نشریه فناوری های جدید در صنعت غذا
سال ششم شماره 4 (پیاپی 24، تابستان 1398)

In the present study, the effects of temperatures (40-60 °C) and different times (5-60 min) on polyphenols and flavonoids extraction kinetics using ultrasound bath were investigated, and The IC50 values of DPPH free radical scavenging activity and reducing power of the extracts were calculated. The results showed that the extraction efficiency of phenolic and flavonoid compounds increased with temperature. Also, the highest yield of these compounds were obtained during the first 15 min of extraction, and after that the slope of the extraction decreased. The highest value of phenolic compounds (165.35± 47.69 and 171.13± 36.56 µg GA/g of DW of extract) and flavonoid (9.43± 0.80 and 10.35± 0.93 µg QE/g of DW of extract) were obtained at 15 min, and 50 and 60 ° C, respectively, without significant difference. Therefore, the extraction process can be divided into two stages of rapid extraction and slow extraction. Using the kinetic curves, the maximum efficiency of the antioxidant compounds of ginger rhizome can be found with the least effective time and temperature. In addition, the results showed that ultrasound has a significant effect on the extraction of bioactive compounds from ginger rhizome compared to the traditional method.

Lycopene is a carotenoid pigment withsome special health attributes, which have attracted many researchers’ attention as a valuable ingredient. The stability of many bioactive compounds is limited due to various physicochemical and physiological processes. For this purpose, the application of different encapsulation methods for controlled release and improved stability of bioactive compounds is of great importance. In this study, the effect of various solution concentrations (15, 20, 25, 30 and 35 %w/v) on the production of zein fibers was studied. The optimized concentration was then, applied for the encapsulation process of lycopene at two levels (0.05, 0.075 %w/w). The physical and chemical properties of lycopene-containing zein fibers and the profile of lycopene release in three phases of gastrointestinal (GI) tract (mouth, stomach and small intestine) were investigated. The results of scanning electron microscopy (SEM) showed that uniform, homogeneous and beads-free fibers were obtained at the optimum conditions. The lycopene loading efficiency was measured between 85.68-88.07%. The results of FTIR test indicate that the physical entrapment of lycopene in zein microfibers was successfully occurred. In addition, controlled and stable release of lycopene in the GI simulated system which shows its appropriate bioaccessibility was observed. Encapsulation using zein electrospun microfiber has the potential to serve as a targeted delivery system for lycopene. The use of this method is therefore, recommended for the encapsulation of lycopene in the food industry.

Application of novel technologies such as microwaves pretreatment of oil seeds might increase efficiency of oil extraction, a higher quantity of nutraceuticals, and a better oxidative stability of oil. In this study, Milk thistle seeds were pretreated with microwaves (800W) for two different times(2min and 4min), to investigate the process of enhancing oil extraction yield, physicochemical properties, tocopherols and fatty acids profile of milk thistle seeds oil extracted from Iranian ecotype, namely Babak Castle (in East Azarbaijan). To compare the results, oil was also extracted from non-treated Milk thistle seed by solvent as control sample. Results showed that microwave pretreatment of Milk thistle seed increased the oil extraction yield, Total phenolic content, and tocopherols of the oil extracted by solvent. Some physicochemical properties of seed oil such as chlorophyll content (1.03-1.91 mg pheophytin/kg oil) and saponification value (181-188 mg KOH/g oil) increased, but acid value (4.20-2.14 mg KOH/g oil), peroxide value (6.22-3.23 meq O2/kg oil), and iodine value (109-100 g I2/100g oil) decreased by treatment with microwaves. Microwave pretreatment of milk thistle seeds showed negligible influence on profile and the amount of fatty acids in obtained extracts, while among the fatty acids, oleic and linoleic acids decreased, but palmitic and stearic acids increased by treatment with microwaves. Moreover, the results showed that the longer pretreatment with microwaves resulted in slightly lower unsaturated fatty acids contents from Milk thistle seed oil. In conclusion, the results recognized microwaves pretreatment as a promising technique for intensification of oil extraction and tocopherols of oil from milk thistle seeds.

Harvested rice has a high moisture content and it should be reduced to avoid corruption. In this study, the hot air drying was used to evaluate the kinetics of drying. This research was carried out under three variables including hot air velocity ( 0.65 , 0.8 m/s), hot air temperature ( 50 , 65 0C), and final moisture content (11, 13%). Modeling of rice drying was done by a multilayer perceptron artificial neural network. In order to evaluate the performance of training algorithms and transfer functions in predicting the drying behavior of paddy rice, three algorithms including Levenberg Marquardt, Resilient Bach Propagation and Scale Conjugate Gradient and two transfer functions including logsig and tansig were used. The results showed that the maximum drying time was approximately 8 hours at temperature of 500C, hot air velocity of 0.65 m/s and final moisture content of 11% and the minimum drying time was 1.21 hours at temperature of 650C, hot air velocity of 8 m/s and final moisture content of 13%. In general, the drying time decreased with increasing the temperature, hot air velocity and final moisture content. Also, the results of modeling showed that the levenberg Marquardt training algorithm had the best performance compared to the other algorithms. In general the topology of 3-11-1 with levenberg Marquardt training algorithm and logsig transfer function had the lowest mean square error and the highest correlation coefficient.

Artificial Neural Networks (ANNs) are powerful modeling techniques that work in brief with arrays of neurons in memory and biological learning. In this research, the classification of dynamic and quasi-static loading type (broad and thin edge) was investigated using input data of phenol, antioxidant, vitamin C content and stiffness with artificial neural network. In this experiment for the classification of two Radial basic function and Multilayer perceptron networks were used with two hyperbolic tangent and sigmoid activation functions in one layer. According to the obtained results, the best value for R and Percent Correct for dynamic loading was (Percent Correct = 100 - R = 9999997), loading the thin edge (Percent Correct = 100 - R = 9999993) and loading the wide edge (Percent Correct = 100 - R = 9999992), which was created in the RBF network with a sigmoid function activation and 8 neurons in the one hidden layer. Also, the most accurate data found for the dynamic loading type, the wide edge and the thin edge was observed in the networks created for the RBF network, and this network has been able to 100% accurately classify the data rate for all loads. In sum, the neural network with the input of general data has the desirable capability in the stacking of dynamic loading and quasi-static data.

Rice and corn flours are appropriate alternatives for developing gluten free products and modification of some of their properties by different processes could be effective for improvement of gluten-free products quality. This study was conducted to study the effect of extrusion process on physic-chemical properties of free-gluten blend flour of rice and corn (1:1 ratio). For this purpose, extrusion treatments with variables of die temperature (110, 145 and 180 °C) and feed moisture (12, 15 and 18 %) were applied and features of water absorption and solubility index, damaged starch, color parameters, bulk density and thermal properties by DSC were investigated. The results showed that applying the extrusion process lead to significant changes in all measured features so that the water absorption, solubility index and damaged starch were increased from 1.88 g/g, 4.5% and 8 UCD in control sample to 4.4-7.1 g/g, 11.4-28.5% and 20.2-28.8 UCD in treated samples respectively, whereas bulk density and lightness were reduced. Study of thermal properties showed that gelatinization temperatures including onset (To), peak (Tp) and conclusion (Tc) temperatures were raised significantly but gelatinization enthalpy (∆E) was decreased. Finally due to occurred changes in flour samples during extrusion process, it could be concluded that this process can be suitable pretreatment for production of flours with different functional properties that may be useful for preparation of various gluten-free products.

The aim of this study was to investigate the properties of oil in water nanoemulsion stabilized with whey protein isolate (1% w/v) and quince seed mucilage (0.1 and 0.5% w/v) by low energy method of spontaneous emulsification and high energy method of ultrasound homogenizer. Since the main problem in utilization of spontaneous emulsification method is the use of high amounts of synthetic surfactants, one of the objectives of this study was to investigate the effect of different surfactant to oil ratios (SOR= 1:1, 2:1 and 3:2) and ultrasonic bath supplementation on spontaneous nanoemulsion properties. Nanoemulsion characteristics such as particle size, zeta potential, viscosity and stability of nanoemulsion were studied. In this study, nanoemulsions with the particle size less than 200 nm were well prepared. Increasing the mucilage concentration and the surfactant to oil ratio resulted in a significant reduction in particle size, a slight increase in zeta potential (increase in negativity), increased viscosity, decreased creaming index and increased emulsions stability index. The nanoemulsions from the high energy method and the nanoemulsions treated with ultrasonic bath have the lowest particle size, creaming index, and highest emulsions stability index. The results of this study showed that by a simple treatment with an ultrasonic bath, it was possible to create spontaneous nanoemulsions with very small particle size (with nm dimensions) without using high concentrations of synthetic surfactants.

The food industry generate large amount of wastes annually around the world Food wastes are excellent source of nutritional compounds such as proteins, dietary fibers, antioxidants, and several types of micronutrients Therefore management of recycling food by-products is more valuable with maximum efficiency, in order to manufacture added value and low cost food products. Recently the processing of various types of by- products by extrusion cooking technology has been considered as a high- efficiency process. In this project, the rotatable central composite design was used to investigate the effects of formulation variables containing tomato pomace : rice bran ratio (25: 75-75: 25% w/w), feed moisture content (12-18%) and extrusion conditions including screw speed (120-160rpm) on functional and physicochemical properties of extruded fiber supplement from (tomato pomace- rice bran) including (oil absorption index, bulk density, color indexes (L،* a*,b*) , antioxidant activity and water activity (aW)). The results showed that properties of extrudates were affected by formulation and extrusion conditions. Enhancement of screw speed increased oil absorption index The addition of fiber supplement increased the color indexes(a*,b*) whereas lightness (L*) and bulk density decreased. Increasing screw speed and moisture content caused a decrease in the antioxidant activity. By increasing moisture content and tomato pomace increased water activity (aW) of extruded products. According to optimization results, to provide a modified fiber supplement for application in dietary foods optimum condition was found to be the tomato pomace : rice bran ratio of (25: 75% w/w), screw speed of (137/63 rpm) and moisture content of (13/26%) that required to obtain oil absorption index (2/60g/g) , bulk density (0/6g/cm3) , lightness (L*)(57/18) , antioxidant activity (35/14) and water activity (aW)(0/17).

In this study, biodegradable blend based on wheat starch, gelatin and polyvinyl alcohol was prepared and ethanolic extract of propolis (5, 10 and 20 %) (EPE) as antimicrobial and antioxidant agent was incorporated. The films were prepared by solvent casting method and their microstructural, mechanical, barrier, color, antioxidant and antimicrobial properties were investigated. In the control sample, homogenous structure was not formed due to the incompatibility of the biopolymers with each other, while the addition of EPE caused to formation of uniform structure and cracks were decreased according to SEM observations. FT-IR test approved the formation of new interactions between biopolymers and components of EPE. Addition of EPE caused to decrease the tensile strength, water vapor permeability and opacity. But the elongation to break and yellowness index increased. Total phenol content and antioxidant capacity of the films increased with increasing concentrations of EPE. Different concentrations of EPE significantly affected all properties of the film, exception water absorption. The films containing EPE had more antimicrobial effects on S.aureus compared to E.coli bacteria. Generally, the film containing EPE 10% demonstrated the best physicochemical and functional characteristics. Results of this research revealed that the blend film activated with propolis extract is a good candidate for antioxidant and antimicrobial packaging and increasing the shelf life of foods.

Conditions of enzymatic hydrolysis including time, enzyme types, and degree of hydrolysis is impressive on biological activities of the protein hydrolysate. The aim of the present research was to consider the effect of pepsin, chymotrypsin and combination of two enzymes (E/S:10/1, 5 hr, 37 °C), also the time and degree of hydrolysis on the production of antioxidant peptides from Spirulina platensis protein that was extracted through sonication treatment ( 200 W, 20 KHz, 5 min). The progress of enzymatic hydrolysis and antioxidant activity were considered‏ through the time of hydrolysis by respectively, O-phethaldialdehyde (OPA) and DPPH and ABTS radicals scavenging assays. The content of free amino groups reached from 3.272 to respectively, 3.653, 4.552, 3.713 µM Leu/mg protein for samples hydrolyzed by pepsin, chymotrypsin, and combined enzymes. Antioxidant activity increased by the progress of hydrolysis and finally DPPH and ABTS radicals scavenging activity increased to 23 and 110 after 150 min hydrolysis by pepsin, and to 18 and 159 after 120 min hydrolysis by chymotrypsin. Hydrolysis by combined enzymes Increased DPPH and ABTS radicals scavenging activities to respectively, 25 µM TE/mg protein ( after 90 min) and 230 µM TE/mg protein (after 210 min). Altogether, Our results confirmed the production of antioxidant peptides through pepsin and chymotrypsin hydrolysis of. Also, our results showed that chymotrypsin was more effective compared to pepsin and a combination of two enzymes was more effective for producing antioxidant peptides from Spirulina platensis.