**1. Introduction**

The date palm, *Phoenix dactylifera* L., belongs to the family Arecaceae and is one of the subtropical fruit trees cultivated and spread in Iraq and some regions of the Middle East [1]. It is considered one of the most important fruit trees in Iraq because of its great nutritional and economic value. It is a sacred tree mentioned in all monotheistic religions. The evidence available at present indicates that the Sumerians were the first to be interested in the cultivation of the date palm, and used its fruits as basic food in the Tigris and Euphrates valleys for more than four thousand years BC [2].

The number of date palms in Iraq has decreased significantly in recent years due to the wars, the high salinity rate in soil and irrigation water, and the problem of the

housing crisis that led to the bulldozing of many palm orchards, which led to a severe shortage of dates production. Therefore, it is important to take the necessary measures to develop the production of dates by increasing the number of planted palm trees, as well as increasing the yield, improving the qualities of fruits, and reducing the percentage of spoilage, especially the desired cultivars, such as Berhi and Breim, through conducting some of the pre- and post-harvest treatments and avoiding treatment of fruits with chemicals that have negative impact on consumer health, as consumer demand has increased recently for fruits whose production has bio-safety factors [3, 4].

Chitosan is a vital polymer, the second largest biomaterial after cellulose, which is found in the outer structure of crustaceans, insects, and fungal cell walls. It is also characterized by no toxicity and biological decay and has no local effects on living tissue. It is a compound with vital functions [5], which has attracted the interest of researchers in the last few years for its commercial uses. Chitosan is composed of glucosamine units, which are associated with each other with a type of beta-type (1–4) cyclic bonds. It possesses many free hydroxyl and amino acids that enable it to form ionic, hydrogen, and hydrofluidic bonds with other molecules such as fats and proteins [6, 7].

Cold storage of date palm fruits is one of the important means at present, which is used to try to keep those fruits in the rutab phase as long as possible, thus prolonging the display period of those fruits in the local markets in the rutab phase, as cold storage reduces pathogens and the vital activities of the fruits, especially the process of respiration and the production of ethylene [8]. The activity of ethylene can also be inhibited through the use of the compound 1-methylcyclopropene, which symbolizes (1-MCP) commercially called smart fresh, which is in the form of a white powder that can be dissolved with water and releases the active substance 1-methylcyclopropene in the form of gas, which prevents contact ethylene with its receptors in the cells, which leads to inhibiting the formation of ethylene, and this, in turn, delays the natural ripening processes in the fruit, which keeps it fresh and of good quality for a longer time [9]. Studies have shown that treatment with the compound (1-MCP) limits the rate of ethylene production in fruits, reduces their respiration rate, and delays their entry into the ripening phase compared to untreated fruits [10–13].

Ultraviolet treatment is one of the alternative methods that has spread to be effective in inactivating bacteria, protozoa, algae, and viruses. Ultraviolet rays have the ability to destroy microorganisms, as is the case with heat treatment, but it has better advantages than heat treatment, as it does not affect the sensory properties of fruits, and it has a lower cost than heat treatment from an economic point of view. The radiation treatment process makes foods free of dangerous substances that are commonly used to kill insects by fumigation, such as ethyl dibromide, methyl bromide, and phosphine. Ultraviolet radiation in the range of 250–260nm is lethal to most microorganisms and acts as a strong bactericide [14], in addition that the treatment is certified and approved by various international health organizations.

Ozone (O3) is one of the powerful disinfectants against a wide range of microorganisms [15]. Ozone has number of features that make it suitable as an ideal postharvest treatment, quickly decomposes into oxygen without leaving any residue and is applied either as a gas or it is soluble in water, so it can effectively reduce post-harvest losses during storage for several crops [16–18].

The current study aims to improve the storage behavior of date palm fruits cvs. Berhi and Breim and determination the protein pattern of fruits after six months of storage at 10 2°C. Increasing the display period of the fruits of the two cultivars in *The Role of Some Pre and Postharvest Applications on Storage Behavior and Protein Pattern… DOI: http://dx.doi.org/10.5772/intechopen.109899*

the rutab phase for the longest possible period and improving their storage qualities and marketable of fruits through the use of some natural control treatments before and after harvest, especially chitosan, which is used according to the available references for the first time in the field of improving the yield, qualitative characteristics, and storage ability of the fruits of the two date palm cultivars. In addition to treat the fruits with some post-harvest treatments, which include the use of 1-MCP, ozone, and ultraviolet rays, and studying the physical and chemical changes of fruits during storage under the influence of these treatments.

#### **2. Materials and methods**

The storage experiment which was conducted, where the fruits of Berhi and Breim cultivars that treated with chitosan at the concentration of (0, 1, 2%) could be summarized as follows:

#### **2.1 Chitosan extraction process**

The shrimps were obtained from the local fish market in Basrah and the crusts were washed with water and dried by leaving them exposed to the sun. The method mentioned in [19], was followed for the extraction of chitin from the shrimp. The shrimp crust was crushed into small pieces using an electric mill then, the process of removal of the proteins (deprotienization) has been done by treating the crusts with sodium hydroxide solution at a concentration of 3.5% for two hours at a temperature of 65°c. by 1:10 (weight/volume). The mineral elements are removed in the process called demineralization by using a solution of hydrochloric acid at the concentration of 1 N for 1/2hour at room temperature by 1:15 (weight/volume). Crusts were washed well with water several times, then the pigment was removed by acetone and then by sodium hypochlorite solution at 0.315% for 5 minutes at room temperature by 1:10 (weight/volume). Finally, the white product was washed with distilled water and dried in an oven at 60° C for 24 hours to obtain the chitin.

Chitosan was prepared according to the method mentioned by [20] by removing the acetyl groups (Deacetylation) by treating with 50% sodium hydroxide at 1:10 (weight/volume) at 100°C for 20 hours to obtain chitosan with low molecular weight, and then dried at 110° C for 6 hours. The resulting chitosan is a white powder.

The viscosity was determined by the use of the Ostwald viscometer. After the preparation of the solution, the amount of time required to flow it at a certain distance at 25°. Molecular weight was determined depending on the viscosity of the solution according to [21]. The degree of removal of acetyl groups was determined by mixing 40 mg chitosan with 120 mg potassium bromide and then pressing and dried, then determined by using the Fourier Transform Infrared Spectroscopy (FTIR) Instrument.

The parameters of the product were measured as follows: Viscosity = 64.16 Centi Boyz, molecular weight 720 K, dalton, and the degree of removal of acetyl groups 87.6%.

Fruits have been brought after 18 weeks of pollination to the cold store in the early morning immediately after picking, then cleaned and each part of the three parts was divided into four parts for each cv. The first part was treated with ultraviolet rays at an amount of 1 kgY at intervals (0, 5, 10) minutes, and the second part was treated with ozone at 5 ppm at intervals of (0, 0.5, 1) an hour, and the third part was treated with the compound (1-MCP) at a concentration of (0, 0.5, 1) ppm for 24 hours under 0°C, and the fourth part was immersed in chitosan at the three concentrations (0, 1,

2%). Fruits were packed in the transparent plastic container automatically with six replicates for each concentration, then three replicates were stored at a temperature of 10 2°C for six months and after that, the following characteristics were determined:
