Compositional characteristics of cherry kernel oil as influenced by gamma irradiation and storage periods.

This research work was undertaken to evaluate the physicochemical parameters of oil from the cherry kernel non-irradiated and irradiated at 3 and 6 kGy of gamma irradiation for two storage periods (0 and 12 months). The acid value, peroxide value, thiobarbituric acid reactive substances value, iodine value, saponification value refractive index (peroxide value), and the color parameters of cherry kernel oils were determined. The results indicated that the extracted cherry kernel oils were liquid at room temperature with color varying from light yellow to deep red. The physicochemical properties of cherry kernel oils including acid value, peroxide value, thiobarbituric acid reactive substances, iodine value, saponification value, and refractive index values were 1.19 mg KOH g-1, 9.01 meq2 kg-1, 0.014 mg MDA kg-1, 99.48 KOH g-1 I2 100 g-1, 194.50 mg KOH g-1, and 1.472, respectively. Generally, gamma irradiation doses and storage time increased acid value, peroxide value, thiobarbituric acid reactive substances, and refractive index value of cherry kernel oils, whereas no significant (p > 0.05) change due to irradiation was recorded in iodine value, saponification value, and in color parameter (L*, a*, b*, and ΔE values) of cherry kernel oils. However, the properties of cherry kernel oils revealed that the cherry kernel is a good source of oil which could be used for industrial purposes.

Comparative effect of irradiation and heating on the microbiological properties of licorice (Glycyrrhiza glabra L.) root powders.

PURPOSE: To determine the effect of gamma irradiation, steaming and heating on microbial load and chemical composition of licorice root powder. MATERIALS AND METHODS: Powders were exposed to hot air treatment at 60°C for 24 h, steaming at 1.1 bar and about 121°C for 15 min, and irradiation at 10 kGy using a (60)Co source. Microbial load, moisture, ash, and electrical conductivity (EC) values of licorice root powders were evaluated immediately after treatment, and after 12 months of storage. RESULTS: Total aerobic plate count (TAPC) of licorice roots powder (control sample), including coliform, Escherichia coli, and Klebsiella spp. were relatively high. Irradiation reduced the TAPC by 4 logs and total coliform to negative (less than 1 log(10) colony forming units (CFU) g(-1)) Klebsiella spp., E. coli, and Salmonella spp. were not detected (less than 1 log(10) CFU/g) in irradiated sample. Meanwhile, heating and steaming reduced the total count by 1 and 2 logs with slight effect on reducing the total coliforms counts. Also, irradiated samples were free of coliforms. No considerable changes in the moisture and ash were observed in irradiated powders, but the moisture increased due to steaming, and decreased due to dried heating. CONCLUSION: Gamma irradiation at 10 kGy was more effective than heating and steaming treatments in their microbial decontamination effect on the licorice root powders.

Effect of gamma irradiation on microbial load and quality characteristics of minced camel meat.

The effect of gamma irradiation on microbial load, chemical and sensory characteristics of camel meat has been evaluated. Camel meat was irradiated at doses of 0, 2, 4 and 6kGy of gamma irradiation. Irradiated and non-irradiated meat was kept in a refrigerator (1-4°C). General composition and sensory evaluation of camel meat was done two days after irradiation, whereas, microbiological and chemical analysis was done immediately after irradiation and throughout the storage periods. The results indicated that all doses of gamma irradiation reduced the total mesophilic aerobic plate counts (TPCs) and total coliforms of camel meat. Thus, the microbiological shelf-life of camel meat was significantly extended from less than 2weeks (control) to more than 6weeks (samples irradiated with 2, 4 or 6kGy). No significant differences in moisture, protein, fat, thiobarbituric acid (TBA) values, total acidity and fatty acids of camel meat were observed due to irradiation. There were slight effects of gamma irradiation in both total volatile basic nitrogen (VBN) and lipid oxidation values in camel meat. Sensory evaluation showed no significant differences between irradiated and non-irradiated camel meats.

Effect of gamma irradiation on microbial load and sensory characteristics of aniseed (Pimpinella anisum).

Seeds of anise (Pimpinella anisum) were exposed to doses of 0, 5, 10, 15 and 20kGy in a (60)Co package irradiator. Irradiated and unirradiated samples were stored at room temperature. Microbial populations on seeds, total and inorganic soluble solids in water extract and sensory properties of the latter were evaluated after 0, 6 and 12 months of storage. Results indicated that gamma irradiation reduced the aerobic plate counts of aniseed. Immediately after irradiation, the total soluble solids in an extract of irradiated seeds were greater than those of unirradiated ones. The total soluble solids in an extract of irradiated and un-irradiated seeds increased after 6 and 12 months of storage. There were no significant differences (p>0.05) in inorganic soluble solids between the water extract of irradiated and unirradiated aniseeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of aniseed water extract tested immediately after irradiation; however, after 12 months of storage, no significant differences (p>0.05) were found in color, taste or flavor between extract of irradiated and unirradiated seeds.

Microbial load, acidity, lipid oxidation and volatile basic nitrogen of irradiated fish and meat-bone meals.

Experiments were carried out to study the effect of different doses of gamma irradiation (0, 5, 10, 15 and 20 kilo gray; kGy) on some nutritive components and chemical aspects pertaining to quality of fish meal and meat-bone meal. The radiation doses required to reduce the total microbial load and Salmonella sp. one log cycle (D(10)) in fish meal and meat-bone meal were determined. Results indicated that gamma irradiation of fish meal and meat-bone meal with 5-20 kGy doses had no effects on the total acidity values but increased the values of lipid oxidation and total volatile basic nitrogen. D(10) of total microbial load and Salmonella sp. were 833 and 313 Gy for fish meal and 526 Gy and 278 Gy for meat-bone meal, respectively. It can be concluded that radiation processing could be employed in the recycling of fish and meat-bone meals by using them as feedstuffs in poultry diets with no fear of losing their nutritive components.

Synergetic effect of gamma irradiation and moisture content on decontamination of sewage sludge.

Samples of concentrated municipal sewage sludge, stored for 2, 4 and 6 months, with moisture contents of 2%, 20%, 40%, 60%, and 80% were exposed to doses of 0, 1, 2, 3, 4 and 5 kilogray (kGy) of gamma irradiation. Immediately after irradiation, total microbial count and bacterial pathogens in sewage sludge were determined. The results indicated that in all tested sewage sludge samples, bacterial pathogens including Enterobacter sp., Klebsiella sp., Salmonella sp., and Escherichia coli were initially detected. All doses of gamma irradiation reduced the total counts of microorganisms. D(10) of total count decreased with increase in the moisture content of the sewage sludge. The lowest lethal dose for tested bacterial pathogens was 5 kGy in air dried sewage sludge. In addition for wet sewage sludge having more than 40% moisture, the lethal dose was 1 kGy, for samples taken at different storage periods 2, 4 and 6 months, and therefore the cost per unit could be decreased to half when wet sewage sludge (about 50% moisture) was used.

Effect of gamma irradiation on storability of apples (Malus domestica L.).

The aim of this study was to investigate the effect of gamma irradiation on storability of the two main apple varieties, Golden Delicious and Starking, in Syria. The experiments were performed in 1995 and 1996. Fruits were irradiated with 0, 0.5, 1.0 and 1.5 KGy. Irradiated and unirradiated fruits were stored at 1 to 2 degrees C and under a relative humidity of 80 to 90%. Weight loss and spoilage due to physiological disorders and fungal diseases were evaluated throughout the different storage periods. Firmness, coloration and pH values were estimated immediately after irradiation. The results showed that, in both varieties, gamma irradiation increased the weight loss after 45 days of storage in apples gathered in 1995 but not in the 1996 season. After 180 days of storage, gamma irradiation had different effects on weight loss depending on the growing year and variety, and increased fungal spoilage. Application of gamma irradiation prevented the growth of Aspergillus niger and the formation of skin scald in 'Golden Delicious' fruits. Immediately after treatment, gamma irradiation increased the softening of fruits, changed their color from green to yellow and decreased the pH value of the juice.

Factors affecting storability of apples in Syria.

The aim of the present study was to investigate the effect of some environmental factors (production place and season), production factors (variety, fruit size, irrigation and yield), and storage conditions (refrigerated and non refrigerated rooms) on storability of cv.'Golden' Delicious and cv. 'Starking' apples (Malus domestica, Borkh) in Syria. The results showed a negative relationship between apples' storability and each of the following: temperature from April to September, irrigation before harvest, yield, and fruit size. Whereas altitude, and rainfall through winter had a positive effect on storability of apples.