الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
7. Summary
• The present study was carried out to prepare edible coating materials for preservation of fresh fruits. The manufactured intervals were from chitosan nano-particles loaded with waste peel extract using the ionic gelation technique. The waste peel extracts are prepared from four waste peels to form waste peel extracts (WPE) of pomegranate peel extract (PmPE), banana peel extract (BaPE), orange peel extract (OrPE) and potato peel extract (PtPE).
• Chitosan nano-particles are prepared and loaded with one of the waste peel extracts to form pomegranate peel extracts (PmPE-CsNps), chitosan nano-particles loaded with banana peel extracts (BaPE-CsNps), chitosan nano-particles loaded with orange peel extracts (OrPE-CsNps) and chitosan nano-particles loaded with potato peel extracts (PtPE-CsNps).
• The prepared nanoparticles were estimated by Dynamic light scattering (DLS) and zeta potential (ZP), Fourier Transform Infrared (FTIR) spectroscopy analysis, Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD).
• The antifungal activity of Cs and the edible nano-coating either alone or loaded with WPE of pomegranate peel extract (PmPE), banana peel extract (BaPE), orange peel extract (OrPE), potato peel extract (PtPE) were evaluated.
• It was evaluated against specific phytopathogenic fungi (Botrytis cinerea, Alternaria alternata, Penicillium digitatum, Aspergillus flavus and Aspergillus niger) at concentrations of 0.2, 0.4 and 0.8 mg/ml (by mycelial radial growth).
• The morphological observations of the phytopathogenic fungi treated with the edible nano-coating materials (CsNps, PmPE-CsNps, PtPE-CsNps, OrPE-CsNps and BaPE-CsNps) are examined by Light Microscopy.
• The safety of the synthesized nanoparticles of the edible nano-coating are analyzed by the cytotoxicity tests on the normal human fibroblast cell line (MRC-5) using MTT (3-(4,5 Dimethyl thiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide) assays.
• The edible coating materials (Cs, CsNps, PmPE-CsNps, PtPE-CsNps, OrPE-CsNps and BaPE-CsNps) were applied on the surface of strawberry fruits by dipping method and then stored at 5˚C for 21 days, respectively, to determine the antifungal and antioxidant activities.
• The effect of these coating materials was evaluated on the physical properties (Visible Decay Percentage) of the edible coating throughout estimating some characters during the storage period.
The obtained results could be summarized as follows:
1. The nanoparticles of the edible nano-coating materials were prepared by the ionic gelation method. The average sizes ranged at 20-73 nm and their zeta potential (ZP) had high stable values. Incorporation of PmPE and PtPE into CsNps achieved a high degree of stability.
2. All nanoparticles of the edible nano-coating materials (CsNps, PmPE-CsNps, PtPE-CsNps, OrPE-CsNps and BaPE-CsNps) exhibited a narrow size distribution (unimodal) with low extent PDI recording 0.348, 0.387, 0.501, 0.345 and 0.411, respectively.
3. The shape and morphology of the prepared nanoparticles (PmPE-CsNps, PtPE-CsNps, BaPE-CsNps and OrPE-CsNps) were determined by using a TEM. They had a semi spherical shape with diameter ranges of 14.21-23.45, 16.47-18.82, 23.68-24.23 and 24.41-36.04 nm, respectively. While CsNps presents a uniform and spherical shape with an average particle size of 26.9 nm.
4. The functional groups involved in the edible coating (Cs), nano-coating (CsNps) and CsNps loaded with some waste peel extracts are characterized by the Fourier Transform Infrared (FTIR) technique. The new functional groups formed are –N–H and O–H (polyphenols), C=O, C–H, N-H and C-O. Addition of PmPE, PtPE, OrPE and BaPE to CsNps resulted in a significant increase in the intensity of C–H stretching bands reflecting their successful incorporation into CsNps.
5. The crystalline structure (physical properties) of the tested edible nano-coating (CsNps, PmPE-CsNps, PtPE-CsNps, OrPE-CsNps and BaPE-CsNps) is characterized by X-ray diffraction (XRD). XRD profile of CsNps is characterized by a broad peak with a semi-amorphous structure at 2θ = 19 and 22. XRD profiles of PmPE, PtPE, OrPE and BaPE showed an amorphous character with a flat broad peak. XRD profiles of PmPE-CsNps, PtPE-CsNps, OrPE-CsNps and BaPE-CsNps revealed two sharp diffraction peaks at 2θ=19.0and 23.3 with a high degree of a crystalline structure.
6. The antifungal activity of the edible coating solutions were evaluated against phytopathogenic fungi of fruits (Alternaria alternate, Penicillium digitatum, Botrytis cinerea, Aspergillus flavus and Aspergillus niger) by the mycelial radial growth.
7. PmPE-CsNps displayed a complete reduction (100%) at a concentration of 800 ppm, followed by PtPE-CsNps that achieved a complete reduction (100%) in the radial growth of Alternaria alternate, Penicillium digitatum and Botrytis cinerea at a concentration of 800 ppm compared with other coating materials.
8. The phytopathogenic fungal cells are examined by Light Microscopy in presence of nano-coating edible solutions. The morphological observations showed abnormal changes including mycelial swelling, abnormal shapes, excessive branching and hyphal size reduction. They, also, showed alterations and lyses of the cell wall, cytoplasm aggregation, dissolution of septa and large vesicles, or empty cells devoid of cytoplasm in the mycelium.
9. The synthesized nanoparticles of the edible nano-coating materials are non-cytotoxic. The IC50 values of PmPE-CsNps, BaPE-CsNps, PtPE-CsNps, OrPE-CsNps and CsNps were 898, 814, 867, 660 and 530 µg/ml, respectively. The incorporation of waste peel extracts (PmPE, BaPE, PtPE and OrPE) into CsNps was non-cytotoxic and did not render any serious impact to normal human fibroblast cell line (MRC-5).
The edible coating materials were applied on the surface of strawberry fruits and then were stored at 5˚C for three weeks (21 days). The effect of these coating materials on the physical and the chemical properties of coated fruits were determined throughout the storage period. The obtained results could be summarized as follows:
1. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0% were significantly reduced weight loss percentage during the storage period compared with the other tested treatments). The uncoated strawberries were completely deteriorated after the 2nd week of the storage period.
2. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0% were significantly the most effective treatments in reducing the loss of firmness values as compared with the other tested treatments during the storage period or shelf life.
3. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0% were significantly achieved the highest TSS values as compared with the other tested treatments during the storage period.
4. Generally, the titratable acidity content of the strawberry fruits was decreased with the prolongation of the storage period or shelf life in all tested treatments. The highest TTA content were recorded in fruits coated with OrPE–CsNps, followed by PmPE-CsNps at concentration of 1.0 and 0.8 % during the storage period.
5. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0% were significantly achieved the highest total phenolic contents (TPC) as compared with the other tested treatments during the storage period or shelf life. As the phenolic activity of the edible coating material enhanced due to the presence of polyphenolic compounds (gallic acid, ellagic acid, punicalagin, etc.) in pomegranate and potato peels.
6. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0 % were significantly achieved the highest total flavonoid contents (TFC) as compared with the other tested treatments during the storage period.
7. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0 % were significantly achieved the highest antioxidant activity (AA) values as compared with the other tested treatments during the storage period. As the incorporation of pomegranate or potato peel water extract contained a good quantity of natural antioxidants.
8. The strawberry fruits coated with PmPE-CsNps and PtPE-CsNps (at concentration of 0.8 and 1.0 % were significantly achieved the highest total anthocyanin contents (TAC) as compared with the other tested treatments during the storage period.
9. The correlation matrix analysis indicated that there is a strong positive relationship between PmPE-CsNps (1.0 %) and treatments of OrPE-CsNps (0.8 & 1.0 %), PtPE-CsNps (0.8 & 1.0 %) and PmPE-CsNps (0.8%). A positive correlation, also, is observed between PtPE-CsNps (0.8%) and treatments of OrPE-CsNps (0.8 & 1.0 %), PtPE-CsNps (0.8%), PmPE-CsNps (0.8%) and PtPE-CsNps (1.0 %).
10. A negative correlation was observed in the correlation between PmPE-CsNps (1.0 %) and BaPE-CsNps (0.8 &1.0 %). Another negative correlation also, was detected between PtPE-CsNps (1.0 %) and OrPE-CsNps (0.8 & 1.0 %).
11. The hierarchical clustering heatmap analysis indicated that the edible nano-coating materials (PmPE-CsNps, PtPE-CsNps and OrPE-CsNps) indicate equal positive impact on some parameters (fruit pulp firmness, total soluble solids and total titratable acidity) at zero time and first week of the storage periods.
12. The edible nano-coating materials (Cs, CsNps and BaPE-CsNps) indicate an equal negative impact on other parameters (fruit weight losses, total anthocyanin content, total flavonoid content and total phenolic content) at the specific same times.