lecture 5 practical technology (chapters 8-12)karaali/lecture5.pdf · alfa, beta and gamma rays are...
TRANSCRIPT
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.1
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
LECT
URE
5
PRACT
ICAL
TECH
NOLO
GY
(Cha
pter
s 8-
12)
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.2
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
1 H
EAT
PRES
ERVA
TIO
N A
ND
PRO
CESS
ING
PRACT
ICAL
TEC
HNOLO
GY
2 CO
LD P
RESE
RVA
TIO
N A
ND
PRO
CESS
ING
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
5 FE
RMEN
TATI
ON
PRO
CESS
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.3
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
1 H
EAT
PRES
ERVA
TIO
N A
ND
PR
OCE
SSIN
G(Ch
.8)
Hea
t pr
eser
vati
on o
f fo
od r
efer
s to
con
trol
led
proc
esse
s th
at a
re p
erfo
rmed
com
mer
cial
ly, s
uch
as
blan
chin
g, p
aste
uriz
ing,
and
can
ning
.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.4
1 H
EAT
PRES
ERVA
TIO
N A
ND
PRO
CESS
ING
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
Deg
rees
of
pres
erva
tion
:
Ster
iliza
tion
–Re
fers
to
com
plet
e de
stru
ctio
n of
m
icro
orga
nism
s. T
his
freq
uent
ly r
equi
res
a tr
eatm
ent
of
at le
ast
121°
C of
wet
hea
t fo
r 15
min
or
its
equi
vale
nt.
Com
mer
cial
ly s
teri
le–
Deg
ree
of s
teri
lizat
ion
at w
hich
al
l pat
hoge
nic
and
toxi
n fo
rmin
g or
gani
sms
have
bee
n de
stro
yed
as w
ell a
s al
l oth
er t
ypes
of
orga
nism
s wh
ich
coul
d gr
ow in
the
pro
duct
and
pro
duce
spo
ilage
und
er
norm
al h
andl
ing
and
stor
age
cond
itio
ns. T
hey
may
co
ntai
n a
smal
l num
ber
of h
eat
resi
stan
t ba
cter
ial
spor
es b
ut t
hese
will
not
nor
mal
ly m
ulti
ply
in t
he f
ood
supp
ly(m
ost
cann
ed a
nd b
ottl
ed f
ood
prod
ucts
)
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.5
Past
euri
zati
on–
Invo
lves
a c
ompa
rati
vely
low
orde
r of
he
at t
reat
men
t, g
ener
ally
at
tem
pera
ture
bel
ow t
he
boili
ng p
oint
of
wate
r. T
hese
pro
cess
es a
re s
peci
fica
lly
desi
gned
to
dest
roy
path
ogen
ic m
icro
orga
nism
s an
d to
ex
tend
pro
duct
she
lf-li
fe f
rom
a m
icro
bial
and
en
zym
atic
poi
nt o
f vi
ew.
Blan
chin
g-
A k
ind
of p
aste
uriz
atio
n ge
nera
lly a
pplie
d to
fr
uits
and
veg
etab
les
prim
arily
to
inac
tiva
te n
atur
al
food
enz
ymes
. Thi
s is
com
mon
pra
ctic
e wh
en s
uch
prod
ucts
are
to
be f
roze
n. D
epen
ding
on
its
seve
rity
, bl
anch
ing
als
o de
stro
ys s
ome
mic
roor
gani
sms.
1 H
EAT
PRES
ERVA
TIO
N A
ND
PRO
CESS
ING
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.6
1 H
EAT
PRES
ERVA
TIO
N A
ND
PRO
CESS
ING
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
How
ever
, hea
t su
ffic
ient
to
dest
roy
mic
roor
gani
sms
and
food
enz
ymes
als
o af
fect
s ot
her
prop
erti
es o
f fo
ods
nega
tive
ly, t
here
fore
the
re is
nee
d fo
r “o
ptim
isat
ion”
. Fo
r ch
oosi
ng o
ptim
al h
eat
trea
tmen
t pa
ram
eter
s, t
he
follo
wing
poi
nts
shou
ld b
e ev
alua
ted:
Tim
e-te
mpe
ratu
re c
ombi
nati
ons
requ
ired
to
inac
tiva
te
the
mos
t he
at-r
esis
tant
pat
hoge
n an
d sp
oila
ge o
rgan
ism
s in
a p
arti
cula
r fo
od(t
he m
ost
heat
-res
ista
nt p
atho
gen
in
cann
ed f
oods
is
Clos
trid
ium
bot
ulin
um).
0.78
minut
es a
t 12
7C=1
0 minut
es a
t 11
6C=3
6minut
es a
t 11
0C
Hea
t pe
netr
atio
n ch
arac
teri
stic
s in
a p
arti
cula
r fo
od,
incl
udin
g th
e ca
n or
the
con
tain
er i
f it
is p
acka
ged.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.7
1 H
EAT
PRES
ERVA
TIO
N A
ND
PRO
CESS
ING
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
2 A
lter
nati
ve T
echn
ique
s in
volv
ed:
1. H
eati
ng f
ood
in c
onta
iner
s(Fi
g.8.
8-12
):
Still
or
agit
atin
g re
tort
s
Hyd
rost
atic
coo
ker
or c
oole
rs
Dir
ect
flam
e st
erili
zati
on
In-p
acka
ge p
aste
uriz
atio
n
2. H
eati
ng f
ood
prio
r to
pac
kagi
ng:
Hig
h Te
mpe
ratu
re S
hort
Tim
e (H
TST)
pas
teur
izat
ion
follo
wed
by “a
scep
tic
pack
agin
g”(H
ot p
ack
or H
ot f
ill)
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.8
2 CO
LD P
RESE
RVA
TIO
N A
ND
PR
OCE
SSIN
G(Ch
.9)
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
Cool
sto
rage
gen
eral
ly r
efer
s to
sto
rage
at
tem
pera
ture
s ab
ove
free
zing
, fro
m a
bout
16°
C do
wn t
o -2
°C.
Com
mer
cial
and
hou
seho
ld r
efri
gera
tors
are
usu
ally
op
erat
ed a
t 4
-7°C
. M
ost
food
s wi
ll no
t be
gin
to f
reez
e un
til a
bout
-2°
C or
lowe
r.Fr
ozen
sto
rage
ref
ers
to s
tora
ge a
t te
mpe
ratu
res
that
mai
ntai
n fo
od in
fro
zen
cond
itio
n.Go
od f
roze
n st
orag
e ge
nera
lly r
equi
res
tem
pera
ture
s of
-18
°C o
r be
low.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.9
2 CO
LD P
RESE
RVA
TIO
N A
ND
PRO
CESS
ING(
Fig.
9.1)
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
60°C
51,7
°C
37°C
15,6
°C
4,4°
C
0°C
-17,
8°C
Man
y ba
cter
ia s
urvi
ve a
nd s
ome
may
gro
w
Body
tem
p. id
eal f
or b
acte
rial
gro
wth
Tem
p. in
thi
s zo
ne a
llow
rapi
d gr
owth
of
bact
eria
and
pro
duct
ion
of t
oxin
s by
som
e ba
cter
iaBa
cter
ia c
ausi
ng f
oodb
orne
illn
ess
may
gro
wRe
frig
erat
ed t
emp.
per
mit
slo
w gr
owth
of
bact
eria
Free
zing
tem
p. s
top
the
grow
th o
f ba
cter
ia b
ut a
llow
man
y to
sur
vive
.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.10
2 CO
LD P
RESE
RVA
TIO
N A
ND
PRO
CESS
ING
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
The
prin
cipa
l req
uire
men
ts f
or e
ffec
tive
ref
rige
rate
d st
orag
e ar
e:
Cont
rolle
d lo
w te
mpe
ratu
re
Air
cir
cula
tion
Hum
idit
y co
ntro
l
Mod
ific
atio
n of
gas
atm
osph
eres
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.11
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GYSto
rage
req
uire
men
ts a
nd p
rope
rties
of p
erisha
ble
food
s
94,7
2-5
week
s85
-90
12-2
5To
mat
oes
01
year
-1,
5O
il(ve
geta
be
sala
d)
-9-
12 m
onth
s90
-95
-18-
(-23
)M
eat
froz
en62
-77
1-6
week
s88
-92
0,5-
1,0
Beef
, fre
sh62
-85
8-10
mon
ths
90-9
5-1
8-(-
23)
Fish
fro
zen
62-8
55-
20 d
ays
90-9
50,
5-4,
5Fi
sh f
resh
678-
9 m
onth
s85
-90
-1Eg
g (s
hell)
-Se
vera
l m
onth
s-
4-5
Skim
milk
(d
ried
)
32-3
7Se
vera
l we
ek-
-18
Brea
d
Wat
er %
Sto
rage
life
RH%
Sto
rage
te
mp
(°C)
Commod
ity
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.12
2 CO
LD P
RESE
RVA
TIO
N A
ND
PRO
CESS
ING
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
Ther
e ar
e th
ree
basi
c fr
eezi
ng m
etod
s in
com
mer
cial
us
e(Fi
g. 9
.4-1
0):
Free
zing
in a
ir
Free
zing
by
indi
rect
con
tact
wit
h a
refr
iger
ant
Free
zing
by
dire
ct im
mer
sion
in a
ref
rige
rati
ng
med
ium
: Im
mer
sion
fre
ezin
g is
don
e wi
th c
ryog
enic
liq
uids
: (liq
uid
nitr
ogen
and
liqu
id c
arbo
n di
oxid
e -
196°
C an
d -7
9°C)
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.13
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
(Ch.
10)
Food
deh
ydra
tion
ref
ers
to t
he n
earl
y co
mpl
ete
rem
oval
wat
er f
rom
foo
ds b
y dr
ing
unde
r ar
tifi
cal a
nd
cont
rolle
d co
ndit
ions
tha
t ca
use
min
imum
or
idea
lly n
o ot
her
chan
ges
in t
he f
ood
prop
erti
es (D
ried
milk
and
eg
gs, p
otat
o fl
akes
, ins
tant
cof
fee
etc.
)
Proc
esse
s t
hat
rem
ove
only
par
t of
the
wat
er f
rom
fo
ods
(pre
para
tion
of
syru
ps, e
vapo
rate
d m
ilk,
cond
ense
d so
ups)
are
no
tco
nsid
ered
“foo
d de
hydr
atio
n” b
ut a
re c
alle
d “c
once
ntra
tion
”
(Fig
. 10.
7-22
)
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.14
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
Reas
ons
of d
ehyd
rati
on:
Pres
erva
tion
Reta
inin
g si
ze a
nd s
hape
Prod
ucti
on o
f co
nven
ienc
e it
ems
In f
ood
dehy
drat
ion,
eve
ry e
ffor
t sh
ould
be
mad
e to
sp
eed
heat
and
mas
s tr
ansf
er r
ates
. The
fol
lowi
ng
crit
eria
hav
e to
be
opti
miz
ed f
or t
his
aim
:
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.15
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
Surf
ace
area
:Foo
d to
be
dehy
drat
ed is
sub
divi
ded
into
sm
all p
iece
s or
thi
n la
yers
to
spee
d he
at a
nd m
ass
tran
sfer
Tem
pera
ture
:The
gre
ater
the
tem
pera
ture
dif
fere
nce
betw
een
the
heat
ing
med
ium
and
the
foo
d th
e gr
eate
r wi
ll be
the
rat
e of
hea
t ta
nsfe
r in
to t
he f
ood.
Air
-vel
ocit
y: A
ir in
mot
ion
swee
ps m
oist
ure
away
fro
m
the
dryi
ng f
ood’
s su
rfac
e, p
reve
ntin
g th
e cr
eati
on o
f sa
tura
ted
atm
osph
ere.
Hum
idit
y:W
hen
air
is t
he d
ryin
g m
ediu
m, t
he d
rier
the
ai
r, t
he m
ore
rapi
d is
the
rat
e of
dry
ing.
Moi
st a
ir is
cl
oser
to
satu
rati
on s
o a
bsor
bs le
ss a
ddit
iona
l moi
stur
e.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.16
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
Atm
osph
eric
pre
ssur
e an
d va
cuum
:At
a pr
essu
re o
f 1
atm
, wat
er b
oils
at
100°
C. A
s th
e pr
essu
re is
lowe
red,
th
e bo
iling
tem
pera
ture
dec
reas
es. L
ower
dry
ing
tem
pera
ture
s an
d sh
orte
r dr
ying
tim
es a
re im
port
ant
in
the
case
of
heat
-sen
siti
ve f
oods
.
Tim
e an
d te
mpe
ratu
re:W
ith
few
exce
ptio
ns, d
ryin
g pr
oces
ses
that
em
ploy
hig
h te
mpe
ratu
res
for
shor
t ti
mes
do
less
dam
age
to f
ood
than
dry
ing
proc
esse
s em
ploy
ing
lowe
r te
mpe
ratu
res
for
long
er t
imes
.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.17
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
Conc
entr
atio
n ca
n be
a f
orm
of
dehy
drat
ing
or a
pr
elim
inar
y st
ep in
foo
d dr
ying
but
onl
y fo
r so
me
food
s.
Conc
entr
atio
n re
duce
s we
ight
and
vol
ume
and
resu
lts
in im
med
iate
eco
nom
ic a
dvan
tage
s.
Nea
rly
all l
iqui
d fo
ods
to b
e de
hydr
ated
are
co
ncen
trat
ed b
efor
e th
ey a
re d
ried
bec
ause
in t
he
earl
y st
ages
of
wate
r re
mov
al ,
moi
stur
e ca
n be
mor
e ec
onom
ical
ly r
emov
ed in
hig
hly
effi
cien
t ev
apor
ator
s th
an in
deh
ydra
tion
equ
ipm
ent.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.18
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
The
mor
e co
mm
on c
once
ntra
ted
food
s in
clud
e:
Evap
orat
ed a
nd s
weet
ened
con
dens
ed m
ilk
Frui
t an
d ve
geta
ble
juic
es a
nd n
ecta
rs
Suga
r sy
rups
and
fla
vore
d sy
rups
Jam
s an
d je
llies
Tom
ato
past
e
Frui
t pu
rees
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.19
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
3 FO
OD
DEH
YDRA
TIO
N A
ND
CO
NCE
NTR
ATI
ON
Met
hods
of
conc
entr
atio
n:
Sola
r co
ncen
trat
ion
Ope
n ke
ttle
s
Flas
h ev
apor
ator
s
Thin
-film
eva
pora
tors
Vacu
um e
vapo
rato
rs
Free
ze c
once
ntra
tion
Ult
rafi
ltra
tion
and
rev
erse
-osm
osis
dev
ices
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.20
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS(
Ch. 1
1)
Food
irra
diat
ion
is u
sed
prim
arily
as
a pr
eser
vati
on
met
hod.
Mic
rowa
ve e
nerg
y,on
the
oth
er h
and,
is b
eing
em
ploy
ed e
spec
ially
to
prod
uce
rapi
d an
d un
ique
he
atin
g ef
fect
s, o
ne a
pplic
atio
n of
whi
ch c
an b
e fo
od
pres
erva
tion
.
Ohm
ic h
eati
ngis
the
new
est
and
leas
t us
ed o
f th
e th
ree
tech
nolo
gies
. Ohm
ic h
eati
ng c
an p
rese
rve
food
s by
the
app
licat
ion
of h
eat
and
has
the
abili
ty
to v
ery
rapi
dly
heat
foo
ds w
ith
min
imal
des
truc
tion
.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.21
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
In 1
983
the
FDA
(Foo
d A
nd D
rug
Adm
inis
trat
ion)
ap
prov
ed ir
radi
atio
n as
mea
ns o
f co
ntro
lling
m
icro
orga
nism
s on
spi
ces.
In 1
985
FDA
wid
ened
the
allo
wed
uses
of
irra
diat
ion
to a
ddit
iona
l foo
dssu
ch a
s st
rawb
erry
, pou
ltry
, gro
und
beef
, and
por
k.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.22
Irra
diat
ion
is u
sed
for
thre
e pu
rpos
es:
Cont
rol i
nsec
ts in
foo
d su
ch a
s pi
ces,
fru
its
and
vege
tabl
es (a
s an
alt
erna
tive
to
chem
ical
fum
igat
ion)
Inhi
bit
spro
utin
g or
oth
er s
elf-
gene
rati
ng
mec
hani
sms
of d
eter
iora
tion
Des
troy
veg
etat
ive
cells
of
mic
roor
gani
sms
Incr
ease
in s
afet
y an
d sh
elf-
life
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.23
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
Ult
ravi
olet
ligh
t–
espe
cial
ly w
ithi
n th
e wa
vele
ngth
ra
nge
of 2
00-2
80 n
m, i
s em
ploy
ed t
o in
acti
vate
m
icro
orga
nism
s on
the
sur
face
of
food
s. I
t ha
s lo
w de
gree
of
pene
trat
ion.
Tre
atm
ent
of e
quip
men
t su
rfac
es, w
ater
and
air
use
d in
foo
d pl
ants
are
ad
diti
onal
app
licat
ions
.
X-r
ays
-ha
ve g
reat
er p
enet
rati
ng p
ower
tha
n U
V lig
ht. B
ut t
hey
cann
ot e
asily
be
focu
sed
lead
ing
to lo
w ef
fici
ency
of
use
with
cur
rent
equ
ipm
ent.
App
licat
ions
ha
ve b
een
expe
rim
enta
l rat
her
than
com
mer
cial
.
Alf
a, b
eta
and
gam
ma
rays
are
als
o us
ed
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.24
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
Dos
e de
term
inin
g fa
ctor
s:
Safe
ty a
nd w
hole
som
enes
s of
tre
ated
foo
d
Resi
stan
ce o
f fo
od t
o or
gano
lept
ic q
ualit
y da
mag
e
Resi
stan
ce o
f m
icro
orga
nism
s
Resi
stan
ce o
f fo
od e
nzym
es
Cost
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.25
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
Mic
rowa
ve e
nerg
y in
foo
d ap
plic
atio
ns is
use
d fo
r it
s he
atin
g pr
oper
ties
.
Whe
n m
icro
wave
s pa
ss in
to f
oods
, wat
er m
olec
ules
an
d ot
her
pola
r m
olec
ules
ten
d to
alig
n th
emse
lves
wi
th t
he e
lect
ric
fiel
d. T
he e
lect
ric
fiel
d re
vers
es
915
or 2
450
mill
ion
tim
es p
er s
econ
d ge
nera
ting
in
term
olec
ular
fri
ctio
n, w
hich
qui
ckly
cau
ses
the
food
to
hea
t.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.26
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
Mic
rowa
ve f
ood
appl
icat
ions
:Ba
king
Conc
entr
atin
g
Cook
ing
Curi
ng
Dry
ing
Blan
chin
g
Fini
sh-d
ryin
g
Free
ze-d
ryin
g
Hea
ting
Past
euri
zing
Prec
ooki
ng
Puff
ing
and
foam
ing
Solv
ent
rem
oval
Ster
ilizi
ng
Tem
peri
ng
Thaw
ing
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.27
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
4 IR
RAD
IATI
ON
, MIC
ROW
AVE
AN
D O
HM
IC
PRO
CESS
ING
OF
FOO
DS
Ohm
ic h
eati
ng:
Cons
ider
able
hea
t is
gen
erat
ed w
hen
an a
lter
nati
ng
elec
tric
cur
rent
is p
asse
d th
roug
h a
cond
ucti
ng
solu
tion
suc
h as
a s
alt
brin
e.
Prod
ucts
in a
con
duct
ing
solu
tion
are
con
tinu
ousl
y pa
ssed
bet
ween
the
se e
lect
rode
s, e
ach
of w
hich
ra
ises
the
tem
pera
ture
.
The
solid
pie
ces
and
the
liqui
d ar
e he
ated
nea
rly
sim
ulta
neou
sly.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.28
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
5 FE
RMEN
TATI
ON
PRO
CESS
(Ch.
12)
Ferm
enta
tion
s oc
cur
when
mic
roor
gani
sms
brea
k do
wn f
ood
mac
ro-c
ompo
nent
s (i
.e. C
arbo
hydr
ates
lik
e su
gars
) int
o ne
w pr
oduc
ts (i
.e. a
lcoh
ol, C
O2,
lact
ic
acid
). It
enc
oura
ges
the
mul
tipl
icat
ion
of
mic
roor
gani
sms
and
the
prod
ucti
on o
f th
eir
prod
ucts
of
met
abol
ic a
ctiv
itie
s in
foo
ds.
But
only
sel
ecte
d m
icro
orga
nism
s ar
e en
cour
aged
, si
nce
while
the
ir m
etab
olic
act
ivit
ies
and
end
prod
ucts
are
hig
hly
desi
rabl
e, t
here
are
oth
ers
whic
h pr
oduc
e un
desi
rabl
e an
d to
xic
met
abol
ites
.
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.29
5 FE
RMEN
TATI
ON
PRO
CESS
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
Som
e in
dust
rial
fer
men
tati
ons
in f
ood
indu
stri
es:
Lact
ic a
cid
bact
eria
:Cu
cum
bers
–di
ll pi
ckle
s, s
our
pick
les
Oliv
es –
gree
n ol
ives
, rip
e ol
ives
Vege
tabl
e an
d m
ilk –
tarh
ana
Mea
ts –
saus
ages
suc
h as
sal
ami
Milk
–yo
ghur
t, c
hees
eLa
ctic
aci
d ba
cter
ia w
ith
othe
r m
icro
orga
nism
s:D
airy
pro
duct
s wi
th m
ould
–Ch
eese
s(I.
e. r
oque
fort
, ca
mam
bert
)D
airy
pro
duct
s wi
th y
east
–ke
fir
Vege
tabl
e pr
oduc
ts w
ith
mou
ld –
soya
sau
ceA
ceti
c ac
id b
acte
ria:
Win
e, c
ider
, mal
t, h
oney
, vin
egar
Yeas
ts: B
eer,
win
e, b
rand
y, w
hisk
ey, b
read
etc
.
5 FE
RMEN
TATI
ON
PRO
CESS
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
The
term
fer
men
tati
on r
efer
s to
bre
akdo
wn o
f ca
rboh
ydra
te
and
carb
ohyd
rate
-like
mat
eria
ls u
nder
eit
her
aero
bic
or
anae
robi
c co
ndit
ions
. In
wine
, bee
r an
d br
ead
ferm
enta
tion
s,
the
yeas
ts f
erm
ent
gluc
ose
:
C 6H
12O
6
2C
2H5O
H+2
CO2
Lact
ose
lact
ic a
cid
Stre
ptoc
occu
s la
ctis
Und
er a
naer
obic
cond
itio
ns -
true
fer
men
tati
on.
Ethy
l alc
ohol
ace
tic
acid
Ace
toba
cter
ace
tiU
nder
aer
obic
con
diti
ons
–ox
idat
ion
rath
er t
han
ferm
enta
tion
3/3/
2004
ITU
FO
OD
EN
G.
DEP
.31
5 FE
RMEN
TATI
ON
PRO
CESS
INTRO
DUCT
ION T
O F
OOD S
CIEN
CE A
ND T
ECHNOLO
GY
In a
ddit
ion
to p
rovi
ding
var
iety
to
the
diet
, fe
rmen
tati
on a
lso
aids
in
pres
erva
tion
of
food
s si
nce
end
prod
ucts
of
acid
s an
d al
coho
ls a
re
inhi
bito
ry t
o th
e co
mm
on p
atho
geni
c m
icro
orga
nism
s Fa
ctor
s fo
r co
ntro
lling
fer
men
tati
on:
Aci
dA
lcoh
olU
se o
f st
arte
rsTe
mpe
ratu
reLe
vel o
f ox
ygen
A
mou
nt o
f Sa
lt