نشریه فرآوری و نگهداری مواد غذایی
سال سیزدهم شماره 3 (پیاپی 31، پاییز 1400)

Today, contaminants from synthetic polymers have drawn attention to the use of biodegradable materials. Over the past two decades, the study of biodegradable materials derived from proteins and carbohydrates has expanded widely. These macromolecules can be a good alternative to synthetic polymers derived from petroleum derivatives. Films based on these natural materials, due to their biodegradability, can be a promising solution to the environmental problems caused by synthetic polymers. In addition to biodegradability, these films have good mechanical properties and poor permeability to water vapor, and it is necessary to take measures to improve their impermeability. Therefore, the aim of this study was to investigate the effect of adding titanium oxide nanoparticles and grape seed oil essential oil to sodium caseinate as a factor that enhances its properties.

Sodium caseinate-based nanocomposite films were prepared at different levels of titanium oxide nanoparticles (zero to 1.5%) and grape seed oil at different levels (0 to 500 ppm) based on the central composite experimental design (CCD). The effects of these variables on the physical and mechanical properties, water vapor permeability, antioxidant properties and microstructure of the produced films were investigated.

The results showed that the addition of titanium oxide nanoparticles improved the mechanical properties of sodium caseinate films. In this regard, sodium caseinate films prepared from 1.5% titanium nanoxide and 500 ppm grape seed essential oil have the highest tensile strength. The results of electron microscopy test showed that the addition of titanium oxide nanoparticles and increasing its concentration led to the indirect penetration of water, which reduced the permeability of the films to water vapor to 4.89 kg / m. The addition of grape seed oil essential oil also caused antioxidant effects in the produced films. So that the films containing 250 ppm of grape seed oil essential oil showed 74.86% antioxidant activity.

Overall, the results showed that the addition of titanium oxide nanoparticles and grape seed oil essential oil can have positive effects on the physical and Structural properties of sodium caseinate and help improve its properties. Overall, the results showed that the addition of titanium oxide nanoparticles and grape seed oil essential oil can have positive effects on the physical and Structural properties of sodium caseinate and help improve its properties. Overall, the results showed that the addition of titanium oxide nanoparticles and grape seed oil essential oil can have positive effects on the physical and Structural properties of sodium caseinate and help improve its properties.

Every year during marine fishing, some species that are caught are not suitable for human consumption, and they are known as surplus fishing or low consumption, which is an important factor in wasting these rich resources. Therefore, it is necessary to set arrangements to use such species for human consumption, including the production of surimi. In this regard, additives such as gums can be used to reform and improve the properties of surimi. Therefore, in this study, the possibility of producing surimi from Chacunda gizzard shad was investigated, and the effect of Konjac gum on the physicochemical and textural properties of the product produced from this type of fish was evaluated. In this study, Chacunda gizzard shad was purchased freshly from the dock in Local market in Bushehr (IRAN) and immediately transferred to the laboratory after being placed in an ice chamber. After preparing surimi, Konjac gum in concentrations of 0.25, 0.50, and 0.75 % (w/w) was added directly to the surimi. Then, to prepare the surimi gel, the samples were first placed in a water bath at 25 ° C for 3 hours and then heated at 90 ° C for 20 minutes. After cooling the samples with ice water, the necessary tests were performed on them. The produced surimi was evaluated in terms of chemical composition, water holding capacity, and color factors, and the study of tissue properties and sensory evaluation of the produced gels was performed and compared with the control sample (without gum). Based on the results, the percentage of ash, protein, and fat in the treatments did not change significantly compared to the control sample (p>0.05). As the contraction level of Konjac gum increased, the amount of moisture and water holding capacity of the surimi samples increased significantly. The lightness level (L*) of the surimi and surimi gel increased significantly with the addition of Konjac. The control sample and the sample containing 0.25% of Konjac in the surimi of Chacunda gizzard shad showed more yellowness and redness than other treatments. But in the resulting gel, the amounts of redness and yellowness between treatments were not significant. By increasing the concentration of Konjac in surimi gel, the parameters of texture (firmness, cohesiveness, adhesiveness, springiness, chewiness), breaking force and deformation increased significantly compared to the control sample. Sensory evaluations also showed that the panelists assigned the highest score to the 0.75 % Konjac treatment for surimi gel from the Chacunda gizzard shad. Based on the findings of the present study, it was found that Chacunda gizzard shad has the potential to produce surimi, and by adding Konjac gum, its properties can be improved.

Protease activity of various fruits and vegetables has been studied by previous researchers. Broccoli is one of the most abundant and affordable vegetables which is intrested by consumers and researchers due to its pleasant flavor and nutritional attributes e.g. anticancer and antioxidant compounds, such as sulforaphane, indole-3-carbinol and selenium. This study was conducted to investigate the effect of broccoli juice and soy sauce on physicochemical and textural characteristics of beefsteak with the aim of tenderizating and reducing aging time.

Meat samples were separated from the beef (Round Steak) muscle. The steak samples were cut into cubic pieces (10 cm3) with a weight of approximately 1 kg and free of fat. The marinade composition consisted of 2.6% (W/V) broccoli juice (Protease activity: 12.3 u/g) and 25% (W/V) soy sauce were prepared in three treatments compared to control and were injected into the superficial and deep segments. The samples were analysed at 1, 3, 24 and 48 hours storage in refrigerator (4 ° C ).

According to the results of analysis of variance, the tenderization parameters of all treatments were significantly higher than control (p<0.05). The value of tender parameters composed of myofibrillar fragmentation index, myofibrillar protein solubility, insoluble collagen and shear force were better in treatment containing broccoli + soy sauce than others. Also, scanning electron microscopy results of the treatment containing broccoli juice + soy sauce confirmed this finding. The highest and lowest mean value of drip loss were observed in soy sauce (1.97%) and broccoli juice (1.72%), respectively. In the present study, the rate of cooking loss decreased from 1 h to 48 h in all treatments. During tenderization period, the shear fore mean value of all treatments showed a significant decrease due to enzymatic activity and the progress of the meat aging process. The minimum shear force mean value were recorded in broccoli + soy sauce (128.5N), broccoli juice (151.1N), soy sauce (166.8N) and control (187.5N) respectively during cold storage. Based on our findings, the combination of broccoli juice and soy sauce can be used as an effective marinade in improving beefsteak tenderness.

The result of this study showed that, broccoli juice may have proteolytic components that are effective in myofibrillar proteins degredation. The proteolytic activity of these enzymes was higher at low pH. Therefore, the higher myofibrillar proteins degredation as well as their solubility were obtained in treatment containing broccoli + soy sauce.

saffron as the most expensive spice in the world contains compounds called crocins that grant it unique properties. Extraction and purification of this glycosidic compound is one of the major challenges in saffron processing. Graphene oxide (GO) is an excellent adsorbent due to its properties such as flat structure, high surface area, variety of oxygenated functional groups on the surface and the ease and cheapness of its production from graphite. Therefore, in this study, the extraction and purification of saffron crocins were evaluated using 3D nanostructure of GO modified with chitosan biopolymer.

Graphene oxide synthesis was conducted through improved Hummers method followed by modification with chitosan. 15 ml of crocin solution with different concentration (25, 50, 100 and 200 mg/ml) was mixed with 15mg of nanostructure and under controlled conditions (temperature, pH and stiring rate). In certain intervals (0-200 min), the amount of crocin in solution was determined through reading its absorption at 440 nm. Kinetics (pseudo first and second order models) and isotherms (Langmuir, Freundlich and Dubinin-Radushkevich isotherms) studies of process was investigated. The efficiency of nanostructure in crocin purification was assessed by HPLC at three wavelength of 250, 310 and 440 nm. In order to assess the ability of nanostructure in separation and purification of crocin, saffron extract was used. In order to remove picrocrocin and safranal, dried stigma of saffron was treated in two stages and then extraction was performed using distilled water. The nanostructure was washed with methanol and the extract injected to HPLC.

The best process conditions for crocin isolation were stirring speed = 300 rpm, temperature of 318 K, concentration of 100 mg/l and normal pH of saffron extract. Crocin adsorption was a physiosorption process and followed the pseudo-second-order model and the Freundlich isotherm. HPLC results showed that the purity of the isolated crocin was high and very close to the standard sample.

Instrumental analysis confirmed the formation of graphene oxide/chitosan nanostructures. The effect of process variables including pH, temperature, stirring speed and crocin solution concentration on the separation process efficiency was determined. The adsorption process of crocin on the nanostructures followed a pseudo-second-order model and the adsorption was physical. The results of this study showed that synthesized nanostructures can be well used in the purification process of valuable compounds.

Native starch granules obtained from different kinds of plants have unique and intrinsic characteristics that partially satisfy specific needs. However, those properties are essentially not suitable for most food applications. Hence, the starch must be modified chemically, physically, and enzymatically to improve its functional properties. Due to environmental concerns, strict regulations, and expensive price, physical modifications are receiving increasing attention. Some of the physical modifications applied to starch are pregelatinization, sonication, ball-milling, heat–moisture treatment, and pulsed electric field treatment (Zhu 2015). Among these options, pregelatinization is one of the most popular industrial methods of physically modifying starch. Pregelatinized starch is pre-cooked starch that readily disperses in cold water to form stable suspensions (Nakorn et al. 2009).

Native tapioca starch, containing 13.64% moisture, 0.94% fat, 11.26% protein, and 18.78% amylose was purchased from Sepahan Co. (Isfahan, Iran). The compositions were determined according to the approved methods of the AACC (2000). Amylose content was established by the iodine method reported by Pourmohammadi, Abedi, Hashemi, and Torri (2018). NaCl and CaCl2 were obtained from Fars Glucosin Co. (Marvdasht, Iran). Before each experiment, 5 g of tapioca starch was mixed with (for IS 0.3, 0.88 g and 0.6 g) and (for IS 0.6, 1.76 and 1.2g) of NaCl and CaCl2, respectively (w/w, starch basis) and then suspended in 50 mL of distilled water, and stirred overnight at room temperature then starch solutions were sonicated. Samples were divided two groups: first groups, pregelatinized by ultrasonication and then salts were added to starch solution (AUPS). Second groups salts were added and then sonicated (BUPS) (Fig. 1).Ultrasound- Assisted Pregelatinized Starch: Ultrasonic process was applied according to Abedi et al. (2019) in order to obtain ultrasound-pregelatinized tapioca (UPTS) starch. An ultrasonic generator type UP400S hielscher (400 W, 20 kHz) using an immersible probe in a 100-mL cylindrical jacket glass vessel (180×180 mm2) with the desired temperature (60 °C) and 10 min maintained by a circulating water bath, which varied with pulse durations of 5 s on and 5 s off. The probe was dipped into the 1-cm liquid at the top of the vessel, emitting the sound vibration into the fifty milliliters of tapioca starch (10% w/w) sample via a titanium alloy rod with a diameter of 20 mm.

Ca+2 ions improved the textural properties along with the reduction in syneresis (%) and this effects progressively improved with rising the ionic strength from 0.3 to 0.6. On the other hand, textural and syneresis properties improved following the addition of Ca+2 ions after sonication. Meanwhile, Na+ ions induce to decrease in textural characteristics and increase the syneresis (%) of starch paste and these effects increased with enhancing the ionic strengths from 0.3 to 0.6. The addition of Na+ ions had synergetic effect on negative impact on textural and syneresis properties which might due to the re-crystallization effect of Na+ ions that was proved by SEM morphology.

ions with structural maker or breaker nature with their Valente can affect on starch polymer, meanwhile, the application of ultrasonication along with salts have synegic effect on starch polymers.

Thymus vulgaris is one of the most well-known medicinal plants which its essential oil contains various active ingredients such as thymol and carvacrol with antioxidant, antibacterial, and antifungal activities. This essential oil is very sensitive and loses its properties against different factors. Microencapsulation process is performed for protecting volatile and sensitive compounds to chemical reactions. Modeling of this process can be effective in assessing and predicting conditions affecting on qualitative properties of the product. The purposes of this study are optimization of the production conditions of Thymus vulgaris essential oil microencapsulation and performance comparison of response surface and artificial neural network methods.

In this study, oil in water emulsions, consisting of 5% (weight/weight) of thyme essential oil in an aqueous suspension containing wall materials (10, 33.13, 20, 26.66 and 30%), with different protein (sodium caseinate) to polysaccharide (modified starch and maltodextrin) ratios (0, 66.6, 20, 33.33 and 40%), were prepared by the help of ultrasonic waves (30, 45, 75, 105 and 120 seconds) -. Microcapsules were prepared from prepared emulsions using freeze-drying and the effect of the above factors on the changes in quality characteristics of the capsules, including the microencapsulation efficiency according to the amount of microencapsulated essential oil, the amount of phenolic compounds, and preserved antioxidants were investigated.

The results of process modeling showed that in both methods, qualitative properties of microcapsules were increased with increasing wall concentration, protein-to-polysaccharide , ratio, and ultrasonic duration. Interaction between protein to polysaccharide ratio and ultrasonic time also improved the preservation of total phenolic compounds and antioxidant capacity of Thymus vulgaris essential oil in moderate levels of variables. 28% of wall concentration, 16% protein to polysaccharide ratio, 111 seconds of ultrasonic time and 29% of wall concentration, 18% of protein to polysaccharide ratio and 87 seconds of ultrasonic time were proposed as optimum points of neural network and response surface method, respectively. Among the optimized samples, the optimum sample obtained from the artificial neural network model showed higher total phenolic content and higher microencapsulation efficiency (P<0.05).

The results of this study showed that the independent variables were effective in the microencapsulation process And the protein to polysaccharide ratio had the greatest effect on it. Also, neural network with optimal topology was very effective than response surface methodology in predicting the qualitative characteristics of microencapsulation of Thymus vulgaris essential oil due to its unique ability in processing information and modeling complex systems.

Nowadays, the use of frozen dough and batter has been considered by both producers and consumers. Frozen dough technology has permeated all baking products, including cakes. However, the freezing process due to the formation of ice crystals can have destructive effects on the structure of the dough and the food. In addition, in the production of frozen bakery products, it is necessary to maintain the quality and improve the shelf life and quality of the final product through various additives. Therefore, in this study, we try to use additives including xylitol (5 and 10%) and xanthan (0.5 and 1%) along with heat-moisture treatment (HMT) in the preparation of frozen cake batter layer formulation.

In this cake, brown rice flour was used to produce a gluten-free cake. Flours were subjected to different heat and moisture treatments. The produced batter is then subjected to freezing and thawing, and finally the physicochemical properties of the batter were investigated.

The highest specific gravity of cake batter belonged to the samples prepared without HMT and the lowest weight belonged to the sample without additives and with HMT treatment. The peak value of the control starch distribution curve was higher than the treated starch and the particle size distribution of the control starch was relatively concentrated. D50 was calculated from starch granules for the control sample of 23.889 μm and the treated sample for 21.344 μm. Therefore, freezing and heat-humidity treatment led to a reduction in the average particle size of starch grains in the batter. The results show that the peak, trough and final viscosity of the samples containing xanthan were significantly higher (P0.05). Trough and peak viscosity increased with the addition of xylitol while decreasing viscosity decreased significantly. Xanthan-containing treatments had significantly higher viscosity. Also, with increasing xanthan concentration, viscosity increased significantly. After freezing and storage for one week, the number of bubbles and bubble uniformity decreased while the bubble size increased compared to freshly controlled batter. HMT process increased the initial (To), peak (Tp) and final (Tc) gelatinization temperature of the treated sample compared to the untreated sample. Addition of xanthan gum increased the viscosity of the batter, therefore, the onset temperature of gelatinization.

In this study, for the first time in Iran, frozen cake batter was produced and its properties were improved by adding xanthan and xylitol and applying heat-moisture treatment. In general, the results showed that by applying heat-moisture treatment and adding xylitol and xanthan, it is possible to reduce the defects related to reducing the quality of frozen cake dough, which can lead to its further use.

Rice is one of the most important agricultural products and main food for more than %25 people in the world. Due to increasing consumption of this product, evaluation of quality and characteristics of cultivated rice in different regions of country is of great importance. Additionally, over the past decades, heavy metals contamination in rice cause to be public concern, thus assessment of heavy metal pollution of rice is necessary. Evaluation the characteristics of rice varieties will allow consumers and producers to prepare rice according to their taste and need. Therefore, this study was conducted to evaluate the amount of lead and cadmium, physicochemical properties and cooking quality of champa rice in different regions of Baghmalek, Khuzestan.

In this study, rice cultivated in different regions of Baghmalek was sampled in three replications and transferred to the laboratory for testing. Physicochemical tests including protein, moisture content, ash, total solid, amylose content and thousand grain weight were evaluated based on national standard of Iran. Cadmium and lead content of rice cultivated in different region of Baghmalek were evaluated. Cooking properties of studied rice including cooking time, water absorption, leakage, gelatinization grade and Elongation of rice were evaluated. The tests were performed in a completely randomized design with SAS software and analyzed by Duncan test at a probability level of 5%.

The results of proximate test including (carbohydrate, protein, total solid, ash and moisture) showed that significant difference was between samples cultivated in different region of Baghmalek. In all samples, except for one samples, amylose content were 20-21%. The results of heavy metal evaluation indicated Cd in all samples were in permissible limit but lead content in imported rice and cultivated rice in Sidon and Meydavoud was more than permissible limit. Studied samples with regard to lenght were in medium category and Elongation of rice was in the range of 1.39-1.74. The gelatinization grade of studied samples was in the range of 3.25-4.17. Evaluation of cooking properties including cooking time, water absorption and leakage indicated it was significant difference between studied samples. Thousand grain weight of studied samples had been significant difference and was in the range of 13.07-18.86.

In general, selected rice samples from different regions of Baghmalek exhibited a significant difference in physicochemical properties. With regard to cooking properties and quality, rice samples had desirable status and were comparable to imported rice. Evaluation of the safety status of studied rice samples suggests that control of cultivated regions is necessary.