No abstract

Massive consumption of energy in the drying industry has prompted extensive research regarding various aspects of drying energy and requirements. Thermal utilization efficiency, specific energy requirement, total energy consumption and hypericin content in drying of St John’s Wort were determined using a hot-air dryer. Experiments were conducted at four air temperature levels (40, 50, 60, and 70°C), three air velocities (0.3, 0.7, and 1 m/s) and three sample thicknesses (1, 2 and 3 cm). Based on the results of data analysis, minimum and maximum levels of energy consumption were 0.56 and 3.24 kWh, respectively. The required specific energy decreased with increasing sample thickness. The minimum and maximum required specific energies were 4.41 and 17.53 for 2 cm thick and 4.28 and 13.67 for 3 cm thick layers (kWh/kg), respectively. The maximum and minimum values of thermal utilization efficiency in different treatments were found to be 14% and 72%, respectively. Hypericin content decreased with increasing temperature and increased with air velocity and product sample thickness, so that the minimum and maximum hypericin amounts were 67 and 355 ppm, respectively.

Grading and hydraulic handling of fruits and vegetables are important subjects of study in industries to maintain their quality and reduce their losses. It is thus essential to have knowledge of hydrodynamic properties of agricultural products for sorting, grading, washing, packaging, and storage purposes. This study first determined the physical properties (i.e., mass, density, volume and shape coefficient) influencing terminal and other hydrodynamic properties of Mexican lime (locally known as Jahromi lime). Then, a water column and a video camera were used to measure the terminal velocity and falling time of the samples. The effect of physical properties determined, and the difference between water and lime densities on the hydraulic properties were analyzed in MATLAB. The results show that Mexican lime samples reached their terminal velocity in 2.5 s when the terminal velocity and the falling time were 0.08 m/s and 6.5 s, respectively. The water–lime density difference, volume, and the sample mass had the significant effect (p < 0.05) on the terminal velocity and falling time. However, the shape coefficient had no significant effect. Practical applications Fruits with different densities fall to different depths at a given time, and a properly situated separator can be used for grading them. This research prospect the use of Mexican lime terminal velocity as a parameter for density‐based hydraulic grading to be used in the design and development processes of fruit sorting and grading systems, and regression equations of sample movement were fitted based on their physical properties to find the best model.

Thermal, pasting, and rheological properties of starch-based systems are the key characteristics for its processing. This study aimed to investigate the main and interactive effects of sucrose and xanthan on the thermal, pasting, and rheological behavior of corn starch. A central composite design (CCD) was used to evaluate the effect

Extrusion is a composite process consisting of many different unit operations such as mixing, cooking, pasting, and molding. In this process, the raw material is forced through a tiny opening to be transformed into a product with a desired and unique shape, texture, color, and taste. In combination with different amounts and types of additives, this technique can result in functional food products for a broad range of people suffering from micronutrient deficiency. The hydrocolloid compounds are now employed to improve the texture and performance properties of many food products. Therefore, this study scrutinized the effects of carboxymethylcellulose and locust bean gums at different levels (0.5, 0.75, and 1%) alone or in combination with each other on chemical, physical, mechanical, and textural properties of extruded rice in comparison with the qualitative properties of the control rice. A completely random design was used along with three replications to analyze the test results. Then the means were compared through Duncan's multiple range test at (α = 5%). According to the results, addition of gums increased moisture, ash, total color difference, water absorption capacity, solubility, failure force, rupture energy, elasticity module, and toughness when reduced lateral expansion was compared to the control. Moreover, the addition of gums after the cooking process increased cooking loss, texture hardness, chewability, and elasticity of the specimens in comparison with the control. According to the results of pre‐ and post‐cooking tests, the specimens containing locust (0.75%) and carboxymethylcellulose (0.75%) gums were the best treatments.