Temporary immersion systems (TISs): A comprehensive review.

The temporary immersion systems (TISs) have been widely used in plant biotechnology. TISs have different advantages from the point of micropropagation and production of secondary metabolites over other continuous liquid-phase bioreactors. The current work presents the structure, operation mode, configuration type, and micropropagation or secondary metabolite production in TISs. This review deals with the advantages and disadvantages of TISs and the factors affecting their performance. Future research could focus on new designs based on CFD simulation, facilitating sterilization, and combining TISs with other bioreactors (e.g., mist bioreactors) to make a hybrid bioreactor.

Design of nutrient gas-phase bioreactors: a critical comprehensive review.

To reach an efficient and economical gas-phase bioreactor is still one of the most critical challenges in biotechnology engineering. The numerous advantages of gas-phase bioreactors (GPBs) as well as disadvantages of these bioreactors should be exactly recognized, and efforts should be made to eliminate these defects. The first step in upgrading these bioreactors is to identify their types and the results of previous research. In the present work, a summary of the studies carried out in the field of cultivation in these bioreactors, their classification, their components, their principles and relations governing elements, modeling them, and some of their inherent engineering aspects are presented. Literature review showed that inoculation of shoots, roots, adventurous roots, callus, nodal explants, anther, nodal segment, somatic embryo, hairy roots, and fungus is reported in 15, 2, 2, 2, 3, 2, 1, 1, 37, and 5 cases, respectively.

Performance evaluation of ultrasonic transducer in a mist bioreactor by different nutrient media.

The mist bioreactor has been proved to have a higher performance relative to the liquid phase reactor. The water and conventional media (MS, ½MS, and B5) were tested in a mist bioreactor to evaluate the performance of the misting system. The physicochemical properties of liquids were measured at 0 (Fresh state) and when treated by ultrasonic system for 1 and 2 h. At a given airflow rate, the misting rate for different heights of various media was determined. The results demonstrated that the electrical conductivity of all media increased with the duration of sonication. The ultrasonic effect caused an increase in surface tension of MS and ½MS, while the pH of MS and ½MS reduced with ultrasonic treatment. The inverse trends were observed for water and B5 for these properties. The misting rate increased by increasing liquid height to a maximum value, then decreased to a minimum value at the highest height. For all liquids studied in this experiment, this maximum value of misting performed at height ranged between 3 and 4 cm. The maximum and minimum values of the ultrasonic misting rate belonged to MS ([Formula: see text]) at height 3 cm and B5 ([Formula: see text]) at height 1 cm, respectively.

Ohmic Heating of Lemon and Grapefruit Juices Under Vacuum Pressure- Comparison of Electrical Conductivity and Heating Rate.

Ohmic heating fundamentally depends on electrical conductivity. In this study, grapefruit and lemon juices were ohmically heated under vacuum conditions. The electrical conductivity was measured at voltage gradients (10, 20, and 30 V/cm) and vacuum pressure (0 [atmospheric pressure], -30, and -60 kPa) for four temperature ranges (30, 40, 50, and 60 °C), meanwhile the heating rate was also reported at the same level of pressure and voltage gradient. The electrical conductivity and heating rate considerably vary by voltage gradient relative to pressure. Grapefruit had considerably lower electrical conductivity (about 20%) relative to lemon juice for the same pressure-voltage gradient treatment, while the percent reduction of heating rate (grapefruit relative to lemon) varied from 19 to 32%. The multivariate linear regression of electrical conductivity, including temperature and voltage, was found to be a more suitable model. pH assessments showed that pressure significantly affected the pH of grapefruit and lemon juices (P < 0.01). The combination of different treatments, which created a shorter residence time, caused a greater decrease in pH.

Quality preservation of orange concentrate by using hybrid ohmic - Vacuum heating.

The effect of ohmic-vacuum heating conditions (OHVC) was evaluated on quality parameters during concentration process of orange juice and compared with ohmic heating process under atmospheric conditions (OHAC) and conventional vacuum heating (CVH). The decline of vitamin C in OHVC treatments (10-29.2%) was lower than the OHAC (18.0-38.8%) and CVH (47.4%). Changes of pH for OHVC were lower than OHAC and CVH. The difference in total phenol content of fresh and concentrated juice was 8.0-21.3% for OHVC and 18.5-42.8% for OHAC and 49.6% for CHV. Antioxidant capacity of treatments was lower than the fresh sample at same water content. Increasing of voltage gradient had a positive effect on the saving of vitamin C and total phenol and processing time. Finally, it can be resulted that the combine of vacuum treatment with ohmic heating (as hybrid ohmic-vacuum heating) could maintain food quality parameters.

An artificial intelligence approach for modeling volume and fresh weight of callus - A case study of cumin (Cuminum cyminum L.).

Cumin (Cuminum cyminum Linn.) is valued for its aroma and its medicinal and therapeutic properties. A supervised feedforward artificial neural network (ANN) trained with back propagation algorithms, was applied to predict fresh weight and volume of Cuminum cyminum L. calli. Pearson correlation coefficient was used to evaluate input/output dependency of the eleven input parameters. Area, feret diameter, minor axis length, perimeter and weighted density parameters were chosen as input variables. Different training algorithms, transfer functions, number of hidden nodes and training iteration were studied to find out the optimum ANN structure. The network with conjugate gradient fletcher-reeves (CGF) algorithm, tangent sigmoid transfer function, 17 hidden nodes and 2000 training epochs was selected as the final ANN model. The final model was able to predict the fresh weight and volume of calli more precisely relative to multiple linear models. The results were confirmed by R(2)≥0.89, R(i)≥0.94 and T value ≥0.86. The results for both volume and fresh weight values showed that almost 90% of data had an acceptable absolute error of ±5%.

Ohmic pre-drying of tomato paste.

In this study, the effects of ohmic pre-drying technique on moisture ratio, drying rate, drying time, specific energy consumption, drying efficiency, and effective moisture diffusivity of tomato paste were investigated. Pre-drying experiments were carried out in an ohmic laboratory dryer at voltage gradient levels of 6, 8, 10, 12, 14, and 16 V/cm and oven at 105 and 1.0 m/s air velocity (control sample). Pre-drying was accomplished till the moisture content of the tomato paste reduced from initial moisture content of 90% (w.b.) to a safer level of 70% (w.b.). The ohmic pre-drying reduced the drying time of tomato paste by 80-97%, compared with the hot air drying. Pre-drying took place mainly in warming up, constant rate, and falling rate periods. Six available moisture-ratio models were fitted to the pre-drying data. The results showed that the Midilli et al. model is the most appropriate model for pre-drying behavior of tomato paste. The effective moisture diffusivity varied from 5.39 × 10(-8) to 3.91 × 10(-7)m(2)/s with an activation energy of 2.082 (V/g.cm). Both specific energy consumption and drying efficiency were considerably enhanced by increasing voltage gradient. It was found that the specific energy consumption and drying efficiency varied from 3.72 to 2.29 MJ/kg water and 67.8 to 83.8%, respectively.