Journal of food science and technology
Year:2004 | Volume:1 | Issue:3|Papers Count:9

Traditional Iranian breads, especially Lavash, play an important role in our daily food intake. However regarding the high wastage of bread, which is estimated as around 30%, necessitates conducting a research project on this matter.Among the different quality factors, dough fermentation can also affect the quality of bread.In this research, the effects of some major factors on the Lavash dough fermentation, bread quality and the rate of staling were studied.The treatments investigated in this study are as follows:1- Kind of leavening agent active dried yeast, fresh yeast and a mixture of soda and active dried yeast.2- Quantity of leavening agent2-1- Active dried yeast at the levels of 0.5, 1 and 2% on the basis of flour weight.2-2- Fresh yeast at the levels of 1.5,3 and 6% on basis of flour weight.2-3- Soda at the levels of 0.2,0.5 and 0.8% and also 0.5% active dried yeast on the basis of flour weight.3- Fermentation time: regarding the active dried or fresh yeast, this time varied from 1 and half to 3 and half hours and for the mixture of soda and yeast, it was about 20 minutes.The quality of baked Lavash bread was evaluated by a trained pannel of referees and the results showed that the bread contained 0.2 percent soda and 0.5 percent active dried yeast on flour weight basis with a fermentation time of 1 and half hours enjoyed the best quality and the lowest staling rate.

In the present study, fractional crystallization of beef tallow was carried out through a dry process and in hexane as solvent using different temperatures. In the dry process, the melting point of tallow was changed from 45.6°C to 32.3°C for olein produced in the second step of fractionation. In the solvent medium of 65% hexane, the change in melting point was from 46.5°C to 28.8°C after only one step of fractionation. Solvent fractionation, however, especially at high ratios of solvent to fat, is costly and except when the production of high value -added products is in mind, this process is not economically justified. Thus, considering the kind of oil which is mostly demanded in country, using dry fractionation for the production of certain specific fractions of tallow seems to be appropriate.

The interesterified tea seed oil (Lahijan variety, the ratio of 70:30 of liquid and hydrogenated tea seed oil, at 120°C for 30 min and %1 NaOH as catalyst) as a hardstock of margarine oil (40%) with liquid tea seed and sunflower oils (at the ratios of 100:0,80:20,60:40,40:60,20:80 and 0:100) as a softstock (60%) were applied for the production of breakfast margarine, and their properties were compared with commercial ones. Statistical comparison showed that the samples, E and D (the ratios of 80:20 and 60:40 liquid tea seed and sunflower oils, respectively) have the lowest significant differences with the commercial breakfast margarine in terms of physico-chemical (melting point, iodine value and SFC) and organoleptical characteristics, respectively. Generally, based on the melting point and SFC, these margarines (E and D) are classified as soft margarine. In addition, the trans fatty acid content of E, D and commercial margarines were 1.8, 1.8 and 2.2%, respectively.

Rice breakage is a major concern in Iran. The price drop due to breakage is about 30 to 50 percent. Thus, research on the influence of effective parameters on kernel breakage is essential. There fore a research was conducted in the Rice Research Institute of Iran to study the effects of feed rate and pressure of the Jet Pearler outlet on kernel breakage. The feed rate levels were 150, 200, 250, 300 kg/h and the outlet pressure levels included 125, 150, 175, 200 g/cm2. Rice varieties studied were Khazar (long grain), Binam (medium grain) and Gharib (short grain). The results indicated that with increasing feed rate, at the first, the kernel breakage decreased and then significantly increased. Also with increasing outlet pressure, the rice breakage increased. Breakage of khazar variety was more than Binam and Gharib Varieties, respectively. The results showed that the appropriate combination of feed rate and outlet pressure for Khazar, Binam and Gharib varieties were (300kg/h, 125g/cm2),(250kg/h, 125g/cm2)and (150 kg/h, 150 g/cm2) respectively. The best and simplest regression model for predicting the breakage percent of rice was found from the independent varieties.

Enzymatic reactions (amylolytic and proteolytic) in wheat flour which are the results of improper pre- and post harvest practices, cause problems in bread production and its qualitative parameters.This research was carried out to determine the proper falling number (FN) for the two Iranian traditional flat breads (Barbari and Lavash).The falling number of the germinated wheat flour (GWF), Barbari and Lavash bread flours, was determined. In order to adjust the falling numbers, different amounts of Barbari and Lavash flours Were mixed with the different percents of GWF to reach to FNs of (150, 200,250, 300 and 350)± 10 seconds.The mixtures were tested in Farinograph and Extensograph. Maltose value was also calculated and sensory analysis was done on the baked breads.Results of Farinograph and Extensograph tests indicated that enzymic hydrolysis of glutten which is related to the increase of the percent of GWF, would weaken the strength of glutten network and the dough. Maltose figure test also showed that there is a negative correlation between maltose value and FN. The results of sensory analysis showed that acceptance of breads would be affected by FNs of the flours; therefore the proper FNs for Lavash and Barbari flours were determined to be 350-420 and 250-350 seconds, respectively.Since the reduction of bread wastage is very important from economic point of view in our country, much attention should be paid to the pre and post harvest conditions and also due to the close relation of these practices to the falling number, it should be noticed in the baking process of both breads.

Saffron consists of dried stigmas of Crocus Sativus L. Three times of extraction by ethanol/deionized water (80/20) have been used for sample preparation and immediately injected to HPLC for saffranal (main aroma component of saffron) determinations. The method was modifed by omitting solvent evaporation and solid phase extraction, which was fast and reproducible(146± 9mg/kg) with the minimum detectability was 0.013 ppm and the average recovery 101.14%. The method was linear up to 10ppm. Saffron samples were from two famous producer cities in khorasan, Ghaen and Ghonabad. Four different drying methods (Vaccum Oven, Macrowave, Solar and Traditional) were used for drying the stigmatas. Each of the two analysis methods (HPLC & Spectrophotometric) was used for determination of saffranal in the dried stigmas. Comparison between the two analytical methods specially by focusing on the traditional samples revealed that spectrophotometric method should be replaced by HPLC or modified to receive better selectivity.

Old-age is a natural stage of a human being life which is much more different from the other stages. Whereof our society is often described as a young society there is little tendency to produce food for the old-people and considering that the population of old-people in Iran will increase to 23% in 1429 (solar year), it is obvious that the old-people consumers have the potential to turn into an important power in the market and change the negative attitudes chosen by the use of. Recently, for the first time, a special food has been designed and produced for old-people. This food is specially made for the elderly consumers from either the nutritional or the sensory features point of view. A mixture of low-fat dried-milk powder, wheat gem powder, data-juice and liquid corn oil (as the essential basic materials), and lecithin, natural banana powder Aspartam, Asesulfam k and maltodextrin (as the essential secondary materials) has been used to establish the desired flavor and texture. The process of production includes knowing, testing and buying the raw material, determining the percent of each material in the formula, measuring and mixing the raw material and drying with single drum dryer at industrial measurement, performing chemical analysis sensory assessing by the 12 assessors chosen by the panel group using linear measurement method and 40 elderly as target group hedonic method, statistical analysis of the sealts of narishing assessment and determining the last price. 100 grams of the produced food had 458/41 Kcal energy, 16/12% protein, 17/81% fat, 58/41% carbohydrate and 710 mg calcium and the last price of a package of this product (250 g) estimated to be 12500 Rials for the consumers. Finally we recognized that this food is acceptable for the elderly and can be a good source for part of their daily needs from many aspects such as energy protein fat carbohydrate and lots of vitamins and minerals.

Regarding the increasing consumption of chicken meat in Iran and the importance of hygienic aspects and quality assurance of chicken meat, the effects of trisodium phosphate on organoleptic characteristics of raw and fried chicken carcasses were investigated at the Iranian National Nutrition & Food Technology Research Institute in 2003.Sixty chicken carcasses (30 raw and 30 fried chickens) were evaluated by an experimental method. Ten chickens were dipped in 80 litters of chilled tap water (control) and 8% trisodium phosphate for 1 and 3 minutes. Thirty in-house panelists evaluated the treated whole raw chickens as well as the fried breasts and thighs.Treatment of raw chickens with 8% trisodium phosphate for 1 and 3 min did not affect the external color, overall acceptability and consumer purchase intent after the first and seventh days of storage.There were no significant differences in the external color, texture, flavor and moistness characteristics of the fried chickens (control) and the fried treated chickens with trisodium phosphate (test).Evaluation of the fried chickens revealed that moistness and flavor of the treated chickens with 8%.TSP for 3 min were higher compared to controls.There were no significant differences between the mean score of the test and control chickens in terms of Sensory quality of the raw chickens was not adversely affected by 8% trisodium phosphate for 3 min.