نشریه فناوری های جدید در صنعت غذا
سال هشتم شماره 2 (پیاپی 30، زمستان 1399)

Combined additive manufacturing (AM) and syringe deposition as a process method for complex parts manufacturing, attracted the attention of many industry and research communities due to its ability to shorten design to production cycle. In this method, various materials such as polymers, food pastes, etc. are deposited in layers by a CNC controlled syringe, gradually outlining the shape of the part.

The aim of this research was shaping chocolate parts by AM technology. For this purpose, a commercial 3D printer equipped with a specially designed syringe head with temperature control was used.

DSC test indicated that the proper temperature for tempering of the chocolate is between 32 and 40 oC. The rheology test indicated that by increasing the temperature, the chocolate viscosity was decreased and leaded to more flow rate of the extruded chocolate and thus reduced the shape resolution. On the other hand, the process parameters such as the nozzle height from the printing plate, the nozzle diameter, the software input diameter setting and the temperature of the build plate also affect the print resolution. So, different input diameters were examined at various temperatures and optimum conditions for the best printed part resolution were obtained as follow: nozzle temperature of 32 oC, printing height equal to nozzle diameter, software input diameters of 1.98 mm and plate temperature of less than 10 oC Based on the optimum condition, complex shape of chocolate object were 3D printed.

Probiotics are live microorganisms that adequate consumption of them leads to health effects in the host. Due to the increase in people's awareness and change in their lifestyle in recent years, the tendency to consume probiotic products has increased around the world. Production of probiotic food products have challenge because of inactivation of significant number of probiotic microorganisms during various food processes, storage or interaction with food ingredients. In addition, the digestion and passage of food through the gastrointestinal tract can affect the survival of probiotics. Therefore, maintaining the live population of probiotic microorganisms sufficiently(>106 CFU /ml or g ) until consumption of product should be considered by manufacturers. Incorporation of probiotic microorganisms in the different films and coatings are a new approach that has been proposed in the last decade to develop bioactive films with antimicrobial and health-promoting properties in order to provide new non-dairy probiotic products. The aim of this review study was evaluation of studies of probiotic films and coatings until now to conduct further research based on the available results in future.

The aim of this study was to investigate the effect of CO2 atmosphere and pre-treatment of disinfection on the physicochemical properties of fresh barberry. For this purpose, after removing the foliage, part of the barberry fruit was packed in LDPE/PET packages with a thickness of 45µ and under the CO2 atmosphere (CD). Some of the fruits were first disinfected with commercial solution and then packaged under the natural atmosphere (D) or under a CO2 atmosphere (CDD). The barberry fruits without disinfection and packaged under the natural atmosphere were considered as control (C). Results showed that in packages under the natural atmosphere, the levels of O2 and CO2 decrease and increase, respectively with increasing of the storage period, while in CD and CDD packages, the amount of CO2 inside the package decreased during storage. At the end of 28 days, the moisture loss and weight loss in CD and CDD samples were higher than other samples, especially at 25ºC, while the acidity increased in these samples. At the end of 28 days of storage at 4ºC, the lowest content of anthocyanins, phenolic compounds, ascorbic acid, the DPPH scavenging capacity and the ferric reducing antioxidant power were related to the CDD, D, CDD, D, and D samples, respectively which they exhibited 40.6, 46.6, 58.4, 51.6, and 60% decline compared to harvest time. The lowest values of the above compounds at 25 C were related to CDD, CD, CDD, CD, and D samples, which lost by 48.2, 34.8, 73.8, 55.7, and 63.6%, respectively in comparison to harvest time. At the end of the storage period, the lowest firmness and the highest decay were related to the CDD. It seems that the CO2 atmosphere does not have the ability to maintain the quality of fresh barberry and the pre-treatment of disinfection intensified unfavorable conditions.

In this paper, microwave and ultrasound irradiation were compared for pre-treating the black tea (Camelia Sinensis) leaves powder to increase the weight percentage of extraction yield of effectives compounds in multi stage solvent extraction (MSSE) via three stage extraction with distilled water. Maximum extraction yield by MSSE from the un-pretreated tea sample at optimum condition (135 min extraction time, 65°C extraction temperature and 25 ml/g solvent to solid ratio) was obtained 24.53±0.28% w/w. For microwave pre-treating, the tea samples were leached in distilled water at room temperature for 80 min and then exposed to microwaves at 600 W for 1 min. Maximum extraction yield from the microwave pre-treated sample by MSSE at optimum condition (90 min extraction time, 40°C extraction temperature and 20 ml/g solvent to solid ratio) was obtained 37.06±0.34% w/w. For ultrasound pre-treating, the tea samples were irradiated by ultrasonic waves at a mild condition including of 10 min irradiation time at amplitude of 70% and pulse of 0.7 s. Maximum extraction yield from the ultrasound pre-treated sample by MSSE at optimum condition (108 min extraction time, 55°C extraction temperature and 18 ml/g solvent to solid ratio) was obtained 31.47±0.38% w/w. So both of the pre-treating methods had significant effect on improving the extraction yield and softening the extraction condition in MSSE and the microwave pre-treating was the better one. The extraction yield (37.15±0.19% w/w) obtained by SOX at optimum operating condition (5h extraction time at boiling point of water) was close to those obtained by MSSE from pre-treated samples, but amounts of the total phenolic and flavonoid compounds in the SOX extract were less than those obtained by other extraction methods considered in this study that was due to prolong heating process in the soxhlet extraction.

In this study, the time-dependent (thixotropic) rheological behavior of sage seed gum (SSG) dispersions in the presence of NaCl and CaCl2 salts (0, 10, 50 and 100 mM), and glucose and sucrose sugars (0%, 2%, 4% and 6%) at different shear rates (10-50 s-1) was investigated. SSG dispersions exhibited a thixotropic behavior at all the conditions examined. The data obtained from rheological measurements were fitted well to the second-order structural kinetic (SOSK) model for salt solutions (R2 = 0.918-0.987, RMSE = 0.003-0.017) and Weltman model for sugar solutions (R2 = 0.921-0.993, RMSE = 0.003-0.020). The structural breakdown rate (k) and the structural breakdown extent (0/) values obtained for SSG in CaCl2 solutions were greater and lower than those of NaCl, respectively. Among the salt solutions, the SSG dispersions containing 10 mM NaCl have the greatest initial shear stress (A) and time coefficient of thixotropic breakdown (B) values. The chain stiffness (S) value in the presence of Ca2+ (8×10-4 ̶ 12×10-4 M0.5.Pa.s) was greater than that of Na+ (6×10-4 ̶ 8×10-4 M0.5.Pa.s). For sugar solutions of SSG, the greatest value of k was obtained for sucrose and the 0/ parameter diminished with increasing shear rate. Sugar concentration had a direct and indirect relationships with A and B parameters, respectively. The results of current study revealed that the thixotropic behaviour of SSG solutions is remarkably influenced by the salts and the sugars, so this issue can be considered in food product processing.

The aim of this study was to achieve a foam mat with minimum density and maximum foam mat stability. In order to conduct research, first to produce foam, barberry juice is prepared, basil seed gum (BSG) is extracted and then foam is used using basil seed gum as a stabilizer in different concentrations (0, 0.1 and 0.3%) and agent Egg white powder (EWA) in different concentrations (0.5, 1 and 1.5%) at 50°C was prepared by Foam mat drying method. A concentration of 1.5% egg white and a concentration of 0.3% basil seed gum were selected as the optimal concentration. The effect of different drying temperatures (50, 60 and 700C) on solubility, water absorption capacity, color, bulk density, water activity and FTIR foam consisting of the optimal concentration of egg white powder and basil seed gum in the optimal concentration were investigated. The results of analysis of variance showed that increasing the drying temperature significantly increased the solubility, brightness in the produced powder, while the water absorption capacity, density and aw significantly decreased. At high drying temperatures, denaturation of proteins and placement of hydrophobic groups on their surface are the reasons for reduced water absorption. Basil seed gum can be used to improve foam stability in foods containing egg white albumin.

The use of edible coatings is a way to preserve fruits and agricultural products. Edibles coating by reducing the respiration rate of fruits, significantly, to increase their shelf life and to reduce the amount of waste. The aim of this study is to optimize the production of edible coating for long-term storage of "grapes" (Asgari species due to high corruption and abundance) by response surface method (RSM). Different concentrations of acetylated potato starch (3, 5 and 7 gr) and rice bran oil (zero, 0.5, 1, 1.5 and 2 gr) were used to produce coatings. All samples were homogenized at different velocities of Ultra-thorax (7, 14.5 and 22 rpm). The fruit’s weight loss, Coating’s stability and aw parameters were considered as experimental design responses (optimal custom). Treatments (20 samples in 2 replications) were stored in refrigerated with 4 °C temperature and 70 % humidity for 28 days. Grape’s quality parameters included TSS, TA, pH, and weight loss were studied every 2 weeks. Also the amount of moldy berries was calculated at the end of the storage period. Developed models for emulsion gel’s stability and aw predicted that using 2 % rice bran oil, 6.57 % acetylated potato starch and 7 rpm homogenization rate, led to the formation of coating with the highest stability (93.6%) and the lowest aw (0.77).

< p >Tomato paste is one of the most important flavorings in food, so monitoring the quality and safety of food in this highly-consumed product is drastically important. In this study, a portable electronic tongue system including an array of electrochemical sensors based on graphite pencil electrodes was implemented to detect sodium benzoate adulteration in tomato paste. To adulterate the tomato paste, different values of sodium benzoate (20, 60, and 100 microliters) were added to the natural tomato paste free of sodium benzoate. In the measurement process, a cyclic voltammetric technique with a potential range of 0 to 1 volt was used to detect sodium benzoate. The results showed that pH = 7 was optimal for phosphate buffer, used to detect sodium benzoate. Graphene also performed the best results as a modifier for the electrode surface of the graphite pencil to detect the amount of sodium benzoate in comparison with two other modifiers such as gold nanoparticles and magnetic nanoparticles. The results obtained by classifying the samples demonstrated the high capability of the electronic tongue system for detection of sodium benzoate adulteration in tomato paste. According to the results, the three-electrode sensor system used in this study, including graphite pencil, silver / silver chloride reference and auxiliary platinum electrodes, is efficient in detection of sodium benzoate in tomato paste.