Preparation And Properties Of Chitosan Membrane Complexes / Pomegranate Peel Extract

In this paper, the chitosan/pomegranate peel extract composite film was prepared by tape casting from the raw materials of pomegranate peel extract and chitosan. Through the determination of the mechanical properties, water vapor permeability, colour, transparency, antioxidant properties and antibacterial properties and the analysis of Fourier transform infrared (FTIR) and scanning electron microscope (SEM), the effect of different additional pomegranate peel extract on properties of composite film were researched. Prepare chitosan composite film of chitosan/pomegranate peel extract and carry on meat preservation test, compared the effects with the pure chitosan treatment group and blank group, evaluated fresh-keeping effect of composite film by measuring the total number of colonies, pH value, TVB-N and TBARS values, and study during storage chitosan/pomegranate peel extract composite film of the active substance migration in pork samples. The results showed that:1. The effect of different additional pomegranate peel extract on the structural characteristics of chitosan composite film was anysised by infrared spectra. Results showed that the structure of composite film had changed, which occurred in the amino-NH2and carbonyl-C=O absorption peak. Pomegranate peel extract was rich in phenolics, and hydroxyl group (-OH) of extract hided the absorption peak of the amino group (-NH2). The crosslinking reaction between pomegranate peel extract and amino group (-NH2) of chitosan caused the appearance of the significant absorption peak at1619cm-1. The reason for a greater change of absorption peak at1153cm-1was the effect of pomegranate peel extract on ether linkages (-O-) of pyran ring of chitosan. The SEM images showed that blending between the different additional pomegranate peel extract and chitosan did not appear to demixing, which indicated that chitosan incorporated less than3%of pomegranate peel extract had a good compatibility.2. The different additional pomegranate peel extract was effect on chitosan film with by measuring the water vapor permeability, light transmittance, antioxidant and antimicrobial properties of films. With pomegranate peel extract additional increased, the tensile strength of the composite film was reduced from20.2Mpa to8.7Mpa, elongation at break rate was increased from11.0%to35.1%, this phenomenon indicate that pomegranate peel extract increases the flexibility of chitosan and reducing the strength with chitosan film; Hunter Lab value was represented colour, L value of the composite film was reduced from55.6to31.37, the a value was increased from-0.21to10.74, and b value is reduced from8.05to4.91, T values of the composite film increased from0.78to1.72, this phenomenon indicated that pomegranate peel extract reduces the transparency of the chitosan composite film and increased the colour of the chitosan composite film; The water vapor transmission rate from6.12×10-8g·m/m2·s·Pa reduced to4.67×10-8g·m/m2·s·Pa, this phenomenon indicated that pomegranate peel extract increased the thickness of the chitosan composite film, thereby enhancing the barrier properties of the chitosan composite film; The increase in total phenol content, enhanced composite film DPPH radical scavenging ability, this phenomenon indicated that pomegranate peel extract could enhance the antioxidant properties of chitosan film; Through research on the antimicrobial properties of the five kinds of bacteria and two kinds of fungi, the results showed that adding different proportions of pomegranate peel extract chitosan composite film was antibacterial capabilities have been significantly improved with bacteria of Escherichia coli, Bacillus megaterium, Bacillus subtilis, Bacillus cereus and Staphylococcus aureus and fungi of Saccharomyces cerevisiae and Aspergillus niger, and with the increase of the added amount of pomegranate peel extract, the properties of antibacterial were increased against bacteria and fungi.3. Storage conditions at4±1℃storage period of20days, researched chitosan/pomegranate peel extract the effect of the composite film of preservation by determined within the specified time the total number of colonies, lipid oxidation value, TVB-N and other indicators, and compared with pure chitosan film and blank group preservation effect. The results showed that contain2%pomegranate peel extract of chitosan/pomegranate peel extract composite film had better preservation effect than pure chitosan film and polyvinyl chloride film. During storage composite film had better inhibition in total number of colonies, TVB-N and TBARS values, the pH value, and sensory indicators, effectively extend the storage period of the sample. The active substances of chitosan composite film change a part of the migration, at20days the migration rate close to20%. Due to the high content of Pomegranate peel extract antioxidants substances that migrate into the meat sample had good quality of the meat sample during storage.