SCIENCE BEHIND FOOD PRODUCTS DEHYDRATION (1)

DEDICATED DRYING MACHINES MANUFACTURERSCIENCE BEHIND FOOD PRODUCTS DEHYDRATIONBEFORE DEHYDRATION AFTER DEHYDRATIONDrying operationDrying is an energy-intensive well-studied unit operation in process engineering to reducemoisture content in the food matrix to a level that is safe for storage and transportation, toavoid microbial multiplication, slow down/inactivate microbial activity and the associatedproduct quality deterioration. It involves the removal of water from a wet foodstock by inducingphase changes of water from solid or liquid into a vapor phase via the application of heat(except in the case of osmotic dehydration during which the water is removed without a changein phase by the diffusion of liquid water from solid foods to an osmotic solution through anosmotic pressure difference). The process of drying food materials is extremely complex,involving coupled transient mechanisms of heat, mass and momentum transfer processesaccompanied by physical, chemical, structural and phase change transformations. Drying isapplied in the food industry not only for preservation but also to manufacture foods with certaincharacteristics. The nature of the process along with the food structural characteristics results ina very marked effect on the quality characteristics of the final product. There are many differentmethods of drying food materials, each with their own advantages and disadvantages forparticular applications. Overall, the quality characteristics of the final product are significantlyaffected by the process conditions and the way it is conducted. Thus, dryingDedicated Analytical SolutionsCorporate Office Tel +91-9643480893 Application LabKDM Analytical +91-9540666954 D-198, Mundka Industrial AreaB-2/41 First Floor, Rohini Delhi-110081Sector-16, Delhi-110089 Fax +91- 22612722 web www.kdmanalytical.comIndia E-mail [email protected]

DEDICATED DRYING MACHINES MANUFACTURERoperations need to be precisely controlled and optimized in order to produce a good qualityproduct with the highest level of nutrient retention. The changes caused to the food propertiesinclude discoloring, aroma loss, textural changes, nutritive value and changes in physicalappearance and shape. Conditions of drying have a great effect on quality attributes of driedproduct. For example, higher drying temperature reduces the drying time but may result in poorproduct quality, heat damage to the surface and higher energy consumption. On the otherhand, mild drying conditions with lower temperature may improve the product quality butdecrease the drying rate thus drying period is lengthened. Drying are diverse as various foodmaterials with very diverse physical/ chemical properties need to be dried at different scales ofproduction and with very different product quality specifications. The materials preserved bydehydration vary a lot, not only fruits and vegetables to probiotic microorganisms and animalproducts in the food area, but also other biological materials with important physiologicalactivities.The develop e t of fu tio al foods a learly o tri ute to the glo al o ept of sustai a‐bility. The negative effects related to the application of extreme temperatures in dryingoperations can be minimized by incorporating ingredients that protect structural elements,creating protective structures and avoiding degradation reactions. Management of dryingprocesses in an adequate way can contribute to prevent bioactive compounds losses, maintainand even increase the functionality of dried products.DEHYDRATION ZONEFREEZE DRYING VACUUM DRYING HOT AIR DRYINGDedicated Analytical Solutions Application Lab D-198, Mundka Industrial AreaCorporate Office Tel +91-9643480893 Delhi-110081KDM Analytical +91-9540666954 web www.kdmanalytical.comB-2/41 First Floor, RohiniSector-16, Delhi-110089 Fax +91- 22612722India E-mail [email protected]

DEDICATED DRYING MACHINES MANUFACTURERRINSING ANALYSIS OF GRAPES: BEFORE DEHYDRATION AFTER DEHYDRATION Shrinkage ratio and apparent densities of grapes at different moisture contentDrying Operating Moisture Shrinkage ratio Apparent density g/cm3method condition content% 200 mm Hg (wb) Pretreated Control Pretreated ControlVACUUM 70, 60, 50, 40,DRYING 600 mm Hg 30, 20 sampl sample sampl sampleVACUUM 200 mm Hg 70, 60, 50, 40, 0.921, 0.788 0.854, 0.733 0.565, 0.444 0.623 0.517DRYING 30, 20 600 mm Hg 0.686, 0.478 0.573, 0.482 0.398, 0.338 0.478 0.429VACUUM 70, 60, 50, 40,DRYING 30, 20 0.424, 0.415 0.352 ,0.335 0.313, 0.301 0.382 0.346VACUUM 70, 60, 50, 40, 0.831, 0.669 0.756, 0.603 0.622, 0.521 0.681, 0.533DRYING 30, 20 0.545, 0.421 0.427, 0.363 0.416, 0.398 0.427, 0.386 0.373, 0.335 0.325, 0.309 0.366, 0.347 0.325, 0.317 0.872, 0.752 0.712, 0.584 0.551, 0.42 0.678, 0.568 0.542, 0.372 0.516, 0.396 0.367, 0.333 0.485, 0.473 0.342, 0.325 0.348, 0.318 0.304, 0.288 0.421, 0.310 0.872, 0.752 0.612, 0.455 0.682, 0.572 0.695, 0.583 0.542, 0.372 0.352, 0.296 0.461, 0.409 0.510, 0.436 0.342, 0.325 0.285, 0.276 0.399, 0.275 0.366, 0.281Dehydration and Rehydration is a beautiful Science to add value on your PRODUCTSDedicated Analytical SolutionsCorporate Office Tel +91-9643480893 Application LabKDM Analytical +91-9540666954 D-198, Mundka Industrial AreaB-2/41 First Floor, Rohini Delhi-110081Sector-16, Delhi-110089 Fax +91- 22612722 web www.kdmanalytical.comIndia E-mail [email protected]