IRANIAN JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Year:2016 | Volume:13 | Issue:61|Papers Count:19

A factorial experiment with 3 factor based on RCD was considered in order to evaluate effects of MAP and propolis on postharvest quality of spinach (Spinacia oleraceae cv. Varamin 88). The first factor was storage time in 4 levels of 7, 14, 21 and 28 days; second factor was gas mixture in 3 levels of air composition, O2 15%+CO2 5% and O2 5%+CO2 15%; and third factor was propolis on 3 levels of zero, 5% and 10%. The ANOVA results showed that all characters except chroma and chlorophyll b had significant differences at levels 1 and 5%. The amount of the acid Ascorbic was 275.1 mg/100gfw before storage and after a week this value modified to 171.1 mg/100gfw and after 14 days reached to 141 mg/100gfw. Using of propolis had statically significant effect in probability levels of 1 and 5% on hue angel, TSS, pH, acid, acid ascorbic, weight loss percent, and infection percent. Infection percent severely reduced affected by the use of propolis. The main effect of MAP treatment had significant influence on color indices, appearance quality, acid ascorbic content, weight loss and infection percents. Triple interaction of treatments had significant effect on ascorbic acid content at 5% level. Based on the obtained results use of 10% propolis and O2 5%+CO2 15% was the best treatment to increase the shelf life of spinach.

Fish is known as a perishable food because of its high amounts of polyunsaturated fatty acids and High quality protein. Accordingly, Edible coatings are used to delay spoilage and increase the shelf life of fish.The aim of this study is, using sodium alginate containing alpha-tocopherol antioxidant in order to increase the shelf life of rainbow trout fillet at refrigerator temperature (2±4 oC). In this study, trout fillets, first, were set in 6 orders including: treatments including control treatment, treatment with sodium alginate coating without alpha-tocopherol, treatment with sodium alginate coating containing 0.5%, 1%, 1.5% and 3% alpha-tocopherol, then stored at refrigerator temperature for 16 days in 6.These parameters were measured periodically (every 4 days): peroxide, free fatty acids, TBA and TVB-N. Statistical results demonstrated an increase in all value during storage time, and increasing trend in the control treatment slope was higher than other treatments. The lowest PV and TVB-N and TBA levels were observed in the treatment with sodium alginate coating containing 3% alphatocopherol. The treatment with sodium alginate coating containing 1.5% alpha-tocopherol had the lowest levels at the end of the storage time. According to the results of the present study, sodium alginate coating containing alpha-tocopherol reduces oxidation process in rainbow trout fillets stored in the refrigerator.

Salting-drying carp is a fish products traditionally consumed in Iran. So, in this study, physicochemical and organoleptic changes during processing and storage of salted-dried mullet were investigated. For this purpose, samples of fillet and gutted mullet were salted at 4 oC for 10 days, which was followed by sun drying and storage. Comparing the physicochemical analysis on raw and processed fish showed that the amount of moisture decreased during processing (P<0.05) and amount of salt, fat and total volatile bases nitrogen increased significantly. The protein and pH decreased in beginning of salting and then increased significantly. Thiobarbitoric acid content initially increased during salting and drying and then decreased (P<0.05). Organoleptic properties in fillet and gutted mullet were similar during different stages of processing (P>0.05). It was concluded that the use of salted-dried fillet for mullet had a better result.

In this research, ultrasound-osmotic dehydration kinetic of daikon was predicted by different activation function of neural network such as logarithm sigmoid and tangent hyperbolic. Solid gain and water loss were selected as outputs and immersion time, concentration of osmotic solution, pretreatment type and moisture content were chosen as inputs. In this study, in other to achieved best result in predicting ultrasound-osmotic parameters of daikon was used different arrangement of the two types of neural network. The result showed that using arrangement of type II network with tangent hyperbolic activation function can be predicted daikon ultrasound-osmotic dehydration with higher performance than type I network arrangement. Best configuration of neural network was obtained with 17 neuron per hidden layer. This network was able to predicted solid gain and water loss with R2 values 0.996 and 0.993. This innovative technique could be successfully applied for quantitative monitoring of daikon quality changes during ultrasound-osmotic dehydration process.

In this study, the influence of different cooking method on the oxidation lipid and heavy metal composition and sensory properties of Epinepheluscoioide fillets was evaluated. Cooking of Epinepheluscoioide was prepared according to common consumer techniques: poached, steamed, pan fried (no added oil), deep fried (in olive oil) and microwave. Thiobarbitoric acid (TBA) content was less than 3 mg MDA/ kg in cooked fillet with boiling, poaching, dry- frying and deep frying methods. The free fatty acid (FFA) content of the fillets was significantly reduced by the different cooking methods in compared with raw fish. There was the highest Ni concentration in raw samples. Co and cd concentrations were below limits of detection in all samples. The Cr and pb contents in the raw and cooked sapmles were not significantly different. The results of sensory properties were showed that the texture, odour, flavor, colour and overal likeness properties increased in pan- frying and deep- frying methods and there were not significantly different between boiling, poaching.

Molecular imprinting is an emerging technology for the synthesis of polymeric materials which have specific recognition sites complementary to the target molecule. In the recent few years, molecularly imprinted polymers are considered as the selective sorbents in detection, analytical processes and also drug delivery. There are some conventional methods commonly used in the components separation/recognition (i.e. qualitative or quantitative analysis in food and drugs industry) in natural or synthetic samples, however, there are some drawbacks, especially in complex samples, that limit the application of these methods. Recently, the use of molecular imprinted polymer due to high specific recognition, reliability and reusability, is growing rapidly and the technique has been successfully applied in various fields, ranging from food science, pharmaceutical, environmental science, arms industry and different sensors. It is also used to extract drugs, sugars, amino acids, toxins, pesticides and warfare agents. Although imprinted polymers have unique properties and can be easily prepared, the technique is still new to Iranian researchers, especially in food science field, and to improve and commercialize the technique, further attention and research is needed. In this paper, the concept of molecular imprinting, synthesis and analysis approaches and its application in food sample analysis were comprehensively reviewed.

Celiac disease is an autoimmune digestive disease that is caused by the digestion of gluten. and the only treatment of this disease is gluten-free diet. Therefore the production of gluten-free foods with acceptable quality to the patient is important. So the aim of this study was to investigate the effect of soy milk powder (0, 3, 5, 7 and 10%) as a natural additive on the technological and sensory properties of sorghum flour based gluten-free oil cake. Based on the results, the addition of soy milk powder to gluten free cakes formulation (especially at the level of 5%) decreased the specific weight of the dough. Also the results showed that soy milk powder increased moisture content of samples in all levels. Moreover the highest specific volume and porosity were observed in samples containing 5% soy milk powder. In addition, the results of texture evaluation showed by adding soy milk powder the firmness decreased in both periods (2hr and 1 week after baking). The sample containing 10% soy milk powder had firmer texture than the control sample during 2 hours after baking. Finally the samples containing less than 7% soy milk powder gain the highest scores in sensory evaluation and these samples introduced as the best gluten-free products to the market.

Drying of button mushroom in a combined infrared-hot air dryer at power of 150, 250 and 375 W, temperatures of 50, 60 and 70 °C and air flow rates of 1, 2 and 3 m/s was investigated. The effect of lamp power, temperature and air flow rate on time and drying rate, moisture diffusion coefficients and activation energy were evaluated in a completely randomized design. The results showed that the effect of lamp power, temperature and velocity of air displacement on the drying process of button mushroom production is significant (p<0.05). Increase in infrared lamp power from 150 to 375 W, causes an increase in temperature from 50 to 70 oC, and changes in the airflow rate from 1 to 3 m/s reduced the drying time of the samples 28.6, 42.7 and 15.5 %, respectively. Effective diffusivity coefficients of moisture and activation energy of button mushroom were between 6.2×10-9 to 19.7×10-9 m2/s and 23.76 to 30.73 kJ/mol, respectively. For modeling of the drying process, Page, Newton and Logarithmic models with average correlation coefficient equal 0.996, 0.988 and 0.998 and average standard error equal 0.023, 0.042 and 0.015, had lower error compared to the other models, respectively.

The aim of this study was to determine the effect of different levels (0, 2 & 1%) of dried waste of the red grape juice’s processing as a functional ingredient on the physicochemical parameters and functional properties of beef sausage. For this purpose, physic-chemical analysis including measurement of moisture, protein, fat, carbohydrate, pH and calorie content were carried out. Then, samples from the point of functional properties including Water Holding Capacity (WHC), Expressible Moisture Content (EMC) and cooking loss were evaluated. The results showed that the addition of dried waste from the processing of red grape has no significant effect on physic-chemical properties of samples except for ash and pH (p>0.05) and improved the functional properties through a significant increase in WHC, the reducing EMC and cooking loss in sample. Pearson correlation coefficients indicate a direct relationship between cooking loss and EMC and a reverse relationship between these two factors with WHC. Therefore, the use of the red grape dried waste as a rich source of fiber may improve the properties of technology, functional and nutritional value of the sausage.

It is important to increase storage quality of orange by using of natural coatings. In this research, quality of Thomson oranges coated with chitosan-clay nano composite edible coating and fogger - wax (fog production from Ortho Phenil Phenol by electro fogger with nano dimension) was compared with the sample without coating during storage. Orange quality properties were evaluated during storage for 3 months in a cold storage at 6oC temperature and 85-90% relative humidity. Results showed that fruits coated with chitosan-clay had highest pH, chroma, peel moisture and firmness compared to the other samples. Therefore, this nano coating increased fruit resistance to fungal diseases, retained peel fruit color and inner texture strength during storage. Amount of total soluble solid and acid total of fruit juice for fogger - wax coating decreased and increased during storage, which this trend could indicate fermentation phenomenon in the fruit. So using of chitosan-clay nano composite edible coating can be offered for prevention of decrease fruit quality during storage.

The aim of this research was the enzymatic hydrolysis of pumpkin (Cucurbita pepo) oil cake protein with pepsin to achieve bioactive peptides with the maximum anti-oxidative activity (DPPH radical scavenging activity). For this purpose in this study Response Surface Methodology and Central Composite Design with using 1-2% enzyme concentration, 2-5 hours of hydrolysis and 30-40 °c were examined as independent factors. The results showed that the peptides produced by 1% enzyme concentration, 30 °c and 2 hours of hydrolysis possessed the highest anti-oxidative activity based on the DPPH radical scavenging activity. The anti-oxidative activity of peptides at the optimum condition (82.07%) was to a large extent similar to the amount proposed by software (80.31%). R2 and adjusted R2 estimated by the software were 0.9522% and 0.9092% respectively. Based on the results, it is possible to produce bioactive peptides with high DPPH radical scavenging activity through the optimization of hydrolysis conditions.

Castor (Ricinus communis L.) is one of the medicinal plants that used in pharmaceuticals and cosmetics in developed countries. Oil extracted from this plant is one of the most valuable cathartic and laxative ingredients in medicine. Its oil is also used as biodiesel fuel. This study was carried out to investigate the quality, oil content and physicochemical properties of castor oil in comparison with the wild ones in Boroojerd region. The oil content, Iodine value, acid number, Reflective index, Acidity and ash were determined, 49-61.7 % (w/w), 68-85 (the mass of iodine in grams that is consumed by 100 grams of a oil), 0.36 - 0.90 (oleic acid %), 1/4771-1/4779, 1.9-4.5 (milligrams of Sodium hydroxide required to neutralize the free fatty acids in 1 g of oil) and 1.78-3.6 % respectively. Ricinoleic acid content of oil samples was determined by gas chromatograph method, it was 86.1- 90.4% (w/w). Castor oil varieties were significantly different for all traits at 5% level. The number 1161 (Hamadan) had more yield in the oil content. Thus, according to our results, if the purpose of planting these plants is highest economic yield, wild genotypes have the highest performance and genotype 1161 can be recommended for the Borujerd. Evaluation of physicochemical characteristics of wild castor seed oil belong in Borujerd has not been studied in comparison with usual cultivar. This study is the first report of the oil content and physicochemical characteristics of castor oil that was extracted from wild castor seeds collected in Iran and cultivation in the Borujerdand comparison with the cultivar.

Quality of food products depends upon the quality of the raw materials and pasta as an important food product which is commonly used is not except from this rule. Nowadays pasta is consumed as one of the most favorite food around the world and is considered to be a constant food in the list of the Iranian families’ main meal gradually. In the most countries, pasta is produced from semolina, but in our country normally is produced from white flour that causes lower quality in final product. The goal of this research is considering the effects of using the white flour, semolina and mixture of these flours on the quality of pasta. Five types of white flour, semolina, mixed white flour and semolina with different ratios, including 50% white flour- 50% semolina, 75% white flour- 25% semolina, 75% semolina - 25% white flour were used in producing of pasta. The content of moisture, ash, protein, dry and moist gluten and gluten index was determined. Pasta samples quality were assessed through cooking, cooking loss & color tests. The results showed that the quality of pasta with ratio 75% semolina-25% white flour is similar to the quality of pasta which is produced from 100% semolina. Therefore, regarding the high price of durum wheat; manufacturer could use such flour instead of 100% semolina to produce high quality product.

Demanding for low-fat products was increased because of the importance of the health for the population. But the production of low-fat gluten-free food is not considered. Therefore, in this study, sorghum b-glucan as a dietary fiber in levels of 0.25, 0.5, 0.75 and 1.0% respectively used as an alternative to 25, 50, 75 and 100% of the fat in the formulation of gluten-free rice cake. The results showed that by increasing the levels of b-glucan in the formulation, the moisture content and a* value were increased. However the highest amount of L* value was observed in sample containing 0.5 b- glucan. Also the sample containing 0.25 and 0.5% of b-glucan had the lower firmness than the other samples in 2 hours after baking. On the other hand the results of the firmness in one week after baking showed the texture of samples containing 0.25, 0.5 and 0.75% b-glucan was softer than the control. In addition, the results showed that the samples containing 0.25 and 0.50% b-glucan (especially samples containing 0.5% of dietary fiber), had the highest porosity and specific volume. Finally, the panelists samples containing 0.5% b-glucan (an example in which the 50% fat was replaced) were introduced as the best example in terms of sensory properties to supply the market.

The growing public awareness of health issues, encouraged manufacturers to produce low-fat products. But choosing the best kind of fat substitutes in low-fat products is very important and a key factor, and need especial attention of low fat products producers. Therefore melon seed flour in levels of 0, 5, 10, 15, 20, 25 and 30% were used to replace part of the oil in the formulation of mayonnaise and parameters such as pH, protein, fat, ash, firmness, color values and sensory characteristics (flavor, texture, rub flexibility, color and overall acceptability) were evaluated. According to the results, by increasing melon seed flour in formulation of mayonnaise the amount of pH, protein, ash, firmness and a* value were increased significantly. While the fat, L* and b* values were reduced by increasing melon seed flour. Finally the sensory evaluation results clearly showed that the sample containing 15% melon seed flour had the highest score in overall acceptability. So based on this research results, melon seed flour is introduced as a fat or oil replacer in different kind of sauces especially mayonnaise.

The use of hydrocolloid coatings is one of the pre-treatment methods to avoid excessive oil absorption during frying process. The aim of this work was to evaluate the influence of hydrocolloid coatings (carboxyl methyl cellulose (CMC), hydroxypropyl methylcellulose (HPMC), xanthan and zedo gum) at three concentrations (0.5, 1.0 and 1.5 % weight/volume) on the oil content and quality parameters of shrimp after frying process. The coated and uncoated (control) samples were packaged and stored at -20 °C and after a week were fried at 170 °C for 90 second in sunflower oil. The results showed that all hydrocolloid coatings reduced oil content of fried shrimp. The coated shrimps with 1.5 % HPMC solution had highest moisture content and lowest oil content than the other samples. All coated shrimps had darker color and softer texture than the control. Sensory evaluation indicated that all coated and uncoated shrimps were acceptable. Hence, the use of hydrocolloid coatings could be a suitable approach to production of ready-to-eat low-fat shrimp.

Synthetic preservatives and improver are used to increase shelf life and sensory properties that have harmful effect on human health. Giving to this issue, substitution of this component with substances with natural origin and sensory properties and shelf life increaser characteristic is important. In hence, we this study evaluate probably using of pumpkin in cake, sensory and microbial properties of the cake. According to the results, it is obvious that pumpkins have a positive impact on improving the physical and sensory properties of product. Sensory and physical properties of pumpkin cake with pumpkin showed that the sample containing 3% has been found as the best value to add to the cake. So that it increased shelf life of the product to 120 days; however, shelf life of the control sample (has anti mold but not pumpkin powder) was observed by 90 days. Giving the results of the experiments, we can report that pumpkin can be used to shelf life increasing and as well as physical and sensory properties improving of cake instead of synthetic preservatives and improver.