فصلنامه پژوهش و نوآوری در علوم و صنایع غذایی
سال نهم شماره 4 (زمستان 1399)

Rapeseed oil Deodorizer distillate (RODD) is regarded as a waste material of the rapeseed oil industries obtained during the deodorization process. It contains valuable bioactive nutritive compounds such as phytosterols, tocopherols, and squalene. In the present study, some physical and chemical properties such as color, free fatty acid value (as % oleic), saponification value (mg KOH/g), neutral oil (%), unsaponifiable matter (%), total tocopherols (mg%), total phytosterols (%) were determined ultrasonic assisted separation was applied to quick fractionation of rapeseed oil deodorizer distillate into the lower polar unsaponifiable methanol fraction and upper non-polar saponifiable hexane fraction mainly containing the lipids. The composition of natural lipids found in the methanolic extract of RODD was determined by HPLC while the fatty acid composition was evaluated by gas chromatography-mass spectrometry (GC-MS).Squalene had higher relative standard deviations 3%, while Tocopherols and sterols had low relative standard deviations ranging between 0.11-0.36 and 0.04-0.28% in distillate sample respectively. Based on the results, the most abundant compounds in rapeseed distillate sample were phytosterols (15.5-22.14%).However, the concentration of squalene and tocopherol was 1.9-2.05% respectively.Triglycerides were also the main glycerides of distillate. The results of the present study indicated that the polar lipid bioactive fraction was effectively extracted with methanol without saponification using a nondestructive approach.

For the first time, the effect of the combination of Farsi gum (FG) and pre-gelatinized (pre-gel) cornstarch, as a fat replacer and substitute for xanthan-guar gum, on textural, stability, sensory, average droplet size and rheological characteristics of low-calorie mayonnaise were investigated. FG and pre-gel corn starch combination in ratios of (1:1), (1:2), and (2:1) at three concentrations of 1.5, 2.0, and 2.5% were added to mayonnaise. A mayonnaise sample with guar and xanthan gum (0.5%) was selectedas the blank. Results showed textural parameters, i.e., hardness, apparent viscosity, adhesive force, adhesiveness, and hardness work done, increased by increasing the amount of FG so that was lower than that ofthe blank. Analysis of the average droplet size showed that blank exhibited the highest average droplet size. Average droplet size decreased and the viscosity of all treatments increased by increasing the percentage of gum. Mayonnaise color parameters showed no significant difference between color parameters (p < /em>>0.05). Finally, treatments pre-gel cornstarch: Farsi gum (1:2) 2.5%, pre-gel cornstarch: Farsi gum (2:1) 2.5% and pre-gel cornstarch: Farsi gum (1:2) 2% obtainedthe highest sensory evaluation scores, respectively.

In present study, linoleic acid from sunflower oil and propylene glycol as solvent were used to synthesize conjugated linoleic acid (CLA), and the response surface methodology (RSM) was applied to optimize the process. The results showed that the propylene glycol as solvent and reaction time were found to have positive influence on the response, but the high reaction temperature especially at high solvent levels and reaction time, has led to a reduction in the production of CLA. Solvent content of 6.25 mL, a temperature of 100 °C and a time of 140 min were found to be the optimal conditions in the isomerization for the production of cis9-trans11 and trans10-cis12 CLA isomers. In the next step, the produced CLA were concentrated and purified and used for the enrichment of skim milk. Then, qualitative characteristics of milk including pH, peroxide value, sensory properties and CLA retention during storage of enriched milk in the 5 °C were investigated for 90 days. There was no significant (p < /em>>0.05) difference between the control and treated samples for one month after storage (p < /em>>0.05), but with increasing storage time up to 60 and then 90 days the differences increased (p < /em><0.05). According to the results, the level of remaining CLA in milk, as well as pH decreased over time, but the peroxide value of the samples was increased.

Quality control in agricultural products has always been noticed. In the present study, a new pre-concentration technique for the determination of Tartrazine (TZ) in saffron samples by employing Fe3O4/Graphene oxide-COOH as an adsorbent is presented. Fe3O4/Graphene oxide-COOH was prepared and characterized by scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FT-IR). After extraction, the TZ concentration was measured by the UV-Vis spectrophotometer. The important factors for pre-concentration such as sample pH, amount of adsorbent, contact time and eluent volume were examined and optimum conditions were obtained. The new proposed spectrophotometric method shows good dynamic range of 0.02 to 10 mg/L (R2>0.996) for TZ with a limit of detection (LOD) of 0.01 mg/L after pre-concentration. This method was applied to the analysis of TZ in saffron samples and recovery values and enrichment factor were found as 94% and 5, respectively. Finally, 5 saffron samples were spiked with TZ and analyzed with new spectrophotometric methods, and results compared by HPLC as a standard method. The results of the t-test showed that there is no significant difference between the two methods.

Kefir is produced from the fermentation of milk by microorganisms in kefir grains. Kefir grains include lactic acid bacteria, yeast, and acetic acid bacteria surrounded by a protein matrix and polysaccharide called kefiran. One of the most important antibacterial compounds of this beverage is microbial exopolysaccharide of kefiran. The present study aimed to investigate the effect of milk type, fermentation time, temperature, and stirring conditions on the production of kefiran by kefir grains. Activated kefir grains were added to full-fat and non-fat milk. Fermentation was carried out at 25 and 37 °C under stirred and non-stirred. After 24, 48, 72, and 120 h of fermentation, the grains were separated from kefir extract and kefiran exopolysaccharide was extracted from kefir grains. The effect of these variables and their interaction on the production of kefiran using Design-Expert software and full factorial design have been analyzed. Also, the MIC and MBC of extracted kefiran were determined against Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Shigella dysenteriae. All fermentation conditions and their interactions had a significant effect on kefiran production. Considering all fermentation conditions and interaction of all factors, more kefiran were produced in fermented kefir grains at 37 °C compared to 25 °C, in full-fat milk compared to non-fat milk, under stirred conditions compared to non-stirred and fermented beverages for 48 and 120 h. MIC and MBC of extracted kefiran for tested bacteria were determined in the range of 1.4-11.25 mg/mL.

Nowadays, mathemathical simulation and modeling of drying curves are useful instruments in order to improve control systems for final product quality under various conditions. These approaches are usually applied for studying the factors present in the process, optimization of the conditions and working factors as well as predicting the drying kinetics of products. Two intelligent tools including artificial neural network (ANN) and genetic algorithm (GA) were used in the current paper for predicting tomato drying kinetics. For this purpose, four mathematical models were taken from the literatures, then they were matched with the empirical data. Final step was choosing the best fitting model for tomato drying curves. According to the results, the model proposed by Aghbashlo et al (Agh-m) showed great performance in predicting the moisture ratio of the dried tomato slices. Moreover, the genetic algorithm was utilized for optimization of the best empirical model. Ultimately, the results were compared with the findings observed in ANN and GA models. The comparison indicated that the GA model offers higher accuracy for predicting the moisture ratio of dried tomato with the correlation coefficient (R2) of 0.9987.

Arcobacter butzelri is known as the cause of enteritis, abdominal cramps, bacteremia, and appendicitis in humans, it is also the cause of enteritis and abdominal pain in animals. It has been introduced as the most dangerous species for human health by the International Committee on Food Microbiology and recently as an important zoonotic pathogen. The aim of this study was isolatation and characterization of Arcobacter butzelri based on pathogenic genes (tlyA, ciaB, mviN) in different seasons. Therefore, 238 samples were collected from the effluent of poultry slaughterhouse in Tonekabon, Iran. The suspected colonies were identified using biochemical test and then confirmed using the Polymerase chain reaction (PCR) technique. Out of 42 isolated of A. butzleri, the virulence genes were detected in 15 isolates. The results showed that ciaB gene was present in 13 strains with a frequency of 30.9%, mviN in 11 samples with a frequency of 26.2%, and tlyA gene in 9 samples with a frequency of 21.4%. The results also revealed that the highest frequency of A. butzelri was 8.4% in spring and the lowest rate was 1.2% in winter.

Probiotics, especially lactic acid bacteria, are very useful in the production of health drinks, and increasing the nutritional value of beverages. Probiotic bacteria along with prebiotics are used to produce synbiotic drinks. In this study, the effect of inulin at three levels (1, 2 and 3%), sugar beet fiber (0.75, 1.5 and 2%) and bacteria (Lactobacillus acidophilus) in the production of synbiotic pineapple juice was investigated. The treatments were stored at 4 °C for 25 days and tests for pH, bacterial viability, brix, colorimetry and sensory evaluation were performed at 5-day intervals. With increasing the amount of inulin, sugar beet fiber as well as shelf life, bacterial viability and red-green color (a*) increased, and the values of brix, pH, transparency (L*) and yellow-blue (b*) decreased. The results showed that storage time is one of the most important factors affecting the studied parameters. Based on the results of Brix, pH, colorimetric (L*, b* and a*) and bacterial viability on day 25, treatments containing 3% inulin and 0.75% sugar beet fiber were 19.17%, 3.6,. 68.91, 14.3, -2.19, 12.28 CFU/g, respectively and was selected as the ideal treatment.Therefore, it can be concluded that in order to produce a useful pineapple drink, Lactobacillus acidophilus can be used with inulin and sugar beet prebiotics.