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3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
1
Intr
oduc
tion
to
Food
Sci
ence
and
Tec
hnol
ogy
Lect
ure
4
UNIT
OPE
RATI
ONS
IN F
OOD P
ROCE
SSIN
G
Ch. 5,
pp.
69-8
8
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
2
UNIT
OPE
RATI
ONS
IN F
OOD P
ROCE
SSIN
G
The
num
ber
of d
iffe
rent
food
prod
ucts
and
the
oper
atio
nsan
dst
eps
invo
lved
in t
heir
prod
ucti
onar
eve
rynu
mer
ous.
Proc
esse
sar
ein
a c
onti
nual
stat
eof
evo
luti
on.
The
proc
esse
sus
edby
the
food
indu
stry
can
be d
ivid
edin
toco
mm
onop
erat
ions
calle
dun
itop
erat
ions
.
Food
prod
ucti
onin
volv
esa
seri
esof
uni
top
erat
ions
perf
orm
edin
a lo
gica
lseq
uenc
e. T
hesu
cces
sis
in p
rope
rse
lect
ion
and
com
bina
tion
of u
nit
oper
atio
nsin
toth
em
ore
com
plex
inte
grat
edpr
oces
sing
syst
ems,
and
opti
mis
ing
ener
gy.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
3
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
Exam
ples
of
unit
ope
rati
ons
com
mon
to
man
y fo
od p
rodu
cts
incl
ude:
Clea
ning
Coat
ing
Conc
entr
atin
g
Cont
rolli
ng
Dis
inte
grat
ing
Dry
ing
Evap
orat
ing
Ferm
enta
tion
Form
ing
Hea
ting
/Coo
ling
(Hea
t ex
chan
ge)
Mat
eria
ls h
andl
ing
Pack
agin
g
Pum
ping
Sepa
rati
ng
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
4
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
Mos
tun
itop
erat
ions
are
utili
zed
in t
hem
akin
gof
a v
arie
tyof
fo
odpr
oduc
ts.
E.x.
Hea
tex
chan
ging
orhe
atin
gis
use
din
the
man
ufac
ture
of
liqui
dan
ddr
yfo
odpr
oduc
ts, p
aste
uriz
atio
nof
milk
, ste
riliz
atio
nof
foo
dsin
can
s, r
oast
ing
pean
uts,
bak
ing
brea
d, e
tc.
Uni
top
erat
ions
may
incl
ude
num
erou
sdi
ffer
ent
acti
viti
es.
Exam
ple:
A u
nit
oper
atio
n: M
ixin
g
Mix
ing
incl
udes
: agi
tati
ng, b
eati
ng, b
lend
ing,
dif
fusi
ng, d
ispe
rsin
g,
emul
sify
ing,
hom
ogen
izin
g, k
nead
ing,
sti
rrin
g, w
hipp
ing
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
5
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
Mix
:
To b
eat
in a
ir –
as in
mak
ing
an e
gg w
hite
foa
m
To b
lend
dry
ingr
edie
nts
–as
in p
repa
ring
a t
on o
f dr
y ca
ke
mix To
em
ulsi
fy (t
o ho
mog
eniz
e to
pre
vent
fat
sep
erat
ion)
–as
in
the
cas
e of
may
onna
ise
or m
ilk
To d
evel
op a
bre
ad d
ough
whi
ch r
equi
res
stre
tchi
ng a
nd
fold
ing
(ref
erre
d to
as
knea
ding
)
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
6
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
COM
MON U
NIT
OPE
RATIO
NS
1 -
Mat
erials
Han
dling
Incl
udes
vari
ous
oper
atio
ns:
Han
dan
dm
echa
nica
lhar
vest
ing
on t
hefa
rm
Refr
iger
ated
truc
king
of p
eris
habl
epr
oduc
e
Box
car
tran
spor
tati
onof
live
catt
le
Pneu
mat
icco
nvey
ing
of f
lour
from
rail
car
toba
kery
stor
age
bins
.
Aim
:The
mov
emen
tof
pro
duce
from
farm
topr
oces
sing
plan
tan
dof
raw
mat
eria
lsth
roug
hth
epl
ant.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
7
Emph
asis
mus
t be
giv
en t
o:
Mai
ntai
ning
san
itar
y co
ndit
ions
Min
imiz
ing
prod
uct
loss
es (i
nclu
ding
wei
ght
loss
of
lives
tock
)
Mai
ntai
ning
raw
mat
eria
l qua
lity
(vit
amin
con
tent
and
phy
sica
l ap
pear
ance
)
Min
imiz
ing
bact
eria
l gro
wth
Tim
ing
all t
rans
fers
and
del
iver
ies
so a
s to
min
imiz
e ho
ld-u
p ti
me
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
1 -
Mat
erials H
andling
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
8
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
1 -
Mat
erials
Han
dling
The
mov
emen
tof
pro
duce
from
farm
topr
oces
sing
plan
tan
dof
raw
mat
erials
thro
ugh
the
plan
tm
ayta
kem
any
form
s:
Exam
ple:
Ora
nges
are
mov
edby
truc
ktr
aile
rsto
the
wash
ing
and
grad
ing
area
. The
leng
thof
tim
e is
impo
rtan
tsi
nce
frui
tsan
dve
geta
bles
are
alive
and
resp
ire
caus
ing
a ri
sein
tem
pera
ture
of
a ba
tch.
Thu
s, s
poila
gem
ayoc
cur.
Type
sof
equ
ipm
ents
for
mov
ing
mat
eria
ls:
Pneu
mat
iclif
t sy
stem
sPn
eum
atic
conv
eyor
sSc
rew
conv
eyor
sBu
cket
conv
eyor
sBe
ltco
nvey
ors
Vibr
ator
yco
nvey
ors
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
9
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
2-Cl
eaning
Aim
:Fo
ods
byth
ena
ture
of t
hewa
yth
eyar
egr
own
orpr
oduc
edon
far
ms
in o
pen
enviro
nmen
tsof
ten
requ
ire
clea
ning
befo
reus
e.Cl
eani
ngra
nges
from
:
Sim
ple
rem
oval
of d
irt
from
egg
shel
lswi
than
abr
asiv
ebr
ush
to
Com
plex
rem
oval
of b
acte
ria
from
a liq
uid
food
bypa
ssin
git
th
roug
ha
mic
ropo
rous
mem
bran
e
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
10
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
2-Cl
eani
ng
Clea
ning
can
be
acco
mpl
ishe
d wi
th:
Brus
hes
Hig
h-ve
loci
ty a
ir
Stea
m
Wat
er
Vacu
um
Mag
neti
c at
trac
tion
of
met
al c
onta
min
ants
Mec
hani
cal s
epar
atio
n
(dep
endi
ng o
n th
e pr
oduc
t an
d th
e na
ture
of
dirt
)
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
11
2-Cl
eani
ng
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
Just
as d
iffe
rent
food
mat
eria
lsre
quir
esp
ecia
lcle
anin
g, t
hesu
rfac
esof
foo
dpr
oces
sing
equi
pmen
tne
edth
orou
ghan
dfr
eque
ntat
tent
ion.
The
clea
ning
of e
quip
men
t, a
s we
llas
fac
ility
’swa
llsan
dfl
oors
, m
ust
take
into
cons
ider
atio
nth
ech
emic
alan
dph
ysic
alpr
oper
ties
of b
oth
the
surf
ace
tobe
cle
aned
and
the
type
of s
oil(
seeF
ig. 5
.2)
Mild
lyal
kalin
e de
terg
ents
Mild
lyac
idde
terg
ents
Mod
erat
ely
alka
line
and
neut
rald
eter
gent
s
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
12
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
3-Se
para
ting
Sepa
rati
ngca
n in
volv
e:
Sepa
rati
nga
solid
from
a so
lid–
peel
ing
of p
otat
oes,
she
lling
of n
uts
Sepa
rati
nga
solid
from
a liq
uid
–fi
ltra
tion
Sepa
rati
nga
liquid
from
a so
lid–
pres
sing
juic
efr
oma
frui
t
Sepa
rati
nga
liquid
from
a liq
uid
–ce
ntri
fugi
ngoi
lfro
mwa
ter
Rem
ovin
ga
gas
from
a so
lidor
a liq
uid
–va
cuum
rem
oval
of
air
from
cann
edfo
odin
vac
uum
cann
ing.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
13
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
3-Se
para
ting
Form
sof
sep
arat
ion
in t
hefo
odin
dust
ry:
Han
dso
rtin
gan
dgr
adin
g(v
eget
able
san
dfr
uits
)
Mec
hani
cala
ndel
ectr
onic
sort
ing
devi
ces
(dif
fere
nce
in c
olor
)
Aut
omat
icse
para
tion
(acc
ordi
ngto
size
by
pass
ing
over
diff
eren
tsi
ze s
cree
ns, h
oles
orsl
its.
)
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
14
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
3-Se
para
ting
The
skin
s of
fru
its
and
vege
tabl
es m
ay b
e se
para
ted
usin
g a
lye
peel
er.
Peac
hes,
apr
icot
s ar
e pa
ssed
thr
ough
a h
eate
d ly
e so
luti
on.
The
lye
or c
aust
ic s
ofte
ns t
he s
kin
so it
can
be
slip
ped
from
the
fr
uit
by g
entl
e ac
tion
of
mec
hani
cal f
inge
rs o
r by
jets
of
wate
r.
Dif
fere
nces
in t
he d
ensi
ty o
f th
e fr
uit
and
skin
can
the
n be
us
ed t
o fl
oat
away
the
rem
oved
ski
n.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
15
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
3-S
epar
atin
g
Crys
talliza
tion
is u
sed
tose
para
tesa
lt f
rom
sea
wate
r, o
rsu
gar
from
suga
rca
neju
ice.
Eva
pora
tion
of s
ome
of t
hewa
ter
caus
essu
pers
atur
atio
n, a
ndcr
ysta
lsfo
rm. C
ryst
als
are
then
sepa
rate
dfr
omth
esu
spen
ding
liqui
dby
cent
rifu
gati
on.
New
erm
etho
dsof
sep
arat
ion
incl
ude
seve
ralt
echn
ique
sin
volv
ing
man
ufac
ture
dmem
bran
eswi
thpo
rosi
ties
orpe
rmea
bilit
ies
capa
ble
of s
epar
atio
nsan
dfr
acti
onat
ions
at t
heco
lloid
alan
dm
acro
mol
ecul
arsi
ze le
vel.
Ultra
filtra
tion
uses
mem
bran
esof
suc
hpo
rosi
tyth
atwa
ter
and
low
mol
ecul
arwe
ight
salt
s, a
cids
and
base
spa
ssth
roug
hth
em
embr
ane
but
larg
erpr
otei
nsan
dsu
gar
mol
ecul
esar
ere
tain
ed.
This
is c
arri
edou
tat
am
bien
tte
mpe
ratu
res
avoi
dsth
ehe
atda
mag
eto
sens
itiv
efo
odco
nsti
tuen
ts.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
16
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
4-Disinte
grat
ing
Aim
: To
subd
ivide
larg
epiec
esof
foo
dinto
smaller
units
orpa
rticles.
Cutt
ing
Grin
ding
Pulp
ing
Hom
ogen
izin
g
The
dici
ngof
veg
etab
les
is d
one
on a
utom
atic
mac
hine
s
The
cutt
ing
of m
eat
repr
esen
tsa
tim
e-co
nsum
ing,
han
d-la
bor
oper
atio
n(A
utom
atic
kniv
eswi
tha
“bra
in” a
rebe
ing
rese
arch
edan
dde
velo
ped)
The
cutt
ing
of b
aker
ypr
oduc
tsca
nbe
don
e wi
thfi
neje
tsof
hig
h-pr
essu
re, h
igh
velo
city
wate
r.
Lase
rbe
ams
also
can
repl
ace
kniv
esin
som
ecu
ttin
gap
plic
atio
ns.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
17
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
4-D
isin
tegr
atin
g
Hom
ogen
izin
g pr
oduc
es d
isin
tegr
atio
n of
fat
glo
bule
s in
milk
or
crea
m f
rom
larg
e gl
obul
es a
nd c
lust
ers
into
min
ute
glob
ules
.
The
smal
ler
fat
glob
ules
the
n re
mai
n ev
enly
dis
trib
uted
th
roug
hout
the
milk
or
crea
m w
ith
less
ten
denc
y to
sep
arat
e fr
om t
he w
ater
pha
se o
f th
e m
ilk.
Way
s to
hom
ogen
ize:
Forc
ing
the
milk
or
crea
m u
nder
hig
h pr
essu
re t
hrou
gh a
hol
e wi
th v
ery
smal
l ope
ning
s
Use
of
ultr
ason
ic e
nerg
y to
dis
inte
grat
e fa
t gl
obul
es o
r br
eak
up
part
icle
s.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
18
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
5-Pu
mping
Aim
:Mov
ing
of liquids
and
solid
sfr
omon
eloca
tion
orpr
oces
sing
step
to
anot
her.
Ther
ear
em
any
kind
sof
pum
psan
dth
ech
oice
depe
nds
on t
hech
arac
ter
of t
hefo
odto
be m
oved
.
Gear
pum
ps–
effe
ctiv
efo
rm
ovin
gliq
uids
and
past
es, c
hew
upch
unk-
like
food
sre
duci
ngth
emto
pure
es.
Scre
wpu
mps
–be
stfo
rm
ovin
gfo
odwi
thla
rge
piec
eswi
thou
tdi
sint
egra
tion
(cor
nke
rnel
s, g
rape
s, s
mal
lshr
imp)
An
esse
ntia
lfea
ture
for
allf
ood
pum
psis
eas
eof
disas
sembly
for
thor
ough
clea
ning
.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
19
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
6-M
ixing
Kind
sof
mix
ers
depe
ndon
the
mat
eria
lsto
be m
ixed
Mix
ing:
Solid
swi
thso
lids
–D
ryca
kem
ixLiqu
ids
with
liquids
–m
ilkwi
thco
ffee
Liqu
ids
with
solid
s–
suga
rwi
thwa
ter
Gase
swi
thliq
uids
–co
ke
Coni
calb
lend
er: f
orsi
mpl
em
ixin
gof
dry
ingr
edie
nts
Ribb
onbl
ende
r: C
utth
esh
orte
ning
into
the
flou
r, s
ugar
and
othe
rin
gred
ient
s(in
cak
em
ixes
)
A p
rope
ller
type
agit
ator
-fo
rm
ixin
gso
lids
into
liqui
dsto
diss
olve
them
Incr
ease
in t
empe
ratu
reis
a p
robl
em d
urin
gm
ixin
g.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
20
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
7-Hea
t Ex
chan
ging H
EATIN
G
Add
itio
n of
hea
t en
ergy
to
food
s
Food
s ar
e he
ated
for
dif
fere
nt r
easo
ns:
To d
estr
oy m
icro
orga
nism
s an
d pr
eser
ve t
he f
ood-
past
euri
zati
on
of m
ilk a
nd c
anni
ng o
f ve
geta
bles
To d
rive
off
moi
stur
e an
d de
velo
p fl
avor
s –
roas
ting
of
coff
ee a
nd
toas
ting
of
cere
als
Dur
ing
cook
ing
to m
ake
mor
e te
nder
and
mor
e pa
lata
ble-
To in
acti
vate
nat
ural
tox
ic s
ubst
ance
s –
for
soyb
ean
mea
l
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
21
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
7-Hea
tEx
chan
ging H
EATIN
G
Food
sar
ehe
ated
by:
Cond
ucti
onCo
nvec
tion
Radi
atio
nO
rby
Com
bina
tion
of t
hese
Food
sar
ese
nsit
ive
tohe
at. P
rolo
nged
heat
ing
caus
es:
Burn
edfl
avor
sD
ark
colo
rsLo
ssof
nut
riti
onal
valu
e
Mic
roor
gani
sms
are
mor
ese
nsit
ive
tora
pid
heat
ing
than
are
chem
ical
reac
tion
s.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
22
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
7-Hea
t Ex
chan
ging H
EATIN
G
It is
des
irab
le t
o he
at a
nd c
ool f
oods
rap
idly
to
mai
ntai
n op
tim
al
qual
ity.
Rapi
d he
atin
g is
fac
ilita
ted
if t
he f
ood
is g
iven
max
imum
con
tact
wi
th t
he h
eati
ng s
ourc
e.
It is
acc
ompl
ishe
d by
div
idin
g th
e fo
od in
to t
hin
laye
rs in
con
tact
wi
th h
eate
d pl
ates
as
in t
he p
late
-typ
e he
at e
xcha
nger
used
to
past
euri
ze m
ilk.
For
ster
ilizi
ng f
oods
in c
ans
or o
ther
con
tain
ers
larg
e pr
essu
re
cook
ers
or r
etor
tsar
e us
ed. S
team
und
er p
ress
ure
is u
sed
to
obta
in h
igh
tem
pera
ture
.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
23
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
7-Hea
tEx
chan
ging
: Hea
ting
orco
oling
HEA
TIN
G
Supp
lyof
hea
ten
ergy
Food
sm
aybe
hea
ted
orco
oked
usin
g:
Toas
ters
, dir
ect
inje
ctio
nof
ste
am, d
irec
tco
ntac
twi
thfl
ame,
el
ectr
onic
ener
gyas
in m
icro
wave
cook
ers,
and
soon
...
Proc
esse
ssu
chas
:
Baki
ng, F
ryin
g, F
ood
conc
entr
atio
n, f
ood
dehy
drat
ion,
var
ious
kind
sof
pac
kage
clos
ure
alle
mpl
oyth
eun
itop
erat
ion
of h
eati
ng.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
24
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
7-Hea
t Ex
chan
ging CO
OLI
NG
Rem
oval
of
heat
ene
rgy
May
be
done
to
the
degr
ee w
here
foo
d is
chi
lled
to
refr
iger
ator
tem
pera
ture
0-4
°C
Beyo
nd t
his
rang
e to
whe
re t
he f
ood
is f
roze
n -1
8°C
We
refr
iger
ate
and
free
ze f
oods
to
prol
ong
thei
r ke
epin
g qu
alit
y.
A g
reat
dea
l of
milk
and
cre
am a
re c
oole
d by
pas
sing
th
em in
thi
n la
yers
thr
ough
hea
t ex
chan
gers
.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
25
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
7-Hea
t Ex
chan
ging CO
OLI
NG
Liqu
id e
gg, a
pple
slic
es a
nd o
ther
fru
its
in c
ans
are
com
mon
ly f
roze
n so
lid in
an
air-
blas
t fr
eeze
ror
sha
rp
free
zer
room
mai
ntai
ned
at a
bout
-26
°C. C
ans
are
spac
ed t
o al
low
the
cold
air
, wh
ich
is c
ircu
late
d by
fan
s an
d bl
ower
s to
get
bet
ween
the
m a
nd s
peed
the
fre
ezin
g op
erat
ion.
(fre
ezin
g of
pea
s, b
eans
and
oth
er v
egs.
As
indi
vidu
al p
iece
s)
Use
of
liqui
d ni
trog
en w
ith
its
extr
emel
y lo
w te
mpe
ratu
re
-196
°C. S
pray
ed d
irec
tly
onto
foo
ds t
o be
fro
zen
(mus
hroo
m).
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
26
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
8-Ev
apor
ation
Toco
ncen
trat
efo
ods
byth
ere
mov
alof
wat
er
Als
ous
edto
reco
ver
desi
rabl
efo
odvo
lati
les
and
tore
mov
eun
desi
rabl
evo
lati
les.
Sun
evap
orat
eswa
ter
from
sea
wate
ran
dle
aves
behi
ndsa
lt
Frui
tju
ice
conc
entr
ates
and
tom
ato
past
esar
epr
oduc
edby
evap
orat
ion
All
liqui
dsbo
ilat
lowe
rte
mpe
ratu
res
unde
rre
duce
dpr
essu
rean
dth
isis
the
key
tom
oder
n ev
apor
atio
n(s
impl
eva
cuum
evap
orat
or)
Mul
tipl
e-st
age
evap
orat
ors
can
easi
lyre
mov
ewa
ter
at 5
0°C
and
som
ear
ede
sign
edto
boil
off
wate
rat
tem
pera
ture
sas
low
as
21°C
.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
27
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
9-Dry
ing
Aim
:To
remov
ewa
ter
with
minim
um d
amag
eto
the
food
Whe
reas
evap
orat
ors
will
conc
entr
ate
food
stw
ofol
dor
thre
efol
d, d
rier
swi
llta
kefo
ods
very
clos
eto
tota
ldry
ness
(2-3
%)
Dry
ing:
Topr
eser
vefo
odfr
omsp
oila
ge
Tore
duce
its
weig
htan
dbu
lk.
e.x.
Dri
edm
ilkpo
wder
, ins
tant
coff
ee
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
28
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
9-Dry
ing
Itis
gen
eral
lym
uch
easi
erto
dry
liqui
dfo
ods
beca
use
thes
ear
eea
sier
tosu
bdiv
ide,
eit
her
as a
spr
ayor
a fi
lm, t
hem
oist
ure
can
be r
emov
edm
ore
quic
kly.
Spra
ydr
ier
–M
ilk, c
offe
e, e
ggs
Liqu
idis
ato
miz
edby
a sp
ray
nozz
le, h
eate
dai
ris
in
trod
uced
, The
heat
edai
rin
con
tact
with
the
fine
drop
lets
of
food
drie
sth
edr
ople
ts.
Dru
mdr
ier
–M
ashe
dpo
tato
, tom
ato
pure
e, s
ever
alm
ilkpr
oduc
ts.
Dry
ing
as a
thi
nfi
lm o
n a
drum
orro
ller.
The
drum
is h
eate
dwi
thst
eam
and
the
appl
ied
laye
rof
foo
din
con
tact
with
the
drum
drie
s. M
echa
nica
llysc
rape
dfr
omth
edr
umwi
thlo
ngkn
ives
.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
29
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
9-Dry
ing
Tun
neldr
ier
–Sm
allf
ood
piec
essu
chas
pea
s, d
iced
onio
nsan
dm
ushr
oom
s Bym
ovin
gth
emth
roug
ha
long
tunn
elov
en
Vacu
umfr
eeze
drying
–Br
ewed
coff
ee, q
ualit
yju
ice
prod
ucts
Sub
limat
ion:
Deh
ydra
tion
unde
rva
cuum
wher
ewat
erin
froz
enst
ate
is c
onve
rted
towa
ter
vapo
r. P
rote
cts
allf
ood
qual
ity
attr
ibut
es(c
olor
, fla
vor,
tex
ture
, nut
rien
ts)
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
30
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
10-F
orming
Food
s m
ust
be f
orm
ed in
to s
peci
fic
shap
es
Ham
burg
er p
atti
es a
re f
orm
ed b
y co
mpa
ctin
g gr
ound
be
ef in
to a
dis
k sh
ape
Char
acte
rist
ic s
hape
s of
sev
eral
pop
ular
bre
akfa
st
cere
als
are
the
resu
lt o
f pr
essu
re e
xtru
sion
thr
ough
de
sign
ed d
ies,
und
er c
ontr
olle
d co
ndit
ions
of
tem
pera
ture
, pr
essu
re, d
ough
con
sist
ency
, cut
off
and
othe
r va
riab
les.
Shap
ing
of b
utte
r an
d m
arga
rine
bar
s
Pres
sing
of
chee
se c
urd
into
var
ious
sha
pes
Man
ipul
atio
ns g
iven
to
brea
d do
ugh
to p
rodu
ce v
arie
ty
brea
ds.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
31
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
11-P
acka
ging
Purp
oses
of
pack
agin
g:
Prot
ect
the
food
fro
m m
icro
bial
con
tam
inat
ion,
phy
sica
l di
rt, i
nsec
t in
vasi
on, l
ight
, moi
stur
e pi
ck u
p, f
lavo
r pi
ck u
p,
moi
stur
e lo
ss, f
lavo
r lo
ss, p
hysi
cal a
buse
Cont
ainm
ent
for
ship
ping
Uni
tizi
ng in
to a
ppro
pria
te s
izes
Impr
ove
the
usef
ulne
ss o
f th
e pr
oduc
t
Food
s ar
e pa
ckag
ed in
: met
al c
ans,
gla
ss a
nd p
last
ic
bott
les,
pap
er a
nd p
aper
boar
d, a
wid
e va
riet
y of
pla
stic
an
d m
etal
lic f
ilms,
and
com
bina
tion
s of
the
se, b
y au
tom
atic
mac
hine
s.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
32
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
11-P
acka
ging
Milk
is p
acka
ged
in p
aper
cart
oons
. Con
tain
ers
are
auto
mat
ical
lyfo
rmed
from
stac
ked
pape
rfl
ats,
vol
umet
rica
llyfi
lled,
and
seal
ed.
Oth
erm
achi
nes
form
pou
ches
from
rolls
of p
last
icfi
lm, f
illth
eman
dse
alth
em, a
s in
the
pack
ages
of s
nack
food
s.
Als
odr
awa
vacu
umon
the
pack
age
tore
mov
eox
ygen
, bac
kfl
ush
the
pack
age
with
iner
tni
trog
enga
s, s
ealt
hepa
ckag
ean
dfi
nally
stac
kth
epa
ckag
esin
toca
rdbo
ard
cart
ons
(Exa
mpl
es:
Des
sert
powd
ers
and
dehy
drat
edso
ups)
.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
33
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
12-C
ontr
ollin
g
Way
s of
mea
suri
ng a
nd c
ontr
ollin
g pr
oces
sing
op
erat
ions
to
obta
in t
he d
esir
ed f
ood
prod
uct
qual
ity.
Tool
s ar
e: v
alve
s, t
herm
omet
ers,
sca
les,
the
rmos
tats
, an
d a
wide
var
iety
of
othe
r co
mpo
nent
s an
d in
stru
men
ts
to m
easu
re a
nd a
djus
t fa
ctor
s su
ch a
s:
tem
pera
ture
, pre
ssur
e, f
luid
flo
w, a
cidi
ty, s
peci
fic
grav
ity,
wei
ght,
vis
cosi
ty, h
umid
ity,
tim
e, li
quid
leve
l, et
c.
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
34
UN
IT O
PERA
TIO
NS
IN F
OO
D P
ROCE
SSIN
G
13-N
ew P
roce
sses
New
pro
cess
ing
tech
nolo
gies
are
cons
tant
lybe
ing
deve
lope
d:
Sup
ercr
itical
fluid
extr
action
: Use
sga
ses
such
as c
arbo
ndi
oxid
eat
hig
hpr
essu
res
toex
trac
tor
sepa
rate
food
com
pone
nts.
E.x
. Ex
trac
tion
of c
affe
ine
from
coff
eeto
obta
inde
caff
eina
ted
prod
uct.
Ohm
iche
ating:
The
tem
pera
ture
of p
arti
cula
tes
in a
con
duct
ing
med
ium
is r
aise
dqu
ickl
y. E
.x. S
oups
orst
ews
High
hydr
osta
tic
pres
sure
: Liq
uid
food
ssu
chas
fru
itju
ices
and
beve
rage
sor
part
icul
ate
food
ssu
spen
ded
in li
quid
are
subj
ecte
dto
pres
sure
sas
hig
has
sev
eral
thou
sand
atmos
pher
esIn
acti
vate
micro
orga
nism
san
din
som
eca
sesen
zymic
activity
3/3/
2004
I.T.
U D
EP. O
F FO
OD
EN
G.
35
END
OF
LECT
URE
4
