IRANIAN JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Year:2011 | Volume:8 | Issue:28 (SPECIAL ISSUE)|Papers Count:15

Modified atmosphere packaging is one of the recommended methods to increase the shelf time and quality of fruits and vegetables. To design a good packaging, accurate respiration rate is necessary. In this research, selection of the proper mathematical equation in determining the respiration rate is investigated and respiration rate of peeled and ready to use carrots were measured at laboratory temperature (21±1oC) and refrigerator temperature (7±1oC) in the closed system. In addition, effects of temperature and slicing were studied on respiration rate were studied. It was found both increase in temperature and slicing, increase the respiration rate. Results of this research are necessary to design of modified atmosphere packaging.

In order to investigate the Fatty Acids Composition and some chemical Characteristics in four sunflower hybrids, under three irrigation regimes (irrigation after 50, 100 and 150 mm cumulative evaporation from class A evaporation pan, respectively) an experiment design As a split plot design based on a randomized complete block was conducted at the research field of university of Tehran, college of Abouraihan in Pakdasht, Iran. The results showed that increasing of water deficit stress causes considerable reduced in the amount of oil seed and increased in seed protein, so the highest seed oil and seed protein content obtain in optimum and mild stress conditions respectively. Also the most of seed oil and seed protein contain was obtained by Azargol and Hayes 25 respectively. Investigation on fatty acids compositions in sunflower hybrids seeds indicated that highest fatty acid, palmitic (6.16%) and stearic (4.16%) were obtained in intense water deficit stress and oleic (40.25%) and linoleic (51%) were obtained in mild water deficit stress, respectively. Comparison between sunflower hybrids showed that maximum palmitik, stearic, oleic and linoleic were obtained by Allstar (7%), Hysun 33 (4.20%), Hayes 33 (42.77%) and Allstar (52.66%) respectively. Also in terms of optimum irrigation, mild water deficit stress and intense water deficit stress conditions Hysun 33 was successful to produced maximum Oleic acid. Generally based on the results of this study in optimum and mild water deficit stress conditions Allstar hybrids and in intense water deficit condition Hayes 25 hybrids had met the highest linoleic acid.

Copolymer Polyhydroxyalkanoat (PHAs) is the most well known degradable product of Poly-beta-hydroxybutyrate (PHB). In this research, for producing this kind of polyesters, Azotobacter was separated from soil, and then purified. By changing culture media conditions such as saturated and unsaturated oils (palmitic acid, Olive oil, Castor oil, Sesame oil, Sprout wheat oil, Almond oil, Sweet almond oil, Coconut oil, Snake oil, Nigella seeds oil, Myrtles oil, Walnut oil, Paraffin, Stearic acid, Oleic acid, Chamomile oil, Glycerin), nitrogen, temperature and air blowing, optimum biopolymer growth condition inside the cell was evaluated. With using quantities and qualities methods like spectrophotometer assay and percentage counted by using gas chromatography (GC), and rate of PHB production were investigated. Result shows that among 10 separated Azotobacter strains, AZ7 was capable to produce 80.793% amount of PHB. Maximum amount of this biopolymer (84.48%) in 2% Almond oil as carbon source, 1% yeast extract as nitrogen source, 200 rpm air blowing and 33°C were observed. It seems that AZ7 strain accumulated 80-90% of their cellular dry weight of PHB in different media and in competitive of foreign strain is a native candidate for production of PHB.

Comparison between GM potatoes against non-GM potatoes is considered as a serious obstacle in trading and research institutes in Iran. The use of new analytical methods based on genome evaluation for differential identification between GM/non-GM products has a great importance. Sampling has been carried out from the market of four provinces. After DNA extraction according CTAB method, normal PCR and Real Time-PCR has been used for following up the target and endogen genes, 35S promoter, cp gene and Sucrose synthase gene/B-fructasidase respectively. Absence of amplification in the aforementioned PCRs, conducted the analyses to follow up PVYO and PVYN through the specific primers designed for their detection. All samples have provided good amplification implying contamination of samples by viruses and absence of GM potatoes in Iran market, as well.

Chemical preservatives are usually used to reduce or eliminate pathogenic or spoilage microorganisms but their inordinate applications have resulted in toxigenic residuals and adverse effects on consumers, So many researches have been done to substitute the chemicals with naturally occurring compounds, especially plant essential oils. In this study log P% of vibrio parahaemolyticusATCC 43996 with different concentrations of zataria multiflora Boiss essential oil (0, 0.0025, 0.005, 0.015, 0.03 and 0.045%) in BHI broth during incubation at 35oC for 43 days was investigated. Log P% ofvibrioparahaemolyticus was affected very significantly (p<0.001) with all concentrations of zataria multiflora Boiss. Essential oil Vibrio parahaemolyticus wasn’t grow In any tubes of 0.03 and 0.045%concentrations of essential oil and maximum of log p% was calculated as -4.241. Maximum log P% of this bacterium in 0.015% concentration of essential oil was achievedat 15th day and was 1.761, whereas the maximum log p% for 0.005, 0.0025 and 0 concentrations of essential oil that was 3.902, were achieved at 19th, 4th and 0 day. In conclusion the log P% of vibrio parahaemolyticus was decreased by increasing of zataria essential oil concentrations.

Plant extract are source of natural antioxidant. in recent decades, the need for natural antioxidants in food, pharmaceutical result has been extensive scientific research. the purpose of this investigation study antioxidant activity shallot extract, turmeric extract and their composition effect on delay spoiled rainbow trout during vacuum packaged storage at refrigerate 4oC.fish prepared were divided into four lots, one sector of the samples as the control samples vacuum packaged and others sectors were given a dip treatment in shallot extract, turmeric extract and their composition solution and then vacuum packaged storage at refrigerate 4oC. Chemical (PV, TBA FFA and fatty acid profile) analysis were done at 4oC for 20 days.shallot extract, turmeric extract and their composition significantly (p<0.05) delayed lipid oxidation in treated samples. results showed that antioxidant effect of shallot extract, turmeric extract and their composition during storage and increased shelf-life treated samples with extracts.

Drying is one of the most important steps in grape processing. Drying causes some undesirable effects such as changing the quality of raisin by turning it to brown. Achieving optimum drying conditions can improves quality of raisin. Temperature and pretreatment are important factors in establishing the quality of raisin. In this research the effect of pretreatment (solutions of sodium Meta bisulphide 8 %, sodium Meta bisulphide 8% and potassium carbonate 5%, ethyl oleat 2% and potassium carbonate 5%, ethyl oleat 2% and sodium Meta bisulphide 8 %, ethyl oleat 2% and sodium Meta bisulphide 8% and potassium carbonate 5%) and different drying methods (by sun, shade and air dryers at temperature of 50, 60, 70 and 80 oC with the air flow rate of 1.5 m/s) was studied to understand the quality factors on colour. As some solutions contains sulphite, its remnant was studied too. The analysis of experimental data shown that the optimized drying conditions achieved by Ethyl oleat 2% and sodium Meta bisulphide 8% and potassium carbonate 5%, sodium Meta bisulphide 8% and drying temperature of 50, 60oC.

Enrofloxacin is an important antibiotic in poultry industry in Iran. Also, antibiotic residue is a serious health problem in this industry. This study was conducted to determine whether the doses of enrofloxacin would produce drug residue transfer into eggs when administer to laying hens. Forty hens were assigned to equal groups (n=10). 2, 5 and 10 mg/kg of enrofloxacin was injected to 1, 2 and 3 hens groups, respectively. All of groups were seven days under treatment. Then, eggs were collected at 1 to 7 days of treatment and 3, 6 and 9 days after last injection. Then, enrofloxacin residue was determined using high performance liquid chromatography. The results of this study showed that increment of administered dose of enrofloxacin caused to increase drug residue in eggs. Furthermore, maximum drug residue was observed at seventh day of injections. In addition, drug residue was decreased to zero at ninth day after last injections. On the other hand, enrofloxacin residue concentration was detectable in group two hens at third day after last injections and in group three hens at third and sixth day after last injections. In conclusion, for minimum detection of enrofloxacin residue concentration in eggs must be increased the time between last injection of drug and eggs collecting.

In comparison with traditional extraction methods, aqueous enzymatic extraction of oil from oilseeds is a recent clean technology. This paper reports work performed at laboratory scale to extract soybean oil by aqueous enzymatic extraction method.In the present work the influence of enzymes concentration, extraction time, dilution ratio, particle size and 3 interactions in the final yield are evaluated and process parameters have been optimized by Taguchi method.16 extraction experiments carried out, statistical analysis showed that particle size was the most significant variable in oil extraction. Themaximal oil extraction yield was 61.42%.

Determination of five organochlorine pesticides, lindane, aldrin, dieldrin, endosulfan, dichlorodiphenyltrichloroethane (DDT) residues were carried out on four dairy products (cow milk, cheese, cream and butter) sampled from Tabriz, during 2009-2010 using GC-ECD. Lindane was detected with average of 1.4, <0.05, 0.53, 0.116 ng g-1 in cow’s milk, butter, cheese and cream samples, respectively. Aldrin was detected with means 2.21, <0.05, 0.31, 0. 36 ng g-1 and Dieldrin was detected with means 1.52, <0.05, 0.14, 0.074 ng g-1 in cow’s milk, butter, cheese and cream samples, respectively. Endosulfan was detected with means 1.05, <0.06, 0.18, <0.05 ng g-1 while DDT was detected with means 1.44, <0.07, 0.14, 0.83 ng g-1 in cow’s milk, butter, cheese and cream samples, respectively. This investigation revealed although the averages of OCPs residue in most samples were below the recommended MRLs by European Council Directives, Aldrin levels in some cow’s milk samples and Dieldrin levels in some butter samples exceeded legislated MRLs and may pose a health hazard. It also reflected the reduction use of organochlorine pesticide in recent years in Tehran.

Food born intoxications are kind of current problem in human society and most of them are caused by enterotoxins of Staphylococcus aureus. Also probiotics (Lactic acid bacteria) have been known as health and immune system modulator. In this experiment we assessed the effects of Lactobacillus acidophilus LA5 and Lactobacillus casei 108cfu/ml on growth of Staphylococcus aureus 105cfu/ml at 25oC and 35oC in TSB. Then samples from the co cultured and control were pour plated in Baird parker agar and MRS agar to compute the bacterial count at 0, 8, 24, 48, 72 hours after incubation. We found that Lactobacillus acidophilus (LA5) Lactobacillus casei inhibited the growth of Staphylococcus aureus 29213 and comparing to controls reduced number of S. aureus cells was by 3 logs in 25ºC and 2 logs in 35oC. enterotoxin production by S. aureus was also inhibited in both temperatures of 25 and 35oC due to ELIZA rida screen test. Lactobacillus acidophilus and Lactobacillus casei inhibited the production of entrotoxins A, C and E at 25oC and A and/orC at 35oC. In conclusion, the results of this study revealed the effectiveness of Lactobacillus acidophilus and Lactobacillus casei in inhibition of Staphylococcus aureus growth and enterotoxin production proposed their potential application as antibacterial in food.

4lactobacillus plantarum, strains isolated from natural olive fermentation, was used as a starter culture for aerated olive (Manzanilla green olive) fermentation.Lactic acid bacteria are essential microorganisms in green olive fermentation. Inoculation with a starter culture of lactobacillus plantaru 5–7days after brining could standardize olive proccessing. This lactobacillus plantarum must isolated from olive fermentation that is tolerated to high levels of lactic and acetic acids and high level Nacl concentration and also oleuropein 1%.Fermentation took place in 4 glass baril (15 L) with 7 kg of olives and 7 L of brine. Baril 1,baril 2 that were treated with 8% salt and 0.1% acetic acid. Baril 3,baril 4 that were treated with 6% salt and 0.3% acetic acid. Inoculation took place in 5 days after brining for baril 2,4. Aerated condition for barils were supplied with aeration column for approximately 190 days and incubated in 28°C. The samples (olives and brines) were taken at different fermentation phases. Physical and chemical analyses of olive during the fermentation were including salt, protein, fat, acidity, moisture, ash and in brine olive were including acidity, salt, reducing sugar, pH.In this research, the use of suitable lactobacillus plantarum starter cultures has the potential to improve the microbiological control of process, increase the lactic acid yield and, accordingly, increasing acidity in brine olive and provide the production of natural fermented green olives of consistently high quality. Thus use of inoculation lactic acid bacteria can applied as a new technology during the olive fermentation.

At present, demands for inexpensive and alternative protein sources for animal protein, in order to be used in value–added foods have been increased. Therefore, many researchers shifting on production of plant protein resources. So, the objective of present study was possibility measurements of cottonseed protein concentrate production for human consumption from cottonseed meal. Three different methods, n-butanol: acid, mixed solvents (water: acetone: hexan) and ethanol-ultra filtration, in order to produce cottonseed protein concentrate were examined. Variables (percentage) were nitrogen, nitrogen solubility, fat, crude fiber, total gossypol and free gossypol. Statistical analysis was performed in the three distinct statistical patterns and by using blocks completely random and examination at significantly a=0.01. After comparing resulted data with world standard measurements, results obtained as follow: extraction methods with n-butanol: acid (9 times washing along with Hcl), using mixed solvents (30: 67: 3 ratio along with classic extraction) and ethanol-ultra filtration (alkaline extraction along with ultra filtration molecular weight Cut off: 20000) were suitable. The last extraction method was demonstrated as most appropriate method to produce cottonseed protein concentrate.