International Letters of Natural Sciences Vol. 64

Abstract: Agricultural wastes cause a serious environmental problem in Egypt. Utilization of these wastes by an environmentally friendly way is a very important issue. The objective of this study was to utilize rice straw into high-value products. Antioxidant activity, total soluble phenols, and flavonoids were evaluated in ethyl acetate extract prepared from rice straw after alkaline hydrolysis. Total phenols were found to be 221.6 mg gallic acid equivalents (GAE), while total flavonoids were 4.9 mg rutin equivalents (RE). The extract exhibited strong antioxidant activity measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method and its IC₅₀ value was 0.4 mg/ml. Furthermore, the ethyl acetate extract possessed high antioxidant activity assayed by β-carotene bleaching method and its value of lipid peroxidation inhibition (LPI) was 75.4%. It also exhibited high reducing power and its IC₅₀ value was equal to 0.06 mg/ml. HPLC analysis indicated that this extract contained seven phenolic acids including; protocatechuic, caffeic, syringic, p-coumaric, ferulic, rosmarinic and cinnamic, in addition to two flavonoids; qurecetin and kaempferol. Results indicated that ferulic and p-coumaric acids were the major soluble phenolic acids in rice straw, and their concentrations were 3.9 and 2.9 mg/g DW. It can be summarized that the strong antioxidant activity of ethyl acetate extract, prepared from rice straw, was highly correlated with its high level of phenolic compounds.

Abstract: The total lipid contents and iodine value of fats had been determined in fish from two sections of the Zaporizke Reservoir (Ukraine) with different contamination levels. Research was conducted using the muscle and liver tissue samples from pike-perch (Sander lucioperca), european perch (Perca fluviatis), prussian carp (Carassius gibelio), roach (Rutilus rutilus) and rudd (Scardinius erythrophthalmus). Obtained data showed that at the contaminated zone, the total lipid contents were significantly (p ≤ 0.05) reduced in muscle tissue of pike-perch and european perch in comparison with the samples from “conventionally clean” lower section of the reservoir. Increased iodine value of fats in muscle tissue and liver tissue were detected in the predatory fish and both fish groups respectively. The research results could be used for estimation of the adaptation processes in freshwater fish as well as for indication of environmental contamination level in the natural and artificial reservoirs.

Abstract: In mutation breeding, mutagenic effectiveness and efficiency are the base parameters to predict the mutagenic potency of any mutagen. Studies on mutagenic effectiveness and mutagenic efficiency of physical mutagen (gamma rays) and chemical mutagen (hydrazine hydrates; HZ) on two cultivars of lentil (Lens culinaris Medik.), viz. DPL 62 (macrosperma) and Pant L 406 (microsperma) have been reported. Dry and healthy seeds were treated with four doses of each gamma rays (100-400 Gy), HZ (0.1-0.4 %) and their combinations. Frequencies of the induced agro-morphological variations into different phenotypic categories were estimated in M₂ population that resulted into identification and isolation of wide range of mutants with altered phenotypes. Data on effectiveness and efficiency of various mutagenic treatments calculated on the basis of the frequency of chlorophyll mutations, which showed effectiveness and efficiency were higher at the moderate doses of gamma rays and HZ, while in case of combination treatments; lower doses were most effective and efficient with few inter-varietal exceptions. Phenotyping of the mutants revealed that growth habits was the most sensitive category to which most of the mutant belongs, followed by leaf and flower/pod/seed in both the cultivars studied. Overall, the screened and isolated mutants with economically important agronomic traits can be further propagated in the subsequent generation for development of elite lentil mutant cultivars.

Abstract: Starch was extracted (isolated) from cocoyam with the aid of water solution of oxalic acid and ammonium oxalate in 8 samples of ratios, 1:3, 1:1, 3:1, 2:3, 2:1, 1:2 and 0:0 respectively. The physiochemical properties were investigated in order to unveil its characteristics and unravel the potentials for industrial applications of the cocoyam starch. The physiochemical properties investigated includes; Amylose and Amylopectin contents, water binding capacity, particle size distribution, swelling power and solubility. The results obtained showed that swelling power and solubility of the starch were temperature dependent. The solubility was found to increase with temperature increase as the cocoyam starch showed highest solubility within the 70-90^°C temperature range. The swelling power was found fluctuating between the temperatures of 25-90^°C. The swelling power starch sample isolated with blending ratios of 2:1 and 1:2 were temperature dependent. The Amylose content ranges from 3.06 to 31.21%.