The fresh new decide to try is included having silicone grease to waterproof the material. Visible volume try mentioned with a beneficial steropycnometer ( Loch-Bonazzi while others 1992 ).
Recent, very precise techniques for measuring noticeable volume were advised, along with laser studying ( Uyar and you can Erdogdu 2009 ; Kelkar while some 2011 ), automatic tomography ( Mendoza while some 2007 ; Kelkar while others 2011 ), and you will magnetized resonance imaging ( Kelkar although some 2011 ). These techniques make use of optic products and formal app so you’re able to process and you can do three dimensional photo from things, calculating regularity that have limited distinctions otherwise limited feature. not, the fresh drawbacks of them processes outweigh their advantages, since a specific background will become necessary, together with formal products which is alot more pricey than just old-fashioned techniques.
Compilation off Knowledge
A great amount of really works provides managed brand new conclusion out-of genuine and you may obvious occurrence, in both brand new drying process along with the fresh new rehydration off food products (Desk step one and you will dos). This research glance at several items confronted with certain drying standards and you may in numerous mathematical molds. The new parameters that happen to be analyzed are listed below: pressure (P), relative humidity (RH), drying out air speed (?), and you may drying temperatures (T), yet others. Pretreatments instance blanching, coatings, and osmotic dehydration, among others, were reported ( Boukouvalas although some 2006 ).
Conventional convective drying out, microwave oven drying out, osmotic drying out, spray-drying out, vacuum-drying out, and you will lyophilization are definitely the most commonly made use of procedures; they’ve been examined not as much as both lingering and you may changeable performing criteria ( Pezzutti and you can C ; Doymaz and you may Pala 2002 ). Materials dehydrated by convective strategy is actually described as the reasonable porosity and you will large noticeable density ( Zogzas while others 1994 ). Equivalent properties was claimed to own content dried into microwave oven method, due to the fact that a mix of this type of 2 strategies could be made use of ( Krokida and others 2000 ). Osmotic dehydration results in a rise in visible density for the majority content, and you can a decrease for other people. This phenomenon could have been associated with the rise when you look at the solids through the the osmotic procedure ( Krokida and you can Maroulis 1997 ). Lyophilization output points that have reasonable occurrence, and their porosity; this method supplies the highest quality outcome, as there are no deformations throughout the material, color and aroma was preserved. Still, it will have the downside of being costly and you may requiring long drying attacks ( Krokida and you will ).
Multiple structural parameters away from food products have been evaluated inside the lyophilization techniques. Sablani although some (2007) discovered that apparent density, genuine occurrence, and you will porosity is actually a function of water articles (X) and you may plate temperature; however, you will find deficiencies in quality throughout these tendencies ( Karathanos while others 1996 ; Sablani and others 2007 ; Oikonomopoulou while some 2011 ).
The consequences out-of drying out standards into thickness
Certain people found that effect of relative humidity for the genuine and you may obvious density is actually minimal ( Zogzas while some 1994 ). While the aftereffects of drying out sky speed on density have not been learnt, you’ll be able to harvest data regarding various bibliographic supply it comes to a single procedure; eg study suggest that correct and you can noticeable thickness is actually straight down on lower drying air velocities (Table step 1). not, next research on the topic is necessary. Few studies have stated toward ramifications of new geometry regarding the material into the density, although it has been found to help you dictate noticeable occurrence philosophy. Such as, new thickness regarding entire garlic https://datingranking.net/it/siti-di-incontri-per-anziani/ cloves have a beneficial concave-down figure with regards to X; alternatively, garlic cloves sliced by 50 percent display screen an excellent linear, ascendant desire with respect to the decrease in X ( Lozano while others 1983 ).