الفهرس 
Effect of ChitosanOnly 14 pages are availabe for public view
Abstract
This experiment was carried out on asparagus UC157 F2 during 2017 and 2018 seasons at Laboratory of Handling of Vegetable Crops Department, Horticulture Research Institute. ARC at Giza.
Asparagus spears at the proper stage of marketing were selected with straight, undamaged, 15-19 mm in diameter and 25 cm in length with closed bracts and no visible signs of injury to study the effect of dipping the spears in solution of chitosan at 0.5% or 1% for 3 minutes or carboxymethyl cellulose at 0.5% or 1% for 3 minutes beside untreated control and the effect of packaging material (micro-perforated polypropylene bags and non-perforated polypropylene bags) on quality attributes of asparagus spears during storage at 2°C and 90-95% relative humidity for 20 days in additional 2 days at 10°C (shelf life).
The obtained results are summarized as follows:
1-Weight loss percentage of asparagus spears was increased with the prolongation of storage period at 2ºC plus shelf life conditions at 10ºC.
2- Asparagus spears packed in non-perforated polypropylene bags had the lowest value of weight loss percentage as compared with those packed in micro perforated polypropylene bags during storage plus shelf life.
3- Asparagus spears dipped in chitosan at 0.5 or 1% were the most effective treatments for reducing the loss of weight percentage during storage plus shelf life.
4-Asparagus spears dipped in chitosan at 1% and then packed in non-perforated polypropylene bags had significantly the lowest value of weight loss% after 20 days at 2°C plus 2 days at 10°C.
5-Decay score of asparagus spears was increased with the prolongation of storage period at 2ºC plus shelf life conditions at 10ºC.
6-Asparagus spears packed in non-perforated polypropylene bags had lower decay in comparison to those packed in micro-perforated polypropylene bags during storage plus shelf life.
7-Asparagus spears dipped in chitosan at 1 or 0.5% were the most effective treatments in minimizing decay incidence during storage plus shelf life.
8-No decay was observed in spears treated with chitosan at 1% and then packed in non-perforated polypropylene bags during all storage period plus 2 days shelf life.
9-General appearance of asparagus spears decreased with the prolongation of storage period at 2°C plus shelf life at 10°C.
10-Asparagus spears packed in non-perforated polypropylene bags showed the highest score of general appearance during storage plus shelf life.
11-Asparagus spears during postharvest storage plus shelf life, furthermore, asparagus spears dipped in chitosan at 0.5 or 1% were the most effective treatments in maintaining general appearance during storage plus shelf life with significant difference between them.
12-Asparagus spears dipped in chitosan at 1% and then packed in non- perforated polypropylene bags gave good appearance after 20 days at 2°C plus 2 days at 10°C.
13-A progressive increase in asparagus spears curvature score during storage plus shelf life, however, the spears curvature started to be shown after 12 days of storage at 2°C plus 2 days at 10°C. Extending the storage period up to 20 days at 2°C plus 2 day at 10°C resulted in a significant higher spear curvature score.
14-Asparagus spears packed in non-perforated polypropylene bags reduced the spear curvature compared to those packed in perforated polypropylene bags.
15-Asparagus spear dipped in chitosan at 1% or 0.5% were the most effective treatment in reducing spears curvature (binding or upward growth) during storage plus shelf life.
16-Asparagus spears dipped in chitosan at 1% and then packed in non-perforated polypropylene bags did not observed any signs of spear curvature till 20 days of storage at 2°C plus 2 days at 10°C.
17-There was significant decrease in L value with increasing storage period of asparagus spears showing darker spears.
18-Asparagus spears packed in non-perforated polypropylene bags had the highest value of L value (indicated lighter color).While those packed in micro-perforated polypropylene bags obtained the lowest value of L value (indicated darker color) during storage plus shelf life.
19-Asparagus spears dipped in chitosan at 1% had significant higher L value (indicated lighter spears) during storage plus shelf life.
20-Asparagus spears dipped in chitosan at 1% and then packed in non-perforated polypropylene bags showed the highest L value (indicated lighter color after 20 day at 2°C plus 2 days at 10°C.
21-The hue angle value of spears was decreased with the prolongation of storage plus shelf life (turned to slight color).
22-Asparagus spears packed in non-perforated polypropylene bags reduced the loss of hue angle (more green color) as compared with those packed in micro-perforated polypropylene bags during storage plus shelf life.
23-Asparagus spears dipped in chitosan at 1% and then packed in non-PPPb showed the highest value of hue angle (indicated more green color) after 20 days at 2°C plus 2 days at 10°C.
24-Ascorbic acid content of asparagus spears was decrease with the prolongation of storage period at 2ºC and shelf life conditions at 10ºC.
25-Asparagus spears packed in non-perforated polypropylene bags had lower loss ascorbic acid in comparison to those packed in micro-perforated polypropylene bags.
26-Asparagus spears dipped in chitosan at 1% was the most effective treatments in maintaining ascorbic acid content during storage plus shelf life.
27-Asparagus spears dipped in chitosan at 1% or 0.5% and then packed in non-perforated polypropylene bags gave the highest value of ascorbic acid content after 20 days at 2°C plus 2 days at 10°C.
28-Total soluble solids percentage of asparagus spears was decrease with the prolongation of storage period at 2ºC plus shelf life conditions at 10ºC.
29-non-perforated polypropylene bags reduced the loss in total soluble solids percentage as compared with those packed in micro-perforated polypropylene bags.
30-Asparagus spears dipped in chitosan at 0.5 or 1% had significantly the highest value of total soluble solids percentage during cold storage plus shelf life.
31-Asparagus spears dipped in chitosan at 1% and then packed in non-perforated polypropylene bags showed the highest value of total soluble solids percentage after 20days at 2°C plus 2days at 10°C.
32-Total chlorophyll content of asparagus spears decreased with the prolongation of storage period at 2°C plus shelf life at 10°C.
33-Asparagus spears packed in non-perforated polypropylene bags reduced the loss of chlorophyll content during storage plus shelf life.
34-Asparagus spears dipped in chitosan at 0.5 or 1% had significantly the highest value of total chlorophyll contents during cold storage plus shelf life.
35-Asparagus spears dipped in chitosan at 0.5 or 1% and then packed in non-perforated polypropylene bags showed the highest value of total chlorophyll after 20 days at 2°C and 2 days at 10°C.
36-Phenylalanine ammonia-lyase activity of asparagus spears were significantly increased with the prolongation of storage until 12 days at 2°C plus 2 days at 10°C, and then decreased till the end of storage (20 days at 2°C plus 2 days at 10°C.
37-Asparagus spears packed in non-perforated polypropylene bags inhibited the increase in PAL activity as compared with those packed in micro-perforated polypropylene bags.
38-Asparagus spears dipped in chitosan at 0.5 or 1% had significantly lowest active of PAL enzyme during cold storage plus shelf life.
39-Asparagus spears dipped in chitosan at 1% or 0.5% and then packed in non-perforated polypropylene bags reduced the PAL activity as compared with other treatments, or untreated control after 20 days at 2°C plus 2 days at 10°C.
Second experiment:
The effect of some edible coating and packaging on quality attribute of broccoli florets during cold storage plus shelf life.
This experiment was carried out on broccoli Sakura F1 hybrid during 2017 and 2018 seasons at Laboratory of Handling of Vegetable Crops Department, Horticulture Research Institute Agriculture Research Center at Giza. Head of broccoli at the proper stage of marketing were separated to florets to study the effect of dipping the florets in solution of chitosan at 0.5% or 1% for 3 minutes or carboxymethyl cellulose at 0.5% or 1% for 3 minutes beside untreated control dipping in distilled water for 3 minutes and the effect of packaging material (micro-perforated polypropylene bags or non-perforated polypropylene bags on quality attributes of broccoli florets during storage for 20 days at 0ºC and 90-95% relative humidity in additional 2 days at 10ºC (shelf life conditions).
The obtained results are summarized as follows:
1- Weight loss percentage of broccoli florets was increased with the prolongation of storage period at 0ºC plus shelf life conditions at 10ºC.
2- Broccoli florets packed in non-perforated polypropylene film had the lowest value of weight loss as compared with those packed in micro perforated polypropylene film.
3- Broccoli florets dipped in chitosan at 0.5 or 1% were the most effective treatments in reducing the weight loss percentage during storage plus shelf life.
4- Broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene film showed the least weight loss percentage after 20 days at 0°C plus 2 days at 10°C.
5- Decay score of broccoli florets was increased with the prolongation of storage period at 0ºC plus shelf life conditions at 10ºC.
6- Broccoli florets packed in non-perforated polypropylene bags had lower decay in comparison to those packed in micro-perforated polypropylene bags during storage plus shelf life.
7- Broccoli florets dipped in chitosan at 1 or 0.5% were the most effective treatments in minimizing decay incidence during storage plus shelf life.
8- No decay was observed in florets treated with chitosan at 1% and then packed in non-perforated polypropylene bags during all storage period plus shelf life.
9- Off-odor inside all packages increased considerable and consistently with the prolongation of storage periods plus shelf life.
10- No off-odor of florets packed in micro-perforated polypropylene bags while, those packed in non- perforated polypropylene bags gave slight score of off-odor during storage plus shelf life.
11- All coating treatments gave the lowest score of off-odor compared with untreated florets (control) during storage plus shelf life, broccoli florets dipped in chitosan at 0.5 or 1% was the best treatment, it did not show off-odor during storage plus shelf life.
12- No off-odor was observed in broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags during all storage period plus shelf life.
13- General appearance of broccoli florets decreased with the prolongation of storage period plus shelf life.
14- Florets packed in non-perforated polypropylene bags showed the highest score of general appearance during storage at 0°C plus shelf life at 10°C.
15- Broccoli florets dipped in chitosan at 0.5 or 1% were the most effective treatments in maintaining general appearance during storage plus shelf life.
16- Florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags gave good appearance after 20 days at 0°C plus 2 days at 10°C.
17- Florets opening inside all packages increased considerable and consistently with the prolongation of storage period.
18- Florets packed in non-perforated polypropylene bags showed the highest score of florets opening during cold storage plus shelf life.
19- Broccoli florets dipped in chitosan at 0.5 or 1% were the most effective treatments in reduced florets opening during storage plus shelf life.
20- Broccoli florets dipped in chitosan at 1% and then packed in non- perforated polypropylene bags showed the low florets opening and did not exhibit any changes in their florets opening till 16 days at 0°C plus 2 days at 10°C, and gave very tight and firm heads after the end of storage period plus shelf life.
21- There was an increment in discoloration of the cut surface of broccoli florets as the storage period was prolonged.
22- Non-perforated polypropylene bags prevented the discoloration in the cut surface of broccoli florets and showed the lowest score of discoloration when compared with micro-perforated polypropylene bags which showed the higher score during storage plus shelf life.
23- All coating treatments reduced the incidence of discoloration compared to untreated florets (control).
24- Broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags did not show any changes in the cut surface color till 16 days at 0°C plus 2 days at 10°C and gave non to slight score of discoloration at the end of storage.
25- The hue angle value of broccoli florets gradually decreased as the storage period prolonged.
26- Non-perforated polypropylene bags reduced the loss of hue angle as compared with those packed in micro-perforated polypropylene bags during storage plus shelf life.
27- Broccoli florets treated with chitosan at 0.5 or 1% were the more effective treatment in reducing the loss of hue angle value during storage plus shelf life.
28- Broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags showed the highest value of hue angle (indicated more green color) after 20 days at 0°C plus 2 days at 10°C.
29- Ascorbic acid content of broccoli florets was decrease with the prolongation of storage period at 0ºC plus shelf life conditions at 10ºC.
30- Non-perforated polypropylene bags reduced the loss in ascorbic acid content as compared with those packed in micro-perforated polypropylene bags.
31- Broccoli florets dipped in chitosan at 1% was the most effective treatments in maintaining ascorbic acid content during storage and shelf life.
32- Broccoli florets dipped in chitosan at 1% or 0.5% and then packed in non-perforated polypropylene bags gave the highest value of ascorbic acid content after 20 days at 0°C plus 2 days at 10°C.
33- Total soluble solids percentage of broccoli florets was decrease with the prolongation of storage period at 0ºC or shelf life conditions at 10ºC.
34- Non-perforated polypropylene bags reduced the loss in total soluble solids percentage as compared with those packed in micro-perforated polypropylene bags during cold storage plus shelf life.
35- Broccoli florets dipped in chitosan at 0.5 or 1% had significantly the highest value of total soluble solids percentage during cold storage plus shelf life.
36- Broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags showed the highest value of total soluble solids percentage during cold storage plus shelf life after 20 days at 0°C plus 2days at 10°C.
37- Total chlorophyll contents of broccoli florets decreased as the storage period was extended.
38- Broccoli florets packed in non-perforated polypropylene bags had significantly higher value of chlorophyll content of florets than those packaged in micro-perforated polypropylene bags during storage plus shelf life.
39- Broccoli florets dipped in chitosan at 0.5 or 1% had significantly the highest value of total chlorophyll contents during storage plus shelf life.
40- Broccoli florets dipped in chitosan at 0.5 or 1% and then packed in non- perforated polypropylene bags showed the highest value of total chlorophyll, while untreated florets packed in micro-perforated polypropylene bags gave the lowest value of total chlorophyll content.
41- Total phenolic content of broccoli florets was decreases with prolonged storage for all treatment of storage period at 0°C or shelf life conditions at 10°C.
42- Broccoli florets packed in non-perforated polypropylene bags had highest value of total phenolic content as compared with those packed in micro-perforated polypropylene bags.
43- Broccoli florets dipped in chitosan at 1 or 0.5% had significantly the highest value of total phenolic content during storage plus shelf life.
44- Broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags showed the highest value of total phenolic content after 20 days at 0°C plus 2days at 10°C.
45- Peroxidase (POD) activity of broccoli florets increased along storage period.
46- Broccoli florets packed in non-perforated polypropylene bags had reduced the enzyme activity as compared with micro-perforated polypropylene bags during storage and shelf life.
47- All coating treatments gave the lowest active of peroxidase enzyme as compared with untreated florets (control). Broccoli florets dipped in chitosan at 1% gave the lowest active of enzyme during storage plus shelf life.
48- Broccoli florets dipped in chitosan at 1% and then packed in non-perforated polypropylene bags showed the less active POD,while untreated control packed in micro-perforated polypropylene bags gave the highest active POD after 20 days at 0°C plus 2 days at 10°C.