IRANIAN JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Year:2016 | Volume:13 | Issue:56|Papers Count:20

Fruits, vegetable and juices are always interested due to their nutritional contents such as vitamins, minerals and antioxidants. They also seemed to be a suitable media culture for lactic acid bacteria growth and lactic fermentation. In this research, production of a functional beverage red beet juice and fermenting in 37oC by lactic acid bacteria was carried out. Bacterial growth kinetics, sugar consumption, Acid production and changes in antioxidant activity have been investigated. Lactobacillus reuterii were found to grow faster and produced higher amount of viable cells during fermentation followed by L. delbruckii, L. acidophilus, L. casei, L. paracasei, L. rhamnosus, L. plantarum and L. helveticus. Reducing sugars including sucrose, fructose and glucose were consumed by L. casei and L. delbruckii were more intended to use lactose. Lactic acid was the predominant produced lactic acid which was manufactured by L. reuterii. Antioxidant activity and total polyphenolic compounds increased significantly fermentation and maximum reduction in EC50 has been observed in fermentation by L. rhamnosus and, L. acidophilus in anti-oxidant activity and L. casei, L. rhamnosus and L. helveticus in total polyphenolic compounds. Finally, L. casei was found to growing well in this beverage, resulted in producing functional fermented beverage.

This study aimed to evaluate the effect of squid protein hydrolysate prepared from protamex (P1, P2, P3) and alcalase (A1, A2, A3) enzymes respectively, at 0.5%, 1% and 1.5% concentration and also control sample (0%), on some physicochemical and organoleptic properties of low-fat set style yoghurt such as viscosity, synersis percentage, water holding capacity, acidity, pH, odor, taste, texture and color. Results showed that the lowest viscosity (416/66) was for control sample. Protein hydrolysates of both of enzymes increased viscosity while the highest amount was for P3 and A3. The highest pH and lowest acidity were for the control sample and protein hydrolysate in yogurt formulation decreased pH and increased acidity of samples. Maximum synersis obtained with control sample (4.47); protein hydrolysate decreased synersis while 1% protein hydrolysate with alcalase had the lowest synersis (0.33). Results of organoleptic tests showed that alcalase samples, especially in higher concentrations, modified odor and taste of low-fat yoghurt but these changes were not clear in texture and color. Generally, squid protein hydrolysate with alcalase and protamex in yoghurt formulation improved functional properties of low-fat yoghurt and it was more efficient in alcalase treatments in comparison with protamex.

In this study, the effect of sucrose substitution by date and glucose syrup in kombucha production has been investigated due to heath and economic benefits of date syrup. The effect of this substitution on the rheological, flavor and organoleptic properties of final product have been analyzed in order to evaluate possible marketability and consumer acceptance as the diverted product.Results showed that date syrup has the significant effect on the growth and persistency of microorganisms which effect on its healthy characteristics but its sour taste and flavor was stronger than blank sample.kinetics of glucuronic acid and total acid production have been evaluated by first order equation.result showed that at the first day after filtering (treatment pasted 10 days for initial fermentation) initial value of glucuronic acid and total acid were higher in date syrup added kombucha and the increment of glucuronic and total acid production was high in date syrup treatment which indicated that prescence of simple sugars (glucose and fructose) in date syrup can affect on microbial groth and both initial value and rate of acid production during the storage of filtered kombucha.

Yarrowia lipolytica is unusual yeast that has the ability to produce important metabolites such as lipase enzymes. Lipase enzyme has many applications in different industries including manufacturing of detergents, food industry, pharmacy, fuel and etc. In this paper, we studied the lipase enzyme produced by the yeast under different treatments of nitrogen sources such as yeast extract, peptone, soybean meal, sesame meal and sesame meal extracts on the medium of Czapek Dox Broth. Selected treatments of nitrogen resources include treatment solution (100%), solution (50%) containing with sesame cake extract (3.6%), solution (50%) containing with sesame cake extract (3.6%) in distilled water, solution (50%) containing with yeast extract (3.6%) in distilled water and solution (50%) containing with peptone (3.6%) in distilled water on the medium (CDB). Fermentation time levels are considered 3, 4 and 5 days. Among examined treatments, Treatment solution (50%) containing with sesame cake extract (3.6%) on the medium (CDB) showed the highest lipase activity (91.5900±0.56241 and 67.5200 ± 0.01000 enzyme units, respectively) in the fourth day of incubation with stirring speed (120 rpm) and temperature (30 oC). The results show use of sesame cake extract increases lipase activity more than use of yeast extract and peptone at the level of 5%. Also, statistical analysis of resulted data showed use of sesame cake extract increases lipase activity significantly at 5% level in comparison with yeast extract and peptone.

The diversity and abundance of quality characteristics of agricultural products, has been the main reason for the development of non-destructive methods. Machine vision and artificial intelligence are powerful techniques for diagnosing most physical, mechanical and chemical properties of agricultural products. Before export fruits are classified by shape, volume and weight. Ranking fruit through taste (sweet or tart) non-destructively plays an important role in marketing, choice power and its application. In this research, it was detect the taste of Thompson orange while combining artificial intelligence (AI) and visual machine technique. A closed circuit digital installed in special frame, under specific height and light was used to take picture from samples vertically. Also, an algorithm (program) based on AI was developed to diagnose the variety and taste of Thompson orange through apparent characteristics in Matlab software. The results showed that the success rate of taste determination for Thompson orange using ANFIS and ANN-GA (Artificial Neural Network-Genetic Algorithm) was 96.67 and 90.0% respectively.

In this study to determine the effect of sonication time and intensity on the activity of the alphaamylase, Aspergillus Oryzae PTCC 5164 as a Producer of enzyme was used in the solid staste fermentation system. A combination of wheat and barley (0: 100, 50: 50, 100: 0) as a substrate, Ultrasound with the intensity treatment (35, 5/67 and 100%) and 5, 10 and 15 minutes were used. Statistical analysis with software Design Expert 6.0.2 showed that the effect of ultrasound on enzyme produced in culture platform is different. Alpha-amylase production with barley as the substrate had more resistant during the sonication. Also by increasing the time and intensity of sonication, negative effects of cavition became more apparent and enzyme activity decreased. Diminishing activity of the alpha-amylase produced, depends on the duration and intensity of sonication and combination of solid culture. Probably the p0®p* amide transitions and secondary structural components, especially b-sheet, of the enzyme was significantly influenced by ultrasound.

In this study, low soluble and mechanical-tension resistant nanocomposite films were developed by adding different concentrations (5, 10 and 15% dw) of nanoclay type Cloisite Na+ (CNa+) to the soy flour polysaccharide. In order to investigate the physico-mechanical, structural and thermal properties of the developed nanocomposite, it has been synthetized by soluble molding method. When the nanoclay was added to the biopolymer film, water solubility decreased, although the aforementioned trend was more significant when the concentration of the nanoclay was raised. The film transparency was significantly declined when the nanoclay was added. By adding the nanoparticle, the film strength increased and this was increased when the nanoparticle concentration increased. Elongation at break decreased when the nanoparticle concentration was increased. The XRD results indicate that pure film specimen is amorphous whereas the biopolymer structure is becoming order and crystallinity increased when the nanoparticle was increased. These results revealed the peaks shifting to the lower degrees, increasing the interspace between nanoclay layers and intercalation. From morphological point of view, a homogenous texture caused by adding nanoparticle to the polymer matrix was investigated using SEM. This study aimed to be successful for using the soy polysaccharide film as well as nanoparticle in order to introduce a new film in which used for nanocomposite synthetize.

Osmotic dehydration is one of the drying methods that have been considered in recent years. Water and solute transfer through process can be determined by the percentage of water loss (WL) and solid gain (SG). In this study, image processing technique has been used to analyse osmotic dehydration of potato and determining the amount of water loss that is the main parameter in this process. Experiments performed for two different solutions (15 wt% salt and mixture of 35 wt% sucrose and 10 wt% salt) and three temperature levels at 35, 45 and 55oC. Water loss estimated from changes in samples volume; Sample’s volumes determined using image processing of pictures from different sides of samples at the start of process and at the end of it. Experimental results obtained from the osmotic dehydration of potatoes can be summarized as: the amount of water loss increased with increasing temperature; using a mixture of salt and sucrose as osmotic medium gets more water loss comparing use of salt as an osmotic agent in solution. The overall results of the image processing indicate that the approach used in this study can be reached acceptable data; While the pace of work is much more than the conventional methods.

Omega 3 fatty acids are large group of polyunsaturated fatty acids with long carbon chain length. These fatty acids don’t produce in human body and should be provide by nutrients. The most important omega3 fatty acids are Eicosapentaenoic acid and docosahexaenoic acid that have beneficial effects on the human health. DHA is important in treatment of disease such as cancer, Alzheimer, heart attacks, arteritis romatoid, anxiety, inflammation and malignant diseases. In this research, the aims were to find suitable carbon and nitrogen sources to increase production of omega 3 fatty acid by native strain of schizochytrium. Also quantitative and qualitative effects of different carbon and nitrogen sources were determined on growth of strain production of omega 3 fatty acids rich in DHA. The results showed that the best carbon sources are glucose and glycerol and the best nitrogen source is yeast extract. Glucose increased production of biomass and glycerol increased production of omega 3 fatty acids. Finally, biomass, oil and DHA were produced 0.76, 0.5 and 0.48 g/L by schizochytrium strain in selective medium, respectively. The results showed novel native strain of Schizochytrium has potential for production of omega 3 fatty acids.

In this study, pomegranate arils were dried by infrared dryer to find a suitable mathematical model, effective moisture diffusion coefficient and activation energy. The experiments were performed at four air velocity levels (0.3, 0.5, 0.7 and 1 ms-1) and three infrared radiation levels (22, 31 and 49 W cm-2). Experimental data with semi-theoretical and empirical models were evaluated to find the best model. Among the models, Midili's Model was selected based on R2, c2 and RMSE criteria. Effective diffusion coefficient of pomegranate arils was in the range of 0.4×10-9 to 3.21×10-9 m2 s-1. Activation energy was calculated by using Arheneus exponential model. The values of activation energy were determined in first method between 0.43 to 1.17 W g-1 cm-1 and second method between 1.1 to 0.72 W g-1 cm-1.

Studies have shown that camel milk and its fermented products have therapeutic properties and high nutritional value. Lactic acid bacteria play important role in Fermented dairy products. The aim of this study is to determine the lactobacillus community of camel milk. A total of 9 Lactobacillus were isolated from camel milk of Golestan province in Iran. The log10 CFU of Lactobacillus per ml on MRS medium under anaerobic condition at 20, 37 and 450C included 8.792±0.14, 8.301±0.07 and 7.301±0.03 respectively. Isolates were identified on the basis of Biochemical and Phenotypic Characteristics as Lactobacillus paraplantarum, Lactobacillus ferintoshensis, Lactobacillus brevis, Lactobacillus pantheris, Lactobacillus johnsonii, Lactobacillus mali. Presence of Lactic acid bacteria was confirmed by band formation of PCR product in 1500 bp (amplification 16S rRNA gene using B27F-U1492R universal bacterial primer). Evaluation of their technological properties of isolates showed that isolated Lactobacillus from camel milk have lipoliticy, Proteolytic activity and high acidifying activity (except for Lb. mali and Lb. johnsonii). Also, all isolates, except Lb. Johnsonii, have autolytic activity in fair level. Based on technological properties of isolates, Lb. paraplantarum, Lb. Brevis and Lb. pantheris are suggested as good candidates for camels milk processing or other fermentation process.

In this research drying kinetics, moisture diffusivity and determination of most appropriate mathematical modeling and activation energy of Mazafati dates species were studied under a cabinet solar dryer. Drying experiments were carried out at three air temperatures of 50, 65, and 80oC and three air velocities of 1.0, 1.5, and 2.0 m/s. Effect of temperature and air velocity evaluated on drying time and shrinkage by using a completely randomized statistical design. Results showed that the effects of temperature and air velocity are significant on drying time. The average increase of temperature from 50oC to 80oC caused the drying time to decrease by 70.77%. For determination of most appropriate model, the highest value of R2 and the lowest values of c2 and RMSE were used. For mathematical modeling, eight empirical models were fitted on experimental data and the best model was selected. The result of regression analysis showed that Page model has the best fitting with data. Moreover, the lowest and highest value of moisture diffusivity were obtained as 4.309×10-10 and 0.0188×10-9 m2/s at temperatures of 80oC and 50oC, respectively. Also the values of activation energy in the drying of Mazafati dates species were found between 31.22 to 42.27 kJ/mol.

In the past, the inspection of cracks on eggshell was typically conducted in the industry by floodlighting, however, it gives eye fatigue, makes misjudgment and is not easy to detect hairline crack. Recent research into the automation of the detection of eggshell cracks is focused both on optical and mechanical detection principles. In this study eggs were excited by a light mechanical impact on different locations of the eggshell and vibrational frequency response of the eggshell combined with pattern recognition was attempted to differentiate intact egg and cracked egg. The pattern recognition was conducted by Principal Component Analysis (PCA) and Support Vector Machine (SVM). The optimal number of principal components was obtained 7 according to maximum error for predictive model and high discrimination between intact and cracked eggs. The result was found that the vibrational impulse response method distinguish intact egg and cracked egg with the level of 100% and 87.5% accuracy, respectively.

Molds can be noted as one of the major factors in bread corruption that mainly caused by Aspergillus, Fusarium and Penicillium. In addition to the economic losses caused by mold, types of toxins produced by them can also cause health problems. Chemical preservative such as propionic and sorbic acids are mainly used for preventing mold growth that it is not receptive to consumers. In recent years due to increasing public awareness, Customers demand to reduce the use of chemicals and the use of natural preservatives. Lactic acid bacteria are one of the biological preservatives that because of the antimicrobial properties and in some cases due to the positive effects on organoleptic properties have received much attention. In this project, the effect of spraying the bacterium Lactococcus lactis PTCC 1336 at three concentrations (zero, 104 cfu /cm2 and 106 cfu /cm2) and also the combined use of calcium propionate in three levels, zero, 2 and 4 % (w/w) on improving the duration of preservation and its effect on organoleptic properties of bread and also its effect on reducing the amount of calcium propionate was investigated. In those bread, the quantity of pH, acidity, and the amount of mold formation (macroscopic and laboratory observations) were measured. The results showed Spraying bacterium Lactococcus lactis PTCC 1336 on bread Can be more powerful Compared with calcium propionate Compared with calcium propionate reduces the mold. So the least amount of mold at the sample M3P3 (Samples containing 106cfu/cm2, 0.4% PC) observed. as well The results showed concomitant use of Lactococcus lactis PTCC 1336 and calcium propionate Activity on mold synergistic effects are produced.

Q fever is a worldwide disease with is common between humans and livestock. This disease is created by an obligate intracellular Rickettsia called Coxiella burnetii. This study was conducted to identify the amount of C.burnetii prevalence in the raw Sheep milk in Khorramabad and its surrounding towns. In this cross-sectional study (from Spring 2013 to Winter 2013), 72 Sheep milk samples were collected Randomly. These samples were tested for the presence of C. burnetii by the Nested PCR method.In this survey, number 15 out of 72 (20.83%) sheep milk samples were positive for C. burnetii. The prevalence of C. burnetii varied during different seasons The analysis of the collected data in different seasons and areas revealed that, more than 79/16 percent of the samples were negative and about 20.82 percent were positive in terms of C.burnetii presence. It can be concluded from this study the season and the region of sample collecting affects the amount of bacteria exerted, and that Sheep milk can be one of the potential sources of C. burnetii in Iran.

There are many health effects of prebiotic products. Apple juice is a beverage that is used in most countries. Aim of this study was producing prebiotic clear apple juice that moreover having healthy effects for consumers, have not any bad effects on its visual properties such as color and clarity that are important factors in increasing customer acceptance of the product. Prebiotic combinations such as Inulin, fructooligosaccharide and polydextrose, each of them were added to clear apple juice in three dosages: 1.5, 2.5 and 3.5 percent and one sample were prepared as a blank without adding any prebiotic. All of the samples were hold in 4 and 25 °c temperature for 6 month and their spectroscopic characteristics including a٭ (redness), b٭ (yellowness), l٭ (whiteness) and dE (color changing) On the first day of production and at intervals of one month for 6 months were measured. The results showed that increasing in temperature and time increases the rate of color changing for each sample in comparison to the control sample. In samples that contain inulin color changing was further than blank, and in samples that contain polydextrose and fructooligosaccharide it was less than blank. Increasing the amount of fibers has not noticeable effect on the color of samples and increasing in dosage of added material increases the variation amount in comparison to blank sample. Adding fructooligosaccharide and polydextrose in compare with inulin create greater transparency and less color changing in product and in terms of Colorimetric characteristics are more appropriate than inulin for adding to apple juice.

In order to increase the shelf life, improve availability and reduce the storage and transportation costs, our study aimed at concentrating of two kinds of juices obtained from two raspberry cultivars (modified black and wild red) by two new techniques of vacuum and microwave in three pressure levels 12, 38/5 and 100 kPa. The influence of concentration process and operational parameters (concentrating duration and pressure) on color factors (a*, b* and L*) and antioxidant activity of the final product were assessed. Considering that the samples color is influenced by the presence of anthocyanins, relationship between color and antioxidant activity were determined by a high coefficient of determination (R2=1). Results suggest color and anthocyanins deteriorate over time. Deterioration rate depends on the kind of concentration process and process pressure, being higher in evaporator-rotary technique and atmospheric pressure. Moreover, anthocyanin half-life times in the pressures 100, 38.5 and 12 kPa were 93.7, 97.7 and 103 min in evaporator-rotary technique and 146.5, 233 and 480 min in microwave technique for modified black raspberry, respectively while being 93.5, 115.5 and 117 min in evaporator-rotary and 118, 480 and 515 min in microwave technique for wild red raspberry, respectively.