Showing 7 results for Keramat
L. Mosharraf Boroujeni, J. Keramat,
Volume 4, Issue 4 (winter 2001)
Abstract
Recent restrictions on the use of artificial food colours have prompted extensive research on natural pigments as suitable substitutes. The red beet Beta vulgaris L. has been found as a suitable source of natural red pigment since beet powder and concentrates can conveniently be used in food products. In this research, hot and cold extractions of randomly selected red beets were used after preparation and blanching. The extracts were filtered and passed through a column of Amberlite XAD-7 resins after adjusting the pH to 2.5. The adsorbed colour compounds were extracted from the resins by eluting the column with acidified alcohol. The solvent was removed by vacuum rotary evaporator and solid colour was obtained, using a freeze dryer.
Physicochemical properties of the solid colour were determined by measuring ash and sugar contents of the solid colour. Also, its purity and stability were investigated under different conditions.
The amount of ash and sugar were negligible. The highest stability was observed at a pH value of 5 under cold and dark storage conditions. The purity of the solid colour was determined by scanning in the range of visible wavelengths and preparative TLC. The result showed that purity of the colour as a hundred percent betacyanins. The yield of production was calculated as 2.7 g powder per kilogram of beet. The colour was used in producing ice cream and frozen sherbets, which showed to be a suitable replacement for artificial colour carmoisine. Also the production cost of the colour was as low as less than 0.1 percent of that of ice cream or frozen sherbets.
J. Keramat, M. Khorvash,
Volume 6, Issue 1 (spring 2002)
Abstract
Iran, as the biggest producer of dates, has 25 percent of the world date production. More than 400 varieties of dates have been identified in Iran. Dates have a high nutritional value they contain considerable amounts of sugar, vitamins and minerals. For instance, 2830 kilocalories of energy are obtained from one kilogram of dates. Dates are economically suitable replacements for sugar in bee feeds. However, feeding bees with some varieties, which contain certain amounts of mannose and potassium, are harmful. This investigation was carried out in order to identify the most suitable variety of dates useful for bee feed and to determine its nutritional value as human food. In this study, the dominant varieties of date including Bam Mazafati, Behbahan Kabkab, Booshehr Kabkab, Jiroft Mazafati, Kangoroad, Khanizi, Khasi, Saameran, Shahani, Shahdadi and Zahedi, were collected and analysed. The amounts of moisture, fat, protein, ash, and minerals such as sodium, potassium, and calcium were determined. Also, sugar composition of the above varieties consisting of glucose, fructose and sucrose, was measured. Chemical methods (Lane-Eynon and Shaffer-Somogyi) and high performance liquid chromatography were used for sugar determination.
The results showed that, except for moisture and protein contents, there was no significant difference between fat and ash contents of the samples. Shahdadi and Zahedi had the highest and lowest moisture contents, respectively. Behbahan Kabkab and Shahdadi had the highest and lowest protein contents respectively. Jiroft Mazafati and Saameran had significantly the lowest amounts of potassium and mannose, respectively, while Kangoroad had significantly the highest amount of sucrose, which is use full for bees. Therefore, these three varieties were found to be suitable replacements for sugar in bee feeds, but considering their price, Saameran is recommended as the best feed for bees. On the other hand, with respect to the minerals and sugar contents, Behbahan Kabkab was found as the most nutritious date for human food.
J. Keramat, G. H. Kabir, B. Ghanaati,
Volume 6, Issue 4 (winter 2003)
Abstract
Citrus juice and concentrate are among the major industrial products in Iran. Large quantities of citrus peels with considerable amounts of pectin are also produced. Pectin could be extracted from the peels to be used as a gelling agent in some food products. Unfortunately, all pectin used in the food industry is imported. This study was carried out to find the best conditions of pectin extraction from orange peels. Samples of orange peels were collected from a concentrated orange juice factory. Pectin was extracted by sulfuric, nitric and hydrochloric acids. Certain qualitative and quantitative tests, such as yield of extraction and cost of extraction were determined. Also, food safety aspects as a result of using the above acids were considered. Hydrochloric acid was found to be the most suitable acid. In the second part of the research, the effects of temperature (85 and 90˚C), time (40, 50 and 60 minutes) and pH (1.6, 1.8 and 2.0) on the yield of extraction, purity, gelling ability, percentage of methoxylation and degree of esterification of the extracted pectins were measured. Statistical analysis of the results showed that the best conditions for the extraction of pectin include a pH level of 1.6, a temperature of 90˚C and a period of 50 minutes.
Sh. Dokhani, J. Keramat, S. Roofigari Haghighat,
Volume 7, Issue 2 (summer 2003)
Abstract
Three potato cultivars (Solanum tuberosum L.), spring Marfona, autumn Cosima and Marfona, obtained from Isfahan Province, were stored under different conditions: 4oC, darkness 12oC, fluorescent light room temperature, darkness and room temperature, daylight. Relative humidity of the above stores was 85 to 90%. Analyses were carried out to determine total glycoalkaloids, α-solanine, specific gravity and total solids, during 30 days for the spring cultivar and 90 days for the autumn cultivars in stored tubers. α -Solanine content of each cultivar was determined by HPLC, in mg per 100 g dry weight, at the beginning, the midinterval, and the end of storage periods. Also, amounts of α-solanine in autumn cultivars, which showed the highest levels after storage for sixty days, were determined before and after heat processing for frying and cooking. Data were analyzed statistically by completely randomized design with Duncan’s multiple range test. The results revealed that the amount of α-solanine of the spring cultivar considerably increased under 12oC and flourescent light as compared with the other storage conditions. The amounts of α-solanine considerably increased during the storage of autumn cultivars which were stored at 12oC under flourescent light compared with those stored at room temperature and daylight, room temperature and darkness, and at 4oC and darkness, respectively. The amount of α-solanine decreased due to spring conditions during the storage period for cultivars stored at room temperature and darkness. In spite of the decreasing effect of peeling, before frying and after cooking, frying and cooking processes had no effect on the amount of α-solanine in the samples. Therefore, according to the above results, the most appropriate storage conditions to prevent increasing effect of α-solanine in potato tubers was 4oC in darkness.
J. Keramat, Kh. Talebi, L. Mosaffa,
Volume 9, Issue 1 (spring 2005)
Abstract
Vegetable crops are exposed to repeated spraying against the pests and diseases during the growing sessions. Crops such as greenhouse cucumber are usually harvested a short time after spraying, bearing a high level of pesticides with them. This fact justifies a research on this problem. This research was carried out to determine the effects of metalaxyl (a fungicide commonly used in greenhouse) residue in cucumbers grown under traditional and modern greenhouse conditions. Cucumber plants were sprayed with two different doses: 1/1 000 and 2/1000 metalaxyl in modern and traditional greenhouses. Samples were collected 1, 2, 4, 7, 10, 14, 21 and 28 days after spraying with metalaxyl. The fungicide residue was extracted, cleaned up by TLC and the final solution was analyzed by HPLC. Data were analyzed statistically by t-test (paired observations) and Duncans multiple range test.
The results revealed that the amount of metalaxyl residues increased in the first four days following spraying. This amount of the residue was 10 times higher than MRL (0.5 mg/kg), while a lower level of MRL (0.5 mg/kg) was detected 21 days after the application. Results also showed that a lower dose of application left a higher residual level than the higher one. On the other hand, no significant differences (p<0.05) were found between the amounts of residues in peeled and unpeeled cucumbers. Thus, fruit peeling does not reduce the fungicide residue in cucumber. Also, there were no significant differences (p<0.05) between the results obtained from modern and traditional greenhouses. Therefore, cucumber must either be harvested before or at least 14 days after spraying with metalaxyl.
E. Khanipour, J. Keramat, R. Shokrani,
Volume 11, Issue 40 (summer 2007)
Abstract
Producing food colors from natural sources, such as tomatoes, which could be used instead of synthetic colors, is important in relation to health and safety aspects of the consumers. In this research, solvent extracting was carried out by using three non-polar solvents, including petrolium ether (bp=55°C), n-hexane (bp=60°C) and a mixture of n-hexane: ethanol: aceton (1:1:2, bp=50°C). Also, two different temperatures (room temperature and boiling point of the solvent) and three different periods of time (2,4 and 6 hours) of extraction were tried. Using mixture of the solvents (at boiling point) for six hours showed to be the optimum conditions for extraction and there were significant differences between this treatment and other conditions for extractions. In addition to the above results, the same volumes of the solvent and samples were found to be the best ratio in comparison with the other volumes ratios. It was significant at P .05.. The yield of color extraction from tomatoes and tomato powder was 0.14 and 0.24% (w/w), respectively. Also, the purity of the extracted color was 82.65% lycopen. The extracted color showed a good stability in sunflower oil for three months at 4°C.
S. H. Hosseiniparvar, J. Keramat, M. Kadivar,
Volume 11, Issue 40 (summer 2007)
Abstract
This research was carried out to determine the optimum conditions for acidic extraction of gelatine from cattle bones. The effects of different treatments such as pH (1.8 to 2.6), temperature (60 to 80°C) and time (40 to 120minutes) on yield of extraction, gel strength, viscosity and absorption (420 nm) was measured. Coefficients of central composite rotatable design (CCRD) and regression surface response.... (RSREG) were used. The coefficients for yield, gel strength, viscosity and absorption were 0.990, 0.991, 0.998, 0.928, respectively. According to variance analysis of the data, there were significant differences between the effects of three variables (pH, temperature and time) on yield of extraction and viscosity, but no significant difference was observed between the effects of temperature and pH on gel strength and absorption, respectively. Comparisons of the averages of functional characteristics of acidic and commercial gelatin showed that viscosity and strength of acidic gelatin were higher than those of commercial one. The optimum conditions were found to be: pH=1.88, temp. 80°C and 118 min., to reach the highest yield and pH=1.88, temp. 60°C and 48 min. to get maximum strength, and pH=2.56, temp. 69°C and 118 min. to obtain the maximum viscosity and finally, pH=2.6, temp. 62°C and 48 min. for minimum absorption. Also, the results revealed that there were significant differences between trace elements content (Fe, Ca and Pb) of commercial and acidic gelatins. Although, acidic gelatin contained higher amount of the elements, but these amounts were still less than maximum values which are allowed to exist in gelatin. Amino acid compositions of both gelatins were almost identical.
