جستجوی مقالات مرتبط با کلیدواژه « عدد پراکسید » در نشریات گروه « صنایع غذایی »

Corn seed contains almost 5.5% of oil of which about 85% can be found in germs of seeds. Proper steps are necessary to take, from the point of view of harvesting time and percentage of moisture retaining in the seed during harvestinh time, to improve the quality of oil extracted from the seeds. In the present study, the effects of temperature at four levels (45, 55, 65 and 75 °C), seed moisture content at harvest time at three levels (30, 35 and 40% (d.b)), and hot air velocity at two levels (1 and 2 m/s) on the total oil content, oil color, free fatty acids and peroxide value were investigated. A factorial experiment in a completely randomized design was used to analyze the data and the mean comparison was conducted by Duncan's multiple-range test at α = 5%. Based on the results, the most appropriate drying temperature was found 55 °C, and the best moisture content at harvest time was found 30% d.b and the best hot air velocity was found 2 m/s. The peroxide value of samples (before drying and in all dried samples) was not significant because the treatments were not given enough time to begin the oxidation mechanism.

Acrylamide, also known as acrylic amide and prop-2-enamide, is a white, odorless, crystalline, water-soluble solid, with the chemical formula C3H5NO and relative molecular mass of 71.08. Acrylamide is classified by the International Agency for Research on Cancer (IARC) as a probable human carcinogen. Acrylamide is formed in some foods such as potato chips, French fries, and toast due to heating. French fries are one of the most popular products in the world; their texture characteristics and special taste are attractive to customers. The sensory attributes of French fries depend both on the raw material and technological parameters used for French fries production. A factor affecting the flavor and texture of French fries is the frying (temperature, time, and type of frying oil). They are widely consumed among teenagers and young people in the community, which makes this age group more exposed to the dangers of acrylamide. The major pathway leading to acrylamide formation in foods is a part of the Maillard reaction with free amino acid (Asparagine) and reducing sugars through the decarboxylation of the Schiff base in a Strecker-type reaction. Although the formation of acrylamide in foods has its major routes through asparagine and reducing sugars, several other formation routes are suggested via Acrolein and ammonia. Oil is one of the most important components in the preparation of French fries due to its heat transfer and effects on taste. Due to the use of oil at high temperatures for a long time, the deteriorative chemical processes of hydrolysis, oxidation, and polymerization occur. Finally, various compounds such as aldehydes, epoxides, hydroxy ketones, and decarboxylated compounds are formed; these compounds can be reacting with amino acids. Therefore, these compounds may react with the asparagine in potatoes and increase the concentration of acrylamide in fried potato products.

15 kg of Agria potatoes were prepared from the (SPI) Institute. Four kinds of oil (Sunflower oil, frying oil, and canola oil) were purchased from a chain store and soybean oil prepared from Korosh food industries. 1.5 liters of oil were poured into the fryer, the temperature reached 180°C and, stabilized. After 1 hour, 200 g of sliced potatoes (2×2×2 cm) was poured into the hot oil. Frying time was 5 min. Heated oil and fried potatoes were sampled for testing. The fryer remained on at 180°C. After 3 hours, the second sample of raw potatoes was fried for 5 min. The third and fourth samples were prepared 3 hours apart. GC-ECD method was used for acrylamide measurement. 2 g of sample and 20 ml of distilled water were poured into the Falcon tube. Then 3 ml of Carrez I, II solution was added to the solution and centrifuged at 5000 rpm. The water layer was discarded. Then 2 ml of hexane was added. The solution was centrifuged again. The hexane layer was discarded. 10 ml of the remaining solution was extracted with potassium bromide, bromic acid, and bromine water and injected into the GC. The fatty acid profile test was performed by ISIRI 13126 2 & 4 methods. ISIRI 4093 was used as a method for Peroxide value measurement. Anisidine and totox values are determined by methods defined in ISIRI 4093 was calculated by the ISIRI 4093 method. Data were verified by ANOVA variance analysis.

According to the obtained results, values of total monounsaturated fatty acids are canola oil (%65.74), frying oil (%39.32), sunflower oil (%23.11), and soybean oil (%22.00). Also total polyunsaturated fatty were determined 65.41, 61.04, 26.21 and 43.99% for sunflower, soybean, canola and frying oils respectively. Oils containing polyunsaturated fatty acids (PUFAs) have less resistant to oxidation than monounsaturated fatty acids (MUFAs). Oxidative stability decreases with increasing number of double bonds. Accordingly, oleic acid has the highest thermal stability among unsaturated fatty acids, followed by linoleic acid and the lowest stability of linolenic acid. The results of peroxide, anisidine, and totox values determination showed that changes in these factors are affected by time (P<0.05). At most heating times, the highest values of peroxide were observed in soybean oil, and the lowest values were observed in frying oil (P<0.05). In all treatments by increasing of heating time, the amounts of anisidine and totox values increased significantly (P<0.05). The results of statistical analysis of different treatments indicated that in most heating times, the highest levels of anisidine and totox values and the lowest values were observed in soybean oil and canola oil respectively. Increased Peroxide value indicates that the level of the primary lipid oxidation products increased, which resulted in the formation of hydroperoxides. Peroxide and anisidine values indicate the rate of oxidation reactions at the beginning and the end of the process. In fact, the totox values simultaneously measures the amount of peroxides and their degraded products and provides a better estimate of the progress of oxidative degradation of oils and fats. Based on the results obtained from calculate of the totox value, the oxidation ratio of the studied oils was as follows:Soybean oil > Sunflower oil > Frying oil > Canola oil.According to the results, by increasing of heating time, the amounts of acrylamide in all treatments increased significantly (P<0.05). Therefore, the highest amounts of acrylamide were obtained in soybean oil and the lowest values were observed in canola oil (P<0.05). The correlation coefficient between totox value and acrylamide at different heating time was as follows: In the first hour of heating (R2 = 0.967), in the fourth hour of heating (R2 = 0.95), after 7 hours (R2 = 0.646) and in the tenth hour of heating was equal (R2 = 0.98), respectively. It shows that the levels of totox and acrylamide had a high correlation with each other and in fact the values of totox had a direct effect on the values of acrylamide.

The amounts of unsaturated fatty acids are effective in the oxidation of oils, and this effect is mostly due to double bonds. Oxidation of oils produces primary oxidation (hydroperoxides) that are degraded and secondary oxidation products such as aldehydes, ketones, and other might be produced. Secondary oxidation products in oil might be converted to acrylamide precursors in food without the presence of sugars, and by increasing the production of these products, more acrylamide might be formed. The results of this study showed that there is a high correlation between acrylamide in fried potato samples with the totox values in the oils. Therefore, the type of oil and heating duration influenced on formation of acrylamide in French fries.

Peanut is a high-protein, nutrient-rich legume that is popular all around the world. Peanut butter is a kind of food paste made from ground roasted peanuts. It is found to be one of the most susceptible food products to oxidation due to its high content of PUFAs. Peroxide value is the only mentioned parameter for oxidation of peanut butter according to ISIRI 5690. Although oxidation pathways are mostly known, there are a lot of ambiguities about oxidation in real situations after production and during storage so there is a lack of studies in this field.   The present study investigated the effect of packaging and storage conditions on the oxidation of peanut butter in polypropylene single serving cup (PP) and polyethylene terepthalate (PET) jar due to widespread applications of these plastic materials in food industries. Peanut butter stabilized with mono and di-glycerides was filled in PP single serving cup (size: 30 g), and PET jar (250 g), then heat sealing was applied. Determination of chemical composition (moisture, fat, protein, sugar, ash and salt), fatty acids profile and microbial quality (total count, coliform, E. coli, coagulase positive Staphylococci, Salmonella, mold and yeast) was performed for produced samples. The study was conducted for 160 days at storage temperature of 4, 25 and 40°C on peanut butter and storage stability at specific time intervals (0, 30, 60, 90, 120, 160 days) was evaluated for changes in p-Anisidine value, peroxide value, acidity and sensory analysis. All analyses were carried out in triplicate and significant differences were determined using Duncan's multiple range test (p<0.05).   Peanut butter had a fat content of 54.55±0.85% which contained 80.92% unsaturated fatty acids (57.57% MUFAs and 23.35% PUFAs). PUFAs are susceptible to oxidation and are easily incorporated into the chain reaction mechanisms of lipid degradation. There was no sign of microbial contamination in produced peanut butter. Time and temperature had a significant interaction on peroxide value, p-Anisisdine value, acidity and sensory analyses in both of packaging materials. Different trends were observed in peroxide value data of peanut butter packaged in different plastics. Peroxide values were higher in PP compared with PET due to higher oxygen permeability through PP. PP cups stored at 40 ̊C had the highest amounts of peroxide value (52.55± 2.27 mEq/kg) and p-Anisisdine value (4.10± 0.22). Oxidation of peanut butter in PET jar occurred at lower rate. One notable point is that peroxide value at 40°C (4.61±1.04 mEq/kg) was less than 4°C (15.51±1.09 mEq/kg) and 25°C (14.19±0.78 mEq/kg) after 160 days. These values never reached the maximum standard limit (12 mEq/kg) at 40°C. Temperature of 4°C might not provide enough energy to convert hydroperoxides into other oxidation products so peroxides accumulated in peanut butter. Though significant differences were observed among data of acidity in both of packaging materials but differences were not large enough to be of value in a practical sense. As it was expected peanut butter did not provide its initial fresh taste especially at higher temperature but no sign of off-flavor and rancidity was detected by panelists. According to the obtained results,using polypropylene single serving cup for peanut butter led to decrease its shelf life due to its higher permeability to oxygen. In this situation samples should be kept under cold storage. To overcome this problem coated PP or other plastic materials with higher oxygen barrier properties are suggested. Peroxide value was the only indication of oxidation which was mentioned in ISIRI 5690, while it seems that determination of such a parameter in this product is not a proper index of quality.

The most important safety and quality concern of pistachio export is its contamination with aflatoxin and oxidation and hydrolysis of fats. Therfore, this study is aimed at investigating the effects of red pepper, black pepper, and bell pepper extracts on the amount of aflatoxin production and oxidation process in pistachio and its sensory properties. For this purpose, the antifungal activity of pepper extracts was first evaluated, and then, after coating pistachio samples with each type of pepper extracts by 0.1, 0.5, and 1 % (v/w) including nine treatments and one control, Aspergillus flavus was inoculated to pistachio samples. Then, aflatoxin amount, peroxide value, and sensory properties were measured and evaluated during the days of first, 30th and 60th of storage. The results showed the highest radial growth of fungal mycelium in control and the lowest radial growth of colonies was observed in red pepper extract at concentration of 105 µL/L, which had a significant difference with other concentration of this extract and with similar concentrations of black and bell pepper extracts (P<0.05). The lowest amount of aflatoxin was obtianed from treatments containing 1% of red pepper and black pepper extracts and highest in the control sample. Also, the results indicated that with increasing the extracts concentration, the peroxide value and sensory desirability decreased significantly. Treatment containing 0.5% of red pepper extract had the highest sensory desirability, and the extracts of 0.5% bell pepper and 0.5% black pepper were afterwards. The studied pepper extracts had a significant effect on reducing the amount of aflatoxin and improving the sensory properties of pistachio compared to the control during storage, and in general, pistachio sample coated with 0.5% red pepper extract is introduced as the best treatment.

In this research, the chemical characteristics of sesame, rapeseed and sunflower oils prepared in the presence of the customer were compared with similar industrial-refined samples during two months of storage. Their levels of iron, copper, arsenic, and lead were also measured. The average of moisture and sedimentation contents of refined oil samples and sesame and rapeseed oil samples prepared in the presence of the customer were in the range of Iranian standard, but the average values for sunflower oil samples prepared in the presence of the customer was higher than the Iranian standard limit. The mean of the refractive index, iodine, and saponification values of all samples was in the range of standard. The oxidative stability index of prepared oils in the presence of the customer was less than the standard. The mean acidity and peroxide value of all oil samples were in the standard range but increased significantly during storage so that all samples were unusable on the last day of storage. The anisidine value of all samples increased during storage so that the average of this index in oil samples prepared in the presence of the customer was not in the standard range from the 40th day of storage. The Totox index of all oil samples also increased during storage, which was higher in sunflower oil. The results also showed that the cox index of sunflower oil was higher than the others. The average of the studied metals in all oil samples was in the standard range. The findings of this study showed that industrial refined oils have better chemical properties and stability and it is suggested not to use oils prepared in the presence of the customer for frying and it is recommended that keep them for a short time to cooking purpose.

Meat and meat products undergo chemical and microbial spoilage during production, transportation, storage and consumption. Antimicrobial edible coatings containing natural herbal extracts and essential oil possess various benefits and are currently used to design novel active biodegradable packaging. Natural polysaccharides are considered as potentially good candidates to fabricate edible coatings and provide a shelf life extender. There are no researches in the literature concerning the potential effect of Carum copticum essential oil (CCEO) enriched Scutellaria lateriflora seed mucilage (SLSM) based edible coatings on the quality and shelf life of lamb during refrigeration storage. The objective of this study was therefore to investigate the inhibitory effect of CCEO loaded SLSM edible coating towards lipid oxidation and microbial spoilage of lamb during cold storage conditions.

In this study, SLSM was extracted from whole seeds using hot-water extraction. Edible coating was prepared by dissolving 2 g of the extracted SLSM and 0.1 g of Tween 80 in 100 mL of sterilized distilled water. The mixture was stirred and heated for 2 h. Afterwards, CCEO was added to the SLSM solution at 0, 1, 1.5, and 2%, and the obtained solution was used as an antimicrobial coating for extending the shelf-life of lamb slices. The control and the coated lamb samples were analyzed periodically for microbiological (total viable count, psychrotrophic count, Escherichia coli, Staphylococcus aureus and fungi), chemical (peroxide value and pH), and sensory characteristics (color, odor and overall acceptability).

SLSM extended the microbial shelf life of lamb by 3 days, whereas SLSM + 1% CCEO, SLSM + 1.5% CCEO and SLSM + 2% CCEO resulted in a significant shelf life extension of the lamb by 6, 6, and 6 days, respectively as compared to the control samples. The results demonstrate that the EO-rich edible coating functions as an oxygen barrier and, in turn, limits the growth of most important and aerobic psychrotrophic bacteria, i.e. Pseudomonas species, which are mainly responsible for the fresh lamb spoilage under aerobic conditions. The results showed that the pH of lamb coated with SLSM and samples containing CCEO was lower than the control. The results showed that the peroxide value in the control sample increased from 0.4 to 9.7 meq oxygen/kg during 9 days of refrigerated storage. Based on the finding of this study, the use of CCEO-loaded coating manifestly lowered the meat lipid oxidation. The resultant edible coating manifestly improved the shelf life of lamb through suppressing microbial spoilage and inhibiting lipid oxidation. The coating containing 2% CCEO conferred good quality characteristics to the lamb and expanded its refrigeration shelf life.

There are different ways to reduce the risk of spoilage and increase the shelf life of agricultural products, one of which is ultraviolet radiation. The UV irradiation system has seven UV-C lamps, that for microbial deactivation, the effects of lamps number (3, 5 and 7), the distance of lamps from pistachio kernels (10, 20 and 30 cm), and the UV-C radiation time (15, 20 and 30 minutes) were evaluated. Based on Aspergillus flavus inactivation, the application of 3 lamps, the distance of 10 cm, and the irradiation time of 30 minutes were selected as the best treatment for irradiation of dry pistachio kernels. The results indicated that UV-C irradiation had no significant effect on peroxide and acidity values (p <0.05), but UV-C irradiation caused a significant (p<0.05) increases of the total phenolic content in pistachio kernels. According to the panelists scores, the texture of irradiated sample obtained a higher score than the control sample. However, no significant difference was observed in terms of other sensory characteristics (appearance, aroma, and taste) between the irradiated and control samples.

Lipid oxidation is the main factor for degradation of fats and fat containing foods. The progression of fat oxidation can be investigated by oxidative stability tests as well as physical and chemical methods.
In this study, the possible correlation between peroxide and diene conjugated values and between anisidine and triene conjugated values in raw and roasted hazelnut samples were investigated. To test
the so called correlation the samples were stored in accelerated shelf-life conditions at 55, 65 and 75°C. The results showed that the peroxide, anisidine, conjugated diene and triene values in raw
hazelnut oil were 0.29 meq O2/kg, 0.22, 0.817 and 0.081, and for roasted hazelnut oil were 0.967 meq O2/kg, 0.456, 1.347 and 0.22, respectively. First order linear equations with high regression
coefficient (93- 99%) could describe the correlation between the peroxide and conjugated diene values and between the anisidine and conjugated triene values. The highest regression coefficient
(98%) was observed for raw and roasted hazelnuts oil was determined at 75 °C As per the lack of significant difference (P>./05) between the components of equations obtained for both raw and
roasted samples at different temperatures (at 55, 65 and 75 °C), a general equation was used to express the correlation between the defined indices. Finally, a high correlation was found between the
actual values and the predicted values related to deterioration indicators.

Persian walnut (Juglans regia) from Juglandaceae family is one of the most important fruits in the world that has an important role in human health. It contains a notable list of plant nutrients that has been found to have disease preventing and health promoting properties. Walnut is a source of bioactive compounds such as phenolic and flavonoid complexes where they act as antioxidants and free radical scavengers. It also contains pleasant flavor and high concentration of minerals and fatty acids. Extending shelf-life of this perishable fruit has been accomplished due to its high oil level and oxidation of oil (Tajeddin, 2004). Rate of loss in walnut kernel quality and quantity between harvest and consumption affects its productivity. Control of temperature is the most effective tool for extending the shelf life of fresh horticultural products. However, to reduce high losses and keeping product’s quality, packaging method is very important as well as low temperature. Therefore, in this study, the effect of temperature (4 and 25 oC) and packaging methods (vacuum and air packaging) on the changes of walnut kernel compounds was evaluated to improve quality of its storability during six month cold storage. Walnut harvested from a commercial garden at the mountain regional of Raber, Kerman province. All chemical materials for different tests obtained from Merck Company, Germany. Immediately after walnuts harvesting, they were dehulled and dried in expose of sun shade with the circulation of natural air. The walnuts were then transferred to the laboratory and their wooden shells were removed. Subsequently, about 25 g of walnut kernel was packaged in the polyethylene films with 87μm (0.087 mm) thickness, under a vacuum machine and stored at 4°C and 25°C to be later assessed for further analyses intended for six months. Phenol, flavonoid, carbohydrate, protein, water percent, color parameters (C, h, WI), organoleptic characteristics, and peroxide value of kernels were measured every month during storage time. The control samples of packaged walnuts under environmental conditions were also stored. The current study carried out as a factorial assay on the basis of a completely randomized design with three replications at Hormozgan University. Data were subjected to ANOVA using SAS software version 9.4. Verification of significant differences was done using Duncan's Test at 1% probability level. Results showed that carbohydrate and proteins decreased during storage time. Both of vacuum package and low temperature contorted the reduction of different characteristics of kernel such as bioactive compounds during storage significantly. Sensory properties were also reduced during storage, especially at the end of period, in all conditions except for treatment at 4°C and vacuum packing. Control samples (temperature 25°C and air-containing packags) during the experiment showed a lower quality for all factors. Samples that stored in low temperature and vacuum package had better brightness (higher chroma, Hugh, lightness (L) and white index values (Wi)) than other treatments. The treatments had a significant role in the preventing of increasing peroxide value. The peroxide value in treated samples was increased from 0.023 to 0.68 meq/g, while in vacuum packages it was changed from 0.023 to 0.37 meq/g. Increasing of peroxide value was observed from 0.023 to 0.68 and from 0.023 to 0.25 meq/g in room temperature and cold temperature, respectively. After six months, the average peroxide value in all samples was less than one milliequivalent per oil kilogram. Decreasing of phenolic compounds (30%) and flavonoids (35%) and increasing the peroxide index simultaneously led to the reduction of the appearance and organoleptic properties of the control samples. Generally, vacuum package and low temperature condition that using in this study showed the best effect on the nutritional compounds quality of walnut kernel such as bioactive components during six months storage. Shelf life enhancement of walnut by vacuum packaging in the different polymers has been already reported by Tajeddin, 2004.

In this study the kernel and almond ground are placed in the accelerated condition (45, 60 and 75 °C) and then their shelf-life are estimated by Arrhenius equation. Also kernel and almond ground are placed in the actual environmental conditions for 10 months and are evaluated their oxidation process and finally kernel andalmondground’s shelf-life are compared with the estimated time of accelerated test. The measured indexes included peroxide value for measuring the first products of oxidation andconjugated trienes value was considered as second oxidation products scale during the spoilage. The lowest rate constant of hydroperoxides and conjugated trienes was obtained in 45 °C for almond Kernel and the highest rate constant was obtained in 75 °C for almond ground. The highest activationenergy and acceleration factor are 56.18 and 1.83 KJ/molK for each 10 °Ctemperature change (Q10) for hydroperoxides and the lowest value of making conjugated trienes was 37.44 and 1.5 KJ/molK by the extractedoil of almond ground during the acceleratedstorage and keeping. According to the results of mean error of shelf-life predication was obtained 49 percent by peroxide value and was obtained 27.25 percent by conjugated trienes and the conjugated trienes had better estimation of shelf-life than peroxide.

Oxidative stability of walnut (Juglansregia L.) was evaluated over a period of 1 year storage in various conditions. The whole walnuts, walnut kernels, walnut chopped kernels, walnut kernels packaged in polyethylene (PET) under vacuum and poly propylene (PP) contain of CO2 were kept in a normal condition (temperature, 19-30˚С and relative humidity (RH), 35-45%). The whole walnuts and walnut kernels were also kept in refrigerator (4˚С, RH 75%). Some quality parameters for the oil extracted from walnut kernels were measured throughout the storage. Peroxide value of whole walnuts, walnut kernels and walnut chopped kernels pass over 2 meq O2/kg after 12, 10 and 8 months storage, respectively. Peroxide value of the packaged nuts and the nuts stored at cold storage were increased only 1 meq O2/kg over a period of 1 year storage. According to the statistically analysis results, the effect of storage condition and storage time on oxidative stability of walnuts were significant (p walnuts shell > contact surface of walnut kernels with environment were defined to maintain the quality of walnut kernels during long term storage.

Lipids and oils are susceptible to oxidation. Analytical protocols are requiredfor measuring their oxidation progress. Spectrophotometric, iodometric, andcolorimetric methods may apply for measuring the early stages of lipid oxidation.In this study, walnut samples were selected and were kept shelled or unshelled at62, 72 and 82˚С to evaluate the relationship between peroxide value andconjugated diene value. A number of chemical and physical characteristics ofwalnut kernel oil were determined. Measuring walnut oil conjugated dienes wascarried out spectrophotometrically by reading UV absorption at 233 nm. Peroxidevalue was measured by conventional titration method. The results showed thatperoxide value, conjugated diene value and acidity (by oleic acid) of fresh walnutwere 0.3 meqO2/kg, 4.354 μmol/g and 0.064 %, respectively. First order linearequations were found to correlate peroxide and conjugated diene values inextracted oil from whole walnut and in walnut kernel, during storage at differenttemperatures (62, 72 and 82˚С), with a regression coefficient of 0.98 and 0.99. Ageneralized equation was used for expressing the relationship between peroxideand conjugated diene values in walnut, because there was no significant differencebetween the equations slopes and intercepts for three temperature conditions andtwo walnut forms.

Consumption of food containing cholesterol and saturated fatty acids such as butter can increase serum cholesterol and cause cardiovascular diseases. Therefore many efforts have been done for decreasing these constituents in foods. In this study, hazelnut and walnut powders were added to butter samples in amounts of 0 (not enriched sample), 10, 20 and 30% for evaluation of chemical characteristics (acid value, peroxide value and oxidative stability). Samples were then packed in 2 forms; vacuum and common packed and stored for 90 days at 5°C in refrigerator and were analyzed every 30 days. Adding hazelnut and walnut to butter samples caused significant increase in acid value of samples. Also rising trend of acid value in nut enriched samples was higher during storage. Control samples (without nut) showed higher peroxide value than nut enriched samples. During storage both control and nut enriched samples showed significant increase in peroxide value. Although all of nut enriched samples’ peroxide value were lower than standard limit during storage. Vacuum packed samples also showed lower acid and peroxide value than common packed samples. Adding nuts to butter samples also caused a decrease in oxidative stability of butter samples. This study shows that butter enriched in hazelnut and walnut can be introduced as a new and functional dairy product to consumers, because of its essential fatty acids content.

The influence of different levels of NaFeEDTA compound on the physicochemical and sensory properties of Petit Beurre biscuit was evaluated. NaFeEDTA was added to biscuit formulation in levels of 576، 720، 864، 1008 and 1152 mg/kg so that 100 gram of fortified biscuits to be contained 7. 2، 9، 10. 8، 12. 6 and 14. 4 mg iron/100 g respectively. Fortified biscuits were stored in polyethylene pouches for 60 days under ambient temperature condition (17-20°c) and far from light. Fortification with NaFeEDTA had not significant effect on pH، moisture and ash content of fortified comparing to the control. The data measured an Atomic Absorption instrument showed that iron content was significantly different between the fortified and control samples (P<0. 05). The percent of iron loss for fortified samples ranged between 2. 63%، 0. 33%، 0. 64%، 2. 53% and 1. 18% respectively. The peroxide value was increased in all samples during a 60-day storage period; however this increase was higher in the fortified biscuits as compared to control especially after 28 days. NaFeEDTA compound at different levels had not significant effect on breaking strength of fortified biscuits. Sensory evaluations were showed that the addition of NaFeEDTA to the biscuit formula have significant effect (P<0. 05) on the color، texture، and flavor of fortified biscuits. With regard to the results and also the use of NaFeEDTA in the proposed fortification range (10 mg iron، 67 mg EDTA/person per day)، 720 mg/kg (9 mg iron/100 g) level of NaFeEDTA as an optimum level for biscuit fortification was suggested.

In this experiment، acetone was used to extract the phenolic compounds of grape pomace by colorimetric method (Folin-Ciocalteu). The phenolics extract levels of 50، 150، 250 and 350 ppm were used to assess their antioxidant activity in raw soybean oil. On day 0، 4، 8 and 12 the proxide value for soybean oil was estimated. Also، the TBA value for soybean oil on day 0، 5، 9 and 13 was estimated. The results showed that the phenolic compounds whose content in grape pomace is 64 g/kg DM has an antioxidant activity. The level of 150 ppm of tannin extract from grape pomace showed a desirable activity to prevent the oxidation of raw soybean oil. The antioxidant activity of this level was higher than those obtained by the level 200 ppm from synthetic antioxidants. Therefore، the use of phenolic compound in grape pomace as natural antioxidants can be recommended.

Some physico-chemical characteristics of Iranian linseed oil (Linum usitatissimum) such as oil content (44. 25%)، refractive index (1. 47)، peroxide (7. 21meqO2/Kg Oil)، iodine (170. 67gI2/100g Oil)، acid (3. 10mgNaOH/g Oil) and saponification (191. 73mgKOH/g Oil) values and fatty acid profile (C:، C18:0، C18:1، C18:2، C18:3) were studied. For preservation of ω-3 ingredients، the linseed oil that containing 43. 18% of ω-3 fatty acid، were kept in frozen condition (nitrogen atmosphere and -30 º C temperatures) and its peroxide value was determined after 0، 7، 30، 60 and 90 days. Statistical analysis showed significant difference (p<5%) average amount of peroxide value only in first 7 days of storage time and its increase (8. 30%) conformed to international standard.