نشریه پژوهش های علوم و صنایع غذایی ایران
سال دوم شماره 1 (پیاپی 3، نیمه اول سال 1385)

Gelatin is a protein hydrocolloid. Because of its unique characteristics such as gel forming, thickening, stabilizing, emulsifiing, foam and film forming, is widely used in food industries. In this research, in order to optimize the factors which affect enzymatic extraction method of gelatin, the effects of three variables, enzyme concentrations(2-10 ppm), time(8-16 hours) and temperature(60-80 ˚C) on the yield of extraction, gel strength, viscosity and absorption in 420 nm were investigated. The rotatable central composite experimental design was used, and the data were analyzed by using of response surface regression(RSREG).Correlation coefficients of fitted regression models of yield, gel strength, viscosity and absorption for enzyme extraction method were determined as 0.953, 0.998, 0.995 and 0.935, respectively.Analysis of variance for the overall effects of process variables in enzymatic extraction method on regression models showed that the enzyme concentration, the time of enzyme treatments and temperature had significant effects on gel strength and viscosity regression models, however the effect of temperature on both yield and absorption regression models was not significant(p > 0.05).The optimum conditions obtained from response surface regression models in enzymatic extraction method for yield, gel strength, viscosity and absorption which were verified experimentalls were (6.1 ppm, 15.6 hours, 70 ˚C), (9.1 ppm, 11.9 hours, 70.3 ˚C), (7.86 ppm, 14.9 hours, 77.5 ˚C) and (2.8 ppm, 10 hours, 60 ˚C), respectively.

In recent years several types of protein rich products derived from sesame seeds or sesame meal such as sesame milk are found in the market and have been attracted consumers both in developed and undeveloped countries mainly due to bearing health benefits. Since Iranian consumers have not yet been familiar with such healthy milk analog products, the objective of this study was to introduce the best formulation of sesame milk made from dehulled sesame seeds as well as sesame meal according to Iranian preferences. In order to make a beverage which is almost equal to composition of milk, two main factors were chosen as variable namely pH(6.5, 7.5, 8.5), and time of mixing and extraction (15 to 30 min), the ratio of sesame to water was fixed at 1:6 based on literature and our previous work. The optimum combination of those factors was then determined in a complete randomized design method with a factorial experiment. The selected sesame milk trials from both sesame seeds and sesame meal were then formulated as follow: sugar (0, 5, 6, and 7 %) and vanillin (0, 40, 60, 80 ppm) and all samples were organoleptically judged on the basis of overall acceptability. The collected data were then statistically analyzed using a nine point hedonic method. The results shown that the best sesame milk formulation is the one obtained as follow: the ratio of seed to water (1:6), natural pH (6.5), 15 min mixing time, 6% sugar and 40ppm vanillin.

In this study Salix aegyptica hydrolat based carbonated drinks were formulated. Differents ratio of Salix aegyptica hydrolat (egyption willow water) mixed with carbonated water, citric acid and sugar to adjust the final drink to 10-12 Brix and desirable acidity. Sensory properties of the products were evaluated at a ranking test by a trained panelists for choosing the best formulation. Evaluation of the product shelf life, samples were stored at different conditions during 6 months and their physicochemical and microbial properties were determined bimonthly. The product factors were evaluated in this study included: acidity, pH, total soluble solids (TSS), turbidity, fungal growth and total count of aerobic and mesophilic microorganisms. The results showed that pH, acidity and TSS had no considerable change, but turbidity increased during storage. Turbidity of samples that stored in presence of light and ambient temperature were increased considerably. Microbiological evaluations showed that total count of aerobic and mesophilic microorganisms was higher in samples that stored at ambient temperature and transparent bottles.On the basis of the results obtained from sensory evaluations at the end of storage time, it was indicated that all different stored trails were as good as the fresh sample.

Samples of crushed and cooked canola seeds (Okapy Double Zero) were extracted using supercritical carbon dioxide (SCCO2) at 34 MPa and 40ºC and a commercial organic solvent (AW406). The oil solubility in SCCO2 was determined and extracted oils were examined with respect to their chlorophyll contents, nonsaponifiable matters, fatty acid composition and iodine value. The yield of SCCO2 extraction was significantly (P

In this study, Geometrical, Gravimetrical and Frictional properties of four common varieties of Iranian canola seeds (namely: SLM, Hyola, Okapi, Orient), containing the mean moisture value of 6.5% (w.b.) were investigated. Geometrical and Gravimetrical properties included length, diameter, geometric mean diameter, sphericity, thousand seed mass, volume, true density, bulk density and porosity. The results indicated that the length ranged from 1.925 to 2.153 mm and diameter from 1.54 to 1.93 mm. Maximum geometric mean diameter was 2 mm in Hyola and minimum was 1.669 in SLM and maximum sphericity was 0.93 in Hyola and minimum 0.85 in SLM. Thousand seed mass ranged from 3.06 to 4.07 g, volume from 2.34 to 3.25 mm3 in Orient and Hyola varieties, true density from 1156 to 1302 kg/m3 in Okapi and Orient, bulk density from 710.92 to 738.79 kg/m3 in Hyola and SLM and porosity ranged from 37-44.02% in Okapi and Hyola. Also, in this research, Frictional properties of canola seeds including filling and emptying angle of repose, static coefficient of friction on five surfaces (galvanized iron, glass, fiberglass, rubber and plywood) were measured. Filling and emptying angle of repose ranged from 27.88o to 28.54o and 25.48o to 27.60o, respectively. In all four varieties, the highest static coefficient of friction was obtained for rubber and the least for glass.

The aim of this research was optimization of refining of raw sugarcane juice using bentonite for production of natural liquid sugar or cane honey. Non-sugar substances of raw sugarcan juice contains: colorants, polysaccharides, gums, proteins, etc that affect on efficiency and quality of the final product and should remove from raw sugarcane juice. Gelatin is a protein which is used as an aid clarifier in food industries. In order to make favorite purification at bentonite refining, it is better that used gelatin of A type for obtaining purification and favorite density at bentonite sediments.In this study, the effects of conditions of raw sugarcane juice refining using of bentonite accompanied by gelatin (at 5 levels 0, 0.02, 0.04, 0.06 and 0.08 gr/l), time (at 6 levels 0, 30, 60, 90, 120 and 150 min) and temperature (at 6 levels 25, 40, 55, 70, 85 and 100C◦) investigated. processing with bentonite compared to control sample were studed with respect to brix, sucrose percent, purity, ash, turbidity and color until optimum quantities of requirement to gelatin, time and temperature of processing with bentonite for reach to desirable quantity were recognized. Experimental results indicated which 0.02 gr/l gelatin in 100C° for 60 min processing with bentonite are optimum conditions for purification of raw cane juice.