سال:1393 | دوره: | شماره: |تعداد مقالات:10

Salt curing (Kencing) is a method used for preserving food products, including fish, that is believed to influence the quality and chemical composition of the finial product. The present study is focused on the alteration of protein quality and amino acid profile of Scomberoides commersonnianus after stacking during 190 days of shelf life in ambient temperature. A12 assorted of specimens were collected from Gheshm Island, Hormozgan Provience, North-West of the Persian Gulf and were transferred to the laboratory for processing. The samples were divided into six batches and cured with common salt. The samples were used for quality control at six intervals, including day 0(before salt curing),15, 30, 90, 150 and 190 (after salt curing); and TVN, crude protein, ash, moisture and salt contents were measured. Moreover, the amino acid profiles of the product were also being evaluated at three intervals including day 0(before saltcuring), 90 and 190 (after saltcuring). The increment of crude protein, ash, salt, moisture and TVN contents were significant after 190 days of preservation (p<0.05).18 amino acids were distinguished in the fresh sample, including 8 and 10 essential and non essential amino acids, respectively. The total amino acid content decreased significantly after 190 days curing with salt (p<0.05). The results indicated that the salt curing of Scomberoides commersonnianus could be a helpful method in preserving the product for just 90 days after processing, and the quality of the product was decreased significantly after 90 days of preservation.

Iodine is an essential trace element in the human diet. The following work presents the latest information concerned with iodine determination in raw milk, in Iran. Iodine content of milk was determined by Sandell-Kolthoff method where the samples were taken from Holstein dairy cows, in Shahrkord, the central part of Iran. Thirty six samples were taken from transportation tanks in semi industrial farms (group 1) and 66 samples were taken from 66 cows in an industrial dairy farm (group 2). The mean iodine content of group 1 was 148.02±85.36  µg/L, where the minimum and maximum iodine concentrations were 20 µg/L and 289 µg/L, respectively. In group 2 the mean iodine content was 314.27±32.72 µg/L, where the minimum and maximum concentration were 227 µg/L and 378 µg/L, respectively. Milk iodine concentration in group 1 is significantly different from the amounts obtained in group 2 (P£0.05). Mean iodine value of all the samples was 225.59±9792 µg/L. Mean iodine concentration did not changed in rainy and dry seasons. This study indicated that cow's milk might be an important source to provide the body with the required iodine.

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Considering the possibility of the harmful side effects of synthetic antioxidants, it is necessary to substitute the synthetic antioxidants by the natural ones, the antioxidants that have been consumed by man for years. The mango seeds were washed and air dried and the kernels were removed manually from the seeds. Mango seed kernel oil was extracted by hexane using soxhlet extraction apparatus. The results indicated that according to mango varieties, the seed represented 6 to 7% of the whole fruit weight and this consists of 10.2% oil that contains approximately 55% and 45% saturated and unsaturated fatty acids, respectively. The induction periods of the mango seed kernel oil samples were 58.8 - 85.2 hours. Subsequently the antioxidant activity was investigated after adding 1, 5 and 10 percent crude mango seed kernel oil to tallow as a substrate free of natural antioxidants and determining the induction period and peroxide values at the predetermined temperatures. The addition of 1, 5 and 10% of mango seed kernel oil to tallow caused significant increases in the induction periods of the treated oil. These results provide useful information on utilization of mango seed kernel oil as a natural antioxidant concentrate.

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Determination of the amount of sugar in sugar beet is usually accomplished by polarimetric method in sugar industry. This method is not accurate due to impurities such as sodium, potassium and amino-nitrogen that are present and might cause some errors in the evaluation of the technical quality of sugar beet. In this research, 7309 samples of sugar beet from two semi-arid county, Isfahan and Chahar-Mahaal, were analyzed by Betalyzer for two consecutive years. Comparison between the experimental results and the estimated one based on the Reinefeld model showed that this model couldn’t successfully estimate the amount of sugar loss in molasses for semi-arid areas. Therefore a new model based on the obtained results has been developed and was suggested for this type of climatic condition, especially for samples with 13.5-17.5% sugar content.

Fried products derived from potato, particularly potato crisp have been widely included in food basket of the households in the recent years in Iran. Potato crisp, among other products, is of great importance and is considered as competitive products. This product is in the list of the food products with high acrylamide content. Therefore, due to the nutritional importance of this product and the fact that previous works have not been carried out regarding the quantity of acrylamide present in the potato crisp sold in Iranian market, the evaluation of the presence of this chemical compound in such product is vital and quite necessary. Seven typical potato crisps sold in the market (salty and in one shape) including five samples of the Iranian potato crisps (T1, T2, T3, T4, T5) and two samples of the foreign potato crisps (T6, T7) were randomly chosen and tested. Quantification of acrylamide was carried out by modern unit of LC-MS-MS. According to the results the highest quantity of acrylamide was found in the sample T1 (1456/67 mg/Kg) and the lowest quantity was in T7 (220 mg/Kg). Statistical analysis also showed that there was a significant difference between the potato crisps produced in Iran and abroad (p=0.0013). The results revealed that the quantity of acrylamide in the potato crisps produced in the foreign countries is less than those in the potato crisps produced in Iran.

Two probiotic bacteria (Lb. acidophilus and B. lactis) were immobilized on the alginate coat of strawberry pieces and were added to the prepared sweet non fat dietary stirred yogurt. Physico-chemical parameters namely pH value, titratable acidity and synersis along with the viability of probiotic bacteria of the samples were evaluated over the 8 days of storage at 5oC at 2 day intervals. A significant decrease in pH value occurred after 6 and 8 days and the titratable acidity significantly increased after 8 days. Synersis did not show significant changes probably due to the presence of applied hygroscopic nature of some ingredients in the samples. Some free probiotic cells were identified in yogurt matrix of the samples due to the migration phenomenon. The decrease trend of embedded cells happened slower than the free ones. This might be due to the protective effects of alginate coat on the survival of probiotic bacteria surrounded by yogurt.

In this study nine new varieties of sunflower seeds were obtained and subjected to oil extraction using soxhlet apparatus. The extracted oil was analyzed for fatty acid composition and phosphorus content to measure the phospholipid concentration. The results indicated that Armavirski variety had the highest oil content. The fatty acid composition of the extracted oils indicated that Armavirski followed by Alstar varieties had the highest concentrations of oleic acid and lower concentrations of linoleic acid as compared to other varieties. Therefore the two varieties mentioned earlier might be considered as suitable substrates for frying and cooking practices.

Fats and oils are made of triglycerides. The fatty acids are the main constituents of triglycerides. There are minor components present in the oils and fats that are of great importance in human health, namely tocopherols and phenolic compounds that exhibit antioxidant activities. The concentrations of these compounds vary during ripening and maturation of olives. The object of the present study is to find out the time when the maximum concentrations of these compounds are present in the fruit, therefore the harvesting time can be determined. In the present work, two varieties of olives, Koroneiky and Arbeqina were selected and obtained during the months of Mordad, Shahrivar, Mehr and Aban in Fars province. The phenolic comopounds were determined according to the official method of analysis. The results indicated that phenolic compounds were increased during ripening periods and then started to decline during maturation. It was concluded that for Arbeqina variety the end of Aban and for Koroneiky variety beginning of Azar were selected as the best harvesting point in respect of phenolic compounds concentrations.