The fresh new sample is covered which have silicone polymer oil so you can water resistant the information presented. Obvious volume are mentioned that have good steropycnometer ( Loch-Bonazzi while some 1992 ).
Previous, extremely specific strategies for measuring obvious frequency was indeed suggested, and laserlight browsing ( Uyar and you will Erdogdu 2009 ; Kelkar while others 2011 ), automated tomography ( Mendoza and others 2007 ; Kelkar while others 2011 ), and you will magnetized resonance imaging ( Kelkar while others 2011 ). This type of techniques utilize optic gizmos and you will authoritative application to processes and carry out three-dimensional photo out-of objects, figuring frequency that have finite distinctions otherwise finite function. Although not, brand new drawbacks of these techniques outweigh its positives, due to the fact a certain background is necessary, plus authoritative equipment which is much more costly than old-fashioned process.
Compilation regarding Training
Many works has managed the choices out of genuine and you may obvious occurrence, both in the latest drying out processes and in new rehydration from foods (Desk step one and you may 2). These studies consider multiple food exposed to individuals drying criteria and in different geometric shapes. The latest parameters which have been learned are as follows: tension (P), relative dampness (RH), drying sky speed (?), and you will drying temperature (T), among others. Pretreatments like blanching, coatings, and you can osmotic dehydration, and others, were advertised ( Boukouvalas while others 2006 ).
Traditional convective drying, microwave oven drying out, osmotic drying, spray-drying, vacuum-drying out, and you will lyophilization are the most commonly utilized steps; they truly are examined significantly less than one another ongoing and you can changeable performing conditions ( Pezzutti and you will C ; Doymaz and you will Pala 2002 ). Product dehydrated by convective strategy is described as its reasonable porosity and you can large apparent occurrence ( Zogzas and others 1994 ). Similar features was indeed claimed having materials dehydrated on the microwave method, due to the fact that a mixture of these types of 2 tips can be put ( Krokida and others 2000 ). Osmotic dehydration leads to an increase in apparent occurrence for the majority materials, and you may a decrease for other people. It phenomenon might have been related to the increase inside solids during the brand new osmotic procedure ( Krokida and you can Maroulis 1997 ). Lyophilization output issues which have lowest density, and their porosity; this method supplies the very best quality outcome, as there are zero deformations throughout the thing, color and you may fragrance is preserved. Still, it does feel the disadvantage to be pricey and you can requiring much time drying symptoms ( Krokida and you may ).
Numerous structural details away from foodstuffs was in fact evaluated for the lyophilization process. Sablani although some (2007) found that apparent density, genuine occurrence, and you will porosity is a purpose of wetness content (X) and plate temperature; not, there clearly was a lack of clearness on these tendencies ( Karathanos while others 1996 ; Sablani while some 2007 ; Oikonomopoulou while some 2011 ).
The sites web de rencontres japonais effects regarding drying out requirements towards the occurrence
Certain article authors have found that aftereffect of relative humidity with the correct and you will apparent occurrence try minimal ( Zogzas although some 1994 ). While the ramifications of drying out air velocity to your thickness haven’t started analyzed, you can gather analysis regarding various bibliographic present it comes to 1 thing; like analysis suggest that real and noticeable thickness try lower at the down drying heavens velocities (Dining table 1). not, further lookup on the subject will become necessary. Few studies have stated to your effects of the fresh new geometry of the materials toward density, although it has been seen to help you dictate visible density opinions. Like, brand new density away from entire garlic cloves provides a great concave-down profile with regards to X; however, garlic cloves sliced by 50 percent display screen an excellent linear, ascendant desire with respect to the reduced amount of X ( Lozano and others 1983 ).