نشریه پژوهش های علوم و صنایع غذایی ایران
سال نوزدهم شماره 2 (پیاپی 80، خرداد و تیر 1402)

 Sweet Pepper (Capsicum annum) has a very important place among the vegetables produced in the world. Therefore, it is necessary to apply practical solutions to increase their sustainability to develop and improve production. The growing consumer rejection of chemical additives and the demand for more natural products have increased attention to some methods, including the drying method. One of the physical changes that occur during the drying of food is its reduction in volume. Vacuum drying is a method in which water and other solvents that have been absorbed into the volume or surface of the material are removed. Combining vacuum with heating can be an effective way to dry; because in this case, a high level of dryness can be achieved without the need for a large increase in temperature. A thermal process that is applied to vegetables and fruits as a pre-process step for freezing, drying and canning to inactivating enzymes, modifying texture, preserving flavor and nutrients, and extracting Interstitial air. 
 
 This study aimed to investigate the impact of various factors ethyloleate (concentrations 0,2,4%), sodium chloride(concentrations 0,2,4%) and blanching on the drying kinetics, physical properties, chemical composition and nutrients of green bell pepper, dried under vacuum at 60°C and pressure of 10 kpa using the response surface methodology. At the end of the drying time, 10 g of the treated samples were weighted to investigate the drying kinetics and the rest of the samples were kept for analysis. To achieve the drying kinetics, the samples were taken out of the oven (Behdad Company, model 3494, made in Iran) at 30 minute intervals and weighed by a digital scale, and dried down to moisture content of 12% ., and then for relevant analyzes on dried samples, the samples were stored in plastic packages until the day of experiments. Investigation of independent and interaction effects of immersion in different concentrations of sodium chloride and ethyloleate solution on the kinetics and drying time separately in blanching and non-blanching samples on the parameters of color, chlorophyll content, phenolic substances and vitamin C remaining in dried Sweet peppers were evaluated using minitab16 software and response level method (RSM).
 
 The results showed that the drying process occur in the range of falling rate and also effect blanching in boiling water for 3 minutes and immersed in an alkaline solution of ethyloleate and sodium chloride with concentrations of 2 and 4% for 1 minute, significantly increase the drying rate. In blanching and treated samples with 4% ethyloleate and sodium chloride, the drying time was about 3.5 hours, while the control sample was dried under the same conditions for 7.5 hours. Pretreatment of samples, showed the chlorophyll content, phenolic compounds and vitamin C were higher than the control sample. Due to the effectiveness of ethyloleate in the protection of ascorbic acid, phenolic compounds and residual chlorophyll, the highest amount of ascorbic acid with a value of 39.77 was related to the samples treated in ethyloleate solution with a concentration of 4% and 4% NaCl and the minimum value of 17.98 was related to the control treatment. The highest amount of residual chlorophyll was 23.6 in the pretreated samples with a concentration of 4% ethyloleate and 4% NaCl and the lowest amount was related to the control sample with a concentration of 12.9%. The color of the dried samples showed that the lowest amount of color changes was related to the non-blanching sample with 4% ethyloleate and 4% NaCl with a value of 4.94. While the blanching and ethyloleate solution had no positive effect on the color of pepper and dried samples were dark. Comparison of blanching with non-blanching shows that blanching samples cause darkening of the primary color of the samples.The best sample in terms of quality and speed of drying, was belonged to the samples which blanched, treated with 4% solution of ethyloleate and sodium chloride.
 
 In order to achieve the best quality in vacuum drying of pepper samples, pretreatments of blanching and using a concentration of 4% solution of ethyloleate and sodium chloride showed the most desirable quality. The best quality of dried samples were obtained when subjected to constant temperature and pressure during drying conditions. The benefits obtained using the pretreatment of ethyloleate and sodium chloride as an appropriate method of drying include increasing the absorption of water, keeping the chlorophyll, phenolic compounds and vitamin C content with time-saving in drying.

Sorghum is a valuable source of starch for human use, being a drought-tolerant cereal grain that contains a large amount of starch (approximately 70%). However, native sorghum starch has limited application in the food industry due to its poor functional properties. Modification of sorghum starch would overcome its shortcomings and tailor it to the targeted application. Among physical methods, non-thermal plasma is a novel method for starch modifications. Plasma is an ionized gas including electrons, atoms, ions, radicals, and quanta of electromagnetic radiation that affects the functional properties of starch. The effect of plasma on starch is influenced by apparatus type, treatment conditions (feed gas, time, and power), and the source of starch. Two main mechanisms of starch modification are known as  cross-linking and oxidation together with depolymerization. Although the effect of plasma on many types of starch has been investigated, no research has yet been found on sorghum starch modification by non-thermal plasma. So, this investigation determines the effects of non-thermal plasma on sorghum starch to overcome the deficiency of the native form and to explore wider applications for sorghum starch.
 

 Sorghum starch was extracted by alkaline steeping and purified using toluene-salt-water treatment. Dielectric Barrier Discharge (DBD) plasma was performed to modify sorghum starch. The applied DBD plasma setup consisted of two flat rectangular aluminum electrodes with the dimension of 6.5×45 cm and 7×18 cm and an electrode distance of 3 and 6 mm for air and argon plasma, respectively. Each of the electrodes was covered with a mica sheet as a dielectric barrier. DBD reactor was supplied with alternating current (AC). The frequency was adjusted to 375 Hz. Starch samples were treated for 1, 10, and 20 min at 23 kV at atmospheric pressure. The amylose content of sorghum starch was determined by iodine binding colorimetry. Evaluation of other chemical parameters including protein, lipid, ash, and moisture was carried out according to AAC methods. The clarity was determined using a spectrophotometer at 650 nm. The swelling and solubility of 1.5% sorghum starch suspension (at 55, 65, 75, and 85 °C) were measured using the centrifuge method. The centrifuge-filtration method was performed to evaluate freeze-thaw stability of sorghum starches up to 4 cycles.
 

 Chemical parameters showed that the extracted sorghum starch was purified. The amount of protein, lipid, ash, and amylose was 0.39, 0.15, 0.59, and 29.23%, respectively. Plasma caused significant altering in sorghum starch properties. Compared to the argon plasma, the air plasma was more effective at increasing the clarity, solubility, and freeze-thaw stability. Increasing the time of treatment also improved the above-mentioned functional properties. The clarity of native starch (14.02%) was increased to 56.10% for the sample treated with air plasma for 20 min, probably due to intense oxidation and depolymerization of starch molecules. While the lowest clarity (13.07%) belonged to the 1-min argon plasma treated sample, this value was improved with increasing time of treatment. Probably cross-linked bonds were predominantly formed during the first minute of argon plasma treatment, resulting in a reduction of paste clarity, while a competitive depolymerization and oxidation reaction could be a reason for the increase of paste clarity. Solubility was increased for all treatments (except for argon-1 min). The highest solubility in each of the temperatures was found for 20 min air plasma treated sample. Depolymerization of starch molecules under plasma treatment produces low molecular weight fragments which leach out easily and increase solubility. The swelling power of 20 min air plasma treated starch was lower than that of native starch, probably due to the structural disintegration. Other samples had higher swelling power. The lower freeze-thaw stability of 1 and 10 min argon plasma treated samples may be due to cross-linking which increase retrogradation. The 20 min air-plasma treated sample had higher stability than other samples in 3 and 4th cycles of freeze-thawing. The freeze-thawing stability of other samples was similar to that of the native starch.
 

 Non-thermal plasma treatment improved the functional properties of sorghum starch. The best results were detected for the sample treated with air plasma for 20 min. Cross-linking may be the main reaction in the first minute of argon-plasma treatment. However, this mechanism was suppressed in a longer treatment time. It may also be stated that the effect of oxidation along with depolymerization was predominant in air-plasma treatment.

 Natural preservatives extracted from herbs are important sources for bioactive compounds that can be used in protection of food products. Essential oils are aromatic oily liquids, obtained from plant material like flowers, buds, seeds, leaves, and roots. Unfortunately, most natural compounds are biologically instable, poorly soluble in water and they distribute poorly to target sites. Currently, some novel methods have been introduced in order to improve their stability and their bioavailability, among which is the use of liposomal encapsulation. Microencapsulation reduces reactivity with the environment (water, oxygen, light), decreases the evaporation or the transfer rate to the outside environment, promotes handling ability, masks taste and enhances dilution to achieve a uniform distribution in the final product when used in very small amounts. Essential oils, as natural extracted compounds extracted from plants, are unstable compounds with low water solubility and unable to achieve target cells. Essential oils encapsulation by nanoliposomes is a novel method for increasing their biological activity and protecting them from destructive factors. The aim of this study was production and optimization of nanoliposomes containing Z. teniur essential oil and investigating their antibacterial effects against pathogens (Staphylococcus aureus and Escherichia coli).
 
 Lipid film hydration method was used to produce nanoliposomes containing Z. teniur essential oil. Soy phosphatidylcholine and cholesterol were the main wall materials and chloroform was used as the mixing solvent . The particle size of nanoliposomes and their zeta-potential were investigated using laser diffraction method. In order to determine the minimum inhibitory concentration and the minimum bactericidal concentration of Z. teniur essential oil against examined bacteria, serial dilution method was used. Also, antioxidant activity of free and nano-encapsulated essential oil of Z. teniur was determined by DPPH method.
 
 According to the results, highest encapsulation efficiency achieved by using 80:20 ratio of soy phosphatidylcholine to cholesterol in nanoliposomes’ wall structures. In general, by increasing the ratio of phosphatidylcholine to cholesterol, encapsulation efficiency was improved. Zeta-potential of nanoliposomes was equal to -5.3 mv and mean particle sizes were in the range of 94.7-119.9 nm. Results indicated that essential oil ejection from nanoliposomes has direct relation to the time of storage and after 30 hours, ejection rate will increase considerably. Ejection rate was higher in phosphate buffer pH=7.4 in comparison with phosphate buffer pH=5.4. Minimum inhibitory concentration and minimum bactericidal concentration of free essential oil against Escherichia coli was 100 and 175 (µl/ml) respectively. Although, Minimum inhibitory concentration and minimum bactericidal concentration of nanoliposomes containing Z. teniur essential oil were equal to 75 and 150 (µl/ml) respectively. Also, results shown that , minimum inhibitory concentration and minimum bactericidal concentration of encapsulated Z. teniur essential oil against Staphylococcus aureus were lower in comparison with free form of Z. teniur essential oil. Staphylococcus aureus (as Gram-positive bacteria) was more susceptible than Escherichia coli (as Gram-negative bacteria).
 
 Encapsulation of Z. teniur essential oil by nanoliposomes led to improve antibacterial effects of essential oil against Staphylococcus aureus and Escherichia coli. Also, investigating of antioxidant activity showed that encapsulated Z. teniur essential oil in nanoliposomes was more effective than free form of Z. teniur essential oil in scavenging of DPPH free radicals. Using nanoliposome encapsulation technology can be an effective way for increasing the efficiency of natural antibacterial compounds and essential oils encapsulated in nanoliposomes are suitable alternatives for synthetic preservatives used in food industry nowadays. The use of liposomes containing Z. teniur essential oil can provide the necessary protection against growth of spoilage and pathogenic microorganisms such as Staphylococcus aureus and Escherichia coli in food products.

Mayonnaise is one types of sauces that has always been loved and preferred by consumers because of its unique texture and taste. Sauce is a semi-solid or liquid food ingredients that consists of emulsifying edible vegetable oils (at least 66%) in a liquid phase including vinegar, water, lemon juice, and egg yolk (Bortnowska and Makiewiewicz, 2006). According to the National Standard of Iran (No. 2454), if the amount of fat in mayonnaise is reduced by at least 25% (from 66% of fat), it is considered reduced fat mayonnaise, and if it is reduced by 50% in fat, mayonnaise is considered low-fat. (National Standard of Iran 2454, 1394). Fibers are edible parts of plants or similar carbohydrates that cannot be absorbed in the gut and only irritate the gut. Dietary fiber contains polysaccharides, oligosaccharides, lignin and related plant materials. Dietary fiber intake can reduce the risk of cardiovascular disease, high blood pressure, diabetes, obesity, cancer and some gastrointestinal disorders. They can alter tissue properties, eliminate hydration, stabilize high-fat foods and emulsions, and improve shelf life (Zhang et al., 2017). Barley (Avena sativa L.) is an important crop with about 21 million tons annually production worldwide. The seed has been used to raise public awareness about the health benefits of beta-glucan, which helps lower blood cholesterol and glucose levels. Protein is the second most abundant element (12 to 20%) in barley after starch, which contains organic amino acids, due to its high lysine content because globulins make up 70 to 80% of total barley protein. Alcohol-soluble prolamins, on the other hand, are the main storage proteins in other cereals (Nito et al., 2015).

 In this study, nitrate, ethanol, methanol, chloroform, ethylene glycol and acetic acid were prepared from Merck Company (Germany) and sunflower oil from Rana Company, vinegar from Somayeh Company, salt from Aali Company, sugar from Pardis Company, mustard from Bijan Company and Barley Malt Pulp was prepared from Behnoosh Company. Chemical extraction method was used to extract fiber. (Salehifar and Fadai Noghani, 2013). To prepare the mayonnaise samples, the powder ingredients including salt, mustard and sugar, vinegar and water were first mixed well and uniformly with a mixer (IKA WERK, Germany). Then, according to the formulation, the fiber extracted from barley malt pulp was gradually added to the above mixture, which was stirring, and the eggs were added to the mixture and mixed thoroughly to obtain a uniform composition. At this stage, the oil was added dropwise with continuous pouring. Finally, the samples of mayonnaise prepared were kept at refrigerator for further analysis. In all samples, the amount of sugar (11.5 g), white vinegar (23.1 g), eggs (39.45 g), salt (4.50 g), water (24.6 g) was constant (Bostani et al., 2011). In this study, in order to reduce the amount of oil, it was replaced with fiber extracted from barley malt pulp at five levels of 0, 5, 10, 15 and 20% (w / w).

 The effect of replacing different percentages of fibers extracted from barley malt pulp with fat at levels (5, 10, 15 and 20%) on physicochemical properties (fat, fiber, ash, viscosity and colorimetry (L*) a*, b*) and sensory characteristics (taste, smell, color, texture and general acceptance) were determined using analysis of variance at 5% probability level. Various properties of low-fat mayonnaise showed that as the percentage of barley malt fiber increased, the amount of fat, radiance and yellowness in low-fat mayonnaise treatments (P <0.05) decreased, and the addition of fiber increases the viscosity, fiber, ash and redness of mayonnaise, treatments (P> 0.05) as well as protein content. In the treatments, which was statistically significant (P> 0.05), the results of sensory evaluation of mayonnaise samples showed that the addition of fiber extracted from barley malt pulp resulted in a significant reduction in taste, texture, color and the general acceptance of mayonnaise samples (P <0.05), while the decrease in odor score was not statistically significant (P> 0.05), so that the treatment containing 20% barley malt fiber had the lowest sensory score (taste). Smell, texture, color, acceptance k Li) and treatments containing 5 and 10% barley malt fiber received the highest sensory scores (taste, odor, texture, color, general acceptance) from the panelists.

 According to the results, treatment 3 (containing 10% barley malt fiber) was introduced as the best treatment in the present study.

Sargassum and Padina are two genera of brown algae that are widely scattered in temperate regions. Sargassum species are categorized as tropical and sub-tropical brown seaweed which are valuable sources of bioactive compounds including dietary fibers, carotenoids, vitamins, and minerals. These brown algae demonstrate diverse biological activities such as antioxidant, antimicrobial, and anti‑Alzheimer, due to the presence of flavonoids, triterpenoids, flavonoids, sterols, polyphenols, and pheophytine. The genus Padina is scattered in many environmental conditions, mainly in the tropical marine waters, and belongs to the family Dictyotaceae. Some bioactive components isolated from Padina species have been demonstrated hypoglycemic, hypolipidemic, anti-obesity, hepatoprotective, cardioprotective, immunostimulatory, and antimicrobial activities., The aim of this study was to prepare an extract from two species of algae Padina and Sargsum by massaging and ultrasound assisted-methods  as well as analyzing their compounds and investigating the antioxidant, antimicrobial and enzymatic properties of the extracts. According to the obtained results, ultrasound assisted method was a suitable method for extraction. This extract can be used as a combination of antioxidant, antimicrobial, anti-Alzheimer's and nitrate reducing agent in food additives.

Chemical materials were supplied by Sigma-Aldrich GmbH (Sternheim, Germany). The algal species utilized in the current investigation; namely, Padina distromatic and Sargassum angustifolium were collected from the coastal region of Chabahar bandar, Sistan and Baluchistan Province, Iran. To eliminate all the impurities and extraneous materials, they were washed by using distilled water and then dried at ambient temperature (24-48 h) until the constant weight. Extraction by maceration was compared with the extraction using ultrasonic assisted method. Determination of chemical compounds was parformed using GC-MS device. Investigation of antioxidant properties and total polyphenol and flavonoid content were also performed. The degree of free radical scavenging was done according to DPPH method. Evaluation of antimicrobial effect of algae extracts were the main challenges in our research. S. aureus ATCC25923, Listeria innocua ATCC 33090, E. coli ATCC 25922 and S. typhi ATCC 6539 were used for antimicrobial test. Determination of minimum growth inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were performed using wells in agar.The enzymatic activity was also determined. In this study, the activity of acetylcholinesterase was investigated using the method introduced by Ellman et al. (1961) and also the activity of nitric oxidase was determined using a kit protocol (Nvand-Iran). Factorial experiment in the form of a completely randomized design was used to analyze the data. Duncan's multiple range test was used to determine the difference between the means at the 95% confidence level, and SAS software version 2.9 will used for statistical analysis.

The current study investigated the antioxidant, antibacterial, anti-inflammatory, and anti-Alzheimer’s attributes of two brown algae namely Padina distromatic and Sargassum angustifolium which were collected from the coastal region of Chabahar Bandar, Iran. The results clearly indicated that the type of algae and extraction techniques used in this investigation highly affected phytochemical compositions, antioxidant, AChE inhibitory, scavenging, and antimicrobial activities. Considering both extraction yield and phytochemical components, extraction by ultrasound assisted method provided better results. Among all algal extracts, UPE presented the highest AChE inhibitory activity, and antibacterial activity and USE presented the highest antioxidant activities, total phenols and flavonoids, reflecting the presence of various bioactive components. The extracts of two various seaweeds utilized in the current study highlighted considerable inhibitory action against four pathogenic bacteria. According to the observations of the antibacterial assay, S. aureus was the most sensitive microorganism, while L. innocua was revealed as the most resistant bacteria to the extracts of P. distromatic and S. angustifolium. Further, the chemical components responsible for the antioxidant, AChE inhibitory, and antibacterial power were confirmed by GC-MS analysis. The findings of the current investigation confirmed the potential of the health benefits and therapeutic effect of brown marine algae. Thus, the extract of P. distromatic and S. latifolium could be an effective supplement to be incorporated into the products’ formulation in the food and pharmaceutical industries as well as in medication to alleviate several disorders such as Alzheimer.

 All the different species of hazelnut trees produce edible nuts. Hazelnuts are one of the most nutritious nuts, with a protein content of about 12%. They are also a good source of energy, with a fat content of about 60%, and an excellent source of carbohydrates, half of which are dietary fiber. Hazelnuts also contain minerals (Ca, Mg, P, K), vitamins (E and B), and antioxidants. Hazelnut kernels may be eaten raw or roasted. Roasting alters and significantly enhances the color, texture, and appearance of nuts. These changes increase the overall palatability of the nuts and are mainly related to non-enzymatic browning. Non-enzymatic browning, however, causes a decrease in nutritional value due to decrease in protein digestibility and loss of essential amino acids. The most widely used nut roasting method is the convective heat transfer process, which is performed in a hot air oven working either in continuous mode or in batch systems. Therefore, modifying this process for improving product quality is very important. Color is among the most important quality attributes of dehydrated foods for consumers. Empirically, color is also an effective quality indicator because the brown pigments increase as the browning and caramelization reactions progress. Therefore, this study aimed to investigate the effect of high roasting temperature and storage time on color changes and oxidation of hazelnut paste oil.

 After getting hazelnut kernels, the Roasting process was performed with hot air at 130 and 170 ℃ for 20 minutes. Hazelnut paste is produced as practiced in the industry. Quality analysis was roasted hazelnut paste color changes and fat oxidation. L *, a *, b * color index, (∆E), acidity, and peroxide value were measured in three intervals (0, 10, 30 days’). All experiments were performed in three replications. Average Data was compared using one-way ANOVA and done by SPSS version 21.

 The main purpose of roasting is to improve the flavor, the color, and the crispy and crunchy texture of the product. The roasting process is very important to determine the characteristic roasted flavor and color of the product: in particular, temperature modulation is an important independent variable significantly affecting the quality features of hazelnut. In this study, ANOVA analysis results showed a significant difference between the treatments. Both roasting temperature and storage time affect the acidity and peroxide value. The increased temperature and storage increased the acidity and peroxide index, which indicated fat oxidation at higher temperatures. For ten days, the sample's peroxide value increased. After that, these parameters decreased because the first autoxidation products changing to the second product. Due to the release of free fatty acids after the basic hydrolysis of triglycerides, the acidity of the samples increased. The Browning color of roasted products was desirable. Discoloration during the roasting process of hazelnut kernels is mainly related to non-enzymatic browning. The brown pigments increase with the development of browning reactions. Results showed that the color index includes the L*, a*, b*, and ∆E values of the samples only affected by roasting temperature. With increasing the temperature, the L* value decreased but other values increased. Color indicators significantly changed and are not desirable for the consumers. The rate of color changes increased, including browning, indicating a non-enzymatic browning reaction in the samples during roasting.

According to the results, hazelnuts roasted at 130℃ introduced as the best treatment. It is recommended that the storage time does not exceed ten days.

 The consumption of milk and its products is considered as a main indicators of development of human societies. In order to promote the health of children and provide the sufficient amount of calcium and nutrients and make the consumption of these products attractive. Necessary measures should be taken to increase milk consumption in society and increase the diversity of these products (Keshtkaran et al., 2013). Gelatin as one of the gelling agents used in dairy desserts is a hydrocolloid with unique functional properties and has been used in various industries for a long time (Karim & Bhat, 2008). Gelatin is extracted from the partial hydrolysis of skin collagen, white connective tissue, and animal bones. One of the problems with using gelatin in dairy desserts is the instability at ambient temperature. Therefore, it is necessary to evaluate the characteristics of other native hydrocolloids as an alternative. Tragacanth is a dried gum secreted from several plant species and Iran is the largest exporter in the world. Structurally, the material is regular, odorless and hard. It can be used in various food products. The simultaneous utilization of hydrocolloid mixtures is used to create a synergistic property and to improve these products. Starch originated from a variety of sources , including corn, rice, wheat, potatoes, cassava, bananas, and sorghum (Murphy, 2000) is used in the food industry. Among the sources of starch production, wheat is cultivated in large quantities in Iran.

 In this study, pasteurized milk was purchased from Salamat Dairy Products Company, gelatin made in Pakistan, tragacanth gum and Gonabad wheat starch were purchased from Kian Shimi Company and sugar and vanilla were purchased from confectionery stores located in Mashhad. Ingredients for dessert production include 80% milk, 10% sugar, 0.1% vanilla, tragacanth gum at concentrations of 1.3%, 1%, and 0.7% and starch at concentrations of 3% , 2%, and 1% by weight (powder selection) according to the method of Tarrega et al. 2004 with a slight modification. A sample containing 1.5% gelatin was considered as a control sample. The mixture was heated to 90 ° C for 20 minutes, stirring at medium speed. The samples were then placed in special containers and cooled to ambient temperature. Prior to testing, the samples were refrigerated (4-5 ° C) for 24 hours. The samples were coded based on the concentration of gum and starch (: T% of tragacanth gum and: S% of wheat starch).

 The flow behavior in all dairy dessert samples was similar to the control  and was pseudoplastic type. The Power model was selected as the best model (R <98, RMSE> 1.6). As the concentrations of tragacanth gum and wheat starch increased, the parameters of hardness, consistency, adhesion and adhesion strength increased significantly, and the samples 0.7T2S, 0.7T3S and 1T, 1S had the same value in terms of all textural parameters. At constant concentration of starch, with increasing tragacanth gum from 0.7% to 1.3%, the rate of syneresis of samples decreased from 0.34% to 0.06% and at constant concentration of gum, with increasing concentration of wheat starch, Syneresis decreased significantly from 0.34 to 0.24%. Increasing the shelf life of the samples naturally led to an increase in syneresis. In the samples 0.7T3S, 1T3S, 1T2S, and 1.3T3S, the increase of syneresis occurred to a lesser extent.. According to the results of analysis of variance, the effect of gum on zeta potential was very significant (p <0.05). Increasing the concentration of hydrocolloids in most samples led to an increase in the amount of negative charge and zeta potential. In most samples, at a constant concentration of tragacanth gum, with increasing the concentration of wheat starch from 1% to 3%, the span decreased, while at a constant concentration of starch, the increase in tragacanth gum from 0.7% 0 to 1.3% led to increase the span. Among the dairy dessert samples, 5 dairy dessert samples include: 0.7T2S, 0.7T3S, 0.7T1S, 1T2S and 1.3T1S, were selected the best in terms of physical and rheological characteristics to the control sample. They were more similar, selected and used for sensory evaluation. The results of comparing the mean of the data showed that different concentrations of tragacanth gum and wheat starch had a significant effect on the sensory characteristics of the samples including: color, flavor, sweetness, adhesion, gum state and overall acceptance (P> 0.05) and increasing the concentration of tragacanth gum and wheat starch had no significant effect on other sensory properties (p> 0.05).

 In general, due to the similarities of the physical, rheological and sensory properties of the treatment samples with the control, 1S1T sample  was selected as the most suitable sample to replace the sample containing gelatin.

Lactic acid bacteria (LAB) and their bacteriocins are widely used as natural and safe preservatives in food products, to control both pathogenic and spoilage microorganisms. This study aimed to isolate and identify LAB from several traditionally produced fermented fruits and vegetables from different parts of Iran, screening their potentials for producing bacteriocin-like substances production and evaluate their antimicrobial activities against various pathogens. The effect of heat treatment and different pH values on the stability of bacteriocins were also assessed and compared with commercial nisin for their possible application in the food industry as an alternative to chemical preservatives.

 Lactic acid bacteria were isolated from several fermented products like hawthorn, mixed fruit pickles containing quince and apple, mango, and medlar. pickle, and tThe isolates were identified using phenotypic (physiological and biochemical) and genotypic (16S rDNA gene sequencing) methods followed by drawing phylogenetic tree based on the neighbor-joining method. The bacteriocins were prepared from the neutralized and cell-free supernatant (CFS). To precipitate the bacteriocins, ammonium sulfate (75%), potassium phosphate buffer, and methanol-chloroform were used, and extraction was completed with a high-speed centrifugecentrifugation. After freeze-drying, the precipitate was kept as crude bacteriocin. The bacteriocin activity was measured by the critical method, and the effect of heat, storage time and pH on the stability of bacteriocins was evaluated. The minimum inhibitory concentration (MIC) and the minimum inhibitory bactericidal concentration (MBC) of the examined bacteriocins were determined on against the pathogenic strains of Escherichia coli and Staphylococcus aureus and compared with commercial nisin.

 In this research, from 162 isolated strains of LAB, four isolates (10A, S6, Sa, and Ab) were selected based on the highest amount of antimicrobial compounds and diameter of the inhibitory zone against pathogenic strains. then the isolates were identified as different strains of Lactiplantibacillus plantarum (previously classified as Lactobacillus plantarum). The phylogenetic position of the isolates was determined by drawing a phylogenetic tree. The drawn tree consists of two clusters and the first cluster consist of two sub-clusters, with two different strains of L. plantarum in each of them. In the next step, bacteriocin of the isolates was extracted using saturated ammonium sulfate and high-speed (23000g) centrifugingcentrifugation. Partially purified bacteriocins from different species showed high inhibitory effects on tested indicators, which were estimated, for L. plantarum 3360 (10A) and L. plantarum lb51 (Ab), 64000 AU/ml against Staphylococcus aureus and Escherichia coli. All selected bacteriocins indicated a stable effect at different temperatures of 60 and 121°C for 20 min and 4 and -20°C for 6 months, this effect was the examined bacteriocins were also stable against at acidic and alkaline pHs too. Also, the inhibitory property decreased under very acidic (pH < 3) and very alkaline (pH > 8) conditions, but this reduction was not significant at the 95% confidence level. Bacteriocins with 64000 AU/mL activity had higher antimicrobial properties against the pathogens compared to an equal amount of commercial NiseenNisin-S (680 AU/mL). The results of MIC and MBC showed that isolates 10A and Ab have the highest inhibitory properties compared to other extracted bacteriocins and/or nisin. Since heat and chemical preservatives are used in food preparation, the stability of bacteriocins against heat and different pH is important, therefore, after extraction and purification, the extracted bacteriocins can be used as a biological preservative in the production of various food products in the range of acidic and alkaline pH, including juices, meat products, and sauces. Encapsulation of these peptides and their application in food products needs further investigation.

Wheat germ is a valuable nutritional supplement and a by-product of the flour milling industry used for animal feed and oil extraction. Quinone compounds found in wheat germ have anti-cancer properties that are abundantly found in wheat germ. The aim of this study was to investigate the effect of fermentation conditions on the bioactive compounds in wheat germ with anti-cancer properties. For this purpose, the Saccharomyces cerevisiae 5022 and Lactobacillus plantarum strain 1058 were used for fermentation of wheat germ under different pH levels (4.5, 6, and 7.5) over different time (24, 48, and 72h). Response Surface Methodology was used to find the optimal fermentation conditions and to investigate the effects of above-mentioned conditions on DPPH radical scavenging activity, total phenolics and dimethoxy benzoquinone (DMBQ) content. Moreover, the amounts of bio-peptides and gamma aminobutric acid (GABA) were also determined under optimum conditions.

To accomplish the fermentation process, 10 g of wheat germ was suspended in 200 mL of sodium phosphate buffer solution. Bacterial and yeast cells were then separated from the culture medium by a centrifugation at 6,000×g for 5 min at room temperature. The harvested cells were then washed with sterile phosphate buffer multiple times, resuspended in water to achieve a cell population of 108 CFU/mL, and finally homogenized using a vortex unit. The yeast and bacterial cells were incubated at 28° C and 37° C, respectively, for 24, 48, and 72 h at pH levels of 4.5, 6.0, and 7.5. Upon the completion of each fermentation process, the obtained samples were lyophilized. Total phenolic content (TPC) was measured using the method adapted  by Liu et al. (2017). Briefly, the Folin-Ciocalteu phenol reagent was diluted ten times using distilled water. Subsequently, 0.1 mL of the extract was mixed with 0.75 mL of the diluted reagent. After 10 min, 0.75 mL sodium carbonate solution (2% w/v) was added to the mixture and vortexed. The absorbance was measured at 765 nm by a spectrophotometer. The antioxidant activity of fermented wheat germs was assessed using the free radical scavenging activity of the samples evaluated through a DPPH radical assay. Briefly, 2 mL of wheat germ extract was diluted with 100 mL 90% methanol aqueous solution. The methanol extract was then mixed with 4 mL of DPPH stock solution. The tube was subsequently kept in the dark for 45 min. The absorbance of each sample was then read using a spectrophotometer at 517 nm (Adedoyin et al., 2013). Dimethoxy benzoquinone (DMBQ) content was measured by an HPLC system. Briefly, 10 g of lyophilized wheat germ sample was dissolved in 250 mL of distilled water and extracted three times by shaking with 200 mL of chloroform. The chloroform layers were collected, washed three times with distilled water, and exposed to sodium sulfate solution to induce drying of the sample. The filtrate was then evaporated using a vacuum evaporator at 30° C to achieve a stable dry material. The dried sample was thereafter dissolved in the mobile phase and injected into the HPLC column to determine the DMBQ content. The HPLC system was equipped with a C-18 column and a UV detector operating at 245 nm. The mobile phase consisted of 20% acetonitrile-80% water (v/v) mixture at a flow rate of 0.5 mL/min and a temperature of 25° C.

The highest biological activity was found when fermentation proceeded by L. plantarum under pH 6 for 48 h. Under these optimal conditions, total phenol content (3.33 mg of GAE/g), free DPPH radical scavenging (86.49%), dimethoxy benzoquinone content (DMBQ) (0.56 mg/g), peptide content (607 μg/mL) and gamma aminobutyric acid (GABA) (19983.88 mg/kg) were significantly higher than those of raw non-fermented samples. During the fermentation process, increasing the pH levels led to enhancement of antioxidant activity, total phenolic and DMBQ contents up to 48 h followed by a decline. Also, the fermentation time had a positive effect in the amount of the antioxidant activity, while it allowed an increased followed by a decrease in the contents of total phenolic and DMBQ. These findings underscore the importance of fermentation conditions of wheat germ by L. plantarum and Saccharomyces cerevisiae and can potentially serve as a promising way for the development of valuable products with anti-cancer and antioxidant functions.

 Marinated chicken meat is one of the traditional foods in Iran which is an indoor and outdoor popular food in different areas of Iran due to its convenience and pleasant taste. It is also one of the authentic foods which is categorized in Iranian traditional kebabs. This product is constituted of fresh pieces of chicken meat, diced in different pieces, marinated with salt, lemon juice, verjuice, vegetables, saffron, spices, fruits and oil and then supplied as fresh and/or frozen form. After the seasoning, it is grilled using a skewer. Therefore, it is necessary to investigate its microbial load, shelf life, and quality changes during storage. To the best of our knowledge, there are no reports on the chemical and microbial properties of processed chicken meat used as a factor to predict its shelf life. Thus, the present study was designed to examine the relationship between physicochemical, microbial and sensory properties of the marinated chicken meat during storage using symmetric multivariate (determination of correlation coefficients and principal components analysis) and asymmetric methods (partial least squares regression).

 In this study, 30 samples of marinated chicken meat were collected from restaurants. Then, the asymmetric method (completely randomized factorial and partial least squares regression) and symmetric method (coefficients of determination and Principal components analysis) were used for the study of chemical (aw, TVN, pH, O/R) and microbial (total count, Staphylococcus aureusand Escherichia coli) and organoleptic characteristics of samples on the storage days of 0, 3, 6 and 9.An aw meter was used to measure the aqueous activity (aw), an automatic Kjeldahl device was used to measure total volatile nitrogen (TVN) and a pH meter was used to measure pH and redox potential (O / R). The dilution method was used to count the total bacteria. The cooked meat and bird parker media were used to identify Staphylococcus aureus. The MPN method was used to identify Escherichia coli. Sensory evaluations were carried out by 10 trained panelists. All assessors of the internal sensory panel assumed the basic odor test and color vision test. Each sample contained 50g marinated chicken meat, which was given to panelists in plastic containers at room temperature. The color, odor and overall acceptance of the marinated chicken meat were assessed. Each evaluator randomly evaluated the samples and served drinking water before each evaluation. Each parameter was scored in a 5-point scaling ranging from 1 (lowest) to 5 (highest). The data on the physicochemical, sensory and microbial properties of marinated chicken meat were statistically analyzed using Minitab 15 software (Minitab Inc., State College, PA, USA). The mean values of the treatments were compared by Duncan's multiple range test at a confidence level of 95%. Each experiment was performed in three replications. The PCA and PLSR modeling were also performed on the datasets.

 Results from the statistical analysis suggest that the microbial and chemical parameters of marinated chicken meat were greatly capable of predicting its shelf life. Determination coefficients, principal components analysis (PCA), and partial least squares regression (PLSR) models are able to extract relevant information and offer an easy and promising approach for the interpretation microbial and chemical properties of samples and their correlation with shelf life. The obtained results indicated that three parameters including pH, redox potential and total count had the highest correlation with shelf life, recommended as the predictive components. The results of measuring water activity in chicken meat samples during storage at refrigerator temperature showed that the aw parameter did not change significantly during storage time in the samples while the pH, TVN and O / R parameters were significantly affected. Changes in the total count, Staphylococcus aureus and Escherichia coli were also significant during refrigeration. Sensory evaluation experiments showed that all samples had no signs of spoilage until the sixth day.

The obtained results indicated that three parameters including pH, redox potential and total count had the highest correlation with shelf life, recommended as the predictive components. Overall, we can produce a product with higher quality and shelf-life if high quality raw materials are supplied with suitable pH values and also, hygienic production is considered.

 Hydrocolloid is a term refers to all polysaccharides extracted from plants, seeds, and microbial sources that regardless of their biological and nutritional role has various functional properties in food products such as concentration and gel production of aqueous solutions, stabilization of foam, emulsions and dispersed systems, prevention of ice and sugar crystals, control of the release of flavor compounds and consequently control and improve food quality. Ultrasound has been widely used in the food industry due to its numerous physical and chemical effects. The effect of ultrasound is due to cavitation, heating, dynamic mobility and shear stresses to the sample. Today, ultrasound is used as a green new technology with unique effects on food storage and processing. One of the newest applications of ultrasound is altering the structure of polymers such as polysaccharides. Changes in the structure of hydrocolloids lead to modification in their functional properties.

 In this study, effect of ultrasonic waves, time (0-90 min) and processing temperature (25-75 °C) on physicochemical, rheological and functional properties of locust bean gum was investigated. In this regards, different parameters including changes in pH, solubility, minimum gelatinization concentration, viscosity and emulsifying properties (Emulsifying capacity, emulsion stability and particle dimensions) of treated locust bean gum were determined. Response surface methodology in central composite design was used to evaluate the effect of independent variables on qualitative properties of locust bean gum and model their changes. The best treatment condition was determined and the optimum treated samples were evaluated and compared in microstructure using scanning electron microscopy, rheological properties (rotational and oscillatory test) and Fourier transform infra-red.

 The results showed that with increasing the time of ultrasound treatment, pH, and viscosity of the hydrocolloid decreased and its solubility and minimum gel concentration increased. However, with increasing temperature, pH, minimum gelatinization concentration and hydrocolloid viscosity increased and its solubility decreased. Optimization of treatment conditions was performed by considering the achievement of the best hydrocolloid performance characteristics. Two different temperature and time conditions were proposed for the desirable treatment of the hydrocolloid using ultrasound. In the first case, the selection criteria were to achieve the best solubility and emulsifying properties of the hydrocolloid, and in the second case, the selection criteria were solubility and emulsifying properties improvement while maintaining the gelatinization properties of the hydrocolloid. Based on the desired quality factors, optimization was performed and the results showed that in the first optimal sample (treated at 40 ° C and 48.9 minutes), solubility and emulsifying properties and in the second optimal sample (treated at 66.67 ° C and 15 Min) by maintaining the gelation properties of hydrocolloid, the solubility of the hydrocolloid increased significantly. The performance of treated samples validated developed models. SEM results showed that the ultrasound increased three-dimensional structure of gum. The smaller microscopic structure was observed in untreated sample and the larger one was in treated with ultrasonic waves for 40.9 minutes at 40 ° C. Therefore, ultrasound caused agglomeration of treated freeze dried gum. It is noteworthy that several holes observed in the structure of treated gum with ultrasonic, which can increase solubility of the gum. The flow behavior of the sonicated and control samples showed that the viscosity of all samples decreased with increasing shear rate, which indicates their pseudoplastic behavior. At low shear rates (about 0.01 per second), the viscosity of the control sample was higher than that of the sonicated samples. However, at high shear rates (about 40 per second), viscosity of the three samples were almost the same. Therefore, the control sample was more affective to shear rate compared to the treated samples. The modulus of elasticity (G ') and viscosity (G' ') of the treated specimens were lower compared to the control. Also, the frequency sweep of samples shown that in the frequency range under study, G 'and G'' were frequency dependent and with increasing frequency, the amount of these two parameters increased. This observation indicates the influence of rheological properties of the samples on the frequency changes that are commonly observed in suspensions. At low frequencies, the predominance of viscous behavior over elastic was observed in all three control and ultrasonic samples (G ''> G ') and this feature was higher in the treated samples than the control. The modulus of elasticity and viscosity of the treated sample for 49 minutes was lower than other treated samples for 15 minutes, which shows the effect of ultrasound on the rheological properties of the hydrocolloid.

 The results of this study showed that ultrasonic waves provide a good opportunity to change the physical and functional properties of carob seed gum. It is possible to significantly improve the solubility and emulsifying activity of this hydrocolloid using ultrasound. It is necessary to determine the treatment conditions of the sample according to the intended application.

 Thermal process is the most prominent option for treating foods. During the heat treatment, food nutrients response simultaneously but adversely under pH, temperature, moisture, and other provided conditions. It might result in an irreversible transformation of composition and structure that influences oxidative stability and sensory properties. The use of antioxidants is one of the most common methods to prevent edible oils oxidation. Safety concerns of synthetic antioxidants including tert-butylhydroquinone (TBHQ) as food additives have led to increasing demands for natural ones. Phenolic compounds such as Gallic Acid (GA) and Methyl Gallate (MG) represent to possess markedly high activity to scavenge free radicals which are among the most powerful natural sources of oxidative inhibitors in foods. Apart from their antioxidant activity, GA and MG also exhibit multiple biological characteristics such as anti-atherogenic, anti-spasmodic, and anti-microbial activities. This study aimed to investigate the oxidative stability of the in-use sunflower (S) and palm (P) oils as affected by the GA, MG, (GA+MG), and TBHQ to clarify their antioxidant behavior.

Antioxidants Gallic acid, Methyl gallate and TBHQ (Purity>98%) were purchased from Sigma Aldrich, USA. All solvents and chemicals were provided from Merck, Germany and Sigma Aldrich, USA with analytical grade. Antioxidant-free sunflower and palm oil were prepared from Three Goals factory, Neyshabur, and potatoes (Agria variety) from Fariman region, Khorasan Razavi.

Chemical changes, oxidative stability and quality indices of the in-use sunflower oil (S) and palm (P) (65:35 w.t. %) were evaluated during 8-hour heat treatment at 180 °C through GA, MG, GA/MG (25:75, 50:50 and 25:75) and TBHQ. All experiments were carried out in quadruplicate, and data were subjected to analysis of variance (One-way-ANOVA). Mean data were compared based on Duncan's multiple range test at 5% level (p<0.05). Observations of the chemical properties showed that sample S mainly contained Linoleic fatty acid (61.53%) and Oleic acid (25.50%) and for sample P, Oleic acid (41.90%) and the saturated long-chain fatty acid of Palmitic acid (38.9%). Also, the total phenolic content (TPC) and tocopherol (TTC) of sample P were 53.12 and 185)µg.g-1(, respectively, and sample S were 36.01 and 490 )µg.g-1(. The results of oxidation stability test were analyzed based on Carbonyl value (CV), Conjugated diene value (CDV) and acidity (FFA) parameters. According to our findings, all parameters increased significantly at different speeds during the heat treatment (p<0.05). Moreover, the oxidative stability of the in-use oil was significantly promoted by the antioxidants added, meaning that the control treatment and the treatment containing synthetic antioxidant TBHQ had the highest and lowest FFA%, respectively. The CDV of the antioxidant-free treatment was reduced by 68.6% in the presence of GA75+MG25.In addition, the CV change rate of the antioxidant-free sample in the presence of TBHQ was reduced by 70.2%. It was concluded that the natural antioxidants were capable of being competed with TBHQ antioxidants.

The results of this study showed that the heat treatment affected the nutritional value, quality indexes and chemical structure of the treatments, decreasing the quality and stability of the oil. As observed, all FFA, CDV and CV parameters increased significantly at different speeds during 8-hour frying process. The analysis also indicated that the oxidative stability of the treatments increased at the presence of antioxidants during the heat treatment at 180 °C. Thus, the control treatment and the treatment containing synthetic antioxidant TBHQ had the highest and lowest acidity, respectively. Also, the CDV of the antioxidant-free treatment decreased by 68.6% in the presence of GA75+ MG25. In addition, the rate of CV changes was declined by 70.2% through the TBHQ. The results indicated the key role of this synthetic antioxidant in preventing the formation of secondary compounds in the advanced stages of oxidation.It is evident that most synthetic antioxidants are volatile and heat sensitive. Furthermore, there are some limitations in applying TBHQ to promote oxidative stability of food products due to its toxic potential. Evidences have also been reported on the mutation caused by  the synthetic antioxidant TBHQ in the living organism's body. Compared to synthetic antioxidants, natural polyphenolic antioxidants such as MG and GA which widely distribute in plants mainly have antioxidative properties. Compared to GA and MG, GA+MG antioxidants have a longer induction period and higher oxidative stability. Promoting oxidative stability with such an arrangement of antioxidants is a good option in taking advantage of this class of natural antioxidants. According to the results of this study, it can be inferred that with a slight increase in natural antioxidants levels, we might be able to obtain the oxidative stability level comparable to the behavior of synthetic antioxidant TBHQ. Of course, it is worth noting that the addition of natural antioxidants to food such as edible oils should also be done according to national and international standards.