نشریه فناوری های جدید در صنعت غذا
سال پنجم شماره 2 (پیاپی 18، زمستان 1396)

The aim of this study was to produce D-limonene microcapsule with resistant coat (Gum Arabic and maltodextrin) for manufacturing flavored crystal rock candy. Oil-in-water emulsions were prepared at concentrations of 10% and 20% and related characteristics including particle size and emulsion capacity were examined. Microcapsule properties produced by spray drying process such as surface oil content, oil retention, encapsulation efficiency, release rate and morphological characterization by SEM were also evaluated. The results showed that an increase in GA concentration had significant effect on examined factors as the higher ratio of GA/MD led to decrease in z-average diameter. Moreover, the release rate decreased due to increase in wall materials concentration upon 6 weeks at room temperature. Optimal microcapsule by its properties (75/25 of GA/MD by 20% of wall materials), was used to produce flavored rock candy so that, the effect of temperature, pH and the amount of microcapsule on yield and the time for formation of first crystal were investigated. The influence of pH and the amount of microcapsule on yield and also syrup’s temperature and the amount of microcapsule on the time for formation of first crystal were significant (P

Potato chips is one of the popular snacks among peoples, specially child’s, which deep frying at high temperatures is used for its preparation, and can cause to destructive reactions like oxidation which is the main chemical deterioration of chips. So in this research, the effects of addition of aqueous extract of safflower (0.5, 1 and 2%) as a natural antioxidant on oxidative stability of potato chips at two methods, immersion and spraying under storage (2 months) was studied. Oil uptake measurement of chips showed that by increasing the extract concentration of safflower, it reduced as well as peroxide value. After 60 days, the most and lowest amount of acid value were for control (1.06±0.05 mg/g) and the immersed specimen at 2% safflower extract (0.75±0.009 mg/g), respectively. The effect of safflower extract addition by immersion or spraying method and also their concentrations were significant on anisidine value (p

The positive characteristics of nanofibers such as high surface area-to-volume ratio, appropriate flexibility of the functional group and superior mechanical performance, in cooperation with placing the cyclodexterins would provide an appropriate platform for the production of neutroceutical nanocarriers. Electrospinning as an easy and non-thermal method is a suitable choice in nanofiber production. Different factors influence the nanofiber production of which the solvent selection is of great importance. In this paper we aim to study the optimized solvent system for electrospinning of cellulose acetate polymer and cyclodexterin. In this way, the influence of single and binary solvent systems i.e. Dimethylformamide (DMF), Dimethylacetamide (DMAc), acetone: DMAc (1:2), acetone: DMAc (2:1), acetone: DMF (1:2), and acetone: DMF (2:1), on the morphology and the diameter of nanofibers was investigated. The embedment of cyclodexterin in the nanofiber structure was studied using the phenolphthalein absorption technique. The polymeric solutions showed a non- Newtonian pseudoplastic behaviour. The application of binary solvent system of acetone: DMF (2:1) at 20% (w/v) cellulose acetate polymer, 2% (w/v) cyclodexterin, under the processing condition 25 kV, 1.5 ml/h, and the needle to collector distance of 150 mm is suggested for the production of cyclodexterin nanocarriers.

Drying is one of the most common techniques for agricultural production processing which improves shelf life of the final product. The drying experiments were conducted in a laboratory cylindrical non continuous rotary dryer equipped with automatic temperature and full rate control devices. Drying temperatures from 30 °C to 65 °C and occupancy rate between 25 to 66 % were assessed in the process. In this study the effects of hot air drying temperature (30, 45 and 60°C), and occupancy rate (25, 50 and 75 %) at constant air velocity (0.8 m/s) on failure force, color of watermelon seeds, sensory attributes (color), germination rate on the samples and energy consumption were investigated. Results showed interaction effect of the two factors (temperature and fulling rate hopper) was significant on germination rate samples, energy consumption dryer and color parameter (a). Temperature effect on all measured traits and also the effect of fulling rate hopper were significant for all traits except failure force in vertical load direction. Dried samples at 30°C with 50% fulling rate hopper had the highest percentage of germination with cylindrical dryer. The highest value of color parameter (a) occurred in the condition of temperature 45°C with 50% fulling rate hopper. In each one of drying temperature, with increasing fulling rate hopper, energy consumption for drying the samples increased. Optimal temperature and fulling rate hopper for drying watermelon seed for providing market (nuts) and seed consumption with cylindrical dryer, the samples should be dried at 60°C with 25% fulling rate hopper, and 30°C with 50% fulling rate hopper respectively.

Along with increased production and fruit and vegetable processing, there is a lot of byproducts. Eggplant cap is also one of the byproducts which contains valuable materials such as pectin which is both economically and environmentally beneficial. The general objective of this research was to investigate the effect of three temperature variables (60, 75 and 90°C), time (50, 100 and 150 min) and pH (1.5, 2.52 and 3) on the rate of yield, percentage of galacturonic acid and degree of pectin esterification extracted from the eggplant cap. The response surface methodology was used to optimize the extraction conditions. In order to study the physicochemical properties of obtained pectin, emulsion stability tests were carried out at different days and temperatures and flow behavior in different concentrations and FT-IR were performed. According to the results, the highest extraction yield of the eggplant cap was observed in 12.30% under severe conditions of extraction at 90 °C, 150 min and pH 1.5. The highest galacturonic acid percentage of extracted pectin of eggplant cap was observed 39.84%, at 75°C, 100 min and pH, 2.52. The highest esterification degree of extracted pectin of eggplant cap was 51.750, at 60°C, 50 min and pH 3. The results of analysis of variance showed that extraction temperature was the most effective factor on the yield and esterification degree of extracted pectin. The highest emulsion stability of eggplant cap pectin was at 4 °C and the first day. With increasing the concentrations of pectin samples (from 0.1 to 2%), their viscosity was increased and flow behavior of all samples were Newtonian and their flow index was close to one. FT-IR results also showed that the strong absorption between 3000 cm-1 in the extracted pectin samples was related to intra-and extracellular vibration of the hydrogen bond in the galacturonic acid polymer.

Lime is a good source of polyphenols, vitamin C and minerals. Lime juice contains high amounts of water making it susceptible to enzymatic and microbial deterioration. Concentration of lime juice increases its shelf life, while decreases the costs of storage and transport. Nevertheless, conventional thermal methods for concentration of fruit juices may adversely affect their physicochemical, nutritional and sensorial properties. Therefore, novel thermal methods with minimum adverse effects on the quality attributes of the final product are eagerly sought by food technologist. The present study was aimed to investigate the effect of different heating methods, including conventional heating, vacuum heating and microwave heating on the physicochemical characteristics, phenolic compounds and sensorial properties of lime (Citrus auranti folia) juice concentrates. Reconstituted lime juices were prepared from different concentrates and their quality attributes were compared with those of fresh sample (the control sample). The results showed that the pH of reconstituted samples did not noticeably differ from that of control sample (p≤0.05), but their acidity was significantly (p≤0.05) lower, attributed to degradation of acidic compounds during thermal treatment. Findings showed that juices made of concentrates, regardless of heating method, had significantly (p≤0.05) lower vitamin C, polyphenols, and flavonoids, weaker antioxidant activity and less pleasant sensory properties compared to the fresh lime juice. However, the concentrates prepared by vacuum and atmospheric heating methods yielded the best and the worst results, respectively. Low temperature of vacuum heating and shorter process time of microwave heating could account for the better quality attributes of the concentrates made by these methods compared to the concentrate produced by the atmospheric heating method. It is concluded that the best heating method to concentrate lime juice with the best quality attributes is the vacuum heating method.

Energy and exergy analyses were conducted of the continuous combined infrared-hot dryer with current bed structure. The experiments were carried out at three levels of air temperature (40, 50 and 60 °C), three levels of air velocity (0.5, 1.0, and 1.5 m/s) and three levels of infrared power (500, 600 and 700 W) under without and 100% air recirculation for savory. Using 100% air recirculation indicated that specific energy consumption could be saved from 29.10 to 50.34% as compared without air recirculation. The use of high levels of infrared power and air temperature and low levels of air velocity with air recirculation led to increase energy efficiency (p<0.05). Maximum energy efficiency for without and 100% air recirculation modes was obtained 20.90% and 30.21%, respectively. Specific energy loss is strongly influenced by air velocity and air recirculation mode (p<0.05). Energy loss varied between 8.54 and 37.24 MJ/kg-water, and 5.21 and 20.04 MJ/kg -water for without and 100% air recirculation modes, respectively. The air temperature and velocity had the greatest effect on exergy efficiency, maximum value of it was obtained 10.21% for conditions of 60ºC, 0.5 m/s and 700 W with 100% air recirculation. The exergetic improvement potential vaired between 2.73 – 5.12 Mj/kg water and 2.35 – 4.02 MJ/kg water for whitout and 100% recirculation modes, respectively.

In this study the stability and release of microencapsulated fish oil prepared by different wall materials (fish gelatin, κ -carrageenan and fish gelatin+ κ carrageenan), physical and chemical methods (coacervation, spray drying and freeze drying) were examined. In-vitro controlled release of the microcapsules and peroxide (PV); ρ-Anisidine values during 10 days storage at accelerated conditions (45 °C) were investigated. The results of solubility of protein powders and oxidative stability showed that fish gelatin was the best wall material and coacervation was the best method to encapsulation of fish oil. These powders had higher solubility and lower PV, p-AV than the other treatments. The highest and lowest core releases were observed by coacervation method (93.16 and 80 %). At spray and freeze drying methods, gelatin had more release than the other wall materials. Comparison of the different methods and wall materials confirmed that combination of matrices, drying methods are effective on physical characteristics and oxidative stability of encapsulated fish oil.

Coating of tomato fruits with edible hydrocolloids improves some their postharvest qualitative features. The effect of 1% solution of trehalose, including Artemisia sieberi essential oil as an edible coating on the some qualitative features of cherry tomato including water loss (%), firmness (N), titrable acidity (%citric acid), ascorbic acid (%), antioxidant activity (DPPH assay), color (L*a*b*) and organoleptic characteristics was evaluated during ten days of storage compared to non-coated sample in the refrigerator (4C and 75-85% RH). The essential oil was extracted from the aerial parts of A. sieberi with hydrodisstilation and using Clevenger apparatus and added to trehalose (0. 5, 1, and 1. 5% v/w). The weight, firmness, titrable acidity, ascorbic acid and antioxidant activity of all samples decreased during storage, but at the end of storage fruit coated with trehalose and essential oil showed a lower weight loss and higher firmness and antioxidant activity compared to uncoated cherry tomato. Coating of fruits delayed the decrease of titrable acidity and ascorbic acid during storage. The results indicated that the coating retained the lightness (L*) and increased the redness (a*) of the tomatoes. This coating also improved some of the sensory and appearance properties (color, odor, texture, taste) of the tomato without any adverse effect on its overall acceptance. It is concluded that trehalose comprising A. sieberi essential oil as a novel coating clearly delayed ripening and senescence effects on cherry tomatoes and promoted the storage postharvest quality of fruits.

High nutritional value and bioactive compounds in hazelnut has become a valuable nutrient. One of the ways to increase per capita consumption of hazelnut is processing of it with different methods such as production of hazelnut milk. In this study, application of different roasting methods (infrared, microwave and hot air oven) blanching time (0, 15 and 30 min) and pasteurization conditions (5 min at 95°C, 15 min at 85°C and 25 min at 75°C) in hazelnut production were investigated. Also, the asymmetric methods (completely randomized factorial and partial least squares regression) and symmetric methods (coefficients of determination and principal components analysis) were used for study of physicochemical characteristics, color parameters and sensory aspects. The results of this study showed that pH, physical stability index and L * significantly increased (p˂0.05) but the acidity, total solids content, protein, fat, viscosity and b * decreased with increasing of blanching time. Hazelnut roasting using infrared method, blanching for 15 minutes at 95 °C and then pasteurization for 15 minutes at 85 °C achieved the best physicochemical and sensory properties of hazelnut milk. It could be found from principal components analysis (PCA) that roasting methods of microwave and hot air oven results in the increase of sensory scores of cooked, chalky, roasted and bitter flavors. pH and acidity had the best significant correlation coefficients with physicochemical and sensory properties. Obtained R2 of partial least squares regression models were above the medium range. It shows the high efficiency of these models in prediction of sensory characteristics of infrared hazelnut milks from color analysis indices.

Antioxidants are the molecules that can scavenge reactive free radicals and prevent the other molecules from oxidation. So, they contribute an important role to prevent of various diseases. Studies show that in addition to the nutritional values of dates, the fruit extracts have the potential to scavenge free radicals due to the presence of antioxidant compounds. The aim of this study is statistical analysis and to optimize extraction process conditions of an Iranian date using Response Surface Methodology (RSM), for the first time. Methanol has been used as the extraction solvent. The independent variables include extraction time (30-60-90 min), temperature (30-50-70 0C), solvent to solid ratio (10-25-40 cc/g), and solvent percentage (10-50-90) min. Total phenolic contents and antioxidant activity of the extracts have been considered as response variables. Box-Behnken design and Response Surface Methodology have been used to determine the parameters levels and modeling the responses, respectively. The results show that the optimal conditions to maximize total phenolic contents and antioxidant activity of date extract, include extraction time, 90 min, temperature, 70 0C, solvent to solid ratio, 39.89 cc/gr, solvent percentage, 10.11 (V/V), resulting in total phenolic contents and antioxidant activity of date extract in 633.36 mg(GAE)/100g(FW), and 59.46 % (based on DPPH radical scavenge). The predicted conditions are in good agreement with the experimental data, indicating the model accuracy.

Concern about the safety of synthetic antioxidants has led to extensive research for the plants, which is a rich source of natural antioxidant. Walnut leaf is a rich source of phenolic compounds and these compounds are the most important of natural antioxidants. In this research, the effect of regions (Shahrood, Damavand and Hezarjarib) and extraction methods (Immersis, Ultrasound and Microwave) on the yield of phenolic compounds extracted from walnut (Juglans regia L.) leaves in a factorial experiment with three replications in a completely randomized design has been analyzed. Then antioxidant activity of all sample extracts was evaluated by the reducing power of Iron (III) and DPPH free radical. The extracts of walnut leaves from Damavand region which prepared by ultrasound-assisted extraction method had the highest amount of phenolic compounds. The highest amount of phenolic compounds with 245.08±0.46 mg/g (based on Galic acid) and the lowest amount with 170.49±7.4 mg/g (based on Galic acid) were observed in samples extract obtained from Damavand walnut leaves employing ultrasound -assisted extraction method and Hezarjarib walnut leaves employing traditional extraction method, respectively. A positive correlation was observed between the total phenolic content and the antioxidant activity of the extract. The lowest level of EC50 for DPPH and reducing power tests was observed for ultrasound-assisted extraction method and Damavand region.