Using conductometric method, the changes in the acidity of L-ascorbic acid in the mixed solvent dimethylsulfoxide (DMSO) - water were monitored. The mixed solvent used was two-component system consisting of nonpolar and polar solvents. Dissociation constants of L- ascorbic acid was determined in pure water and in the mixed solvent DMSO - water with different molar ratios of two solvents: xDMSO = 0.500, 0.333, 0.250, 0.200, 0.166, corresponding respectively to DMSO - H2O, DMSO - 2H2O; DMSO - 3H2O, DMSO - 4H2O; DMSO - 5H2O. Concentrations of freshly prepared solution of ascorbic acid were in the range from 0.00002 to 0.05 moldm -3 . Molar conductivity resistance values were measured for a given concentration of freshly prepared solutions of L-ascorbic acid and 24 hours old solutions. Using Ostwald's dilution law values for the molar conductivity at infinite dilution () and dissociation constants (K), i.g. pK ( log K) were calculated. The results obtained for different concentrations of L- ascorbic acid in the mixed solvent DMSO - water indicate that during a time, pK values declined and acidity increased. Following pK values in the dependence on xDMSO for a freshly prepared solution of L-ascorbic acid. The curve with two inflection points was obtained corresponding to the system of mixed solvent DMSO and DMSO - 2H2O and DMSO - 3H2O. In 24 hours old solution of L-ascorbic acid, inflection points were not observed. The results indicate the possibility of different adducts in the mixed solvent or in old solutions as well as accumulation of degradation products over time.

Aim of this study was to evaluate the biotransformation of simple phenols after ingestion of edible fruits and mixed food. It was analyzed hippuric acid in urine as biomarker of conjugation in the liver cells of glycine with aromatic phenolic acids such benzoic and salicylic acid from ingested food. Measurement of hippuric acid in urine samples of 10 healthy individuals: 5 female and 5 male with a mean age 51,5 years were recruited to participate in this study. Urine samples were collected for 24 hours. The additional meals 300 g of fruits: blueberry, cherry, raspberry, melon, blackberry and mixed food were given immediately before the 24 hr urine sampling. Otherwise, the meals given during 24 hr was a usually food. Biotransformation of phenols in edible fruits, that are together with liver glycins precursors of hippuric acid biosynthesis, was evaluated by direct spectrophotometric measurement of excreted hippuric acid in urine at 410 nm. It was established that the highest quantity of hippuric acid was after ingestion of 300 g of bilberry fruits (p< 0,003), and same quantity of cherries (p< 0,003). Concentration of excreted hippuric acid was twice higher after ingestion of these fruits in comparison with hippuric acid concentrations in urine after ingestion of common - mixed food. Quantity of biosynthesised hippuric acid was in direct correlation with the concentrations of its precursors, primarily phenol acids and other simple aromatic acids ingested with food.

Content of total phenols and total anthocyanins was estimated in edible fruits from Bosnia by photometric methods. Cyanidin-3-galactoside chloride was used as a standard for determination of total anthocyanins, and galic acid served as a standard for determination of total phenols. Total content of phenols was 12.7 mg/g in elderberry fruits, 10.4 mg/g in bilberry, 9.8 mg/g in blackberry, 8.8 mg/g in wild cherry, 6.1 mg/g in cultivated blackberry, 3.5 mg/g in cultivated strawberry, 2.4 mg/g in average in sour cherry fruits from different locations and the lowest quantity of total phenols was in edible parts of melon, only 0.2 mg/g. Total content of anthocyanins was 6.8 mg/g in wild cherry, 6.7 mg/g in elderberry fruits and 4.5 mg/g in bilberry. Wild bilberry fruits from different locations had in average 3.5 mg/g, cherries from different locations 1.3 mg/g, cultivated blackberries 1.0 mg/g, cultivated strawberries 0.8 mg/g while melon fruit had no anthocyanins at all. Acidity was measured in macerate of edible fruits by direct insertion of electrode. pH values in the macerates were as follows: 3.03 in bilberry, 3.45 in blackberries, 3.59 in sour cherries, 3.92 in wild cherries, 4.44 in elderberries and 6.19 in melon.

Neutral red is a dye the azine structure which has been used as an acido-base indicator and a dye in histochemistry. In 1960 Goldhaber introduced Neutral red into the medium of resorbing bone cultures to localize the osteoclast in the living cultures. Using time-lapse microcinematography in order to follow the osteoclasts, he reported excellent contrast could be obtained with Neutral red due to the avidity of osteoclasts for this dye. Unfortunately, however, the photodynamic effect resulting from subsequent exposure of these cultures to light precluded this approach, and again in 1963. it was observed that the death of the osteoclasts was probably due to a photodynamic effect related to the dye in the cell, the presence of oxygen and the frequent exposure of light by our time-lapse photography. VIS and UV irradiation induced photolysis of Neutral red, and from Neutral red cation produced with photons a Neutral red radical. This Neutral red radical can be inhibited with action of an antioxidant, such as melatonin, glutathione, ascorbic acid, E vitamin, etc. We developed an assay with Neutral red photolysis which utilizes a VIS and UV irradiation technique for quantification the inhibition of photolysis with action of an antioxidant. In this method Neutral red acts double, as a free radical generator and as a photosensitizer.

Abstract Content of total phenols and total anthocyanins was estimated in edible fruits from Bosnia by photometric methods. Cyanidin--galactoside chloride was used as a standard for deter-mination of total anthocyanins, and galic acid served as a standard for determination of total phenols. Total content of phenols was . mg/g in elderberry fruits, . mg/g in bilberry, . mg/g in blackberry, . mg/g in wild cherry, . mg/g in cultivated blackberry, . mg/g in cultivated strawberry, . mg/g in average in sour cherry fruits from diff erent locations and the lowest quantity of total phenols was in edible parts of melon, only . mg/g. Total content of anthocyanins was . mg/g in wild cherry, . mg/g in elderberry fruits and . mg/g in bilberry. Wild bilberry fruits from diff erent locations had in average . mg/g, cherries from diff erent locations . mg/g, cultivated blackberries . mg/g, cultivated strawberries . mg/g while melon fruit had no anthocyanins at all. Acidity was measured in macerate of edible fruits by direct insertion of electrode. pH values in the macerates were as follows: . in bilberry, . in blackberries, . in sour cherries, . in wild cherries, . in elderberries and . in melon. KEY WORDS: Total phenols, total anthocyanins, fruits, antioxidants.

This is a review of studies dealing with the physiological role of chromium in the body and its harmful effects to human health. Trivalent chromium is discussed as a trace element essential to normal metabolism of hydrocarbons and to functioning of some enzymes. Toxic and carcinogenic effects of chromium due to occupational exposure, environmental pollution, food contamination and accidental poisoning are described.