نشریه فناوری های جدید در صنعت غذا
سال ششم شماره 3 (پیاپی 23، بهار 1398)

In this research via CT scan, the relationship between physical properties of pears and storage times with bruise due to loading force was investigated. Before loading and storing, 50 pears were examined using CT scan and 27 pears with zero bruise percentage were selected. Dimensions of pears (length, width, thickness) were measured, then properties such as the equivalent diameter, geometric mean diameter, spherical coefficient, surface area and aspect ratio of calculus were calculated, then selected pears were subjected to quasi-static loading with a thin edge pressure with three forces of 15, 20 and 25 N and 5, 10 and 15 days storage was used to investigate the effect of forces on pears. Then, after loading and storing, using the CT scan in each period of storage, the rate of pear bruise was calculated. The results of the experiments showed that there is an inverse relation between geometric diameter, arithmetic and equivalent diameter, spherical coefficient and aspect ratio with the bruise percentage. Also, a direct and unreasonable relationship between the level of the surface area and the percentage of bruising was obtained. Also, according to the obtained results, during the 5-day storage period, the amount of geometric diameter, arithmetic and equivalent diameter, spherical and aspect ratio on the percentage of bruising were not significantly affected and percentage of bruising can be almost zero and with increasing storage, the above parameter's will affect the percentage of bruising.

In this paper, the effect of carboxyl methyl cellulose (CMC), konjac gum (KG) and sage seed gum (SSG) and their mixtures on dynamic rheological properties of the instant camel yogurt samples were investigated, Then, these properties were optimized using mixture design models and firefly algorithm. The results of the stress sweep tests for different samples showed that the elastic modulus (G ') values were greater than viscous modulus (G') indicating behavior essentially like that of solids. Results showed the synergistic effect of these three gums, especially the synergistic effect of SSG and CMC on the critical strain and the yield stress of instant camel yogurt samples. Frequency sweep test results showed that samples had a typical weak gel-like structure behavior at any given frequency and complex viscosity (*) had a linear correlation with frequency. SSG had the most positive effect on k’, k" and k* but the combination with CMC and KG could also improve this effect. All the linear terms in the predicted models for the n’, n" and n* parameters were insignificant (P

The machine vision system is one of the newest systems for identifying the quality of agricultural products. Apple is one of the fruits whose apparent quality used by customer to select this product at the market. Automatic detection of faulty apples through the machine's visual system is difficult due to the non-uniform of distribution of on the surface and the similarity between actual defects with the color changes of the fruit peel. For this purpose, in this study, a new method for detecting apparent defects of apple using a machine vision system with a combination of auto-correction of light was presented. In order to classify the samples, the histogram of the taken images was corrected based on the RGB method, then three-color and 11 textural features were extracted. Based on the results of the feature selection, the best features for the highest accuracy in the classification were respectively entropy, energy, correlation and local smooth. Finally, for categorization of data, two classifiers namely relevance vector machine (RVM) and support vector machine (SVM) were used. Based on the classification results, the accuracy of the RVM classification was 95% in the sound group, 82% in the unsound group and 88.5% in for total accuracy; but the accuracy of the SVM classification was 100% in the sound group, 94.23% in the unsound group and 97.11% for total accuracy. Therefore, in order to detect sound samples from unsound ones the SVM classification is more suitable than the RVM, due to the greater accuracy and less error.

Tea is one of the strategic products in north of Iran. The tea produced in tea factories have different qualities as it is affected by various factors such as weather conditions during growth, soil, harvest time, as well as processing and preparation methods. In addition to its appearance, other essential properties of tea are its chemical compounds and aromatic characteristics. Investigating new and accurate methods for tea quality assessment has a significant effect on the development of tea processing industries. In this research, an electronic nose system was used to extract the characteristics of tea aroma and applying of these features for qualitative classification of black tea. Extracted Features from a sensor array, including ten different metal oxide gas sensors (MOS) were used for classification of five qualitative categories of black tea by means of chemometric methods. Results showed that the best classification performance was obtained by Artificial Neural Network (ANN) with a total classification accuracy of 88.00%. Also, Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM) resulted in accuracies of 78.00% and 86.67% respectively. Based on the results of Principle Components Analysis (PCA), it was found that MQ7 and MQ2 sensors had the highest effect on the separation of different classes of tea. Generally, the performance of electronic nose system was suitable for qualitative classification of Iranian black tea.

Heating is one of the most commonly used methods for accessing various purposes in the food process. The main problems with microwave heating are the possibility of cold and hot spots. The aim of this study was to investigate the uniformity of temperature distribution in Fandoghi Pistachio under the microwave heating process under study conditions. Independent factors included the shape of product geometry, the position of the thermometer and the heating time. This research was based on a completely randomized design based on a factorial experiment of 2×6×4. Independent factors included the shape of product geometry, the position of the thermometer and the heating time. These experiments were performed separately for 900 and 630 w microwave power, and the temperature of the pistachio product was measured and recorded during the four-time heat treatment at six different positions of the product as an associated factor. The results of this study were based on two types of analysis of the comparison of the mean temperature of the samples and the determination of the relative non-uniformity index. The results showed that all the main effects were significant at 1% level in both applied power states. Comparison of means showed that in treatment "B" (cubic - 630 w) in 5 positions of 6 positions, there is no significant difference between the mean temperature under investigation. This means that the temperature distribution at different product positions at the end of the microwave heating period has been quite uniform. Subsequently, the cubic – 900 w and cylindrical- 630 w had the highest uniformity in temperature distribution. By calculating the relative non-uniformity index, the highest uniformity was obtained in cubic - 630 w.

Optimization of fermentation control with potential application of rice bran sourdough in novel fermentation technologies is increasing every day to come up to suitable alternatives for additives in bakery. In this research after isolating the dominant starter of the traditional rice bran sourdough and its identification using PCR and specific primer, it was used to make a traditional sourdough and evaluating the sourdough pan bread qualities by RSM method, under the impression of fermentation time (8, 16 and 24 h), fermentation temperature (26, 32 and 38 °C) and sugar content (1.5, 3 and 4.5 %). In this research, results of evaluating the proportion fitted models showed that by increasing the temperature and fermentation time in a constant sugar content, the titratable acidity (TTA), microbial population dynamics, specific volume, porosity, the total color difference (TCD) and cohesiveness were significantly increased and decreased respectively. However, there were a trend decreasing in the hardness and over acceptability of bread texture (P0.05). The result of this research a model was defined for any dependent variable. Also for evaluating the accuracy of the fitted models, desirability and lack of fit test were determined.

In recent years much attention has been paid by researchers to the quinoa due to diverse functional properties, high nutritional value and gluten-free feature rather than other protein grains. The quinoa protein can be used as a nutritional supplement and a valuable food source for babies, children and adults in the formulation of sauces, sausages, soups, etc. The aim of this study has been comparing the effects of both alkaline extraction and ultrasound methods on the physicochemical and functional properties of quinoa protein isolate. Physicochemical properties includes Moisture content, fat, protein, carbohydrate, ash, weighted efficiency and color (L*,a*,b*), and functional properties including water and oil absorption capacity, foam production capacity and its stability, emulsifying capacity and its stability were examined . The results of the experiments showed that ultrasound assissted extraction without any effect on protein amount created higher extraction efficiency. It also showed the higher water absorption capacity (2/76 ml/g) and fat absorption capacity (4/63 ml/g) than the alkaline method. The alkaline method had better functions in foamability (foam production capacity 10/08% and its stability 38/88%) and emulsification properties (emulsifying capacity 17/57% and its stability 62/04%). The results have been showed that produced protein isolates have good functional properties and can be a substitute for other protein sources in different food formulations.Keywords: foam, emulsifying capacity, color properties, extraction efficiency, gluten free

One of the important concerns regarding the food safety is widespread adulteration in food production which necessitates the development of precise and rapid diagnostic instruments more than ever. In this study, a cylindrical resonator sensor, developed in previous studies and examined for quality detection of some food materials, was applied for detection of adulteration in sesame oil mixed with corn, canola and sunflower oils. To measure the dielectric response of oil in 0-150 MHz frequency range, a new sensor with 400 mm long cylinder was fabricated. Adulteration samples were prepared with mixing pure sesame oil with the above mentioned oils at 15, 30 and 45% by weight and each sample was measured with three replications using the dielectric sensor. Statistical methods of principal component analysis (PCA), linear discriminant analysis (LDA) and support vector machine (SVM) were evaluated for detection of adulteration type and level from the dielectric spectral data. The biplot of the first two principal components showed excellent discrimination of adulteration type and level with 96% of variation explanation. As the best result, LDA classifier showed 96.7% accuracy for adulteration detection.

Three methods of solar drying (I), sun drying (II) and shade drying (III) used to reduce the moisture content of peppermint from 87 to 7% (wet basis). The increase of air-drying temperature (∆T) for peppermint dehydration in method II reached up to 4oC after absorbing of daily solar energy (Iave=957 W/m2). However, in the method I, this parameter (∆T) reached to 18oC after the ambient air passed through a double-pass heat collector (with only 1.26 m2 area). Although the enthalpy of drying air in the method I reached to 35 kJ/kg (40% more than the other methods because of the high heat intensity of solar collector Iave=840 W/m2), only ~16% of accumulated solar heat used to increase the peppermint temperature and evaporate its extra moisture. This is the reason that exergy in the inlet and outlet of the method I during drying peppermint reached to 24 and 38%, respectively. Furthermore, the drying capacity of peppermint in the method I was 100% more than the ones dried in methods II and III at the similar conditions. The total heat loss (because of connecting pipes and drying chamber) in the method I during peppermint drying was < 4% of the total heat collected in solar drier, which is negligible.

In this research, the microcapsulation of polyphenolic compounds of citrus aurantium extract was designed to provide a solution by improving their stability and protecting them against oxidation, light, moisture and temperature. For this purpose, a lab scale spray-dryer was used to produce microcapsules of Citrus aurantium extract using maltodextrin(MD), gum arabic(GA) and their combination(MD+GA) as a coating material. Quizzes powder production yields, phenolic compounds content and encapsulation efficiency, antioxidant capacity, moisture content, hygroscopicity, bulk density, solubility, morphology and particle size were evaluated. The results of this study clearly showed that the encapsulation of the Citrus aurantium extract with spray dryer by using maltodextrin was effective and had higher productivity(above 90%) than two other wall materials. Also, maltodextrin capsule has a higher yields(87.4%), better antioxidant activity(60.91%), low moisture content(2.10%), low hygroscopicity(45.76%), low bulk density(0.449g/ml), high solubility(79.38%) and morphological structure were better than other capsules. Particle size was not significantly different in samples. Finally, the microcapsule of the Citrus aurantium extract dried by maltodextrin was presented as the comprehensively microcapsule.