نشریه فناوری های جدید در صنعت غذا
سال نهم شماره 4 (پیاپی 36، تابستان 1401)

The application of edible coatings is one of the most effective ways to maintain the quality of fruits. In this study, the quality of sweet lemon fruit was evaluated in a completely randomized factorial design with edible coating of chitosan-clay nanocomposite in three levels, olive oil and carnauba wax in comparison with uncoated samples during refrigeration for 4 months. During the storage period of sweet lemon fruits, chemical characteristics (acidity, brix and ascorbic acid) as well as mechanical properties (maximum skin tensile force, fruit skin punch modulus) were measured. The results showed carnauba wax and chitosan-clay nanocomposite had better performance in maintaining lemon quality and mechanical properties than samples without coating. Moreover, among the coatings used, 5%chitosan-clay nanocomposite coating had higher preference than other coatings. In this research, Artificial Neural Networks (ANN) , linear and nonlinear regression method were used to predict the quality of lemon The results showed that the ANN has a better forecasting accuracy to predict the lemon properties compared to linear and nonlinear regression models and the LM learning algorithm with tansig transfer function had the best result. The best fit for the qualitative parameter was acidity with the coefficient of determination (R|) of 95%. The result of sensivity analysis indicated that the highest sensitivity coefficient was obtained for the punch modulus against the time feature with 47.96%.

This project was carried out to optimize the extraction and microencapsulation of color compounds of the processing waste of (Urtica dioica). Response surface method to investigate the effects of independent variables of ethanol solvent concentration (100, 50, and 0%), solvent to the raw material ratio (in three ratios of 30, 45, and 60%), three times (1, 4 and 7 hr) and Three temperatures (20, 40 and 60° C) were performed on extraction efficiency, chlorophyll content, and pheophytin of ethanolic extract of nettle color extract. Optimization of the extraction process based on the models obtained from the optimal extraction conditions, the solvent to raw material ratio was 33:67, the solvent concentration was 100%, the extraction time was 7 hours and the extraction temperature was 25°C. Under optimal conditions, the extraction efficiency was 7.99%, the amount of chlorophyll and pheophytin extracted were 54.75 and 341.54 mg/100gdry matter, respectively. In order to stabilize the extract, the microencapsulation was applied with two walls of maltodextrin and polyvinylpyrolidone by a spray dryer. Production capacity of microcapsules, moisture, bulk density, color properties, and glass transition temperature of microcapsules of Urtica dioica extract were investigated. Also, the stability of the color compounds of microcapsules during 21 days of storage in different humidity and temperature conditions was evaluated. The results showed that the microencapsulated colored compounds with maltodextrin had better physicochemical properties compared to other microcapsules. The number of color compounds in the microcapsules decreased during 21 days of storage, but the microencapsulation caused more protection and stability of the color compounds in the microcapsules in different humidity and temperature conditions. The coefficient of determination was more than 0.90) and was introduced as the optimal treatment. Both microcapsules were stable at room temperature with 121.35 and 82°C glass transfer temperatures, respectively.

Marketability of the produced products largely depends on their appearance. Therefore, the aim of the present study was to develop the required algorithms to extract, select, and classify the images’ features of hawthorn samples in order to classify different fruit classes based on the ripeness stages. Six hundred of hawthorn fruit samples were prepared. Afterward, a lighting box was designed and constructed to capture images from hawthorn specimens under controlled lighting conditions. After imaging and saving the images of hawthorn samples, image processing operation in MATLAB Software was done. In this step after image preprocessing, color and texture features were extracted. Through all extracted features, some features were selected as efficient ones by sequential selection method with quadratic base in MATLAB Software. Linear and quadratic discriminant analysis methods were used to classify the efficient features. The obtained results indicated that the methods were able to classify the images of hawthorn samples with same accuracies (98.67 %). Furthermore, accuracy, precision, sensitivity, and specificity parameters were calculated for the classifier models. The results indicated that the accuracy of hawthorn samples by classifier models based on linear and quadratic discriminant analysis models were 98.67 and 99.33 %, respectively in the train step and they were same as 98.67 % in the test step. Also based on the results of the determined parameters, the quadratic discriminant analysis model hade better performance than the linear discriminant analysis model.

In this study, the effect of whey protein isolate-inulin conjugates (1: 1 and 1: 2) and apple pulp extract (200 and 300 ppm) as alternatives to sodium metabisulfite was used for drying of apple. Polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) were performed to perform the Millard reaction. Also the content of total phenol, total flavonoids, antioxidant activity by DPPH and total antioxidant methods, water activity, amount of soluble solids, color index, activity of peroxidase enzyme (POD) and polyphenol enzyme Oxidase (PPO), structure analysis as well as sensory evaluation of the dried apple samples coated with whey protein isolate-inulin conjugates and apple pulp extract were investigated. The results of this study showed that the samples coated in 1% of whey protein isolate - inulin (1: 2) containing 300 ppm of apple extract had higher phenolic and flavonoid compounds than the other samples. Also, the concentration of 1% whey protein isolate - inulin (1: 2) containing 300 ppm of apple pulp extract had higher score of aroma, taste, color, texture and acceptability attributes. The results showed that of whey protein isolate-inulin conjugates and apple pulp extract showed strong inhibition against the browning of the dried apple. Therefore, it can be used as a preservative to prevent browning in apple slices as a substitute for sodium metabisulfite.

The aim of this study was to investigate the effect of fatty acid attached to chitosan (CS) in terms of saturation on some physicochemical properties of hempseed oil Pickering emulsion powders were obtained by a newly designed spray dryer equipped with an electrostatic collector. Firstly, CS-stearic acid (SA) and CS-oleic acid (OA) nanogels were prepared. The results of IR spectra showed a successful binding between CS and fatty acids. In addition, the D50 of CS-SA nanogels was lower than that of CS-OA. Then, hempseed oil-in-water Pickering emulsions were stabilized by CS-based particles/maltodextrin (MD) and dried by the spray dryer equipped with the electrostatic collector. The results showed that droplet size of reconstituted emulsion from oil powder with CS-SA/MD coating (886.4±146.4) was significantly (p≤0.05) less than that of emulsion with CS-OA/MD (1415.8±130.0). SEM images also showed that hempseed oil encapsulated with CS-SA/MD had more sphericity, porosity, and crystallinity compared to that encapsulated by CS-OA/MD. Moreover, hempseed oil encapsulated with CS-OA/MD had higher oxidative stability that encapsulated by CS-SA/MD.

The photoacoustic method is a sensing technique resulting from combination of optical and ultrasonic methods. The photoacoustic effect is the product of local heating with absorption of light energy, instantaneous expansion of matter and generation of pressure and sound propagation in the matter. In this study, in order to develop a photoacoustic spectroscopy system with LED light sources, in the first step, the photoacoustic interaction with a cuvette filled with liquid was simulated using Comsol Multiphysics 5.5. In the second step, a photo-acoustic spectroscopy system with light sources at eight wavelengths from 395-940 nm was designed and constructed. Finally, in order to evaluate the photoacoustic system, three samples i.e. milk, water and olive oil were subjected to photoacoustic spectroscopy and the measurement results were compared with the simulation results for the same samples. The results showed that the intensity of the acoustic response of the samples at different wavelengths varied significantly with the light absorption coefficient, so that the maximum amplitude of the acoustic signal was obtained for milk, water and olive oil at the wavelengths of 450, 395 and 450 nm with values of 0.34, 0.22 and 0.74 Pa, respectively. This was in agreement with the simulation results in terms of relative differences. Moreover, the adulteration of adding water to milk at volume ratios of 5, 10, 15 and 20% was evaluated with the system and analyzed with principal component analysis (PCA) which showed a satisfactory discrimination of adulterated samples from pure milk. The system developed in this study can be used to assess the quality of food liquids.