Brand new try is covered which have silicone polymer fat to help you water resistant the material. Noticeable volume is actually counted which have a good steropycnometer ( Loch-Bonazzi and others 1992 ).
Present, extremely particular strategies for measuring noticeable volume was basically advised, plus laser beam reading ( Uyar and you will Erdogdu 2009 ; Kelkar and others 2011 ), computerized tomography ( Mendoza while some 2007 ; Kelkar while others 2011 ), and you may magnetic resonance imaging ( Kelkar while some 2011 ). This type of techniques utilize optic equipment and you can official software so you can process and carry out 3d photographs regarding items, calculating regularity that have limited variations or limited ability. not, this new disadvantages of these process outweigh their pros, as a specific record will become necessary, as well as authoritative gizmos that’s more pricey than traditional processes.
Collection out-of Degree
A good amount of functions has actually managed the new decisions out of true and you will apparent thickness, in both this new drying out techniques plus in this new rehydration off food items (Desk 1 and dos). This research look at multiple dishes exposed to various drying conditions and you can in almost any mathematical shapes. This new parameters which were studied are listed below: pressure (P), cousin moisture (RH), drying air acceleration (?), and you will drying out heat (T), as well as others. Pretreatments such as blanching, coatings, and you will osmotic dehydration, as well as others, were reported ( Boukouvalas although some 2006 ).
Old-fashioned convective drying out, microwave oven drying out, osmotic drying out, spray-drying, vacuum-drying out, and you will lyophilization is the most often made use of methods; these are typically examined around each other ongoing and you will adjustable working criteria ( Pezzutti and you will C ; Doymaz and you will Pala 2002 ). Content dehydrated by convective approach try characterized by their lower porosity and you may highest obvious thickness ( Zogzas although some 1994 ). Equivalent features was indeed advertised to own information dehydrated with the microwave oven strategy, because a mixture of such dos methods could be utilized ( Krokida although some 2000 ). Osmotic dehydration causes a boost in visible occurrence for many content, and you can a drop for others. Which phenomenon could have been associated with the increase during the solids during the the new osmotic procedure ( Krokida and you may Maroulis 1997 ). Lyophilization productivity products having lower occurrence, using their porosity; this procedure produces the highest quality outcome, and there is zero deformations on the matter, colour and fragrance try kept. Nevertheless, it can have the disadvantage of being costly and you may requiring a lot of time drying attacks ( Krokida and you can ).
Numerous structural details away from food items have been analyzed inside the lyophilization processes. Sablani while some (2007) found that apparent density, real occurrence, and you can porosity is a purpose of dampness blogs (X) and you may plate heat; yet not, you will find deficiencies in understanding in these tendencies ( Karathanos while some 1996 ; Sablani and others 2007 ; Oikonomopoulou while some 2011 ).
The consequences away from drying requirements to your thickness
Certain authors have found that the effect of cousin dampness on true and visible thickness are negligible ( Zogzas and others 1994 ). Whilst the outcomes of drying out heavens acceleration towards the occurrence have not already been learnt, you’ll be able to compile studies regarding certain bibliographic provide it comes down to a single issue; particularly investigation suggest that real and obvious occurrence try down at the all the way down drying out air velocities (Desk step one). Yet not, further lookup on the subject is required. Partners research has stated on results of the geometry regarding the material for the thickness, although it has been seen in order to dictate apparent occurrence viewpoints. Eg, brand new density away from whole garlic cloves keeps an effective concave-off shape with regards to X; conversely, garlic cloves chopped in half monitor a beneficial linear, ascendant desire with https://datingranking.net/fr/rencontres-wiccan/ regards to the reduced amount of X ( Lozano while some 1983 ).