Journal of Agricultural Science and Technology 

About: Journal of Agricultural Science and Technology is an academic journal published by Jomo Kenyatta University of Agriculture & Technology. The journal publishes majorly in the area(s): Agriculture & Population. It has an ISSN identifier of 1680-7073. Over the lifetime, 2383 publications have been published receiving 23216 citations. The journal is also known as: JAST.

Effect of the Three Herbal Extracts on Growth Performance, Immune System, Blood Factors and Intestinal Selected Bacterial Population in Broiler Chickens

Abstract: A research study was conducted to evaluate the effects of three herbal extracts and an antibiotic –virginiamycin- on growth performance, immune system, blood factors and selected intestinal bacterial populations in broiler chickens. A total of four hundred and eighty 1-day old male broiler chicks were assigned to the basal diet (control) , basal diet supplemented with 15 ppm of virginiamycin, basal diets with a 0.1% dose of either thyme (Thymus vulgaris ), coneflower ( Echinacea purpurea ), garlic ( Allium sativum ) or a blend of the three extracts in the drinking water. The highest and the lowest body weight and weight gain were related to virginiamycin and coneflower, (P 0.05). Garlic ( Allium sativum ) significantly reduced the serum levels of cholesterol, LDL, and triglyceride as well as significantly increasing the level of HDL. Thyme ( Thymus vulgaris ) improved hematocrit percentage and hemoglobin concentration, but not significantly. The colony forming units of Escherichia coli in digesta of ileo-cecum in the blend group showed a significantly lower number compared with control. However, there was no difference observed in E. coli counts between blend group and others, except for control. The lactic acid bacteria counts in the thyme group increased as compared to other groups, except for coneflower (P< 0.05).

Total Phenolic Contents and Antioxidant Activity of Pomegranate (Punica granatum L.) Peel Extracts

Abstract: The phenolic compounds of pomegranate (Punica granatum L.) peel extracted by two methods (solvent and ultrasound-assisted) with five solvents (acetone, methanol, ethanol, water and ethyl acetate) were compared with supercritical fluid extraction (SFE). The total phenolic compounds were determined according to the Folin-Ciocalteu reagent using tannic acid as standard. The overall results showed that acetone with sonication produced the maximum amount of phenolic compounds from pomegranate peel extracts (PPE). Furthermore, the effect of the acetone extract of pomegranate peel (0.010-0.050 %) on the stability of soybean oil during heating at 60 o C (oven test method) was determined by measuring peroxide and thiobarbitoric acid values. At a 0.050 % level of pomegranate peel extract, its antioxidant activity was greater than 0.02 % of the two synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The pomegranate peel extract possessed a relatively high antioxidant activity and might be considered as a rich source of natural antioxidant.

Chemical Composition and Physicochemical Properties of Pumpkin Seeds (Cucurbita pepo Subsp. pepo Var. Styriaka) Grown in Iran

Abstract: Chemical composition and physicochemical properties of pumpkin seeds and fatty acids of their oil were determined. It was found that the seeds contained 41.59% oil and 25.4% protein. Moisture, crude fiber, total ash, and carbohydrate contents were 5.2%, 5.34%, 2.49%, and 25.19%, respectively. The specific gravity, dynamic viscosity, and refractive index of the extracted pumpkin seed oil were 0.915, 93.659 cP, and 1.4662, respectively. Acid value (mg KOH/g oil), peroxide value (meq O 2/kg oil), iodine value (g I 2/100 g oil), saponification number (mg KOH/ g oil), and unsaponifiable matter content (%) of the extracted oil from pumpkin seeds were 0.78, 0.39, 10.85, 104.36, 190.69, and 5.73, respectively. Total phenolics compounds (mg gallic acid/kg oil), total tocopherols (mg �tocopherol/kg oil), total sterols (%), and waxes (%) were 66.27, 882.65, 1.86, and 1.58, respectively. Specific extinctions at two wavelengths of 232 nm (K232 ) and 270 nm (K270 ) and R-value (K 232 /K 270 ) were 3.80, 3.52 and 0.74, respectively. Gas chromatographic analysis of the pumpkin seed oil showed that the linoleic (39.84%), oleic (38.42%), palmitic (10.68%) and stearic (8.67%) acids were the major fatty acids. Compared with other vegetable oils, the present study revealed that pumpkin seed oil can be a valuable source of edible oil.

Chemical Characteristics and Oxidative Stability of Sesame Seed, Sesame Paste, and Olive Oils

Abstract: Raw (intact) sesame seed showed a high content of oil, protein and ash: respectively, 52%, 24% and 5%. Studies were conducted on some quality characteristics of sesame and olive oils. The following values were obtained from raw sesame, sesame paste and olive oils, respectively: unsaponifiable matter 1.35, 1.46, and 1.50%; total phenols 14.21, 16.82, and 53.33 mg kg -1 oil; chlorophylls 0.04, 0.09 and 1.88 µg g -1 ; carotene 2.62, 3.66 and 19.10 µg g -1 ; refractive index 1.47, 1.47 and 1.47; saponification value 186.6, 185.75, and 97.94; iodine value 113.35, 91.34, and 81.23, acidity along with of 1.64, 1.10, and 1.12 mg KOH g -1 oil. Fatty acid profiles of raw sesame, sesame paste and olive oils showed a predominance of oleic acid (41.68%, 41.94%, and 52.14%, respectively) followed by linoleic-acid (38.29%, 37.48%, and 17.82%). Storage effect at 65°C of raw sesame, sesame paste and olive oils were later on studied. Results showed that the oxidative stability of raw sesame oil was higher than that of sesame paste oil. Due to its all favorable properties, sesame oil could be used in either food or cosmetic products.

Modification of drastic model to map groundwater vulnerability to pollution using nitrate measurements in agricultural areas

Abstract: DRASTIC model has been used to map groundwater vulnerability to pollution in many areas. Since this method is used in different places without any changes, it cannot consider the effects of pollution type and characteristics. Therefore, the method needs to be calibrated and corrected for a specific aquifer and pollution. In the present research, the rates of DRASTIC parameters have been corrected so that the vulnerability potential to pollution can be assessed more accurately. The new rates were computed using the relationships between each parameter and the nitrate concentration in the groundwater. The proposed methodology was applied to Astaneh aquifer located in north of Iran. Samples from groundwater wells were analyzed for nitrate content in thirteen locations. The measured nitrate concentration values were used to correlate the pollution potential in the aquifer to DRASTIC index. Pearson correlation was used to find the relationship between the index and the measured pollution in each point and, therefore, to modify the rates. The results showed that the modified DRASTIC is better than the original method for nonpoint source pollutions in agricultural areas. For the modified model, the correlation coefficient between vulnerability index and nitrate concentration was 68 percent that was substantially higher than 23 percent obtained for the original model