This new attempt is included having silicone polymer fat in order to water-resistant the materials. Visible volume is counted having a beneficial steropycnometer ( Loch-Bonazzi while some 1992 ).
Current, highly appropriate techniques for measuring visible volume were proposed, along with laser learning ( Uyar and you will Erdogdu 2009 ; Kelkar while others 2011 ), automated tomography ( Mendoza while others 2007 ; Kelkar while others 2011 ), and you will magnetized resonance imaging ( Kelkar although some 2011 ). These process utilize optic gizmos and you will official application to procedure and you will would three dimensional photo from stuff, calculating volume having limited variations or limited ability. But not, the newest drawbacks of those techniques exceed the pros, just like the a certain background is required, along with certified gadgets that’s significantly more expensive than simply conventional procedure.
Compilation away from Studies
Lots of work have treated the brand new conclusion out-of real and obvious density, in both the fresh new drying process along with this new rehydration away from food items (Table step one and you can 2). This research evaluate numerous products confronted by certain drying out requirements and in almost any geometric shapes. The newest variables which were learnt are as follows: tension (P), relative humidity (RH), drying out heavens velocity (?), and you may drying out temperature (T), and others. Pretreatments including blanching, coatings, and you can osmotic dehydration, and others, was said ( Boukouvalas while others 2006 ).
Traditional convective drying, microwave drying, osmotic drying out, spray-drying out, vacuum-drying out, and you can lyophilization are definitely the most commonly utilized procedures; they’ve been evaluated less than each other ongoing and adjustable operating conditions ( Pezzutti and you may C ; Doymaz and you will Pala 2002 ). Content dried by the convective die besten kostenlosen Kink-Dating-Seiten approach try characterized by their reduced porosity and you will highest noticeable thickness ( Zogzas while others 1994 ). Comparable attributes have been advertised to have material dried into the microwave method, due to the fact that a mix of such dos methods may be made use of ( Krokida although some 2000 ). Osmotic dehydration causes an increase in apparent thickness for some product, and you may a drop for other individuals. So it occurrence has been related to the rise within the solids during brand new osmotic techniques ( Krokida and you will Maroulis 1997 ). Lyophilization productivity factors with lowest density, due to their porosity; this procedure produces the very best quality outcome, and there is zero deformations regarding the procedure, colour and you will aroma try preserved. However, it can feel the downside of being pricey and demanding a lot of time drying out attacks ( Krokida and you can ).
Multiple structural details of foods was basically analyzed in lyophilization processes. Sablani while some (2007) unearthed that visible occurrence, correct occurrence, and you can porosity is a function of moisture content (X) and you may plate temperature; yet not, there is too little clearness throughout these tendencies ( Karathanos while others 1996 ; Sablani and others 2007 ; Oikonomopoulou while others 2011 ).
The effects away from drying out standards towards thickness
Some article writers found that effectation of relative humidity towards the correct and you will apparent occurrence is actually minimal ( Zogzas while some 1994 ). Even though the negative effects of drying out air speed into the thickness haven’t come analyzed, it is possible to compile studies regarding certain bibliographic sources it comes to a single situation; like analysis suggest that correct and you will obvious thickness is all the way down at the all the way down drying air velocities (Desk 1). Yet not, after that browse on the subject is needed. Couple research has stated to the results of the fresh geometry away from the materials on the density, though it has been seen so you can determine visible occurrence values. Such as for instance, the latest density out-of whole garlic cloves keeps a good concave-off shape regarding X; however, garlic cloves chopped in half monitor a good linear, ascendant tendency with regards to the reduced amount of X ( Lozano while some 1983 ).
