ýALAyý,
ý\
Iý
i
W
EMCJA
mml
1"1'",
11
PILOT SCALE PRODUCTION
OF SUGARS FROM SAGO STARCH
Hafizah Binti Booty
Master of Science
2011
Akademik
Maklumat
Khidmat
Pusat
SARAWAK
MALAYSIA
SITI
IJNIVER.
P.KHIDMAT MAKLUMATAKADEMIK
UNIMAS
1111111111111111111111
11111
1000246247
PILOT SCALE PRODUCTION
OF SUGARS FROM
SAGO STARCH
HAFIZAH
BINTI BOOTY
A thesis submitted
in fulfillment of the requirement for the Degree of
Master of Science (Biotechnology)
Faculty of Resource Science and Technology
UNIVERSITI MALAYSIA SARAWAK
2011
DECLARATION
I hereby declare that no portion of the work referred to in this thesis has been submitted in
for
degree
or qualification
another
support of an application
or institution
HAFIZAH
learning.
higher
of
BINTI BOOTY
07021255
August 2011
i
to this or any other university
ACKNOWLEDEMENTS
First
of all, I would
throughout
heartfelt
the
project.
gratitude
encouragement
like to convey my deepest gratitude
I would
Also,
Prof.
to my supervisor,
and comment
like
during
to Allah
S. W. T for His blessings
my
appreciation
to express
Dr. Kopli
this project
Bujang
sincere
for his advice,
and
guidance,
and thesis preparation.
Special thanks to all my seniors who had given useful technical advice, patience and help
in the laboratory
Lenny,
Merlina,
friendship
friends
lab
like
I
thank
to
mates
and
my
would also
work.
Ugam,
and
Nur
and advice while working
Hafizah,
for
their
continuous
together in the laboratory.
namely,
encouragement,
I am also thankful
to
Lab assistants Mr. Ajis and Mr. Amin for their assistance.
Lastly,
I thank
my parents
Mr.
Booty Osman and Mdm.
blessings, financial support, encouragement
Halimah
and patience throughout
you so much.
ii
Bujang
for the
this project. Thank
ABSTRACT
(Production
(1L)
from
hydrolysis
lab
scale
of sugars was performed at
of various types of
flour).
The
(sago,
tapioca
starch slurries was enzymatically
sweet
potato
and
corn,
starch
hydrolysed for four hours at the starch concentration
Filtration
suspended in 1L water).
of sugar syrup with
powdered activated
charcoal
of glucose was based on the yield referred as
(PAC) was made and the measurement
dextrose equivalent
(200g
DS
20%
of starch powder
of
(DE). Upon filtration,
the highest sugar (mainly
glucose) recovery
(84%
DE),
by
followed
DE,
tapioca
99%
by
corn
starch
at
starch
sago
was produced
(72%
DE).
(76%
DE)
starch
and sweet potato
starch
concentrations
The effectsl of different
in hydrolysis of sago starch (HSS) were then studied) Evidently,
starch
50% DS
(TRS)
30%
40%,
to
highest
total
and
compared
sugars
the
reducing
amount of
generated
20% DS at 413 g/L, 377 g/L, 298 g/L, and 205 g/L, respectively.
filtered
from
glucose produced
much higher concentration
HSS (20% DS) gave the highest recovery (99% DE), a
(89%
DE)
DS
40%
30%
to
and
compared
of glucose produced
DS (81% DE). Furthermore,
Enzymatic
DE.
63%
at only
larger
However, the amount of
lowest
DS
50%
the
sugar yield
produced
of
the concentration
hydrolysis
thereafter
of sago starch was performed
DS
20%
of sago starch
scale using
at 5L and 50L working
volumes.
at a
It was
(suspended
DE
PAC
in
66%
5L
1,000g
water)
yields
after
of sago starch
observed that
from
hydrolysed
10,000g
DE
62%
of
of sago starch.
to
produced
compared
Consequently,
(99%
by
33%
66%),
from
200g
1,000g
the
to
to
reduced
sugar
yield
the
process
scaling up
but scaling up further
1,000g to 10,000g reduced the sugars yield by only 4% (66% to
62% DE). These results confirmed
significant
loss in sugar
yield.
that the process could be further
In
addition,
111
60°C
was
proved
scaled up without
to
be the
best
temperature
conditions
for sugar
syrup
be
the most promising
to
starch seems
or hydrolysed
as an alternative
sago starch
raw material
(HSS).
Sago
for the sugar
industry of Malaysia.
Key words: Sago starch, enzymatic
hydrolysis
(PAC), dextrose equivalent (DE)
iv
of starch, powdered activated
charcoal
PENGHASILAN GULA DARIPADA KANJI SAGUDAI. AM SKALA INDUSTRI
ABSTRAK
Penghasilan gula melalui proses hidrolisis
berenzim telah dijalankan
kanji telah berjaya dihidrolisiskan
oleh enzim dalam tempoh empat jam pada kepekatan
(200g
dilarutkan
DS
20%
tepung
sago
sago
kemudiannya
pada skala
(sagu,
kanji
jenis
jagung, ubi kayu dan keledek). Cairan
tepung
empat
IL menggunakan
kanji
kanji
dijerap
paras gula diukur
warnanya
dalam
IL air). Larutan
(PAC) di mana
serbuk arang teraktif
menggunakan
gula pula
kepada nilai setara dektros (DE). Terbukti
dengan merujuk
hidrolisis
kanji sagu menghasilkan
hidrolisis
kanji jagung (84% DE), kanji ubi kayu (76% DE) dan kanji keledek (72% DE).
paras glukosa yang tertinggi
Kesan terhadap perbezaan kepekatan
kanji
(HSS)
turut
sagu
dikaji.
substrat
99% DE, diikuti
(kanji sagu) ke atas proses hidrolisis
bahawa HSS dengan kepekatan
Terbukti
paras gula penurun yang tertinggi
menghasilkan
iaitu
bahawa
berbanding kepekatan
50% DS
40% 30% dan
20% DS, maisng-masing pada 413 g/L, 377g/L, 298 gIL dan 205 g/L. Tetapi larutan gula
HSS (20% DS) yang telah dijerap
paras glukosa tertinggi
menghasilkan
kanji
ke
atas
enzim
dalam
(20%
diteruskan
DS)
sagu
dengan karbon
5L air)
teraktif
menghasilkan
ditingkatkan
kepekatan
50% DS kanji
lagi dengan mengekalkan
menunjukkan
30%
pula
hidrolisis
kepekatan
kanji sago yang
66% DE selepas proses penyahwarnaan
menghasilkan
berbanding
substrat
telah berjaya
glukosa sebanyak 63% DE. Kajian
20% DS pada skala 5L dan 50L air. Keputusan
diampaikan
air yang
sebanyak 99% DE, diikuti
iaitu
hanya mampu menghasilkan
sebaliknya
oleh serbuk arang teraktif
40% (81% DE). Kepekatan
(89% DE) dan kepekatan
substrat
warnanya
dengan 10, OOOgkanji sagu diampaikan
62% DE sahaja.
Manakala,
apabila
kuantiti
daripada 200g kepada 1,000g, telah berlaku pengurangan
V
dalam 50L
kanji
sagu
paras glukosa
(99%
Apabila,
kepada
66%).
33%
sebanyak
1,000g kepada 10,000g pula, hanya
kanji sagu ditingkatkan
kuantiti
4% penurunan
daripada
Berdasarkan
dicerap.
yang
nilai
kanji
hidrolisis
ke
lanjut
kajian
sago pada skala yang
terhasil,
atas proses
glukosa yang
lebih
besar masih
boleh diteruskan.
larutan
optimum
untuk menyimpan
dijadikan
bahan alternatifdalam
Kata kunci: Kanji
Tambahan
suhu
60°C merupakan
kesimpulan,
Sebagai
sagu.
gula
industri
sagu, hidrolisis
pula,
kanji
kanji
suhu
boleh
sagu
gula di Malaysia.
karbon
berenzim,
serbuk
sagu
dektros
V1
teraktif,
nilai
Pusat Khidmat Makiumat Akademik
UNIVERSITI MALAYSIA SARAWAK
TABLE OF CONTENTS
Pages
Declaration
1
Acknowledgements
11
Abstract
111
Abstrak
V
Table of contents
List of Tables
Vii
List of Figures
List of Abbreviations
X11
xi
xiv
INTRODUCTION
1
1.0
Introduction
1
1.1
Objectives
4
CHAPTER 1
CHAPTER 2
2.1
2.2
LITERATURE
5
REVIEW
5
Sugars
2.1.1
Sources of sugars
7
2.1.2
Sugar Productions
9
2.1.3
Types of sugars
12
2.1.4
Application
13
2.1.5
Sugar industries
of sugars
in Malaysia
14
16
Starch
2.2.1
Sago Palm (Metroxylon
2.2.2
Sago starch and its properties
21
2.2.3
Extraction
23
2.2.4
Applications
2.2.5
Sago starch industries in Malaysia
30
2.2.6
Other starch sources
32
vii
sagu)
of sago starch
of sago starch
17
29
2.3
2.4
Conversion
of starch
hydrolysis
2.3.1
Enzymatic
2.3.2
Large scale enzymatic
Purification
CHAPTER 3
3.1
3.2
36
of starch
hydrolysis
of starch
38
39
of sugars
2.4.1 Sugar de-colorization
2.5
34
to sugars
using activated carbon
41
Storage and handling sugar products
42
MATERIALS AND METHODS
44
Materials
44
3.1.1
Starch
44
3.1.2
Enzymes
44
3.1.3
Powdered Activated Charcoal (PAC)
3.1.3.1 Pretreatment of PAC
44
45
3.1.4
Pilot scale (50L) stainless steel hydrolyser
45
Methods
47
3.2.1
Enzymatic hydrolysis of starch
47
3.2.2
Lab scale production of sugar from enzymatic
hydrolysis of starch
3.2.2.1 Effects on various types of starch
3.2.2.2 Effects on different sago starch
concentrations
48
viii
48
48
3.2.3
3.3
CHAPTER
Pilot scale enzymatic hydrolysis of 20% DS
sago starch
3.2.3.1 Hydrolysis of 1Kg sago starch
suspended in 5L water
3.2.3.2 Hydrolysis of 10Kg sago starch
in
50L water
suspended
49
49
51
3.2.4
Purification of sugars using Powdered
Activated Charcoal (PAC)
54
3.2.5
Effects of storage at different temperatures
56
methods
57
3.3.1
Reducing sugars
57
3.3.2.
Starch
58
3.3.3
Colour
59
3.3.4
Protein
60
Analytical
4
RESULTS
61
4.1
Lab scale enzymatic hydrolysis of starch
61
Effects on various types of starch
61
4.1.2. Effects on different starch concentrations
64
Purification of sugars using Powdered Activated
Charcoal (PAC)
67
4.2.1
Effects on different types of starch
67
4.2.2
Effects on different sago starch
concentrations
73
4.1.1
4.2
4.3
Pilot scale enzymatic hydrolysis of 20% DS sago
starch
78
4.4
Effects of storage at different temperature
PAC
purified sago syrup
on
conditions
82
ix
CHAPTER 5
DISCUSSION
85
CHAPTER 6
SUMMARY
87
REFERENCES
88
APPENDIX A
102
APPENDIX B
104
APPENDIX C
107
X
List of Tables
Table
1
Physicochemical
properties
(Ahmad
of sago starch
et al., 1999).
Table 2
Sugar recovery obtained from enzymatic
sago, corn, tapioca and sweet potato.
Table 3
Sugar production from enzymatic hydrolysis of sago starch at
different starch concentrations (20%, 30%, 40% and 50%).
Table 4
Table 5
hydrolysis
of various
22
starch,
62
65
Percentage of protein and colour removal before and after PAC
treatment on filtered sugar syrups.
Sugar recovery obtained from hydrolysed starch (sago, corn, tapioca
(from
PAC
before
5 replicates).
treatment
and after
and sweet potato)
69
71
Table 6
Sugar recovery obtained from HSS before and after PAC treatment
different sago starch concentrations (from 5 replicates).
Table 7
Sugars recovery obtained from pilot scale hydrolysis of sago starch
(20% DS) at 5L and 50L, (from 5 replicates).
Table 8
Effects of storage temperature
sago syrup.
Table 9
Dried matter, moisture and starch content based on (1%, w/v) of
flour.
tapioca
and
sweet
potato
corn,
sago,
107
Table 10
Amount of protein loss after purified with PAC.
107
Table 11
Percentage of color removal in after PAC treatment
sago, corn, tapioca and sweet potato starch.
Table 12
Percentage of color removal after PAC treatment
DS.
30%,
40%
50%
20%,
and
concentrations;
Table 13
Table 14
Table 15
on TRS concentration
at
of PAC purified
from hydrolysed;
from HSS at various
Percentage of color removal after PAC treatment from pilot scale
(20%
DS)
hydrolysis
of
sago
starch
at 5L and 50L working
enzymatic
volume.
Amount of total reducing sugar obtained from enzymatic hydrolysis of
sago, corn, tapioca and sweet potato starch.
Amount of TRS obtained from HSS at various concentrations;
20%,
30%, 40% and 50% DS before and after PAC treatment.
76
79
83
107
108
108
109
109
Table 16
Amount of TRS obtained from pilot scale of HSS at 5L and 50L
before
PAC
treatment.
and
after
volume
working
109
Table 17
Amount of TRS obtained from HSS when stored at various
temperatures; 60°C, 4°C and room temperature (RT).
110
XI
List of Figures
Flow diagram of operation in a raw sugar mill (Andreis et al.,
1990).
9
Figure 2
Sago palm (Metroxylon
19
Figure 3
Typical sago estate in Sarawak.
20
Figure 4
Harvested sago logs awaiting collection.
24
Figure 5
Sago logs are transferred
mills.
Figure 6
Sago logs are debarked using either an auto debarking machine or
manually with a machete.
26
Figure 7
Debarked sago logs are rasped and mixed with water for starch
extraction.
26
Figure 8
Schematic plan of a typical sago mill in Sarawak, (Bujang pers.
comm., 2009).
27
Figure 9
Separation of starch slurry from the waste water.
27
Figure 10
Bagged sago starch ready for export.
28
Figure 11
(a) Schematic design and (b) 50L vessel for Pilot-scale enzymatic
hydrolysis of starch.
46
Figure 12
Lab scale enzymatic hydrolysis of sago starch using a stainless
(5L).
steel vessel
50
Figure 13
Process of saccharification
Figure
1
sagu) in Sarawak.
(a)
(b)
lorry
using
or as
sago rafts to sago
(50L)
hydrolyser.
the
using
pilot scale
25
51
process of the hydrolysed sago starch from the
prototype 50L system.
52
Figure 15
Hydrolysed sago starch (HSS) with reddish brown colour.
53
Figure 16
Removal of colour and impurities
columns.
55
Figure 17
Effects of starch concentrations on HSS after 6 hours.
Figure 14
Harvesting
(a)
Figure 18
from purified HSS using PAC
64
Sugar syrups from enzymatically hydrolysed starch upon
filtration on Whatman (0.45 µm);
From left: sago starch (MA); tapioca starch (MB); corn starch
(MC); sweet potato starch (MD)
(b) Sugar syrups upon filtration and purification on PAC;
From left: sago starch, tapioca starch, corn starch and sweet
potato starch
xii
68
Figure 19
Comparison of sugar recovery (DE) before and after treatment
with PAC.
70
Figure 20
(a) Filtered sugar syrups using Whatman 0.45µm cellulose nitrate
membrane filters.
From left: HSS 20%, 30%, 40% and 50% DS
(b) Purified sugars syrup on PAC.
From left: HSS 20%, 30%, 40%, and 50% DS
74
Figure 21
Comparison of sugar recovery (DE) from HSS at different starch
PAC
before
treatment.
and
after
concentrations
75
Comparison
Figure 22
Figure 23
Figure 24
Figure
25
(DE)
obtained from pilot-scale
of sugar recovery
hydrolysis of sago starch before and after treatment
enzymatic
with PAC.
Removal of colour and proteins from HSS (a) before and (b) after
PAC filtration.
Stability of PAC purified sago sugar syrup under storage at
different temperature after 21 says (from 5 replicates).
Formation
(brown
of melanoids
days
during
21
syrup after
colouration)
storage at 4°C.
in PAC purified
78
80
82
sago
84
Figure 26
Starch standard calibration
curve from Iodine method at 590nm.
104
Figure 27
Glucose standard calibration curve from DNS method at 575nm.
105
Figure 28
Protein standard calibration curve from DC Protein Assay Kit
(BSA)
Serum
Albumin
Bovine
as standard at 750nm.
using
106
X111
List of Abbreviations
%
Percentage
%/kg
Percent per kilogram
cm
Centimeter
DE
Dextrose equivalent
DS
Dry substrate
g
Gram
g/L
Gram per liter
HCl
Hydrochloric
hr
Hour
hrs
Hours
H2SO4
Sulfuric acid
HSS
Hydrolysed sago starch
HPLC
High performance liquid chromatography
kg
Kilogram
L
Liter
M
Molarity
mg/L
Milligram
min
Minute
mL
Milliliter
mug
Milliliter
nm
nanometer
NaCl
Sodium chloride
NaoH
Sodium hydroxide
OD
Optical Density
xiv
acid
per liter
per gram
PAC
Powdered activated charcoal
RM
Ringgit Malaysia
R2
Correlation coefficient
RT
Room temperature
t
Tones
tons/ha
Tones per hector
TRS
Total reducing sugar
USD
US dollar
v/v
Volume per volume
w/v
Weight per volume
w/w
Weight per weight
pLJg
Microliter
µm
Micrometer
µL
Microliter
xv
per gram
CHAPTER 1
INTRODUCTION
1.0
Introduction
Sugar industries
in Malaysia can be categorized as well developed as reflected by the
rapid increase in direct domestic consumption
which is amplified
by an equally fast
(FOMCA, 2006). Commercial sugar that we consumed
growing food processing industry
these days is derived from sugar cane. Sugar cane is a very easy and profitable
grow but rather ineffective in reproducing
processing industries
in Malaysia
still
naturally
(Braun,
depend on imports
plant to
1997). Up till now, sugar
for about 90% of its raw
materials which has reached a record of 1.0 million tones, compared to export at 101,000
tones. Owing to lack of raw materials
sugar naturally
and increases in industrial
application
of cane
lead to higher price of this commodity.
Starch is one of the essential energy source of the living world. Nevertheless,
(Chulavatnatol,
plant species can actively accumulate and store starch
only some
2001). Sago, corn,
known
the
plants with high starch content which is
potato, cassava and rice are among
a natural
raw material alongside other starch-producing
is
Sago
extracted
starch
wheat.
plants such as tapioca, rice and
from the sago palm (Metroxylon
),
spp. also known as
"rumbia" by local people (Ahmad et al., 1999). This crop is found abundantly in the state
of Sarawak
mainly
Mukah,
Igan and Oya and well-known
More
90%
Malaysia.
than
in
of all sago-planting
producer
Sarawak in East Malaysia. The largest (75%) sago planting
1
as one of the great starch
areas are found in the state of
area is in Mukah where over
50% of the sago starch is produced (Bujang and Ahmad, 1999). A fully cultivated
estate has about 138 palm/ha/year,
and at about 185 kg starch/palm,
sago
a total of 25.53 tons
can be expected.
starch/ha/year
Sago starch is utilized in the form of sago flour or sago pearl. Other than foodstuffs, sago
for
be
to
adhesives
paper or even as a stabilizer
produce
used
starch can also
in
(Aziz, 2002). Sago starch is highly recommended in the production
of
pharmaceuticals
sugar for fermentation
products,
pharmaceutical
100,000 tones of sago starch are used annually
including
the food industries,
sago planting
commercialized
bioconversion
and cosmetics. About
application
in Malaysia
for various
household, and glue manufacture.
With about 90% of all
has
industry
in
the
a remarkable
country, sago sugar
areas
in Sarawak.
A study
done by Bujang
potential to be
(2004) has discovered
of sago starch into glucose is a more sensible alternative
(US$0.50/kg) fetches a higher price then sago starch (US$0.20/kg).
2
applications
that
since glucose
Our previous study has shown that sago starch is highly recommended as the starchysubstrate
for sugar production
to be used in the production
of ethanol
Bujang, 1998) and lactic acid (Bujang et al., 2000). This study highlights
and potentials of sago starch as an alternative
the highest recovery of sugar
from
for
the production
sago
starch,
glucose) produced
using sago starch, a locally available and cheaper substrates.
3
the importance
source to sugarcane for the production of
is
determine
The
the
to
aim
study
of
commercial sugars.
(mainly
(Adeni and
of commercial
sugars
1.1
Objectives
The principle
aim of this research
is to maximize
glucose production,
recovery and consequently to enhance the value of sago starch in Malaysia.
purification
In order to
achieve this aim, the objectives of the research project are to:
i)
compare the amount of sugars produced from enzymatic
hydrolyzed of different
starch sources
ii)
develop the separation and purification
iii)
different
the
of
effects
study
procedures of sago sugars
starch concentrations
during hydrolysis
in order
to
maximize glucose recovery
iv)
from
hydrolysis
the
pilot
scale
enzymatic
of
sugars
study
recovery
of sago starch
(20% DS) at 5L and 50L
v)
develop the optimum conditions for storage of liquid sago sugars
4
Pusat Khidmat fNaklumat Akademik
UNIVERSITI MALAYSIA SARAWAJi
CHAPTER 2
LITERATURE REVIEW
2.1
Sugar
Sugar is a class of edible substance, mainly sucrose. It is a broad term applied to a large
number of carbohydrates
present in many plants and characterized
sweet taste. In non-scientific
white crystalline
by a more or less
use, the term sugar refers to sucrose or "table sugar", a
(Anonymous,
Wikipedia,
2010;
disaccharide
solid
2009a). Scientifically,
(simple sugar) or disaccharide.
sugar refers to any monosaccharide
carbon, hydrogen and oxygen belonging to a class of carbohydrates.
into three main groups; monosaccharide, disaccharides
It is composed of
It can be categorized
and polysaccharides.
the simplest sugars in the monosaccharide family. The disaccharides
Glucose is
are formed by the
union of two monosaccharides with loss of one molecule of water, which includes lactose,
maltose and sucrose. Polysaccharides
are polymers that contain many monosaccharide
residues; one of the common example is starch.
Sugar has a central position in human consumption
animals.
The sugar we normally
sugarcane; therefore, the industrial
sugar and sugar beet processing.
flavor
and properties
and serves as a major foodstuff for
used nowadays is made of sucrose obtained
production
from
of sugars today is mostly based on cane
Sucrose is a common table sugar that is used to alter
such as preservation,
5
mouth
feel and texture
in foods and
beverages.
they
Sugar may dissolve in water to form syrup. Generically
also have specific
preparing
name such as "honey"
or "molasses".
known as "syrup",
Manufacturing
and
foods may involve other sugars such as palm sugar and fructose, obtained
from corn (maize).
According to Toth and Rizzuto (1990), back in the 15th century, sugar was economically
important
to all European.
European
sugarcane was planted in large plantations
Indonesia,
Philippines
in Venice.
Later
in other regions in the world including
India,
sugar was mainly
and the Pacific. Toth and Rizzuto
110,000,000 tons of sugar per year was used in manufactures
refined
(1990) revealed that
and consumed worldwide.
One of the early applications of sugar, it was a crude pharmaceutical
bitter
the
today
to
or unpleasant taste of medicine.
still used
masked
6
over
ingredients,
as it is
2.1.1
Sources of Sugars
Sugar primarily
(Andreis
from
beet
from
sugar cane and
sugar
et al., 1990). It also
comes
honey, sorghum, maple sugar and in many other sources. Sugar is
appears in fruits,
normally
leaves
for
in
and
as
a
source
of
energy
plant
growth and at the
synthesized
same time will be sent to the stalks for storage. The sweet sap in the stalk source gives
rise to sugar.
(Andreis,
tropical
1990; Toth and
or subtropical climate
requires a
Sugarcane cultivation
Rizzuto, 1990), with a minimum
photosynthesizer
of 600mm annual rainfall.
It is one of the most efficient
that can convert as much 20% of incident solar into biomass. One thing
from
it
is
that
propagates
cutting with at least one bud, rather
usually
about sugarcane
than from seed. Once planted, a stand of cane can be harvested several times. Usually,
each successive harvest gives a smaller yield, and most eventually
justifies
replanting.
the declining yields
Average yields is about 100 tons of sugarcane per hectare producing
10 tons of cane sugar.
Sugar
beet is a member
Amerenthaceae,
of the
Chenopediaceae
subfamily
high
root
contains
concentration
a plant whose
under
the
family
of
(Food-Info,
of sucrose
2009). It is a temperate climate biennial root crop, producing sugar during the first year
for
flowers
it
the
the
in
to
over
winter
and
see
and seeds in the second
of growth
order
harvested
in
first
in
It
is
the
therefore
spring
and
autumn
sown
year.
or early winter.
The sucrose is stored in the bulbous root, which bears a strong resemblance
to a fat
Typical
for
(Food-Info,
beets
is 17% by weight but
2009).
content
sugar
mature
parsnip
the value depends on variety and location, and it does vary from year to year. Up untill
7