Iranian Food Science and Technology Research Journal
Year:2013 | Volume:9 | Issue:2|Papers Count:12

Removing of ions from different water and waste water is one of the most important of nanofiltration potential for different aims, such as softening of potable water, remove of heavy metal ions and purification of waste water to reuse. In this study nanofiltration was used to remove of the most important ions (Na +, K+, Ca2+, Mg2+, SO2-4, Cl-) in sugar beet press water to reuse of this stream. Effect of operating parameter (temperature and pressure) and concentration on performance parameter of membrane filtration (flux, fouling and rejection of compounds) was investigated. The results shown that increasing of temperature result in increasing of flux and fouling and decreasing of ions rejections and increasing of Trans membrane pressure result in increasing of flux, fouling and ions rejections. Also, the results shown that increasing of brix result in increasing of fouling and decreasing of flux and ions rejections.

The objective of this study was to evaluate lactic flora identification in fresh (one-day) and ripened (90 day) Koozeh cheese samples as one of the raw milk cheeses. In first step, in order to isolate the different genera of Lactic acid bacteria (LAB), selective and differential (corresponding) media were used as follow: MRS for lactobacilli and pediococci, MRS+ vancomycin for leuconostocs, M 17 for lactococci and KAA for enterococci. Totally, 48 single, purified colonies were selected and identified using confirmatory, biochemical and phenotypic tests down to the genus level. Lactobacilli (33.33%), lactococci (12.5%), pediococci (2.08%), enterococci (47.91 %) and aerococci (4.16%) were determined as the most abundant genera. At last, carbohydrate fermentation profile using API 50 CH and API 20 STREP kits was used for identification down to species level. Finally, following species were identified: Lactobacillus. plantarum, Lb. brevis, Lb. lindneri, Lb. helveticus, Lb. delbrueckii ssp. delbrueckii, Lb. pentosus, Lb. fermentum, Lactococcus. lactis ssp. lactis, Enterococcus.faecium, Ent. faecalis, Ent. avium, Ent. durans and Aerococcus. viridans. In fresh cheese, the Lactococci and lactobacilli genera were predominant but in ripened cheese the enterococci replaced them. Predominant species in fresh cheese were as follow: Lac. lactis ssp. lactis (44.44%) and Lb. plantarum (22.22%) but Ent. faecium (43.58%), Lb. brevis (12.82%) and Ent. faecalis (7.69%) constituted the major part in ripened cheese. We can mention that these predominant lactic acid bacteria play an important role during ripening and also flavor production in raw milk cheeses like Koozeh. So, more precise identification is very necessary using culture- based molecular and culture- independent methods down to strain level.

The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets and frying at 150, 170 and 190oC for 0, 1, 2, 3 and 4 min have been investigated. The results showed an interaction effect of these processing conditions on mass transfer. The most reduction in fat absorption was observed when samples were coated with batter containing 10% white egg and fried at 150oC. The kinetic model based on the Fick’s law was used to describe moisture transfer data. The effective moisture diffusivity of batter without white egg was within the range of 3.97×10-8 and 7.51×10-8m2/s with R2 between 0.91 and 0.86 .In the samples coated with the batter including white egg, the effective diffusivity ranged between 2.26×10-8 and 5.96×10-8m2/s with R2 between 0.98 and 0.87, and fat transfer rate constant was between 1.1×10-3 and 8.9×10-3 S-1 with R2 from 0.82 to 0.99. Activation energy obtained from the Arrhenius plot for the effective moisture diffusivity of batter with and without white egg was 30.01 kJ/mol and ranged from 38.42 to 36.52 kJ/mol, respectively.

Enzymatic browning and formation of brown pigments are some of the most important problems in preparation of mushroom purees. In this study, the effect of some anti browning agents including sodium metabisulphite, ascorbic acid, and citric acid on the whiteness and foaming properties of mushroom purees was investigated. The results showed that soaking with acids and sodium metabisulphite significantly (p<0.05) reduced the browning in mushroom purees after crushing process. There was no significant difference (p<0.05) between whiteness, BI and DE at the start of the process and after I hour in the mushrooms soaked in metabisulphite solutions, where whiteness ,BI and DE changed significantly (p<0.05) after soaking mushrooms in acid solutions. Soaking mushrooms in sodium metabisulphite solution had no effect on foaming properties. As a result, soaking of mushrooms in 0.5 gr/ml sodium metabisulphite solution for 10 minutes was found to be sufficient for maintaining whiteness and foaming properties in mushroom purees.

This study was conducted to evaluate some postmortem changes parameters (pH, color, rigor mortise and sensory evaluation) in kutum, captured by gillnet and beach seine. Eight pieces of kutum were provided from each net and blood was sampled via 5 cc strile syringes from caudal vein and put into special tubes. Then, fishes were placed into isolated boxes between thick layers of ice and transferred to laboratory. Qualitative parameters were investigated in 0, 3, 9, 24,48 and 72 hours after death. Blood samples were centrifuged and serum was used for chemical assay. Based on results, capture method had effect on qualitative indexes, investigated in this research, but beach seine method had minor effects on meet quality than gill net method, also were observed that ice storing for 3 days period don't decrease the meat quality notwithstanding affects on some parameters and the meat retain quality after the period.

In this research, the effects of three variables, whey protein concentrate, WPC (0.7- 2.8%), sodium Ceinate, SC (0.7-208%) as a substitute for egg and carboxymethyl cellulose, CMC (0.66-0.234 % w/w) as thickening agent on sensory (taste and texture) and rheological (Complex viscosity, h*, Storage modulus, G' and Loss modulus, G" ) properties of salad dressing were investigated. The central composite experimental design (CCD) was used and the data were analyzed using response surface methodology (RSM). The results of analysis of variance (ANOY A) showed that P values of all models were significant and lack of fit P values was no significant at the level of 95%. Therefore, the adequacy of models was acceptable. The results showed that the optimum level of hydrocolloids for producing salad dressing with highest rheological properties were 2.27% WPC, 2.27% SC and 0.2341 % CMC. The sensory evaluation of six treatments with improved physicochemical properties and stability of salad dressing (data not shown) and control sample (prepared with eggs) was carried out. The results suggest that there is no significant difference in the overall acceptability between control samples and samples prepared with the alternatives. So milk proteins can be used as a suitable substitute for egg in the salad dressing.

In this study, the optimization of osmotic solutions (containing fructose, calcium chloride and citric acid) were investigated based on maximum water loss (WL) in the osmotic dehydration of quince. The response surface methodology (RSM) and central composite design, with 18 treatment and 3 replicate, was used for optimizing. The results showed that fructose and calcium chloride had linear and quadratic significant effects (p<0.5) on the WL and citric acid had no significant effect at determined range of concentration. The sample containing fructose 47.68%, calcium chloride 3.99% and citric acid 3.49% were selected as the optimum solution by RSM. The control and pretreated samples were subsequently dried by air drying and effects of coating by pectin-carboxymethyl cellose-ascorbic acid based solutions and osmotic dehydration on dried quince quality attributes include color and textural properties were studied. The results of compression test showed that coating and osmotic dehydration caused to decreasing in the hardness of samples which was attributed to plasticizing effects of low molecular compounds in solutions and fruit texture. Coating and osmotic dehydration caused to decreasing in overall color change of the dried quince which was attributed to decreasing contact of quince slice with oxygen, reduction effect of ascorbic acid and chelating and pH decreasing effects of citric acid.

In this study, the physical properties (size, mass, volume, density, geometric diameter, sphericity and friction coefficient on galvanized steel and wood surface) and some mechanical properties of flesh and skin tissue (modulus of elasticity, bioyield stress, yield strain and toughness) for small, medium and large melons of Ghasri variety were determined. Means comparison was done by Duncan's method. The results showed that the density, sphericity index and the mechanical properties of melon's flesh decreased with increasing the size of Ghasri melon, but the mechanical properties of skin increased. The highest values of modulus of elasticity, bioyield stress and toughness of melon skin were obtained for the large size of melon, these values were respectively: 22.4 MPa, 0.93 MPa and 62.18 N.mm. The highest values of density, sphericity, modulus of elasticity, bioyield stress and toughness of flesh were obtained for small size, these values were respectively: 1.11 gr/cm3, 0.624, 156.8KPa, 21.19 KPa, 31.82 N.mm.

Evening primrose (Oenothera biennis) is a biennial flowering plant increasingly cultivated for medicinal use of  g-linolenic acid rich oil of its seeds. In this study, total phenolic and flavonoids content, antioxidant and antimicrobial activity of aceton, ethanolic and metanolic extracts of evening primrose flowers were evaluated. Aceton extract had the highest extraction yield, total phenol and flavonoids content. Extracts were also tested for their antioxidant activity using scavenging activity of 2, 2- diphenyl-l-picrylhydrazyl and reducing power of Fe +3 in comparision with BHT. BHT was the highest in DPPH radical scavenging and reducing power followed by aceton, ethanolic and methanolic extracts. The extracts also showed good antibacterial activity against all of tested microorganism and the tested gram-negative bacteria was more resistant to inhibitory effect of extracts. Among different bacteria tested, Salmonella. typhimurium was found to be the most resistant to aceton and ethanolic extracts. The MBC values, with respect to aceton and ethanolic extracts for Salmonel/a. typhimurium were 10 and 20 (ug/ml), respectively.

The aim of this study was to develop an easy analytical method for determining flam prop-m- iso propyl residues in honey by high performance liquid chromatography with UV detection (HPLC/UV) for routine analysis. Chromatographic separation was carried out at room temperature on a ZORBAX Eclipse XDB- C 18, 100 A pore size, 5 urn particle size (300 mm × 3 mm I.D.) column using a mobile phase of methanol-water (60:40%v/v) in isocratic mode. Homogeneous liquid-liquid extraction method was applied to extract pesticide residues in honey. The main factors affecting the extraction efficiency were optimized by using one variable at a time methodology as follow: volume of methanol: 5 mL, volume of chloroform: 115 mL, the weight of NaCl: 14 g and sample volume: 50 mL. In this method also linear range of 0.002-20 ppm with the correlation coefficients in the range of 0.9987were obtained for Pesticide. The recoveries ranged between 95 and 102% for various spiking levels. The limits of detection were 0.00 I ppm, The extraction method used in the present study was easy, inexpensive, and rapid. Thus, it could be used efficiently in the routine monitoring studies.