mehrdad niakousari

This study aimed to evaluate the effects of intelligent pH-sensitive composite film based on gelatin and Persian gum incorporated with purple carrot extract (PCE) on the freshness of wrapped mozzarella cheese. In this regard, the color, pH, yeast and mold count of control and treatments wrapped with intelligent pH-sensitive composite film during 60 days were evaluated. The results showed that the pH significantly reduced in wrapped cheese with and without PCE (control) samples during storage. However, this reduction was more pronounced in the control sample (P<0.05). Additionally, the application of composite film on cheese affected the color during storage. It was observed that L* and a* values of the composite film-wrapped cheese were significantly higher than the control sample, but the b* values were significantly lower than the control sample. Moreover, poor microbial growth (yeasts and mold) was observed in cheese samples wrapped by composite film with purple carrot compared to the control. Also, the pH of the composite film with extract significantly decreased from 6.33 to 4.85 during storage (P < 0.05), which showed the changes of color from purple to pink. After 40 days, the color changed to pink, indicating the end of the cheese storage. Therefore, it was concluded that the pH-sensitive film, while being an effective method to improve the shelf life of mozzarella cheese, can also use as an indicator for freshness.

In this study, an edible film based on gelatin-Persian gum was prepared and optimization of the edible film was done using Design Expert and Mixture Design. The resulting films were subjected to various physicochemical tests, including pH, total solid, heat seal ability, tensile strength, contact angle, calorimetric and moisture absorption. At first, modeling of responses was done using data regression analysis, and then 3D charts were drawn to show the effects of gelatin (0.5 -1), Persian gum (0.5 -1), and Glycerol (0-0.5) on the film characteristics. Finally, Numerical optimization based on optimization goals was performed and the optimal point with the highest desirability (0.78) was obtained. The ratio of each of the independent variables in the optimal formula was 0.5. Various properties of the optimal film including pH, total solid, heat seal ability, tensile strength, contact angle, moisture absorption, L*, a* and b* were obtained at 6.66, 95.61%, 84.45 N/M, 64.5 N, 77.34°, 4.5%, 70.98, 0.97 and 0.66 respectively. Generally, the findings proposed that the gelatin-persian gum-based edible film can be used as a food packaging material.

The effect of three types of industrial roasting (light, medium, and dark) on the characteristics of two varieties of imported green coffee, Coffea arabica (Arabica) and C. canephora (Robusta) was investigated. The moisture content and water activity of samples decreased significantly during roasting. In dark roasting, the moisture contents of Robusta and Arabica beans were 0.39 and 0.41%, respectively. The caffeine and chlorogenic acid levels in green and roasted Robusta coffee were higher than Arabica coffee. The caffeine increased during roasting and reached 149.7 and 61.8 mg/l in dark roasted Robusta and Arabica, respectively. Chlorogenic acid decreased during roasting and in dark roasting, a very small amount (0-0.21 mg/l) remained in the studied samples. Roasting made the coffee beans crispier. The hardness of green beans decreased from 33.4-34.0 to 14.0-14.8 N in dark roasted samples. The color properties of coffee beans mainly changed from green to brown. Roasting reduced the antioxidant activity of the coffee and it decreased further with increasing temperature and time. The antioxidant potential of dark roasted samples reached 30.1-38.1 % of free radical inhibition at the highest concentration. Roasting produced a significant improvement in the sensory characteristics of the coffee drink. The drink made from Arabica coffee had a better appearance, aroma and taste. The coffee drink made from light roasted Arabica beans had a higher overall acceptance. Mixing two types of Robusta and Arabica coffee and roasting light and medium can be a good suggestion to prepare a coffee with desirable chemical and sensory properties.

Physicochemical properties of sour orange (Citrus aurantium) seeds including its length, weight, density (bulk, tapped, and true), porosity, 1000-grains weight, approximate analysis were assessed.  Color parameters (L*, a*, b*), total phenolic and ascorbic acid contents were evaluated. While soaking seeds in water, prior to oil extraction by n-hexane, an aqueous oily layer (AQO) was formed where its characteristics was determined. The oil content of seeds was extracted by conventional (Soxhlet) and two fairly novel methods (ohmic-assisted extraction (OAE) and ultrasound-assisted extraction (UAE)). To facilitate the oil extraction by OAE, a novel approach was established. In the latter, brine was added to n-hexane to ensure a suitable conductivity was established between the two platinum electrodes. The extraction yield and specific energy consumption for each method were evaluated and oil characteristics including color profile (in terms of ΔE), fatty acid composition, refractive index, total phenolic contents, antioxidant activity and anisidine value were assessed. The highest and lowest oil yield of about 50% and 3% was obtained using Soxhlet and maceration, respectively. The lowest specific energy consumption of 5 kWh/kg was achieved when oil extraction was performed by OAE. The extracted oil contains substantial amount of unsaturated and saturated fatty acids. Interestingly, the highest total phenolic content (about 0.9 mg GAE/ g oil) was associated with the aqueous oil. The extraction of valuable components from a waste in a fruit processing plant not only reduces the environmental impact of waste disposal but also present a new valorization method in the food industry.

Flixweed (Descurainia sophia) seeds (FS) is a rich source of polyphenols, such as coumarin compounds, flavonoids, flavonol glycoside and phenolic acids. In this study bioactive compounds of FS were extracted using ohmic-assisted extraction with water as a solvent. Drink powder was produced from extract with carrier ratios of 50-50, 0-100 and 100-0 of maltodextrin to gum Arabic and carrier content of 30-50% at 120, 140 and 160 ˚C using spray dryer. The powders physicochemical properties including moisture content, insolubility, particle size, total phenolic compounds and antioxidant activity of produced powers were evaluated. The optimal powder of response surface methodology was selected and the extract was reconstructed in such a way that the amount of solid material was similar to the solid material of the initial extract then in term of appearance, taste, aroma, texture and overall acceptance were evaluated. The results of the powder production showed the effects of the percentage and ratio of carriers (maltodextrin and gum arabic) and the effect of temperature on the moisture content and insolubility were significant. The carrier’s percentage and the drying temperature had a significant effect on the antioxidant activity. The percentage and ratio of carriers had a significant effect on amount of total phenolic compounds at level of 5%. Optimization by response surface methodology was selected powder sample produced at 160 ˚C with a ratio of maltodextrin to arabic gum of 100-0 and carrier content of 30% as an optimal treatment. The particle size of the powders ranged from 2617 to 4664 nm. Comparison of sensory evaluation of optimal reconstructed powder with FS extract before drying showed there was no significant difference between two samples in terms of appearance, taste, aroma, texture and overall acceptance scores.

In this study rhubarb stem slices were dried as single layers with thickness of 3 mm in the inlet air temperature range of 50-70  and air velocity of 1 ± 0.2 m/s in a laboratory scale cabinet dryer. The effect of drying air temperature on the drying characteristics was determined and the relationship between the drying parameters with temperature and moisture content was examined. Moisture transfer from rhubarbs slices was described by applying the Fick’s diffusion model. The effective diffusivity changes between 4.56×10-11 and 15.97×10-11 m2/s within the given temperature range and as the temperature increased so did the effective moisture diffusivity.  An Arrhenius relation with activation energy values of 57.4638 kJ/mol expressed the effect of temperature on the diffusivity. The experimental moisture loss data were fitted through 10 thin-layer drying models available in the literature. The models were compared based on the coefficient of determination, mean bias error, root mean square error, and the reduced chi-square between the observed and predicted moisture ratios. The Midilli et al. model has shown a better fit to the experimental drying data as compared to other models.

Flaxseed oil is one of the richest sources of omega-3. The aim of this study was to investigate the effects of different wall materials, weight ratio (WR) and storage time on physicochemical properties and storage stability of flaxseed oil microemulsions.

Encapsulation efficiency and emulsion oxidative stability were measured. Fatty acid composition of oil extracted from emulsions was analyzed by gas chromatography (GC). Particle size distribution and morphology of microemulsions were measured by dynamic laser scattering (DLS) technique and scanning electron microscopy (SEM), respectively.

The maximum encapsulation efficiency of 95.8% was obtained in the emulsion with the highest n-octenylsuccinate-derivatized (n-OSA) starch content. Increasing n-OSA starch concentration led to a higher microencapsulation efficiency and a lower lipid oxidation. Increasing n-OSA starch/sodium caseinate ratio led to a decrease in peroxide values and thiobarbituric acid contents. GC-FID results showed a superior stability of ω-3 fatty acids and improved nutritional quality in microencapsulated flaxseed oil upon storage. The average droplet size distribution of emulsions ranged from 428 to 728 nm. An increase in total solid content with the same oil concentration led to smaller droplets size. Morphological study performed by SEM confirmed the results obtained by DLS technique.

Our findings have important implications for the design and utilization of emulsions as delivery systems for food enrichment.

In this research، Iranian Peas were dried with the use of spouted bed dryer، in order to investigate the operation of Spouted Bed Dryer system، evaluating the effects of temperature on drying rate، and Rehydration ratio، and the parameters of the final product’s color at three temperatures: 45، 60 and 75˚C. The Spouted Bed Dryer used، is a conical-cylindrical kind with a mutual symmetry which had the ability to dry the samples in different temperature and flow rates. Rehydration ability، color، and drying rate of the final product were compared with the peas which were dried through sun drying and thin layer dryer. Drying was done in spouted bed dryer and thin layer dryer at three levels of temperature: 45، 60،75˚C and rehydration ability of the dried product was assessed through putting the samples in distillated water in a 30 ˚C oven، within the period of 320 minutes. The results showed that the designed spouted bed dryer system is able to dry the Iranian peas in a shorter time and with higher quality. In this system، increasing the temperature of drying has a significant effect on drying rate ability، rehydration ability and parameters of the product’s color.

Response surface methodology is a series of statistical techniques that can be used to design experiment, modeling and evaluating the effect of variables on the final obtained results and optimization of process conditions. In this research, optimization of the solvent extraction method of bioactive compounds from seedless barberry (Berberis vulgaris) was carried out using response surface methodology. Central composite design was employed with 13 treatments and 5 replications in central points and the effect of variable factors of temperature (50-70ºC) and extraction time (40-120 minutes). The amount of anthocyanin content, vitamin C, phenolic contents and antioxidant activities of extracted barberry were measured. Close agreement was found between experimental and predicted values of model. Effects of extraction temperature and time were found to be significant on all responses. According to these results, optimal extraction conditions were identified at 50 °C temperature for120 minutes. In this condition the maximum of phenolic compounds, anthocyanin, antioxidant activities and vitamin C contents were 585.725 mg GAE/100ml, 208.392 mg/l, 84.2603% and 1292.56 ppm respectively. The results showed that this methodology could be applied in the extraction of bioactive compounds in the natural product industry.

The main objective of this study is to design and construct the new, spouted bed dryer, for food drying sensitive foods specially. For this purpose, firstly a new design of dryer was planned to achieve the maximum efficiency and flexibility for liquids and solids drying. After constructing and initial setup of spouted bed, basic experiments such as investigation of an inert particles motion, pressure drop, energy consumption were conducted and optimal system requirements for two particle size (5.8 & 7.8 mm) were determined. The results indicated that changes in pressure drop in the dryer chamber containing inert particles are followed from the Ergun equation. Energy consumption in this system is variable in the range of 3-8 kW per hour. Also results reveals that the energy consumption of the new design of spouted bed dryer is less than the spray dryer for liquid foods drying.