Minimally Processed Meat and Fish Products - Minimally Processed Foods - page 191

Advantages associated with sous - vide processing include superior fl avour profi le,
increased tenderness; retained colour and nutrients, reduced oxidative changes and
enhanced shelf life (Church and Parsons 2000 ; Vaudagna et al. 2002 ). In meat prod-
ucts the most important disadvantage associated with this technology is to retain the
juices inside the package during thermal treatment (Szerman et al. 2007 ). This prob-
lem is relevant, especially regarding commercial profi ts and product appearance.
Hence, the use of mild thermal treatments (Vaudagna et al. 2002 ) and the addition of
brine containing sodium chloride (NaCl) and alkaline phosphates are commonly
used to reduce cooking loss. There are also some concerns regarding the risks posed
by anaerobic pathogens, particularly Clostridium botulinum . In order to directly
address this risk, it is recommended by the Sous vide Advisory Committee that sous -
vide products should undergo a pasteurization specifi cally designed to produce a 6D
reduction in the numbers of spores of the most heat resistant type of C. botulinum ,
followed by storage at a temperature to prevent germination of any spores. It has
been claimed however that the required heat treatment caused unacceptable damage
to sensory quality. Therefore, less severe heat treatments have been proposed with
application of additional hurdles (preservatives, salt, spices, bacteriocins).
Application of sous - vide processing in various meat and fi sh products have been
reported by various researchers (Table 10.2 ). These fi ndings suggest that the sous -
vide processing keeps spoilage microorganisms at low level and are effective in
protecting the product from microbial, physical, and sensory quality degradation.

10.2.1.2 Infrared Heating

Infrared (IR) radiation is the part of the electromagnetic spectrum lying between
ultraviolet (UV) and microwave (MW) energy. It can be, near-infrared (NIR), mid-
infrared (MIR), and far-infrared (FIR), corresponding to the spectral ranges of
0.75-1.4, 1.4-3, and 3-1,000

m, respectively. Infrared is a unique heating source
and its thermal energy is primarily absorbed on solid food surfaces and has very
limited penetration capability. Exposing an object to an infrared heating source
causes its surface to increase temperature followed by consequent transfer of heat to
the centre of the solid food by conduction. Most of the solid foods are generally low
in thermal conductivity thus heat transfer to the interior is very slow when compared
with highly conductive materials (Huang 2004 ). In order to achieve optimum energy
and effi cient practical applicability of IR heating in the food processing industry,
combination of IR heating with microwave and other common conductive and con-
vective modes of heating holds great potential.
Infrared radiation does not have any direct necessity to heat the air for keeping
oven temperatures with reduced humidity. These can result energy saving and con-
servation of cooking loss (Sheridan and Shilton 1999 ). These are the features which
made IR heating as an important means of thawing, cooking, drying, roasting, bak-
ing, blanching, and pasteurization of food and agricultural products (Lloyd et al.
2003 ; Ranjan et al. 2002 ; Staack et al. 2008 ). In the IR region, the absorption
coeffi cients of ice and water are approximately same (Sakai and Mao 2006 ), and this

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