فصلنامه پژوهش و نوآوری در علوم و صنایع غذایی
سال دوازدهم شماره 3 (پاییز 1402)

The traditional methods of grading dates, due to the lack of specific characteristics, have led to incorrect grading and wasting both time and money. Date grading based on the classification algorithms could reduce seller and buyer disagreement. It also allows the product to be sold at the right price. In this research, identification of some qualitative characteristics of Mazafati dates and its classification into four categories (grades 1, 2, 3, and 4) has been done according to the opinions extracted from experts  Intending to define a significant link between the quality of dates, mobile image processing application conducted in in Matlab, support vector machine (SVM) was The results of linear, quadratic, cubic, and medium Gaussian SVMs were 100% accurate, meaning that the classification had been  successful. The ROC curve provided a positive classification rate versus a false positive rate for selecting classification training. A grade 1 positive rate of 0.97 indicates that the current classifier allocates 0.97 of the observations correctly to the positive class (primarily rank). In order to make the final verification, the Kappa coefficient was used. All Kappa values are greater than 0.6 and have sufficient stability. Also, the highest Kappa coefficient was related to the cubic method by more than 0.8 and the lowest one was related to fine Gaussian with a value of 0.76. Due to the accuracy and precision of implementation with SVM, this method with high efficiency wascapable of grading dates.

In this research, the possibility of cinnamaldehyde encapsulating with high amylose starch using ultrasound treatment was studied. The resulting microcapsules had an average size of 636.36±59.041 nm. The included cinnamaldehyde was 53.44±1.29, which only increased by 3 percent during 28 days of storage. Also, cinnamaldehyde release was investigated under simulated mouth conditions including temperature, saliva composition, and shear stress, using SPME-GC-MS, which was followed by analytical modeling. Among analytical kinetic models, zero-degree, Korsmeyer-Peppas, and Makoid-Banakar models during in-mouth release, and Korsmeyer-Peppas model during storage had the greatest agreements with release profiles. Using the results a  3 phase, 2D, constant source , reservoir model was simulated and solved using Comsol Multiphysics 5.6. Mesh independence analysis and low RMSE (1.78×10-6) alongside high R2 (0.997) indicated the model’s success in predicting the release of cinnamaldehyde in simulated mouth conditions. Investigating the role of physiological factors and microcapsules properties revealed that interpersonal differences play a more important role in determining the release behavior of cinnamaldehyde from high amylose starch capsules. Model parameters were also optimized using the SNOPT algorithm.

Baking bread is one of the most important stages of bread preparation. The purpose of this research is to investigate the effect of bread baking substrate to improve the quality of produced bread. In this research, the cast iron substrate was used as a reference surface and two ceramic and clay coatings were applied on the cast iron surface for comparison. In order to check the properties of coatings, microstructure, microhardness, hardness measurement, thickness measurement, and thermal shock tests were performed, and finally, the quality of the resulting bread was evaluated according to texture evaluation criteria, staleness test, measurement of heavy metals and sensory evaluation. To analyze the data, ANOVA was used to compare the mean and Duncan's test was used to group the treatments. Based on the conducted studies, it was found that the use of clay and ceramics as a coating on the cast iron substrate, with the protection mechanism of pollution transfer, reduces the transfer of chemical pollution of heavy metals to bread. The highest number of heavy metals including lead 0.565 µg/kg, cadmium 0.023 µg/kg and iron 4.470 mg/kg was obtained in bread produced in cast iron bed. The highest number of heavy metals was obtained in bread produced in cast iron bed and the lowest number of heavy metals was obtained in bread baked in ceramic bed. The samples baked on the cast iron bed had less hardness than the samples baked on the clay and ceramic bed. From the sensory point of view, the highest score for bread baked in a ceramic bed was 4.900 and the lowest score for bread baked in a clay bed was 3.126.

Hot green pepper (Capsicum annuum) is a commonly used spice , that is highly spoilable due to  high moisture content. Therefore, drying is valuable in order to reduce volume, transportation cost and longer shelf life. For this purpose, using an ultrasound-vacuum bath and a water bath-vacuum (50 and 70 °C), under vacuum condition, until reaching 50% humidity were used as a pre-treatment. Then all samples were dried using microwave (360 w) until reaching 10% final moisture content. The diffusion coefficient of hot green pepper slices was calculated using the Fick diffusion model. Applying ultrasound-vacuum pretreatment caused a decrease of the drying time, and increased the diffusion coefficient and drying speed of the product in the microwave sample compared to other samples significantly (P<0.05). Ultrasonic pretreatment significantly reduced changes in the percentage of size change and browning index and increased the rehydration ratio of the sample significantly (P<0.05). In general, applying ultrasonic as a pre-treatment helps to dry green pepper in microwave conditions and increases the speed of drying in microwave and better maintaining the physical characteristics of the product. Finally, the use of ultrasonic can be a perspective to produce a product with better quality and appearance characteristics and more marketability.

In this research, the effectiveness of zein nanofibers containing three concentrations (1, 2, and 3%, w/w) of barije essential oil was investigated to increase the shelf life of shrimp at refrigerated temperature (4±1 °C). Firstly, the minimum growth inhibitory concentration, minimum lethal concentration of Barija essential oil and the amount of inhibitory halo of nanofiber samples containing essential oil during agar diffusion test against bacteria Staphylococcus aureus and Escherichia coli were investigated. Also, the antimicrobial, physicochemical and oxidation properties of coated shrimp such as weight loss, texture, pH, peroxide and thiobarbiotic acid were evaluated. The MIC and the MBC of barija essential oil were 0.2, 0.4 and 0.5, and 1.25 µL/mL against Staphylococcus aureus and Escherichia coli bacteria, respectively. Also, the inhibition zone of the nanofiber coating containing 3% essential oil against Escherichia coli and Staphylococcus aureus bacteria were 186.22 and 280.33 mm2, respectively. Nanofibers containing 2 and 3% of barija essential oil caused a significant decrease (P<0.05) in the count of total and psychrotrophic bacteria in shrimp compared to the control. Nanofibers containing 3% barija essential oil prevented weight loss and increased pH of shrimp and preserved them in the values of 5.03 and 6.75% respectively in coated shrimp samples after 15 days of refrigerated storage. Coating was also able to improved about 5 times the reduction of tissue hardness. The coating of shrimp prevented oxidation. The overall results showed that zein nanofibers containing 3% essential oil increased the shelf life of shrimp.

In this study, a surface discharge plasma system including a cylindrical system was used for the treatment of milk in bottle. Electric discharge was performed to the electrode with the studied frequency and voltage. To optimization the process, the Design Expert software and optimal factorial design were used. The destruction time of Bacillus cereus, Bacillus Coagulans, Bacillus stearothermophilus, and Clostridium botulinum microorganisms, nutritional compounds or the occurrence of chemical reactions, and the time of inactivation of catalase, alkaline phosphatase, lipase, peroxidase, and protease enzymes, bovine serum albumin, immunoglobulins, alpha lactalbumin, beta lactalbumin, lysine and thiamine were also considered as answers in the Design Expert. The simulation was performed by COMSOL a3.5 software for a two-dimensional geometry. Among the four studied bacteria, Bacillus stearothermophilus had the highest resistance to cold plasma and other bacteria showed low resistance. In Cold plasma treatment wich investigated in this study, changes in initial temperature had a greater effect on the amount of production of active species than changes in voltage. Under the influence of non-thermal plasma treatment, the denaturation time of the studied proteins and amino acids has a significant difference at the 5% level. In the meantime, the inactivation time of lysine amino acid was shorter than other cases, and β-lactalbumin protein had the longest destruction time. Cold plasma technology can be used as a new antimicrobial intervention to inactivate pathogens and improve the safety of dairy products.

Due to the damages caused by additives, artificials and chemical flavors, replacing them with medicinal plants is a good solution to improve quality properties and physicochemical characteristics. Despite the nutritional properties and high caloric value of ice cream, the amounts of its antioxidant compounds are very low, which can be added by adding plant and vegetable extracts. The aim of conducting this research was to investigate the effect of using Hymenocrater platystegius Rech.f. plant extract (0.1, 0.5 and 0.9%) on physicochemical (pH, overrun, melt resistance and color indexes), textural (hardness and adhesiveness), rheological (viscosity, consistency coefficient and flow behavior index), and sensorial properties of ice cream in comparison with the control sample. According to the results, with increasing Hymenocrater platystegius Rech.f. extract amount, pH of ice cream samples decreased and overrun and resistance to melting increased significantly. In the texture analyzing test, adding the Hymenocrater platystegius Rech.f. extract to the formulation of ice cream, Hardness and adhesiveness of samples increased significantly (P<0.05). The results showed that all samples exhibited non-Newtonian and shear-thinning behavior and the power law model was highly effective in describing their rheological behavior. In the colorimetric test, increasing the Hymenocrater platystegius Rech.f. extract in ice cream formulation caused a decrease in L* and b* index and an increase in a* index. Also, the sensory evaluation results showed that samples with 0.5% of Hymenocrater platystegius Rech.f. extract, received the highest scores in the case of overall acceptance. Overall, Hymenocrater platystegius Rech.f. extract could be used for producing functional ice cream at the levels of 0.5% that had no negative effect on physicochemical and sensory properties.

Nowadays if essential oils can remain stable in food processing conditions, they can be used as an alternative to synthetic preservatives in food products. In this research, in addition to investigating the compounds of Zataria multiflora and cinnamon essential oils by gas chromatography-mass spectrometry, the antimicrobial properties of two essential oils before and after heat treatment (200 °C; 10 min) against Bacillus subtilis and Aspergillus niger were evaluated. Based on the obtained results, the thermal process did not significantly affect the main compounds of the essential oils. Cinnamaldehyde and eugenol were the main constituents of cinnamon essential oil, while phenolic compounds (thymol and carvacrol) made up 61.5% of Z. multiflora essential oil. The minimum inhibitory concentrations (MICs) of Z. multiflora and cinnamon essential oils against Aspergillus niger were 250 and 4000 µL/mL, respectively, while the minimum fungicidal concentrations (MFCs) were 250 and 16,000 µL/mL, respectively. Against Bucillus subtilis, the MIC and minimum bactericidal concentrations (MBC) values were 7.8 and 15.6 µL/mL for Z. multiflora, and 16,000 and 32,000 µL/mL for cinnamon, respectively. The inhibition zones of heated Z. multiflora and cinnamon essential oils were 20.5 and 16.05 mm against A. niger and 29.00 and 17.00 mm against B. subtilis, respectively. In general, the results demonstrated that the thermal process did not significantly affect the antimicrobial activity of the essential oils, meaning that they are suitable for use as antimicrobial agents in products that undergo thermal processing.

In order to the shelf-life prediction of white shrimp fillet (Litopenaeus vannamei) using Arrhenius mathematical model and Artificial Neural Network at different temperatures (-15, -25, -35, -45 °C), the qualitative changes of the fillet including salt extractable protein (SEP), K index, total volatile nitrogen bases (TVB-N), peroxide index (PV), barbituric acid (TBARS), electrical conductivity (EC) and sensory evaluation (SA) were investigated. For the Arrhenius model, the relative error range between the measured and predicted values for the quality factors i.e. TVB-N, SA, EC, TBRAS, K and SEP was -73.17-15.12, -2.54-13.04, -6.47-1.62, -0.81-0.00, -25.99-2.02, -5.59-0.82%, respectively. Regarding to Artificial Neural Network model, the relative error range between the predicted and measured values for the quality factors TVB-N, SA, EC, TBRAS, K and SEP were 0.00, 0.00, -0.38-0.00, 0.00, 0.00 and -0.08-0.03%, respectively. The MSE values of the Artificial Neural Network model were lower than the Arrhenius model in most of the qualitative factors. The R2 of the frozen shrimp quality factors of the Artificial Neural Network model was higher than the Arrhenius model, except for the SA factor. The artificial neural network model was able to better show the trend of changes in the quality of shrimp stored during the 6 months of the freezing period, at of -15 to -45 °C, compared to the Arrhenius model.

Enriching food is one of the most important ways to compensate for the lack of minerals and vitamins in the body of consumers. In this study, the encapsulation of α-tocopherol in gelatin and maltodextrin microparticles was carried out with the aim of enriching low-fat yogurt and the characteristics of the obtained microparticles (including encapsulation efficiency, zeta potential, particle size, thermal behavior (differential scanning calorimetry) and morphology (scanning electron microscope) were investigated. Based on the results, the encapsulation efficiency and the loading capacity of the microparticles containing α-tocopherol were acceptably high (97% and 25%, respectively). Microscopic images of gelatin-maltodextrin microparticles containing α-tocopherol showed a smooth and spherical surface as well as small cracks on the surface of the microparticles. In addition, the microparticles had a strong negative zeta potential (-27.29 mV), indicating a significant repulsive force between the microparticles and good stability. According to the results, maltodextrin as a potential prebiotic macromolecule increases the survival of Lactobacillus acidophilus during storage. The studied protein-polysaccharide microparticles are suitable for encapsulating α-tocopherol and potentially, they can have many applications in the food industry.