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Nut
ritio
n La
belli
ng a
nd
Prox
imat
e An
alys
is
Food
Con
stitu
ents
:M
ACRO
NU
TRIE
NTS
(Tot
al c
alor
ies,
CH
O, f
at, p
rote
in
cont
ents
:Dai
ly R
efer
ence
Val
ues:
DR
V)M
ICRO
NU
TRIE
NTS
(Vita
min
s,m
iner
als:
% o
f Ref
eren
ce
Dai
ly I
ntak
es-R
DI)
Are
nutr
ition
ally
impo
rtan
t fo
r th
eir
effe
cts
on c
hron
ic a
nd d
efic
ienc
y di
seas
es
Exam
ples
:RD
I an
d D
RVRD
IVi
tam
inA.
....5
000
IUVi
tam
inC.
...60
mg
Vita
min
D...
..400
IUVi
tam
inE.
.....3
0IU
Iron
.....
.....1
8mg
Zinc
......
......
15m
g
DRV*
Fat.
......
......
....6
5gSa
tura
ted
FA...
20g
Chol
este
rol..
..300
mg
Tota
lCH
O...
....3
00g
Fibe
r....
......
....2
5gPr
otei
n....
.....5
0g*C
alor
ie...
......
2000
Nut
ritio
nal C
laim
sFr
eeLo
wRed
uced
/less
/lean
/ligh
tG
ood
Sour
ce/c
onta
ins/
prov
ides
Mor
e/ad
ded/
extr
a/pl
us/
Hig
h/ric
h/ex
celle
nt s
ourc
eM
odifi
ed(S
ee:
Tabl
es3.
5-3.
9 in
tex
tboo
k)
Hea
lth C
laim
sCa
lciu
m a
nd o
steo
poro
sis
Sodi
um a
nd h
yper
tens
ion
Die
tary
fat
and
can
cer,
CH
DFi
ber
and
canc
er, CH
DSu
gar
alco
hols
nad
den
tal c
arie
sFo
late
and
neu
ral d
efec
ts
PRO
XIM
ATE
AN
ALY
SIS
I. M
oist
ure
II. C
arbo
hydr
ates
and
Crud
e Fi
ber
II. L
ipid
s
IV. P
rote
ins
V. A
sh
Purp
ose
of P
roxi
mat
e A
naly
sis:
Esti
mat
ion
and
det
erm
inat
ion
of h
ow m
uch
of t
he
maj
or f
ood
com
pone
nts,
whi
ch a
re M
oist
ure,
CH
O,
Lipi
ds, P
rote
ins,
Ash
, Cru
de F
iber
,exi
st in
a g
iven
fo
od. T
he p
roxi
mat
e an
alys
es t
here
fore
are
:
1. M
oist
ure
Ana
lyse
s2.
Cru
de F
at A
naly
ses
3. C
rude
Pro
tein
-(N
on-p
rote
in n
itro
gen
als
o in
clud
ed)
mos
t pr
otei
ns
cont
ain
16%
ni
trog
en.
Ther
efor
e th
e ge
nera
l “p
rote
in
fact
or”
is
100/
16=6
.25.
If
we m
ulti
ply
the
perc
ent
nitr
ogen
by
6.2
5 ,w
e ob
tain
crud
e pr
otei
n.
4. A
sh -
resi
due
afte
r bu
rnin
g al
l or
gani
c m
ater
ial.
Som
e m
iner
als
beco
me
vola
tile
at
high
tem
pera
ture
s of
bur
ning
and
ther
efor
eca
n be
los
t. A
lso
som
e m
iner
als
occu
r in
the
for
m o
f sa
lts
of o
rgan
ic a
cids
lik
e ci
trat
es w
hich
con
tain
car
bon
and
are
lost
.5.
CH
O a
nd C
rude
Fib
erTo
tal
carb
ohyd
rate
= 1
00 -
[moi
stur
e +
crud
e fa
t +
crud
e pr
otei
n +
ash]
.Cr
ude
fibe
r:re
sidu
e le
ft
afte
r al
kalin
e an
d ac
id
dige
stio
nof
org
anic
mat
ter
If w
e su
btra
ct t
he t
otal
of
1-5
from
100
, we
get
the
nitr
ogen
fr
ee
extr
act
by
diff
eren
ce.
Doi
ng
this
no
rmal
ly u
nder
esti
mat
es n
itro
gen-
free
ext
ract
.
MOIS
TURE
and
Tota
l so
lids
ANALY
SIS
Ch.8
I. I
mpo
rtan
ce o
f W
ater
II.P
rope
rtie
s of
Wat
er
III.
Cla
ssif
icat
ion
of H
2O D
eter
min
atio
ns-D
irec
t M
etho
ds:D
ryin
g an
d D
isti
llati
on
-M
etho
ds M
easu
ring
Phy
sica
l Pro
pert
ies
-Met
hods
Bas
ed o
n Co
lliga
tive
Prop
erti
es
-M
etho
ds M
easu
ring
Che
mic
al P
rope
rtie
s
I. I
mpo
rtan
ce o
f W
ater
WA
TER
has
grea
t im
port
ance
in f
oods
, bec
ause
:1.
Of
its
econ
omic
impo
rtan
ce t
o th
e pr
oces
sor
and
the
cons
umer
, pe
rmit
ting
mat
eria
l ba
lanc
es,
yiel
d an
d lo
ss
calc
ulat
ions
, al
so
for
real
izin
g le
gal
stan
dard
sto
prot
ect
cons
umer
s ,
sinc
e fo
od
com
pani
es
want
to
se
ll as
m
uch
wate
r as
la
w pe
rmit
s.
2. O
f it
s ef
fect
son
sta
bilit
y, t
here
fore
qua
lity
issu
es,
sinc
e hi
gh m
oist
ure
leve
ls a
ccel
erat
e al
l ty
pes
of f
ood
dete
rior
atio
n(ch
emic
al,
enzy
mat
ic,
mic
robi
al).
3. I
t pe
rmit
s un
ifor
m e
xpre
ssio
n of
ana
lyti
cal
resu
lts,
fo
r fo
od
labe
lling
and
for
regu
lati
ons
conc
erni
n g f
ood.
WATER
Wat
er F
unct
ions
Impo
rtant
pro
perti
es o
f wat
er:
1.U
nive
rsal
solv
ent (
salt,
vita
min
s, su
gar,
gase
s, pi
gmen
t)
2.C
apab
le o
f ion
izin
g (H
3O+ ,
OH
- )
3.A
ffec
ts th
e te
xtur
e
4.En
ters
che
mic
alre
actio
ns (h
ydro
lysi
s of p
rote
in =
n a
min
o ac
ids)
5.St
abili
zest
he c
ollo
ids b
y hy
drat
ion
6.N
eces
sary
for m
icro
-org
anis
ms g
row
th
REA
CTI
ON
RA
TES
IN F
OO
D A
S A
FU
NC
TIO
N O
F W
ATE
R A
CTI
VIT
Y
MO
ISTU
RE
AN
ALY
SIS
WH
Y D
O W
E N
EED
MO
ISTU
RE
AN
ALY
SIS?
1.M
ater
ial b
alan
ce
2.M
eetin
g th
e st
anda
rds o
f pro
duct
3.Pr
oduc
t sta
bilit
y (p
reve
nt d
eter
iora
tion,
mol
d,
bact
eria
, ins
ect d
amag
e)
4.Ex
pres
s the
com
posi
tion
on D
ry W
eigh
t Bas
is
5.Ec
onom
ic im
porta
nce
(H2O
is c
heap
)
WA
TER
DET
ERM
INA
TIO
N M
ETH
OD
S
1.D
ryin
g m
etho
ds
2.D
istil
latio
n m
etho
d
3.C
hem
ical
met
hods
4.Ph
ysic
alm
etho
ds
As a
gen
eral
rule
in a
ll an
alys
es, c
hoos
e th
e fa
stes
t sim
ple
conv
enie
nt m
etho
d w
hich
will
giv
e re
sults
with
in th
e de
sire
d ra
nge
of a
ccur
acy
-sav
ings
on
time,
labo
r cos
ts,
will
qui
ckly
cov
er c
apita
l exp
endi
ture
.
CO
NSI
DER
ATI
ON
S IN
SEL
ECTI
NG
TH
E M
ETH
OD
S O
F W
ATE
R A
NA
LYSI
S
1.Fo
rm o
f wat
er p
rese
nt (f
ree
vs. b
ound
wat
er)
Exam
ple:
% w
ater
in m
ilk v
s. no
n-fa
t drie
d m
ilk.
2.N
atur
e of
pro
duct
:
Vol
atile
com
poun
ds
Hea
t sta
ble
-los
s of s
ome
food
com
poun
ds
Uns
atur
ated
fat -
oxid
atio
n -w
eigh
t.
3.H
ow fa
st y
ou c
an a
naly
ze sa
mpl
e.
4.A
ccur
acy
and
repr
oduc
ibili
ty.
5.A
vaila
bilit
y an
d co
st o
f equ
ipm
ent.
The
moi
stur
e co
nten
t of
fo
ods
vari
es
grea
tly
betw
een
food
pro
duct
s -
e.g.
Prod
uct
Moist
ure
cont
ent
%M
ilk87
-91
Melon
s92
-94
Milk
pow
der
4Cu
cumbe
rs96
Butt
er a
nd m
arga
rine
~15
Mea
t an
d fish
50-7
0
•The
re a
re m
any
alte
rnat
ive
met
hods
,thu
s m
any
diff
eren
t pr
inci
ples
of
op
erat
ion.
Ch
oice
of
m
etho
d de
pend
s on
fol
lowi
ng c
rite
ria:
Spee
d -
reso
urce
sav
aila
ble
–de
sire
d le
vels
of
accu
racy
/ pr
ecis
ion
–ope
rati
ng c
osts
•If
you
work
at
a ro
utin
e la
bora
tory
, yo
u pr
efer
qu
ick
met
hods
. H
owev
er, f
or r
efer
ence
labo
rato
ry
accu
racy
is m
ost
impo
rtan
t. F
ollo
wing
are
ste
ps t
o be
fo
llowe
d fo
r de
term
inin
g th
e ov
eral
l co
mpo
siti
on o
f a
food
sam
ple
or c
onte
nt o
f a
spec
ifie
d co
mpo
nent
:
KIN
DS
OF
WA
TER
-D
EGR
EE O
F W
ATE
R
BIN
DN
ESS
Mon
olay
erW
ater
is b
ound
in fo
od -
rest
ricte
d in
its m
ovem
ent
due
to c
harg
es, h
ydro
gen
bond
, phy
sica
l ent
rapm
ent.
Har
d to
re
mov
e fr
om fo
od.
Nev
er b
e ab
le to
rem
ove
wat
er c
ompl
etel
y.
Mul
tilay
erW
ater
-add
ition
al la
yer o
f wat
er a
roun
d fo
od
parti
cle.
Not
as h
ard
to re
mov
e as
the
mon
olay
er.
Mob
ile o
r Fre
e W
ater
-con
sist
ed w
ith id
eal s
olut
ion.
Form
s of
Wat
er in
foo
ds a
nd t
heir
Pro
pert
ies
Wat
er m
ay o
ccur
in s
ever
al f
orm
s in
foo
ds:
1. Fr
ee H
2O (
with
in t
he p
ores
of
mat
eria
l in
the
int
er
gran
ular
spa
ces)
:A
s so
lven
t fo
r m
olec
ular
dis
pers
ion
of
solu
tes,
col
loid
s,
etc.
Whe
n it
exi
sts
as a
sol
vent
, it
can
be
thou
ght
of a
s fr
ee w
ater
, not
bou
nd t
o an
y th
ing
and
ther
efor
e av
aila
ble
for
chem
ical
re
acti
ons,
m
icro
bial
gr
owth
, an
d ph
ysic
al
chan
ges.
It
can
be
obta
ined
by
evap
orat
ion;
ıt
reta
ins
its
usua
l pr
oper
ties
as
solv
ent,
it is
ava
ilabl
e to
mic
roor
gani
sms.
2. A
dsor
bed
wate
r ca
n ex
ist
in m
ono
or p
olym
olec
ular
laye
rs
on
the
inte
rnal
or
ex
tern
al
surf
aces
of
m
olec
ules
in t
he f
ood.
It
is h
eld
tigh
tly
in c
ell w
alls
or
on p
arti
cula
rly
prot
eins
and
sta
rche
s wh
ich
have
str
ong
tend
enci
es f
or f
orm
ing
such
inte
ract
ions
wit
h wa
ter.
Beca
use
fat
is h
ydro
phob
ic, i
t do
es n
ot u
sual
ly in
tera
ct
with
the
wat
er p
hase
in
food
, ho
weve
r, t
here
are
ph
osph
olip
ids
and
lipop
rote
ins
that
ass
ocia
te a
t lip
id-
wate
r in
terf
aces
.
Thes
e ca
n ac
t as
em
ulsi
fier
s. V
an d
erwa
lls f
orce
s ar
e ef
fect
ive
for
phys
ical
ly a
dsor
bed
H2O
(is
fou
nd i
n a
m
ono
laye
r on
the
sur
face
of
mac
rom
olec
ules
).
3.
Wat
er
of
Hyd
rati
on:
Som
etim
es,
wate
r ca
n be
ch
emic
ally
bo
und
to
cert
ain
com
poun
ds
like
lact
ose
(for
min
g a
stab
le
mon
ohyd
rate
), sa
lts
(tar
tara
te),
prot
eins
(h
ydro
gen
bond
ed)
and
poly
sacc
hari
des
(hyd
roge
n bo
ndin
g). T
his
boun
d wa
ter
may
var
y fr
om 0
.5
to
30%
of
th
e to
tal
wate
r pr
esen
t.
This
wa
ter
is
part
icul
arly
dif
ficu
lt t
o re
mov
e fo
r an
alyt
ical
pur
pose
s.
Chem
ical
ly b
ound
wat
er i
s in
th
e fo
rm o
f wa
ter
of
hydr
atio
n or
cry
stal
izat
ion,
It
is u
nava
ilabl
e as
sol
vent
.
Ex:
MgS
O4.3
H2O
: H
ere,
H2O
is
com
plet
ely
diff
eren
t fr
om t
he o
ther
for
ms.
~6%
of
H2O
in a
nim
al t
issu
es,
~10%
of
H2O
in f
ruit
sis
in t
his
form
.
III.
Cla
ssif
icat
ion
of H
2O D
eter
min
atio
ns
Prin
cipl
es o
f m
etho
ds u
sed
for
moi
stur
e de
term
inat
ion:
I.D
IREC
T M
ETH
OD
S:Th
ese
are
base
d on
sep
arat
ion
of w
ater
fro
m f
ood
solid
s an
d m
easu
ring
the
loss
in w
eigh
t or
the
vol
ume
of
wate
r re
mov
ed.
A. O
ven
Dry
ing
Met
hods
: Var
y gr
eatl
y in
con
diti
ons
for
dryi
ng( o
ver
dess
ican
ts o
r in
atm
osph
eric
or
vacu
um
oven
s) B. D
istilla
tion
Tec
hnique
s:
Co
-dis
tilli
ng w
ater
wit
h a
high
boi
ling
poin
t s
olve
nt t
hat
is i
mm
isci
ble
with
wa
ter.
II
.Met
hods
bas
ed o
n ch
emic
al r
eact
ions
of
wate
r.II
I.M
etho
ds
mea
suri
ngso
me
phys
ical
(a)
or
colli
gati
ve(b
)pro
pert
y th
at i
s co
rrel
ated
to
moi
stur
e co
nten
t
IA. D
ryin
g M
etho
ds
Thes
e ar
e es
sent
ially
the
rmal
met
hods
. M
oist
ure
los
is a
fun
ctio
n of
tim
e an
d te
mpe
ratu
re. I
n m
ost
case
s,
dr
ying
m
etho
ds
rely
on
gr
avim
etri
c di
ffer
ence
bef
ore
and
afte
r dr
ying
, us
ing
heat
tr
ansf
er b
y co
nduc
tion
on
conv
ecti
on.
Dry
ing
met
hods
have
adva
ntag
es o
f be
ing:
-Sim
ple
-Fas
t(in
frar
edm
etho
d),
-Han
dlin
g la
rge
num
ber
of s
ampl
es-
Inex
pens
ive
(equ
ipm
ent)
Prin
cipl
es g
over
ning
moi
stur
e lo
ss:
*Hea
t tr
ansf
er r
ate
(sel
dom
a li
mit
ing
fact
or)
*Tem
pera
ture
**S
urfa
ce a
rea
of p
rodu
ct, p
arti
cle
size
*D
iffu
sion
of
wate
r th
roug
h pr
oduc
t*V
apor
pre
ssur
e di
ffer
ence
s (R
H a
t su
rfac
e vs
. pro
duct
), nu
mbe
r of
sam
ples
in o
ven,
air
ex
chan
ge r
ate
in o
ven,
vac
uum
app
lied
or
not,
ai
r m
ovem
ent
in d
ryer
, etc
.
*1 m
ole
of s
olut
e di
ssol
ved
in 1
liter
wat
er
rais
es it
s bo
iling
poi
nt b
y ~0
.5ºC
.Thu
s bo
iling
po
int
elev
atio
n co
ntin
ues
duri
ng m
oist
ure
rem
oval
pro
cess
.
DR
YIN
G M
ETH
OD
S–
DR
Y T
HE
FOO
DS
UN
DER
TH
E SP
ECIF
IC C
ON
DIT
ION
S
Type
s of O
ven,
Tem
pera
ture
, Tim
e.
Adv
anta
ges:
Sim
ple,
Rel
ativ
ely
rapi
d, A
naly
sis o
f lar
ge
num
ber o
f sam
ples
at a
tim
e.
Dis
adva
ntag
es:L
oss o
f oth
er o
rgan
ic c
ompo
unds
or g
ases
fo
rmed
by
ther
mal
dec
ompo
sitio
n of
org
anic
co
mpo
unds
.
Oxi
datio
n of
oil.
Erro
r Sou
rce:
Cru
st fo
rmat
ion
from
suga
r.
1. A
ir-ov
en M
etho
d---
put t
he sa
mpl
e (1
0g) i
n fla
t, ta
rred
dis
h -
spec
ified
tim
e an
d te
mpe
ratu
re (1
50C
for 1
hr)
-m
easu
re th
e lo
ss o
f w
ater
.
2. V
acuu
m o
ven
Met
hod
---u
se it
if y
ou d
o no
t wan
t to
expo
se
to h
igh
tem
pera
ture
. U
se 5
0 m
m H
g an
d ar
ound
100
C.
Food
rich
in
fruc
tose
mus
t be
drie
d at
70C
or b
elow
.
3. H
ot p
late
Met
hod
---r
apid
, qua
lity
cont
rol,
use
som
e tim
e, p
ut
in v
acuu
m a
t 100
C, c
ool i
n de
sicc
ator
s, "M
ojon
nier
".
4. M
oist
ure-
bala
nce
---ba
lanc
e in
ove
n w
ith IR
ligh
t and
hea
t.
Mea
sure
the
moi
stur
e lo
ss.
DR
YIN
G M
ETH
OD
S
•Dis
adva
ntag
es:
•Pre
cautıv
e m
easu
res
have
to
be
take
n to
avo
ıd
deco
mpo
siti
onof
sol
ute
com
pone
nts:
Exam
ple:
Fr
ucto
se
cont
aini
ng
food
s
may
de
com
pose
wi
th
unco
ntro
lled
heat
ing
sinc
e fr
ucto
se is
des
troy
ed a
bove
the
100
°C,
•Sol
utio
n: A
pply
vac
uum
, red
uced
tem
pera
ture
and
lo
nger
dry
ing
tim
e.e.
g. A
lso
may
pla
ce i
n va
cuum
de
sicc
ator
over
co
ncen
trat
ed
sulf
uric
ac
id,
phos
phor
us p
ento
xide
, or
mag
nesi
um p
erch
lora
te).
•Ove
n m
etho
ds a
re n
ot g
ood
for
prod
ucts
tha
t ha
ve a
lot
of b
ound
wat
er.
•Dri
ed f
ruit
s co
ntai
n a
lot
of b
ound
wat
er a
nd w
ill
lose
onl
y 75
% o
f th
eir
moi
stur
e by
dry
ing
met
hods
. D
ehyd
rate
d fi
nely
gro
und
carr
ots
requ
ire
6-9
mon
ths
in a
vac
uum
ove
r M
g pe
rchl
orat
eto
att
ain
cons
tant
we
ight
.
DRY
ING
met
hods
have
man
y ot
her
disa
dvan
tage
s:
It i
s no
t sp
ecif
ic f
or a
ll ty
pes
of w
ater
, th
eref
ore
may
lead
to
mis
take
n ca
lcul
atio
nsO
ptim
al d
ryin
g te
mpe
ratu
re m
ay n
otbe
att
aine
dD
ryin
g ca
n be
de
stru
ctiv
e
to
othe
r co
mpo
nent
s (n
onde
stru
ctiv
e vs
. des
truc
tive
met
hods
)
Hea
t So
urce
s us
ed a
re a
ir-o
vens
, va
cuum
-ove
ns,
mic
rowa
ve o
vens
, in
frar
ed o
vens
and
la
mps
. In
id
eal
dryi
ng p
roce
dure
for
the
det
erm
inat
ion
of
wate
r,
weig
ht
loss
es
shou
ld
resu
lt
from
qu
anti
tati
ve
and
rapi
d vo
lati
lizat
ion
of
wate
r on
ly. T
his
depe
nds
larg
ely
upon
:
*Air
mov
emen
t in
the
dry
ing
cham
ber
*Vac
uum
in t
he c
ham
ber.
Fact
ors
infl
uenc
ing
resu
lts
(the
rat
e of
eva
pora
tion
of
wat
er in
ove
ns).
a-D
iam
eter
or
surf
ace
area
of
cont
aine
rs.
b-D
epth
of
cont
aine
rsc-
Mat
eria
l of
con
tain
ers
(Al;
porc
elai
n et
c.D
ryin
g ra
te is
hig
hest
in A
l dis
hes)
d-Po
siti
on a
nd n
umbe
r of
con
tain
ers
in t
he o
ven.
*Des
sica
nts
like
P 2O
5; ca
lciu
m c
arbi
de, s
ilica
gel
will
sp
eed
dryi
ng..
e-D
ryin
g is
a f
unct
ion
of t
ime,
tem
pera
ture
and
wate
r va
por
pres
sure
. The
refo
re in
ord
er t
o be
abl
e to
dec
reas
e th
e te
mpe
ratu
re,
we h
ave
to e
ithe
r in
crea
se t
he t
ime
or a
pply
vac
uum
.In
vacu
um o
vens
, wa
ter
vapo
r pr
essu
re
of
air
in
oven
ca
n be
ef
fect
ivel
y us
ed a
t m
uch
lowe
r te
mpe
ratu
res
thus
av
oidi
ng d
ecom
posi
tion
s or
des
truc
tion
s.
Vacu
um i
s ge
nera
lly a
pplie
d in
2 s
teps
,i.e.
Firs
t go
dow
n to
~3
10 m
m H
gfo
r 30
min
utes
,and
the
n at
tain
<15
mm
H
g. T
ypic
al v
acuu
m le
vels
for
spe
cifi
c co
mm
odit
y ty
pes
are:
100
mm
Hg
for
frui
ts, o
ils, n
uts;
50 m
mH
g fo
r su
gars
an
d su
gar
prod
ucts
; 25
mm
Hg
for
cere
als
and
eggs
.
*Dry
ing
tim
e is
inve
rsel
y re
late
d to
dry
ing
tem
p.
Espe
cial
ly i
n dr
ying
cer
eals
, n
orm
al o
vens
req
uire
14
hour
s wh
erea
s m
icro
wave
ove
ns
requ
ire
3-10
min
utes
fo
r 10
gr
sam
ples
whe
n p
ower
inpu
t ~1
00 w
atts
. *I
n in
frar
ed o
vens
dry
ing
is e
ven
fast
er.
How
ever
th
ere
is
a ri
sk
of
surf
ace
carb
oniz
atio
nsi
nce
the
fila
men
t of
the
IR
lam
p(~5
00W
)de
velo
ps ~
2000
° K,
th
ereb
y m
ight
lead
to
surf
ace
carb
oniz
atio
n
Dry
ing
Cond
itio
ns
Ove
ns i
n wh
ich
ther
e is
hot
air
cir
cula
tion
or
an
iner
t at
mos
pher
e wi
th
vacu
um
(70-
130°
C)is
ap
plie
d fo
r a
spec
ifie
d ti
me
unti
l su
cces
sive
we
ighi
ngs
diff
er b
y <3
mg.
Goal
: Re
ach
high
est
tem
pera
ture
wi
thou
t de
com
posi
tion
or
ch
emic
alre
acti
on
(Tem
pera
ture
-tim
eop
tim
isat
ion)
Type
s of
Equ
ipm
ent:
Hot
Air
Ove
ns-
Eith
er w
orki
ng o
n co
nvec
tion
or
forc
ed a
ir,
it
shou
ld b
e ac
cura
te a
nd u
nifo
rm i
n te
mpe
ratu
re.
So f
irst
rul
e in
dry
ing
is:u
se a
GO
OD
ove
n.-
May
hav
e ba
lanc
es b
uilt
into
ove
n,so
per
mit
ting
se
mi-a
utom
atic
assa
ys-
Som
e ha
ve h
umid
ity
sens
ors
to d
eter
min
e wh
en
dryi
ng is
com
plet
e.
Vacu
um o
vens
–Va
cuum
help
s to
get
rid
of
the
1%+
moi
stur
e th
at i
s bo
und
in m
ost
food
s. W
e ca
n us
e lo
wer
tem
ps,r
educ
ed R
H (v
apor
pre
ssur
e in
ove
n).
It
MU
ST H
AVE
LEA
KS t
o re
duce
VP
,For
th
is a
im, a
ir is
pas
sed
thro
ugh
a dr
yer
such
as
con
c. H
2SO
4or
dri
erri
te..
*Opt
imal
Tim
e-Te
mp
com
bina
tion
: i.e
.16
hrs
at 1
00°C
is m
ost
com
mon
.
*Col
d tr
ap i
s es
sent
ial
for
colle
ctin
g th
e wa
ter
from
sam
ple
to p
rote
ct t
he v
acuu
m
pum
p an
d re
duce
RH
.
Oth
er o
vens
:M
icro
wave
:Ve
ry r
apid
hea
t tr
ansf
er/d
ryin
g:i.e
.6-
8 m
in
for
10g
sam
ple
of m
eat.
Bui
lt-in
bal
ance
s. A
ir e
xcha
nge
syst
ems.
But
requ
ires
ce
ntra
lly
loca
ted
and
even
ly
dist
ribu
ted
sam
ples
.In
frar
ed:
(Fila
men
t T:
2000
-250
0K)
mor
e ra
pid
heat
tr
ansf
er,t
hus
shor
tens
tim
e,bu
t m
ay b
e to
o fa
st a
nd b
urn
sam
ple.
Use
IR
lam
p ca
. 10
cm f
rom
sam
ple.
Thi
n be
d of
fo
od 1
0-15
mm
. Dry
ing
tim
es s
houl
d be
10-
20 m
in m
ax.
Acc
urac
y Pr
oble
ms
1. S
ampl
ing
erro
rs.
2. R
eten
tion
of
wate
r by
ads
orpt
ion,
occ
lusi
on o
r ch
emic
al
com
bina
tion
mak
es lo
ss b
y va
pori
zati
on d
iffi
cult
. Rea
chin
g a
cons
tant
wei
ght
does
not
alw
ays
guar
ante
e th
at a
ll wa
ter
has
been
rem
oved
. 3.
The
re m
ight
be
barr
iers
to
wate
r di
ffus
ion
in f
ood
role
of
dif
fusi
on in
dry
ing.
4.
Chem
ical
de
com
posi
tion
re
acti
ons
poss
ible
es
peci
ally
for
sug
ars
like
fruc
tose
and
sucr
ose
5. O
ther
vol
atile
s
6. E
ffec
ts o
f O
xida
tion
7. A
bsor
ptio
n of
wat
er f
rom
air
:
A.
Ads
orpt
ion
of m
oist
ure
from
air
in
dryi
ng
oven B.
Ads
orpt
ion
of w
ater
fro
m t
he a
ir d
urin
g we
ighi
ng.
Proc
edur
al C
onsi
dera
tion
s
1. Pr
epar
atio
n of
Sa
mpl
e:
Dif
fere
nt
for
Liqu
id
prod
ucts
-Br
ead
vs.F
ruit
s
2. D
ryin
g Co
ndit
ions
: reg
ulat
ion
of t
empe
ratu
re t
o ±
1°C
may
yi
eld
a 0.
1%
diff
eren
ce
in
moi
stur
e co
nten
t.Th
e va
cuum
requ
ired
fo
r di
ffer
ent
prod
ucts
is d
iffe
rent
:100
mm
Hg
is id
eal f
or f
ruit
s,
nuts
, oils
, and
fat
s;50
mm
Hg
for
suga
r an
d su
gar
prod
ucts
, 25
mm
Hg
for
cere
al f
oods
, egg
s, a
nd e
gg
prod
ucts
.3.
Pre
para
tion
of
the
dryi
ng d
ish:
The
dry
ing
dish
sh
ould
be
pre-
drie
d an
d he
ld i
n a
desi
ccat
orun
til
use.
I.B.
Dis
tilla
tion
Proc
edur
es:
Refl
ux
Dis
tilla
tion
with
im
mis
cibl
e so
lven
ts
(Ent
rain
men
t)
This
typ
e of
met
hod
is u
sed
for
sam
ples
whi
ch
cont
ain
othe
r vo
lati
le c
ompo
nent
s.
Ex:S
pice
s
Prin
cipl
e:A
so
lven
t im
mis
cibl
e wi
th
wate
r is
ad
ded
to s
ampl
e an
d th
e m
ixtu
re (
H2O
+ s
olve
nt)
is b
oile
d o
ff a
s an
aze
otro
pic
mix
ture
. U
pon
cool
ing,
the
2 p
hase
s wi
ll se
para
te (
volu
met
ric
dete
rmin
atio
n).
Dep
endi
ng
on
your
pu
rpos
e,
your
so
lven
t's
dens
ity
has
to b
e ei
ther
hig
her
or lo
wer
than
th
at o
f wa
ter.
App
arat
usty
pes:
p. 9
2-95
.
Dis
tilla
tion
was
ori
gina
lly d
evel
oped
as
a ra
pid
met
hod
for
food
qua
lity
cont
rol,
howe
ver,
for
fo
ods
that
mig
ht d
ecom
pose
on
heat
ing,
you
ca
n on
ly
get
appr
oxim
ate
resu
lts
from
di
still
atio
n m
etho
ds.
Dis
tilla
tion
is
pref
erre
d fo
r ce
real
s, n
uts,
oils
, wa
xes,
and
pow
dere
d pr
oduc
ts.
Col
d
DIS
TILL
ATI
ON
MET
HO
D
Con
dens
er
Gra
duat
ed T
rap
Sam
ples
& S
olve
ntH
eatin
g M
antle
Solv
ent
Tolu
ene
Ref
luxi
ng &
Wat
erSe
para
tion
Met
hod
Col
d w
ater
Ther
e ar
e th
ree
gene
ral t
ypes
of
dist
illat
ion:
1. D
irec
t di
still
atio
n fr
om im
mis
cibl
e liq
uids
with
ve
ry h
igh
boiln
g po
int
–e.
g. m
iner
al o
il.
2. D
irec
t di
still
atio
n wi
th im
mis
cibl
e liq
uids
tha
t ha
ve b
oilin
g po
ints
nea
r th
at o
f wa
ter
e.g.
tol
uene
or
xyl
ene.
3. R
eflu
x di
still
atio
n wi
th a
n im
mis
cibl
e liq
uid
–to
luen
e(B.
P.11
0ºC)
, xyl
ene(
B.P.
137
ºC)o
r te
trac
hlor
oeth
ylen
e
Prob
lem
s th
at c
an b
e en
coun
tere
d wh
en u
sing
en
trai
nmen
t di
still
atio
n in
clud
e:
1. In
com
plet
e re
cove
ry o
f wa
ter
as a
res
ult
of
emul
sion
s be
twee
n wa
ter
and
solv
ent.
2. D
rops
of
wate
r cl
ingi
ng t
o th
e co
nden
ser
or
side
of
the
rece
ivin
g tr
ap.
3. D
ecom
posi
tion
of
sam
ple
–m
ore
prob
lem
s wi
th h
igh
boili
ng p
oint
sol
vent
s.4.
Tol
uene
may
con
dens
e to
o so
on i
n th
e tr
ap
and
thus
doe
sno
t ca
rry
muc
h wa
ter
over
int
o th
e tr
ap.
II.C
hem
ical
Met
hods
1. Ka
rl F
isch
er M
etho
d:Ve
ry p
opul
ar m
etho
d, b
ut
Karl
-Fis
cher
Ti
trat
ion
is
seld
om
used
in
hi
gh
moi
stur
e fo
ods.
For
low
moi
stur
e fo
ods
like
cand
ies,
cho
cala
te,
drie
d fr
uits
and
veg
etab
le,
bake
ry d
ough
s, b
aked
pro
duct
s re
aste
dco
ffee
, fa
ts a
nd o
ils, s
ugar
ric
h fo
ods
orfo
ods
rich
bot
h in
re
duci
ng
suga
rs
and
prot
eins
, KF
is
th
e pr
efer
red
met
hod.
Prin
cipl
e: R
educ
tion
of
iodi
ne (
I°→
I-)
to
ioda
teby
SO
2in
pre
senc
e of
H2O
(see
pp.
130
-1).
2 H
2O+
SO2
+ I 2
→2H
I +C
5H2S
O4
Wit
hout
wa
ter
in
the
med
ium
, th
is
redo
x re
acti
on w
illno
t oc
cur.
(see
Fig
.8.6
)
The
basi
c re
acti
on t
akes
pla
ce in
two
sta
ges:
1)(C
5H5N
).I2+
(C5H
5N).S
O2+
(C5H
5.N)+
H2O
→2(
C 5H
5N).H
I+(C
5H5N
).SO
3
2)(C
5H5N
).SO
3+CH
3OH
→(C
5H5N
HSO
4CH
3)Ev
en
thou
gh
the
stoi
chio
met
ry
is
not
exac
t,
at
the
turn
ing
poin
t of
the
tit
rati
on,
for
each
mol
e of
H2O
in
sam
ple,
the
am
ount
of
spen
t KF
Rea
gent
will
co
ntai
n:1
mol
e of
Iod
ine
1 m
ole
of S
O2
3 m
oles
pyr
idin
e1
mol
e m
etha
nol.
So t
his
is b
asic
ally
the
com
posi
tion
of
the
KF R
eage
nt.
1ml r
eage
nt c
orre
spon
ds t
o 3.
5mg
wate
r.Th
e en
dpoi
ntin
volv
es a
cha
nge
in
Redo
xpo
tent
ial,
whic
h ca
n au
tom
atic
ally
be
dete
cted
wit
h us
e of
ele
ctro
des.
Th
ere
now
are
also
aut
omat
ed K
FTit
rato
rsby
Mer
ck.
Ex.:F
ored
ible
oil
indu
stry
,whe
re n
o wa
ter
is d
esir
ed i
n pr
oduc
t, K
F ti
trat
ion
is u
sed
for
auto
mat
ic c
ontr
ols
for
any
trac
e wa
ter.
CH
EMIC
AL
MET
HO
DS
Kar
l Fis
her M
etho
d---
Stan
dard
tech
niqu
e fo
r low
moi
stur
e fo
ods.
Espe
cial
ly g
ood
for r
educ
ing
suga
rs a
nd p
rote
in-r
ich
food
s an
d go
od fo
r foo
ds w
ith h
igh
vola
tile
oils
.
H2O
SO2
I
2
H2S
O4
HI
++
+2
2Th
eory
:
KA
RL
FISH
ER M
ETH
OD
Kar
l Fis
her R
eage
nt:
Dis
solv
e 13
2 g
of Io
dine
+ 4
25 m
l of P
yrid
ine
+ 42
5 m
l of
MeO
H+
105
g of
SO
2.
Titra
te12
0 m
g of
H2O
with
Car
l Fis
her R
eage
nt.
Cal
cula
ted
Con
cent
ratio
n =
mg
H2O
/ml o
f Rea
gent
=5
mg/
ml o
f Rea
gent
% H
2O =
Con
c. x
ml R
eage
nt /
mg
of S
ampl
e x
100
KA
RL
FISH
ER M
ETH
OD
NNNNNN
NNNN
N
NN
H2O
CH3O
H
HSO
4CH
3
I 2SO
2H
ISO
3
SO3
++
+2
+
+
Brow
n M
ahog
any
Colo
r
1. 2.
Met
hod
of c
hoic
e fo
r m
any
low-
moi
stur
e fo
ods
like
drie
d fr
uits
an
d ve
geta
bles
, ca
ndie
s,
choc
olat
e, r
oast
ed c
offe
e, o
ils a
nd f
ats.
The
met
hod
has
been
app
lied
to i
nter
med
iate
m
oist
ure
food
s (b
aker
y do
ughs
, ba
ked
prod
ucts
, fa
t-ri
ch c
akes
, an
d fo
ods
with
hig
h le
vels
of
vola
tile
oils
).
Met
hano
l, su
lfur
dio
xide
, and
pyr
idin
e ar
e ad
ded
in e
xces
s so
tha
t al
l wat
er m
olec
ules
rea
ct.
The
amou
nt
of
iodi
nere
duce
d by
wa
ter
is
titr
ated
by K
F re
agen
t. T
he r
eage
nt h
as t
o be
st
anda
rdis
ed a
gain
st d
isti
lled
wate
r fo
r fi
ndin
g it
s wa
ter-
equi
vale
nce
fact
or,
KFRe
q(ho
w m
uch
wate
r 1
ml o
f KF
rea
gent
will
cor
resp
ond
to).
Prob
lem
s:
1. Ex
trac
tion
m
ay
not
be
com
plet
e or
de
com
posi
tion
may
tak
e pl
ace
duri
ng e
xtra
ctio
n.
Ther
efor
e, f
ound
valu
es w
ill b
e to
o lo
w.
2. I
nter
fere
nce
from
:a)
Asc
orbi
c ac
id w
hich
is o
xidi
zed
by K
arl F
isch
er
reag
ents
to
de
hydr
oasc
orba
tean
dwa
ter(
so
titr
atio
n m
easu
res
both
wat
er a
nd a
scor
bic
acid
).b)
Car
bony
l co
mpo
unds
rea
ct w
ith
met
hano
l to
fo
rm a
ceta
lsan
d re
leas
e wa
ter,
and
fou
nd w
ater
valu
es w
ill b
ehi
gher
tha
n th
e re
al s
itua
tion
.c)
Rea
ctio
n wi
th m
erca
ptan
s, b
icar
bona
tes,
and
ca
rbon
ates
can
cau
se f
adin
g en
dpoi
nts.
d)po
lyun
satu
rate
d fa
tty
acid
s wi
ll re
act
with
I,
yiel
ding
hig
h wa
ter
valu
es.
2.
Gene
rati
on o
f ac
etyl
ene
gas
CaC 2
+ H
2O –
––––
––> C
H=
CH +
CaO
The
amou
nt o
f ac
etyl
ene
gas
that
is
form
ed
afte
r re
acti
on
with
wa
ter
is
mea
sure
d by
a
mon
omet
er.
This
pro
cedu
re h
as b
een
used
for
de
term
inin
g wa
ter
cont
ents
of
powd
ered
foo
d pr
oduc
ts
like
cere
als,
fl
ours
, an
d co
ttag
e ch
eese
.
3. C
obal
t Ch
lori
de P
aper
:
CoCl
2+
H2O
---
----
--->
CoC
l 2*
6 H
2O(d
ry:b
lue)
(w
et:p
ink)
Filt
er p
aper
s ar
e so
aked
in
solu
tion
of
CoCl
2an
d dr
ied.
The
sam
ple
is g
roun
d an
d a
smal
l qu
anti
ty i
s sp
read
on
the
pape
r. T
he s
ampl
e is
cov
ered
to
allo
w co
lor
chan
ge.
Sem
iqua
ntit
ativ
ees
tim
ates
of
free
wat
er in
foo
d ca
n be
obt
aine
d by
mea
suri
ng t
he r
ate
of c
olor
cha
nge
on
the
filt
er p
aper
. Thi
s m
etho
d is
use
d on
hig
h su
gar
food
s su
ch a
s ra
isin
s.
III.
AM
ETH
OD
S M
easu
ring
Phy
sica
l Pro
pert
ies:
Som
etim
es
ther
e is
ne
ed
for
nond
estr
ucti
ve
anal
yses
(i.e.
plan
tbr
eede
rs d
on't
wan
t to
los
e th
eir
very
val
uabl
e sa
mpl
es).
Exam
ples
of s
uch
nond
estr
ucti
ve m
etho
ds
are
spec
tros
copi
c m
etho
ds
like
NM
R (N
ucle
ar
mag
neti
c Re
sona
nce)
,
and
Die
lect
rom
etry
. H
owev
er,
thes
ety
pes
of m
etho
ds a
re n
ot v
ery
spec
ific
, th
ey n
eed
stan
dard
izat
ion
(indi
vidu
al)
wher
e yo
u ha
ve t
o pr
epar
e yo
ur o
wn g
raph
ics
us
ing
stan
dard
s, s
om
ay b
e co
nsid
ered
to b
e ra
ther
“em
piri
cal”.
M
any
para
met
ers
like
the
tem
pera
ture
of m
easu
rem
ent
affe
ct m
easu
red
valu
es.
Belo
w is
gi
ven
a su
mm
ary
of
thes
e m
etho
ds.
PHY
SIC
AL
MET
HO
DS
1. In
frar
ed M
etho
d:A
bsor
ptio
n M
etho
d --
-m
easu
ring
the
abso
rptio
n of
OH
gr
oup
at w
avel
engt
h of
2.8
µ.
Com
mon
Met
hod
-1pp
m(s
ensi
tivity
)0
2040
6080
100
1530456075
% M
oist
ure
by O
ven
Met
hod
% IR Transmission at 2.8µ.
*Spe
ctro
scop
ic m
etho
ds -
Nea
r In
frar
ed:
NIR
→ne
ar ın
frar
ed r
efle
cten
ce:
*Pri
ncip
le;
Reso
nant
fre
quen
cy o
f pr
oton
s in
H
2O
is
diff
eren
t fr
om
that
of
pr
oton
s in
m
acro
mol
ecul
es.
•Use
d wa
vele
ngth
s ar
e 3.
0 an
d 6.
1 um
(f
unda
men
tal
vibr
atio
n fr
eque
ncie
s of
wat
er)
1.93
um (
com
bina
tion
abs
. ba
nd)
and
1.45
um
(fir
st o
vert
one
of t
he O
H s
tret
chin
g)O
ne a
dvan
tage
is t
hat
r
esul
ts d
o no
t ne
ed
expe
rt i
nter
prat
atio
n.A
noth
er i
s it
s ex
celle
ntse
nsit
ivit
y –
can
mea
sure
dow
n to
few
ppm
. Als
o ve
ryra
pid.
Dis
adva
ntag
e ar
e ve
ry e
xpen
sive
equ
ipm
ent
and
very
cri
tica
l sam
ple
prep
arat
ion
step
.
*Gas
Chro
mat
ogra
phic
Met
hods
:Th
e wa
ter
in
sam
ple
can
be
extr
acte
d in
tom
etha
nol
and
anal
ysed
by G
C, w
hich
is v
ery
good
at
sepa
rati
ons
–us
e a
Poro
pack
colu
mn
(bes
t fo
r se
para
tion
of
pola
r m
ater
ials
. W
ater
will
eas
ily b
e se
para
ted
from
met
hano
l an
d m
easu
red
usin
g a
univ
ersa
l de
tect
or (T
CD:t
herm
al c
ondu
ctiv
ity
dete
ctor
)•Q
uant
ific
atio
n -A
stan
dard
cur
ve u
sing
dif
fere
nt
rati
osof
wat
er t
o m
etha
nol
shou
ld b
e pr
epar
ed
and
resu
lts
are
extr
apol
ated
fr
om t
his
stan
dard
cu
rve.
•Adv
:Can
run
aut
omat
ed s
yste
ms-
rapi
dity
•Acc
urat
e/pr
ecis
e (li
mit
ed t
o ex
trac
tion
) •L
ittl
e or
no
inte
rfer
ence
s•D
isad
v:Co
st o
f in
stru
men
t,an
d ex
pert
ise
need
ed
for
relia
ble
inte
rpre
tati
ons.
*Nuc
lear
Mag
neti
c Re
sona
nce
Prin
cipl
e:
Hyd
roge
n nu
cleu
s ab
sorb
s en
ergy
in
sp
ecif
ic r
adio
fre
quen
cy. W
hile
the
re a
re n
umer
ous
form
s (b
indi
ng) o
f H
nuc
lei,
met
hod
can
disc
rim
inat
e be
twee
n wh
atth
eH
is b
onde
d to
e.g
. OH
.
•Wor
kswe
ll fo
r lo
w m
oist
ure
cont
ents
, bu
t sp
ectr
um g
ets
too
com
plic
ated
for
hig
h m
oist
ure
prod
ucts
.•A
dv:
Can
dete
rmin
e/di
stin
guis
h bo
und
wate
r –
one
of t
he f
ew s
uch
met
hods
,-
Rapi
d (1
min
), -
Non
dest
ruct
ive
sinc
e no
nthe
rmal
, no
deco
mpo
siti
on,a
ndac
cura
te.
•Dis
adv:
Hig
h co
stan
d so
phis
tica
tion
in o
pera
tion
NM
R:
Mea
sure
the
hydr
ogen
nuc
lei
H2
nucl
ei o
f wat
er w
ill v
ibra
te (s
pin-
orie
ntal
) in
a fi
xed
mag
netic
fiel
d an
d pr
oper
radi
o fr
eque
ncy.
Abs
orpt
ion
of ra
dio
freq
uenc
y by
the
hydr
ogen
nuc
leus
.
Rap
id/N
on-d
estru
ctiv
e/A
ccur
ate
NU
CLE
AR
MA
GN
ETIC
RES
ON
AN
CE
SPEC
TRO
MET
ER
R-F
Tr
ansm
itter
Det
ecto
r
Sam
ple
Tran
smitt
erC
oil
Rec
eive
r Coi
l
2040
6080
100
0
% M
oist
ure
by O
ven
Met
hod
Relative Detector Response
Nuc
lear
Mag
netic
Res
onan
ce S
pect
rom
eter
*Ele
ctri
cal C
ondu
ctiv
ity:
Empi
rica
lre
lati
onsh
ips
have
be
en
deve
lope
d be
twee
n m
oist
ure
cont
ent
and
elec
tric
al c
ondu
ctiv
ity.
Con
duct
ivit
yof
sam
ple
depe
nds
on:
-M
oist
ure
cont
ent↑
↑-
Salt
con
tent
-
Pack
agin
g -T
empe
ratu
re-
Text
ure
App
licat
ion:
20 g
of
prep
ared
sam
ple
is p
ut in
a s
teel
cup
, a
curr
ent
is p
asss
ed t
hrou
gh t
he v
esse
l, an
d co
nduc
tivi
ty is
re
ad. T
he m
oist
ure
cont
ent
is t
o be
ext
rapo
late
d fr
om t
he
std
curv
eto
be
pr
epar
ed
with
di
ffer
ent
but
know
n m
oist
ure
cont
ents
.A
dv:s
peed
;D
isad
v:sa
mpl
edi
men
sion
s/pa
ckin
g in
ce
llan
d ot
her
com
pone
nts
will
alli
nflu
ence
the
con
duct
ivit
y
Met
hods
bas
ed o
n sp
ecif
ic g
ravi
ty a
nd d
ensi
ty
1.Sp
ecif
ic g
ravi
ty a
nd d
ensi
ty o
f liq
uid
sam
ples
can
be
mea
sure
d us
ing
a py
cnom
eter
, wh
ich
is r
elat
ed t
o th
e wa
ter
cont
ent
of s
ampl
e.
Ther
e ar
e ta
bles
tha
t re
late
den
sity
or m
ost
com
mon
ly s
peci
fic
grav
ity
to s
olid
s co
ncen
trat
ion
; but
the
se s
houl
d al
l be
reco
rded
at
the
sam
e te
mp.
2. A
Wes
tpha
lba
lanc
eca
n be
use
d wh
ich
is b
ased
on
Arc
him
edes
' pr
inci
ple,
“Th
e sa
me
body
will
dis
plac
e eq
ual w
eigh
ts o
f al
l liq
uids
in
whic
h it
flo
ats”
. W
B wi
ll yi
eld
both
den
sity
and
sp
ecif
ic g
ravi
tyva
lues
, t
houg
h sp
ecif
ic g
ravi
ty i
s th
e ea
sies
t to
ob
tain
. The
bal
ance
has
a s
inke
r su
spen
ded
on a
thi
n wi
re t
hat
hang
s fr
om t
he e
nd o
f th
e ba
lanc
e.U
sing
A a
nd B
whe
re A
= t
he w
eigh
t of
the
sin
ker
in a
ir,B
= t
he w
eigh
t of
the
sin
ker
in p
ure
wate
r, a
nd
C =
the
weig
ht o
f th
e si
nker
in t
he
liqui
d, w
ater
con
tent
of
liqui
d sa
mpl
e ca
n th
en b
e ca
lcul
ated
.
Erro
rs c
an b
e ca
used
by
surf
ace
tens
ion
on t
he w
ire
and
by a
ir b
ubbl
es
atta
ched
to
the
wire
or
sink
er.
3.
Spec
ific
gr
avit
y by
hydr
omet
ry:
This
is
th
e si
mpl
est
way
to d
eter
min
e sp
ecif
ic g
ravi
ty, a
gain
bei
ng
base
d on
Arc
him
edes
' pr
inci
ple.
Con
cern
s ab
out
this
m
etho
d in
clud
e:-
clea
nlin
ess
of t
he h
ydro
met
er-
tem
pera
ture
(liq
uid
volu
me,
the
refo
re d
ensi
ty w
ill
chan
ge w
ith
tem
pera
ture
), -a
lar
ge e
noug
h co
ntai
ner
shou
ld b
e ch
osen
so
that
th
ere
is n
o ph
ysic
al i
nter
fere
nce
from
the
con
tain
er
hold
ing
the
flui
d.
Som
e co
mm
on h
ydro
met
ers
are:
A. S
acch
arom
eter
s B.
Bal
ling
C. B
rix
D. B
aum
e'hy
drom
eter
s[0°
Baum
e=
Pure
wat
er,
10 B
aum
e'=
10%
sal
t (N
aCl)]
, E.
Lac
tom
eter
s
Exam
ple:
LACT
OM
ETER
S:Sp
ecif
ic g
ravi
ty o
f “n
orm
al”
milk
is 1
.029
-thi
s co
rres
pond
s to
29º
in l
acto
met
er r
eadi
ng. S
o,
to g
et s
peci
fic
grav
ity
of m
ilk,
you
divi
de
lact
omet
er d
egre
es b
y 10
00 a
nd a
dd 1
. Tot
al
solid
s in
milk
can
the
n be
fou
nd a
ccor
ding
to
the
follo
wing
equ
atio
n:
Tota
l sol
ids
= 0.
25 L
+ 1
.2 F
wher
e L
is t
he l
acto
met
er r
eadi
ng,
and
F is
pe
rcen
t fa
t in
the
milk
.
REFR
ACT
OM
ETRY
:Pr
inci
ple:
Opt
ical
dens
ity
of s
olut
ions
as
well
as
the
refr
acti
on w
ill c
hang
e wi
th c
hang
ing
wate
r co
nten
ts.S
ome
refr
acto
met
ers
may
rea
d as
RI
(dim
ensi
onle
ss)
and
som
e di
rect
ly i
n %
sol
uble
so
lids(
1°Br
ix=R
I of
1%w/
w su
cros
e so
lution
)).
Refr
active
Ind
ex:
RI c
an v
ary
betw
een
1.300
and
1.700
at
20°
C[wi
th s
odiu
m D
line
(λ=
589
ηm
)].
RI a
lso
vari
es w
ith:
-Tem
pera
ture
–C
once
ntra
tion
–W
avel
engt
h of
ligh
t (if
oth
er t
han
Sodi
um D
line
)
III.
BM
ETH
OD
S Ba
sed
on C
ollig
ativ
ePr
oper
ties
:
III.
b.1.W
ATE
R A
CTIV
ITY
(aw)
Know
ing
only
the
wat
er c
onte
nt o
f fo
ods
may
not
be
en
ough
.
Ano
ther
very
im
port
ant
conc
ept
rela
ted
to
moi
stur
e is
“w
ater
acti
vity
-aw
”,wh
ich
is d
efin
ed a
s:A
w= (P
) / (P
o)
= ER
H/1
00“T
he
rati
oof
eq
uilib
rium
va
pour
pres
sure
of
sa
mpl
e (P
) to
the
equ
ilibr
ium
vap
our
pres
sure
of
pure
wat
er (P
o) a
t th
at s
ame
tem
pera
ture
”M
etho
ds
for
mea
suri
ng
aw
are
base
d on
co
lliga
tive
(phy
sico
chem
ical
)pr
oper
ties
of
wate
r:W
hen
solu
tes
are
adde
d to
H2O
, vap
our
pres
sure
↓
osm
otic
pr
essu
re↑,
fr
eezi
ng
poin
t↓,
boili
ng
poin
t↑.
•Mea
sure
men
t of
wat
er a
ctiv
ity
in f
oods
.
1. D
irec
tly
mea
sure
Aw
–a.
cla
ssic
al (m
anom
etri
c) m
easu
rem
ent
ofth
e va
por
pres
sure
or
by u
sing
hyg
rom
eter
s wi
th a
sen
sor
cont
aini
ng h
ygro
scop
ic m
ater
ial
like
LiCl
, th
e co
nduc
tivi
ty o
f wh
ich
will
chan
ge a
ccor
ding
to
the
rela
tive
hum
idit
y in
the
cha
mbe
r ab
ove
sam
ple,
or
psyc
hrom
eter
s.b.
Dew
poi
nt -
mir
rors
2.M
easu
rem
ent
of E
RH (e
quili
briu
m r
elat
ive
hum
idit
y)
Sim
ples
t a
ppar
atus
use
s s
alt-
impr
egna
ted
filt
er p
aper
s. H
ere
the
prin
cipl
eis
:S
alt
will
not
diss
olve
H2O
unl
ess
surr
ound
ing
hum
idit
y le
vel
rise
s to
a p
oint
whi
ch i
s eq
ual
to t
he s
peci
fic
satu
rati
onm
oist
ure
cont
ent
of t
he s
alt
(sta
ndar
d an
d co
nsta
nt v
alue
s fo
r ea
ch
type
of
sa
lt).
Filt
er
pape
rs
are
dipp
ed
into
va
riou
s sa
tura
ted
solu
tion
s wi
th k
nown
ERH
leve
ls, d
ried
and
aff
ixed
insi
de t
he u
pper
lid
of
the
petr
i dis
h;sa
mpl
e is
pla
ced
in lo
wer
dish
, cov
ered
wit
h lid
an
d eq
uilib
rate
d fo
r 20
gho
urs
at 2
0C. A
w of
sam
ple
is b
etwe
en t
he
wet
pape
r of
hig
hesr
aw
and
dry
pape
r of
lowe
st a
w.
The
vapo
rpr
essu
re (
Aw)
of
wate
r ab
ove
a fo
od is
rel
ated
to
its
moi
stur
e co
nten
t. B
ut
the
rela
tion
ship
is n
onlin
ear
for
man
y fo
od
prod
ucts
and
lar
ge e
rror
s ca
n oc
cur
unle
ss
you
linea
rize
the
data
us
ing
a tr
ansf
orm
atio
n.Yo
u ca
n pr
epar
e an
is
othe
rm f
or t
he s
peci
fic
food
but
thi
s wi
ll be
tim
e co
nsum
ing,
and
hyst
eres
ism
ay le
ad
to e
rror
s.
II.b
.2.F
reez
ing
poin
t el
evat
ion
or d
epre
ssio
n:W
hen
wate
r is
add
ed t
o a
food
, th
ere
will
be a
fr
eezi
ng p
oint
dep
ress
ion
, whi
ch c
an b
e m
easu
red
and
is v
alid
for
upp
er a
w le
vels
(>0.
8).
Exam
ple:
F.P.
(fre
ezin
g po
int)
of
unad
ulte
rete
dm
ilk
≅0.5
5ºC.
Each
1%
ad
ded
wate
r ch
ange
s th
e fr
eezi
ng p
oint
of
milk
by
.005
5 ◦
C. P
erce
nt a
dded
wa
ter
can
thus
be
calc
ulat
ed u
sing
the
equa
tion
:
One
mol
al o
f an
y sp
ecie
s de
crea
ses
FP b
y 1.8
6º∆t
(tc-
t 1)=
-1.8
6*m
olal
con
cent
rati
onW
here
m: M
olal
ity
of s
olut
ion
(mol
es s
olut
e/kg
sol
vent
) Tc
= A
vg.f
reez
ing
poin
t of
nor
mal
milk
(-0.
55C)
, an
d T 1
= th
e ob
serv
ed f
reez
ing
poin
t%
add
ed w
ater
= 1
00(T
c-T 1
)/Tc
REPO
RTIN
G RE
SULT
S (C
h.4,
p.6
5-67
)Th
e re
fere
nce
basi
s ch
osen
is
of
ut
mos
t im
port
ance
.The
re a
re t
he f
ollo
wing
alt
erna
tive
s:1
AR(
as r
ecei
ved)
or
-as
is b
asis
:exp
ress
ed o
n un
trea
ted
sam
ples
(als
o so
met
imes
as
“f
resh
weig
htba
sis”
(g/1
00g
tiss
ue).
2.O
D(o
ven-
drie
d) o
r dr
ym
atte
rba
sis:
expr
esse
d on
con
tent
s
exc
ludi
ng w
ater
Sinc
e m
oist
ure
cont
ents
can
var
y gr
eatl
y, i
t is
be
st t
o re
port
it in
dry
mat
ter
basi
s in
ord
er t
o be
abl
e to
mak
e co
mpa
riso
ns.
3-Ed
ible
por
tion
bas
is(S
kinn
ed e
ggs
or W
hole
eg
gs) i
.e. 1
00 g
rof
ski
nned
egg
s4-
Arb
itra
rily
se
lect
ed
basi
s:
See
next
3
exam
ples
Ex 1
:In
cere
als
→a
refe
renc
e po
int
is 1
4% H
2Oco
nten
tis
ta
ken
to e
xpre
ss t
he n
utri
ent
cont
ents
Ex
2:
Qua
ntit
y of
am
ino
acid
sca
n be
exp
ress
ed a
s m
g pe
r ea
ch 1
6 gr
of N
.Ex
.3: a
s --
--g/
100
gof
a s
peci
fic
nutr
ient
–nu
trie
nts
5. P
er s
ervi
ng –
(g /
ser
ving
)6.
...
.../l
ot s
ize
–for
man
ufac
turi
ng o
pera
tion
s7.
In
“sta
ndar
dize
dun
it”s
–
RDI-
reco
mm
ende
d da
ily in
take
s(I
U o
f vi
tam
ins)
,-
....a
ctiv
ity
in s
yste
m (e
nzym
es),
-.....
meq
=02/
g of
pro
duct
–(t
itra
tion
s)8.
“wei
ght”
or “v
olum
e”ba
sis:
For
exam
ple,
ppm
can
deno
te
both
m
g/kg
–we
ight
basi
s(m
ost
com
mon
)or
m
g/L
–vo
lum
e ba
sis.
(air
sa
mpl
ing
or b
ever
age
form
ulat
ions
g/1
10 o
r g/
100
L)
Calc
ulat
ions
in c
onve
rtin
g fr
om o
ne b
asis
to
anot
her
basi
s:
Exam
ple:
Sam
ple
com
posi
tion
is 1
0%
H2O
; 30
%
fat
on (
asis
)ba
sis.
To
calc
ulat
e ho
w m
uch
fat
this
will
cor
resp
ond
to o
n “d
ry m
atte
r” b
asis
:
So
the
sam
ple
cont
ains
33
.33%
fat
on
dry
mat
ter
basi
s.
33.33
)10
100
(10
030
=−
=x
Fatdm
2. F
rom
% O
D (o
ven
drie
d) to
AR
(as
rece
ived
):
%Y O
D =
%
Y AR
x 10
0 (1
00 -
% lo
ssO
D)
3. F
rom
AR
to A
M (a
rbitr
ary
moi
stur
eba
sis)
:
%Y
= %
Y AR
(100
-ar
bitr
ary
moi
stur
e %
) 10
0 -%
moi
stur
e AR
The
“Uni
ts”
used
in e
xpre
ssin
g an
alyt
ical
resu
lts
have
to b
e SI
uni
ts (m
etric
).Li
st o
f com
mon
ly u
sed
SI u
nits
is g
iven
in y
our
text
-boo
k on
pag
e 36
-37.
The
pref
ixes
used
den
ote
the
follo
win
g :
giga
: 109
kilo
: 103
nano
: 10-9
mic
ro: 1
0-6m
ega
: 106
Sign
ifica
nt f
igur
es:
Judg
emen
t of
the
num
ber
of m
eani
ngfu
l dig
its in
a r
esul
t
Rep
orte
d va
lue
shou
ld o
nly
con
tain
sig
nif
ican
t di
gits
(all
know
n t
o be
tru
e, j
ust
th
e la
st o
ne
in d
oubt
)6
4.7
2, 6
.47
2,0
.64
72
, 6.4
07
all
hve
4 s
.d.
43
3.8
+3
2.6
6=
40
1.1
4→R
oun
ded
off→
40
1.1
(th
e n
umbe
r h
avin
g th
e le
ast
sign
ific
ant
figu
re d
icta
tes
it.)
Zero
s ??
?C
onve
rt t
o ex
pon
enti
al f
orm
: If
zer
os c
an b
e om
ited
, th
en t
hey
ar
e n
ot s
ign
ific
ant:
70
00
→7
X1
03
: z
eros
not
sig
nifi
can
t7
00
0.0
→7
.00
0X
10
3 :
zero
s si
gnif
ican
tR
oun
din
g u
p: <
5:d
rop
figu
re;
>5
:dro
p fi
gure
an
d in
crea
se p
revi
ous
num
ber
by 1
Q-V
alu
e fo
r re
ject
ion
of
resu
lts=
X2
-X1
/WX
1:q
ues
tion
able
val
ue,
X2
:nex
t cl
oses
t va
lue,
W:T
otal
spr
ead
of
valu
es.
E
xam
ple:
>0
.76
if t
her
e ar
e 4
obs
erva
tion
s
“EX
PERT
WIT
NES
S”RE
PORT
S:In
som
e co
untr
ies,
cer
tifi
cate
of
anal
ysis
by
an
expe
rt w
itne
ss i
s a
lega
lly v
alid
doc
umen
t.
In
som
e ot
hers
, th
e co
urt
is e
mpo
were
d to
acc
ept
or
to
reje
ct
it.
Re
port
fo
rmat
sh
ould
be
pr
epri
nted
fo
r fa
ster
an
d m
ore
unif
orm
pr
oces
sing
. Th
e re
port
sho
uld
cont
ain
:
•pro
per
sam
ple
iden
tifi
cati
on (
type
, qu
anti
ty,
pack
agin
g, la
belli
nget
c.);
•ana
lysi
s m
etho
d us
ed,
•res
ults
•I
nter
pret
atio
nof
res
ults
.
Mul
tiva
riat
e A
naly
sis
and
Chem
omet
rics
Insi
ght
& U
nder
stan
ding
Thes
e pr
oced
ures
ar
e de
sign
ed
to
extr
act
usef
ul i
nfor
mat
ion
from
lar
ge o
r co
mpl
ex d
ata
sets
. M
ulti
vari
ate
met
hods
ha
ve
broa
d ap
plic
atio
n in
man
y as
pect
s of
pra
ctic
al f
ood
scie
nce
incl
udin
g m
icro
biol
ogy,
ch
emis
try
and
engi
neer
ing.
Expe
rim
ent
Des
ign
Stat
isti
cal
expe
rim
ent
desi
gn
tech
niqu
es
use
expe
rim
enta
l re
sour
ces
(tim
e,
mat
eria
ls,
equi
pmen
t)
effi
cien
tly
to
colle
ct
data
fo
r de
velo
pmen
t of
mod
els.
Mod
elin
g an
d Si
mul
atio
n
Mod
els
can
be
deve
lope
d us
ing
regr
essi
on
or
othe
r m
etho
ds a
nd u
sed
to f
ind
true
opt
ima
in
qual
ity
or
cost
, or
to
se
ek
acce
ptab
le
com
prom
ises
in p
erfo
rman
ce o
f se
vera
l fac
tors
.
Thes
e te
chni
ques
hav
e ap
plic
atio
n in
ana
lyti
cal
met
hod
deve
lopm
ent
and
prod
uct
and
proc
ess
opti
miz
atio
n.
They
ar
e pa
rtic
ular
ly
usef
ul
for
gene
rati
ng
proc
ess
scal
e-up
da
ta,
and
ofte
n m
inim
ize
surp
rise
s du
ring
tra
nsfe
r to
ind
ustr
ial
scal
e op
erat
ion.
Com
posi
tion
/Pro
pert
y Re
lati
onsh
ips
Rela
tion
ship
s be
twee
n pr
oduc
t co
nsti
tuen
ts o
r in
gred
ient
s an
d pr
oper
ties
can
be
disc
erne
d,
and
in m
any
case
s co
ntro
lled
or o
ptim
ized
. The
pr
oper
ties
may
incl
ude
sens
ory
(fla
vor,
te
xtur
e, t
urbi
dity
, per
ceiv
ed c
olor
, etc
.) or
ph
ysic
al (f
irm
ness
, lig
ht s
catt
erin
g, f
oam
, etc
.) pr
oper
ties
or
cost
.
Stru
ctur
e/Fu
ncti
on R
elat
ions
hips
Impr
ovin
g un
ders
tand
ing
of
rela
tion
ship
s be
twee
n th
e st
ruct
ure
of m
olec
ules
(i.e
., am
ino
acid
com
posi
tion
of
pept
ides
) an
d th
eir
biol
ogic
al
(fla
vor)
or
phys
ical
beh
avio
r (f
oam
, ha
ze)
can
lead
to
impr
oved
ingr
edie
nts
and
prod
ucts
.
Patt
ern
Reco
gnit
ion
proc
edur
es a
re u
sefu
l fo
r di
scer
ning
whi
ch o
f a
num
ber
of m
easu
rem
ents
ca
n di
scri
min
ate
betw
een
clas
ses
of s
ampl
es o
n a
desi
red
basi
s; t
he r
esul
ts c
an t
hen
be u
sed
to
clas
sify
new
sam
ples
. A
pplic
atio
ns i
nclu
de t
he
iden
tifi
cati
on o
f sa
mpl
es a
s to
cul
tiva
ror
gro
wing
ar
ea, o
r de
tect
ion
of a
dult
erat
ion.