نشریه نوآوری در علوم و فناوری غذایی
پیاپی 11 (بهار 1391)

Gelatin is a protein substance that is of special importance in the food industry, pharmaceutical, medical and industrial, especially in the food industry is used for making Jelly, ice cream; it is easily absorbed in the body and even to digest other foods through the formation of emulsion. The purpose of this study was to use cheap fishery wastes for production of fish gelatin. This project was conducted at two stages: the first stage conditions of pH (in alkaline and acidic conditions) and type of material (three raw material: shoes, fish, sharks and fish fillet) on some of the most important qualitative and quantitative properties of gelatin (yield, purity, color) were studied. Effects of temperature and pH indifferent levels on the yield of gelatin were evaluated. Results showed the best quality fish gelatin can be produced at 70º C and pH 6.5.

Concerning the accelerating demand trend for the production and consumption the fried potato products, especially potato chips that nowadays have gained a special attraction in Household Shopping, the qualitative evaluation of this product gets of paramount importance. Therefore the purpose of this study was to estimate the oil derivation and acidity، peroxide and rancimat test, salt, protein of available chips on Iranian markets. In this experiment, seven samples of potato chips (salty) including 5 Iranian chips samples (T1 T2, T3, T4, T5) and 2 foreign brand samples (T6, T7), were evaluated through different kinds of qualitative methods. The experimental parameters that had been examined in this research include the measurement of the extracted oil percentage, peroxide value, acidity, and rancimat test, protein and salt. The findings showed that the extracted oil from seven potato chips samples were in the ranges 24/24 (T6) - 41/55 (T4). Also other qualitative parameters such as the acidity (at the oleic acid percent) 0/2 (T6) – 0/87 (T1), peroxide value (meq/Kg) 1/18 (T1) – 5/9 (T7) were determined. Indeed, the oxidative stability of extracted oils were determined for potato chips samples and among them the sample T4 (32/91) had the highest oxidative stability and other samples were T3 > T5 > T2 > T7 > T1 > T6 respectively. Also as to protein ratio, sample T4 (5/47gr) had the maximum and sample T3 (2/71gr) encompassed the minimum unit. Measuring the of salt showed that sample T7 reserved the most and sample T1 the least remedy of this combination.

Helicobacter pylori is one of the most widespread infections worldwide. However the origin and transmission of this bacterium has not been clearly identified. One of the suggested theories is transmission via raw milk from animals to human beings. This study was conducted to detect H. pylori from tap water, raw cow milk, traditional cheese and ice-cream. From June 2008 to June 2009, a total of 182 samples from tap water (n= 40), cow milk (n= 70), traditional cheese (n= 47) and ice-cream (n = 25), were purchased from randomly selected retail outlets in Shahrekord & Shiraz of Iran and were then evaluated for the presence of H. pylori by the culture method and polymerase chain reaction (PCR). A total only one H. pylori was isolated from 70 raw cow milk samples, whereas it was not isolated from tap water, traditional cheese and ice-cream samples. Out of the 182 samples examined, 16 (8.8%) resulted positive for the presence of ureC gene. In particular, 2 of the 40 tap water samples (5%), 7 of the 70 raw cow's milk samples (10%), 6 of the 47 traditional cheese (12.8%) and 1 of the 25 traditional ice-cream samples (4%) examined, resulted positive. The results deserve further investigations on the contamination sources of the water and milk samples and on the major impact that it may have on consumers.

In this research, Daikon mass transfer profile was investigated by ultrasound-osmotic non-thermal method. Daikon slices were soaked into osmotic solution at three concentration levels of manitol (5, 10 and 15 %) and constant concentration of sucrose (35 %) at 25℃. The results showed that water loss increased during the time when the level of osmotic concentration was increasing. Also, water loss values were 42.75 and 36.75 g/g dry solid for non-ultrasound-osmotic and ultrasound-osmotic sample at 5%manitol concentrations, respectively. The results indicated that the effect submerge time and ultrasound wave had a positive effect on F°s of daikon sample during mass transfer process (α=1%).

Foods are generally subjected to thermal treatments during processing operations, which affect the rheological properties of hydrocolloid solutions. In this study, cress seed gum and xanthan gum were prepared at 1% (w/w) and subjected to heating (60ºC-30min, 80ºC-23min, 100ºC-18min and 121ºC-15min) and freezing treatments (-18ºC-24h and -30ºC-15h). Then the rheological properties of hydrocolloid solutions were determined at 25ºC by a rotational viscometer (Bohlin Model). When the hydrocolloid samples were heated, an irreversible increase in viscosity of cress seed gum solutions was observed, whereas xanthan gum would not have the ability to stand against heat treatment. In freezing process, conversion of water to ice leads to an increment in molecular association and improved rheological characteristics of cress seed gum and xanthan gum.

In this study, physical properties of barley were determined in order to design processing equipment and transportation. Investigated physical properties included length, width, thickness, geometric mean diameter, spherecity, thousand kernel weight, bulk and kernel densities and porosity. These properties were investigated for 6 barley lines (EBYT-88-2, EBYT-88-4, EBYT-88-6, EBYT-88-14, EBYT-88-17 and EBYT-88-20) prepared from Gorgan agriculture of Iran and Natural Resources Researches Center. In these lines, EBYT-88-2 had the most length. The thickness, geometric mean diameter and thousand kernel weights, the largest content was related to EBYT-88-4 and equal to 3.59, 2.8, 4.75 and 38.053 cm, respectively. The lowest of sphericity was related to EBYT-88-2 and was not significantly difference with EBYT-88-17. Bulk and kernel densities and porosity of different lines had a significant difference of between lines and highest content of bulk and kernel densities related to EBYT-88-6 and EBYT-88-14, respectively. The highest and lowest of porosity was related to EBYT-88-2 and EBYT-88-14, respectively. Among the investigated chemical properties, the highest content of protein, fat and fiber was related to EBYT-88-4. EBYT-88-20 and EBYT-88-2 was allocated the highest content of carbohydrate and ash compared with other lines. Concerning the studied chemical properties, moisture had a insignificant difference only. Point view of aerodynamic properties, EBYT-88-6 had the highest of terminal velocity (4.117 m/s) and the lowest of drag coefficient (0.0125) among the used lines and this indicated an inverse relation between terminal velocity and drag coefficient.

Drying kinetic of quince (Cydonia oblonga) fruit slices with the thickness 3, 5 and 7mm were dried at three temperature 60, 70 and 80°C using convection hot air dryer studied. For evaluating drying kinetic of quince fruit slabs used from effective diffusivity coefficient (Deff) parameter. Deff changed in 2.77×10-8 – 8.12×10-8 m2/s that amount of Deff in various thickness had difference significant (P<0.01). For mathematical modeling used from among 10 different models with which these models were compared, the coefficient of determination (R2), Mean relative percent deviation (MRPD), Root mean squares error (RMSE) and reduced chi-square (χ2) parameters and finally the chosen model, with the best compatibility from drying process was midlli model.

In this research, the effect of various packaging materials)cellophane, nylon and metal can) and vacuum condition on quality attributes of pistachio nuts was studied. The pistachio nut samples were packed as 250g packages in different package type including cellophane, nylon and metal can under common condition and in nylon and metal can under vacuum condition. then the packages were stored for 6 month at 40 ˚C and ambient temperature. One package of each type was taken monthly and was analyzed for moisture content, peroxide and acid value. Finally, among these five types of packages, nylon especially vacuum nylon was known as the best packaging for pistachio nuts. Samples stored at 40˚C had a shorter shelf life. The analysis of fatty acids composition at the end of storage at ambient temperature showed that loss of linolenic and linoleic acids in cellophane packages was more than vacuum nylon.