BIOCHEMICAL STUDIES ON SOME DESERT PLANTS

Abstract

(75.2%). Our investigation was directed to one of the sources of microbial protein, it is kind of fungi named Truffle which is rich in protein content and grow in the north western coast of Egyptian deserts. Chemical composition of truffle fungus (two species) were studied. The general chemical analysis indicated some differences between the two studied species, white (Tirmania nivea) and Brown (Terfezia boudieri) truffle. The white truffle had a higher content of carbohydrates and fat (54.41% and 7.85%) than the brown truffle (49.58% and 6.52%) respectively. While the brown truffle had the higher content of protein, fiber and ash (22.37%, 7.95% and 13.58%) than the white truffle (22.34%, 7.45% and 7.95%) respectively. Potassium (K) was the highest content in both species, followed by phosphorous (P) and Sodium (Na), Magnesium (Mg), Zink (Zn), copper (Cu) and Iron (Fe) were presented in both species with fairly amounts. The salt soluble protein (Globulin) was the highest amount in both species. PAG electrophoresis of truffle protein showed similar fractions with molecular weight ranged between 34.50 to 218 KDa were detected. Special interest was foucused to the amino acid contents of the truffle protein, which analyzed using amino acid anlayzer. The brown truffle contains a higher percentage of free essential amino acids (89.37%) than the white truffle (69.31 %). Cysteine was the highest amino acid in white truffle, while isoleucin was the highest one in brown truffle. Brown species has almost double content of methionin and lysine than the white truffle. Arginin was the most predominating non essential amino acid in both species followed by glutamic acid. Fatty acids determination by GLC analysis showed that the major fatty acids appeared in white and brown truffle were linoleic (44.0 and 28.2%) and Oleic (37.49 and 62.85%) as relative percentages of total fatty acids. The GLC analysis ofunsaponifiable matter indicated that [3-sitosterol was the major sterol in white truffle (7.70%), while the brown truffle was rich in stigmasterol (42.57%). The study include phytochemical screening which revealed the presence of numerous compounds i.e saponins, alkaloids and/or nitrogen bases, sterols and/or triterpenes and carbohydrates and/or glycosides. To evaluate the biological value of white •and brown truffle an experiment was carried out on 42 rats. The results indicated that addition of white truffle with 10.15 and 20% , to the diet decreased daily gain in body weight to 0.796, 1.256 and 1.409 g/day respectively. Also addition of , brown truffle with 10,15 and 20% to the diet decreased daily gain in body weight to 0.913, 1.358 and 1.467 g/day respectively. Addition of both white and brown truffle to the diet decreased the food intake relative to control which led to slight decreased in food efficiency ratio, protein efficiency ratio and biological value compared with control. Liver weight/body weight ratio was determined in normal and examined rats. The lipid pattern (total lipids, total cholesterol and triglycerides) were determined in serum and liver of rats fed on white and brown truffle compared with casien as source of protein. The effect of truffle diets on LDL, HDL and the ratio of LDL/HDL (risk ratio) were determined. The effects of white and brown truffles on transaminase enzymes, (GOT and GPT), total protein, albumin and globulin in serum were studied. No deleterious effect on liver was detected. The urea• and creatinine were also determined in serum, no toxic effect of both truffle species were detected in kidney. Blood glucose level revealed slight changes in rats fed on truffle diets. Organoleptic evaluation indicated that, the total score of white truffle (80.5%) was higher than the brown truffle