STÀB}UTY =îOËFREEZE-DRŒD mobs
203
tolerate some dehydration upon freezing of the medium. He suggests that perhaps “the
bacteria do not freeze at au but merely dry”; and thus While' the foodstu' undergoes
freeze—dehydratiqn,
undergq‘
terms “pseudç free'ze—drying”.
Eect af Lyoplnhæüon
The
comphcatedonemrcrobrologrcay and chemically;
If we accept
fr0Ïie and dry"layer sysfem‘
l) SilŸerman
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FIGURE 1. Schemaücdrag1amof thefreeze dryfngproœss (from Srlverman and Goldbhth, 1965)
and. Goldblith, 1965) then during the 1Ë(Çphisaüon process, the organgsms are subject
to the stresses of
(Ëçne A & 52): and the
from the
f}?
Thus, as
dn°Ë“ay“maeæes
Ünisms on the surfaçeofthefôod(atpomtf1)aïe iÇXP056dfŒ1ŒËŒPe“°ds°f“m“°
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thermal energy thanwsen—‘=a‘fôrth<°«mü°f°fl€ f99d("‘ POIÊt3 t2)zÏs Frmapmœssmg
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point of view, aè thedrymgcyclepwgressesîêæsïîsP‘emturem
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to minimize the chemicaland0rgmïepücchaz‘ë°Smth° Pf0d“°tTh“S Pred1°ü°n°f
depends on a
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numbers and types0f0rgamsmsadhmmo
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tures bn the survwa1ofselecœdspemes°f0rgamsms1n°°“1“°dmœbeef°ggs “@ m°df=1
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} ‘The data in
°Îf°°ds W°â : ;
.