein, fat, ash, did not show significant differences at the time of one day compared with the two control samples T1 and T2, These percentages increased gradually as the duration of preservation was prolonged and reached their highest values at the time of 14 days. The pH values decreased significantly between (4.36-4.32) at the end of the storage period, compared with the two control samples T1 and T2, which were at 4.16 and 4.23, respectively. It was found that the fatty acid values of all treatments were significantly low compared with the control treatment T1 at the time of one dayThe free fatty acid ratios increased and reached their highest values between (0.29 - 0.32) for all treatments compared with the two control treatments T1 and T2 at the end of the storage period which amounted to (0.39 and 0.35) %.

Preparation and Characterization of Ginger Essential Oil Microcapsule Composite Films

New food packaging has shown research significance in the face of increasing demand for high-quality foods and growing attention paid to food safety. In this study, ginger essential oil microcapsule composite films were prepared by combining microcapsules prepared by a complex coacervation method with gelatin films, and the mechanical properties and active functions of the composite films were analyzed. Fourier-transform infrared spectroscopy and differential scanning calorimetry confirmed the successful encapsulation of ginger essential oil. The scanning electron microscopy of the composite films showed the microcapsules and gelatin film matrix were highly compatible. During the entire storage period, the antioxidant capacity of the ginger essential oil microcapsule films weakened more slowly than ginger essential oil microcapsules and could be maintained at a relatively high level for a long time. The microcapsule films had excellent inhibitory effects on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Therefore, the direct addition of microcapsules to a film matrix can broaden the application range of microcapsules and increase the duration of the release of active ingredients. Ginger essential oil microcapsule films are potential biodegradable food packaging films with long-lasting activity.