convective drying rates of thermally blanched slices of

OSMOTIC DEHYDRATION FACILITATES SUBSEQUENT DRYING

facilitating subsequent convective drying of sliced garlic The pre-dehydration was performed using three concentrations 10 15 or 20% sodium chloride at different temperatures 25 35 or 45C and followed by convective drying at 50 or 60C the solution to garlic ratio was 1:4 (w/w) The period of pretreatment lasted for 180 min The

PAPER OPEN ACCESS Osmotic concentration of pineapple

approximately) During convective drying it is considered that only water comes out Experimentally the curve for convective drying is to weigh the sample at different time intervals to obtain the water content Moisture content and diffusivity were assessed in order to evaluate the performance of drying Table 1 Treatments for convective drying

Air Drying Characteristics of Apricots

Sulfiting‐drying using 80–1000 ppm SO 2 at any temperature in the range 50–80C was found to be the best treatment Thus sulfite was the major factor in controlling dry apricot quality and would be hard to reduce Drying time was reduced by 50% when apricots were dried at 80C compared to 50C and blanching reduced the time by 10

Convective drying rates of thermally blanched slices of

Rates of drying of thermally blanched slices of potato (Solamum tuberosum) of different thicknesses are obtained experimentally in a laboratory convective tray dryer at 85C and 95C A model (Fernando et al 2008) for estimation of dehydration rates of materials with surface layers which describe three parameters (l/D) r and KpHCo

Convective hot air drying of blanched yam slices

Dec 12 2007In this study a laboratory convective hot air dryer was used for the thin layer drying of blanched yam slices and experimental moisture ratio was compared with Newton Logarithmic Henderson and Pabis modified Henderson and Pabis approximation of diffusion modified page 1 two‐term exponential Verma et al and Wang and Singh models Among all the models the

Full Length Research Article

Slices of pineapple were blanched at different temperature-time combinations before being dried in an oven dryer at a dry bulb temperature of 70oC Four thin-layer drying models were fitted to the experimental drying data The results show that drying rates and drying times were affected by the blanching temperature-time combinations

Influence of Sulphite on the Drying Kinetics of Pumpkin

Mar 03 2019The drying curves obtained showed results for a short constant rate followed by a falling rate period The effective moisture diffusivity varied from 6 23510 -11 to 12 80810 -11 m 2 /s for the 4 mm and 9 046 x 10-11 to 21 330 x 10 -11 m 2 /s for the 5 mm samples

Thermal Kinetics Of Colour Degradation Of Yellow Sweet

drying has recently been a subject of interest for various investigators for example con-centrated fruit pulp [11 ]spinach and mustard leaves 12 banana [13 ]garlic 14 rosehip 15 soybean [16 ]mango pulp 17 guava and papaya [18 ]okra 8 bamboo shoot slices 19 apple slices [20 ]and watermelon juice 21 Hence if the kinetics of colour

Hot Water Blanching Pre

Simple cost analysis was also performed to assess the annual cost and custom rate of using two methods of drying It revealed that in heated air mechanical dryer samples blanched for 5 and 15 seconds dry faster (8 hours) In solar glass dryer seaweed samples blanched at 5 seconds dry

NEAR INFRARED DRYING OF APPLE SLICES

The moisture content of apple slices increased during blanching procedure but the drying duration of blanched samples was shorter by 44 min Because of all other conditions was the same this could be considered that drying of blanched apple slices is more effective and practical 0 20 40 60 80 100 120 0 5 10 15 20 25 Temperature C Time min

Effect of Blanching and Osmotic Pre

Methodology: Chayote slices (41 mm thick) were blanched in hot water at 80C or osmo-dehydrated in 10% brine for 3 min or left untreated as control and subsequently dried at 65C Shrinkage of dried samples rehydration ratio and effective diffusivity of samples were determined Experimental drying data was fitted by non-linear regression to

Effect of Blanching and Drying Temperatures on Various

Blanching treatment enhanced the drying rate the kinetics parameter showed that the value of 'k' ranged from 0 008-0 013 and 0 009-0 015 /min in un-blanched and blanched samples respectively The drying temperature caused decrease in color parameters chlorophyll content however RR was observed to increase with the drying temperature

Drying Kinetics of Tomato Okra Potato and Mango in a

Aug 02 2019The design of a solar drier requires detailed information about drying kinetics of the products to be dried The objective of our work is to characterize drying kinetics of tomato okra potato and mango and calculate the main drying parameters namely the drying rate the moisture ratio and the effective diffusivity from the derivative form of the Fick's second law of diffusion

Investigation of ultrasound

Jan 28 2019In the present investigation the ultrasound-assisted convective drying process for zucchini slices was studied In this regard the effects of convective air velocity (in three levels of 1 2 and 3 m/s) and ultrasonic pretreatment time (in three levels of 0 15 and 30 min) on drying kinetic drying time and qualitative characteristics of the dried product were investigated

The Influence of Drying on the Physical Properties of

blanching (dipped in water at 90 oC for 5 min) and the unblanched used as control samples The blanched slices were drained prior to drying Sun Drying Potato slices of blanched and un-blanched samples were spread thinly on a metal tray and directly exposed to the sun

Drying

Drying is a mass transfer process consisting of the removal of water or another solvent by evaporation from a solid semi-solid or liquid This process is often used as a final production step before selling or packaging products To be considered dried the final product must be solid in the form of a continuous sheet (e g paper) long pieces (e g wood) particles (e g cereal grains

Recent developments and trends in thermal blanching

Jun 01 20171 Introduction Blanching is a thermal treatment that is usually performed prior to food processes such as drying freezing frying and canning It is essential to preserve the product quality during the long-term storage because it inactivates the enzymes and destroys microorganisms that might contaminate raw vegetables and fruits during production harvesting and transportation

Effect of pretreatments on convective and vacuum drying

Sep 21 2013Works and plan Pretreatment i) Hot Water Blanching ii) Steam Blanching iii) Microwave Blanching One particular temperature for tray dryer 60 oC 70 oC and 80 oC for each temperature air velocity at 0 5 m/s 1 m/s and 1 5 m/s Drying combination of convective and vacuum dryer Rehydration ratio Shrinkage (%) color and water activity To

OSMOTIC DEHYDRATION FACILITATES SUBSEQUENT DRYING

facilitating subsequent convective drying of sliced garlic The pre-dehydration was performed using three concentrations 10 15 or 20% sodium chloride at different temperatures 25 35 or 45C and followed by convective drying at 50 or 60C the solution to garlic ratio was 1:4 (w/w) The period of pretreatment lasted for 180 min The

Effect of Blanching on Structural Quality of Dried Potato

Potato slices blanched for 2 and 30 min as well as unblanched ones were dried in a convective air drier at 48 C Bulk and true density porosity and shrinkage were monitored with time Blanched potatoes resulted in a significantly more compact less porous product with lower effective water diffusivity than unblanched potatoes

Grape Drying: Current Status and Future Trends

(3) Reduction of the mass transfer coefficient in hot air samples suggested the formation of a crust or shell during drying caused by the higher drying rate Convective drying + ultrasound Grape stalk from Vitis vinifera var Bobal Temperature of 40 and 60C with or

How Drying Preserves Food

Thin uniform peeled slices dry the fastest The peel can be left on the fruit but unpeeled fruit takes the longer to dry Apples can be cored and sliced in rings wedges or chips Bananas can be sliced in coins chips or sticks Fruits dried whole take the longest to dry Before drying skins need to be checked or cracked to speed drying

Investigation of ultrasound

Jan 28 2019In the present investigation the ultrasound-assisted convective drying process for zucchini slices was studied In this regard the effects of convective air velocity (in three levels of 1 2 and 3 m/s) and ultrasonic pretreatment time (in three levels of 0 15 and 30 min) on drying kinetic drying time and qualitative characteristics of the dried product were investigated

Drying Characteristics of Agricultural Products under

In a study thin-layer drying characteristics of blanched and unblanched eggplant slices were determined for different sample thickness (0 5 and 1 cm) and by changing the air temperature from 50℃ to 80℃ in steps of 10℃ (Doymaz and GL 2011) High HA temperature low sample thickness and pretreatment were effective for shortening the