Search

Conductive hydro-drying also known as Refractance Window drying is a relatively new drying technology, which uses hot water to carry thermal energy to materials to be dehydrated. It has a high rete...

Dates are naturally rich in antioxidants and other bioactive molecules. To enhance the shelf life and market value of these bioactive molecules, free flow spray-dried date powder was produced in a ...

This study was designed to establish the interaction effect of various components of pulsed electric field (PEF) system on drying characteristics of carrot, a vegetable rich in carotenoid. Carrots were treated in PEF system of 0.5, 1, and 1.5 kV/cm electric field strength, 0.5 and 1 μF capacitance, and pulse numbers of 10, 30, and 50. The samples were subsequently dried at 70°C until reaching an acceptable moisture content level. Drying rates were significantly (P

This study was conducted to evaluate the effect of different pretreatment methods (blanching, microwave, and pulsed electric field [PEF]) on drying and rehydration behavior of okra. Drying rates were significantly (P

Electrohydrodynamic (EHD) drying is a novel method of non-thermal processing. The drying can be carried out using either AC or DC high voltages. The thermodynamic considerations regarding the lowering of temperature under EHD drying include rapid rates of evaporation and exothermic interaction of the electric field with a dielectric material. Multi-point and plate electrode systems are efficient in accelerating drying of agricultural materials. Compared to hot air (convective) drying systems, EHD drying systems offer lower food production costs along with superior quality in terms of physiochemical properties such as color, shrinkage, flavor, and nutrient content. Compared to convective and freeze-drying, EHD drying systems, given their simpler design and lesser energy consumption, show great potential for bulk and industrial drying applications.

The effect of carboxy-methyl cellulose (CMC) coating on mass transfer process during osmotic dehydration of apple slices and its effect on salt absorption were investigated. The study was conducted using four concentrations of CMC (0.5, 1, 1.5, and 3%) and nine osmotic solutions comprising of glucose syrup (30, 40, and 50%) and salt (2, 4, and 6%). Sample contact time with the hypertonic solution was 15, 30, 60, 120, 180, 240, and 360 min. Both coated and uncoated samples were evaluated in terms of water loss (WL), solids gain (SG), WL/SG ratio, and salt absorption. Optimal condition was obtained when the CMC concentration of 1% was used with hypertonic solution comprising of 50% glucose syrup and 2% salt.

Changes in the structure of food products play important role in the various mass transfer processes during deep-fat frying. The relationship between moisture loss and pore formation were investigated at frying oil temperatures of 170, 180, and 190°C and frying times up to 900 s. Porosity and pore structure were characterized by using mercury intrusion porosimetry and helium displacement pycnometer. Moisture transfer in the samples was modeled using Fick's law and effective moisture diffusivity was computed from experimental data. Pore formation changes significantly (P

The effect of pulsed electric fields (PEF) on drying and some physical properties of apple and potato was evaluated. Pulsed electric field intensities from 0.75 to 1.5 kV/cm with pulse duration within 100 and 300 μs were studied. The number of pulses applied was up to 120. Measurement of porosity and density were conducted using a mercury porosimeter. The drying process was carried out in a convective air oven at 70°C. The compressive strength of apples was reduced between 21 and 47% after treatment. The results show potential advantage for PEF enhanced juice extraction from the tissues even at moderate PEF treatment. PEF treatment increased porosity and particle density but decreased bulk density. Treating the apple samples with PEF resulted in generation of more pores of sizes in the order of cell wall thickness. Thus electric field application affected not only cell membranes but also cell wall integrity. PEF treatment enhanced drying rates of potato samples. Diffusion coefficients of PEF pret...