الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The dietary plant plays an important character in healthcare management system and substantially, in the weight and feed efficiency due to its palatability and it is nutritional endowments. For example, vegetables play an important role in human diets, as they support the normal functioning of the different body systems. Among vegetables, the green leafy vegetables occupy an important position. Among the leafy vegetables, molokhia/Jew’s mallow (Corchorus olitorius L. ; Family, Malvaceae) comes to form a distinct center among these plants, which are widely cultivated in by international countries. In Egypt, Molokhia is one of the popular summer leafy vegetables, which is grown on an area of 18,053 feddans with a total production of 157,241 tons, then harvested, processed and exported to various countries of the world. It is also widely consumed in those countries as a healthy food prepared in different ways as salads, soups, spices, flavouring agent and granishes, Molokhia leaves are rich in, fiber, vitamin C, folic acid, β-carotene, iron, potassium, calcium, magnesium and more than 32 vitamins, minerals and trace elements. The plant has strong antioxidant activity with vitamin E equivalent to α-tocopherol. Consumption of molokhia leaves is reported to be demulcent, deobstruent, diuretic, lactagogue, purgative, and tonic as well as a folk remedy for aches and pains, dysentery, enteritis, fever, pectoral pains, and tumors. Also, they are used for cystitis, dysuria, fever, and gonorrhea. Furthermore, it can act anti-inflammatory and has gastroprotective properties. Finally, every 100 grams of Molokhia contains about 26 calories, and thus it is considered low in calories and rich in fiber, which makes it a suitable dish for those looking for low-calorie recipes that help in losing weight and curbing appetite.
Minimally processed or fresh-cut vegetables such as Molokhia are very popular for consumption due to their convenience and ready-to-use properties, but they provide an ideal medium for microbial development. Steps such as slicing, shredding and improper refrigeration during shelf-life have been associated with an increase in foodborne pathogens such as Salmonella, Shigella spp., Campylobacter, Escherichia coli, Listeria monocytogenes, Yersinia enterocolitica, Staphylococcus aureus, Clostridium spp., Bacillus cereus. Also, decrease in bioactive compounds and antioxidant capacities of the plant were reported. The risk involved with the consumption of minimally processed or fresh-cut vegetables could be minimized either reducing or eliminating external surface contamination. Simply washing of fresh vegetables including Molokhia with water may not remove pathogens and other spoilage microorganisms, therefore, other alternative processes were researched. Some traditional disinfectants (chlorine, bromine, iodine, trisodium phosphate, sodium chlorite, sodium hypochlorite, acids, hydrogen peroxide, ozone, permanganate salts etc.) commonly uses in a washing step as sanitisation treatment. However, certain by-products of this protocol, such as chloroform, haloacetic acids and other trihalomethanes, are potentially harmful to human. So, there were other attempts to reduce the number of microorganisms on the surface of vegetables and maintain their functional properties as well as extend the shelf life by modifying the packaging atmosphere, reducing storage temperatures and using edible films. These treatments are selective in reducing the number of pathogens and preserving the functional properties on minimally processed or fresh-cut vegetables. Therefore, alternative disinfectant treatment needs to be investigated. Among the possibilities, disinfection by non-ionizing UV-C radiation is interesting, because it brings some benefits to the fresh cut industry as its use is approved by the code of Food and Drug Administration (FDA) in the USA on food products to control surface micro-organisms, does not leave a residue, and does not require extensive safety equipment subsequently the cost is relatively low.Several studies have demonstrated the efficiency of UV-C radiation on microbial inhibition growth. To the best of our knowledge, only a few studies have focused on the effect of UV-C radiation on minimally processed vegetables, while there are no studies specifically on molokhia leaves. Therefore, the purpose of this study was to evaluate the effect of UV-Con the microbial quality of minimally processed molokhia leaves. Changes in bioactive compounds and antioxidant capacity during shelf-life were also studied.
Experimental design
Samples are of separate leaves with petioles. The process of manual sorting of samples is carried out to discard of leaves with defects such as yellowing, decay, cuts and bruising. The following treatments were applied to sound leaves according to washing method and UV-C radiation. Leaves were washed for 2 min in tap water at 40C and excess surface water was removed using a handheld salad spinner for 45 s. This treatment was employed as control since it is commonly followed in minimally processed leafy vegetables. For UV-C treatment samples, this treatment was the same as control samples but leaves were subjected to 11.35 kJ m−2 UV-C. For every treatment and immediately after the last step in each case, 120 g of leaves were aseptically placed in polypropylene baskets of approximately 2000 mL(22 cm×20 cm×11 cm) capacity and thermally sealed at the top with a biaxially oriented polypropylene film (BOPP) to constitute a passive modified atmosphere. The oxygen and carbon dioxide permeability of BOPP film at 23 oC and 0% relative humidity was provided by the supplier as 900 cm3 m−2 day−1 atm−1 and 1100 cm3 m−2 day−1 atm−1, respectively.Six replicates of one basket per processing treatment and storage duration (0, 3, 6 and 9 days) were prepared and stored in a clean cold room (80% relative humidity) at 8 0C.