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International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
14
OPTIMIZING PRE LIMING PH FOR EFFICIENT
JUICE CLARIFICATION PROCESS IN SRI
LANKAN SUGAR FACTORIES
M.G.G Natasha Sewwandi
Pro0cessing Technology Division
Sugarcane Research Institute, Uda Walawe, SriLanka
Buddhika Sampath Kumara
Department of Engineering Technology
Sabaragamuwa University of Sri Lanka
Sandya Ariyawansha
Economics Biometry & IT Division
Sugarcane Research Institute, Uda Walawe, SriLanka
Aloka Maralanda
Processing Technology Division
Sugarcane Research Institute, Uda Walawe, SriLanka
Abstract - This study was conducted treating with Milk of
Lime to reach different pH levels (T1- with Initial pH, T2,
T3 and T4 with 6.5, 7.5 and 8.5 of pH respectively) to
determine the optimum pre-liming pH which could result
in best cane juice clarification in Sri Lankan sugar
industries. The experiment design used was RCBD with
five replicates. ANOVA followed by Duncan’s Multiple
Range Test (DNMRT) were used to identify significant
mean differences. Regression analyses were carried out to
model the variation of turbidity, mud volume and CaO
with change of juice pH. Quadratic model (R2 = 99.2 %, p
<0.001) best fitted to explain the effect of pH on turbidity
of juice. Effect of pH on deposited mud volume and CaO
were explained by cubic models with R2 = 99.4 % (p
<0.001) and R2 = 93.9 %, (p <0.001) respectively.
Among tested treatments, pH 7.5 is selected as the best for
turbidity improvement of the clarified juice while pH 8.5 is
the second best. However pH 8.5 (370 ml) was able to
deposited significantly high mud volume than pH 7.5 (270
ml). Further, the amount of residual Ca2+ ions in the
clarified juice at pH 7.5 (2715 ppm) is clearly lower than
the amount of Ca2+ ions remaining in the clarified juice at
pH 8.5 (2945 ppm). It is expected to obtain high turbidity
and higher mud volume with low sugar inversion at
optimum pH. Therefore the results suggest optimum pH
range lie around pH 7.5 to 8.5. Conducting similar
experiment by using mixed juice extracted from sugar
factory mills with pH range around 7.0 to 8.4 at 0.2
increments is suggested to validate the optimum pH.
Keywords - Defecation, Degradation, inversion, Sugar cane,
pH, reducing sugar, Turbidity
I. INTRODUCTION
Clarification is the one of main important process in the sugar
manufacturing process. Because clarification affects the juice
filterability, sucrose crystallization and the quality and yield of
raw sugar produced. The main purpose of sugar cane juice
clarification is to produce clarified juice (CJ) with the lowest
concentration of insoluble and soluble impurities. Screening of
juice eradicates only the coarse particles since flocculation is
necessary to remove the fine and colloidal particles. Therefore
flocculation technique is used in clarification process to
provide clarified Juice [1].
The conventional method for juice clarification in Sri
Lankan sugar industry is that defecation. During the
defecation process, Mixed Juice is heated from ~35-55°C to
~76 0C and treated with Lime as milk of lime or lime
saccharate to raise the pH from ~5.2 to 7.5–7.8 [2]. Lime is
added to react with inorganic phosphate present in the cane
juice to form calcium phosphate floc. These macro-flocs have
a higher density relative to juice and settle by gravity. The
settled flocculated mud impurities are extracted from the
clarifier to recover trapped sucrose. In order to recover the
trapped sucrose, rotating vacuum filters are used. The filtrate
is recirculated and combined with Mixed Juice [3].
In sugarcane, the natural phosphates are occurring in two
forms; inorganic (soluble) and organic (insoluble) phosphates.
Only the soluble phosphate will react with the lime to form a
Calcium Phosphate precipitate. Since presence of phosphates
in cane juice is essential for good clarification process,
phosphate should be added externally before liming if natural
P2O5 content (about 200 mg/l) low in mixed juice [4].
Apart from that during the defecation process, a wide
range of chemical and physical reactions takes place in the
juice. The main chemical reactions include: Precipitation of
amorphous calcium phosphate, proteins denaturation (and
other organics, such as pectins, gums and waxes), inversion of
sucrose due to the combined action of pH and temperature,
degradation of reducing sugars to organic acids due to high pH
and temperature, precipitation of organic and inorganic acid
salts, hydrolysis of starch by the natural amylase in the juice
and formation of colour bodies due to the polymerization
International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
15
(either enzymatically or thermally) of flavonoids and phenolic
compounds [5].
The poor quality of clarified juice contributes to scaling of the
evaporators and pans, and also increases the probability of
sucrose loss to molasses. Clarification also have an impact on
crystal morphology, color, crystal content, and polysaccharide
and ash contents of raw sugar. And also Juice clarification has
a great impact on factory evaporators’ heat transfer
coefficients particularly if scaling occurs from the excessive
addition of lime [6]. Therefore it is important to optimize main
operating parameters such as pH, temperature, type & dosage
of flocculent, etc. to minimize impact to the subsequent
process and overcome existing problems associated with the
juice clarification process in local sugar factories. Among
them pH is the one of important parameter in clarification,
since pH of about 7 is necessary to neutralize the charge on
the fine suspended particle in the juice to facilitate coagulation
and settling. In addition, pH is important to the rate at which
certain reaction occurs especially the precipitation of calcium
phosphate. The juice pH was shown to have suggestions on
the inversion losses, loss of sugar, color formation, sugar
quality, and scaling in subsequent processes. Therefore this
research is carried out some recent laboratory work to quantify
the effects of different pH levels to clarified juice quality and
floc settling behavior reflected by deposited mud volume.
II. MATERIALS AND METHODS
A. Preparation of Milk of Lime –
Fig. 1. For juice clarification in sugar factories milk of lime is
prepared at a concentration of 6 to 10 °Be (degree Baume).
Therefore, milk of Lime solution was prepared with 10 °Be
during this study. For MOL, powdered, hydrate lime
(Ca(OH)2) (37.6 g) was added to preheated (60°C) deionized
water (400 ml) and mixed well.
B. Treatment structure –
The variety SL 96 128, which is the major commercial variety
grown in Sri Lanka was used to obtain the juice for the
preceding analysis. 5L of juice was extracted from the sugar
mill (Mixed juice, MJ) and initial readings of Brix, Pol, Purity,
reducing sugar, turbidity, TSS and TDS of mixed juice were
taken. After that four samples were prepared by measuring 1 L
of mixed juice in to conical flask separately. Then each of
samples were treated with prepared Milk of Lime to reach
different pH levels according to following table and required
quantity of MOL volume was recorded for each sample.
Table - 1 Juice samples treating with different pH liming for
clarification
Treatment No. (Sample)
Limed pH
T1 (Sample 1)
Initial pH ~ 5.44
T2 (Sample 2)
6.5 pH
T3 (Sample 3)
7.5 pH
T4 (Sample 4)
8.5 pH
Then each sample should be heated up to 1010C (little
above the boiling point). After that juice samples were taken
and placed in to separate graduated cylinders of 1000 ml
capacity for settling at least 2 and half hours. From the
graduated cylinders, clarified juice (CJ) samples was taken and
analysed for Brix, Pol, Purity, reducing sugar, calcium oxide,
TSS, TDS, mud volume and turbidity. The experiment was
conducted using randomized complete block design with
five replicates (One block is defined as treatments done in a
day).
C. Sample analysis methods –
Percentage of Brix was measured from the separated juice
using digital brix meter. It is represented percentage of total
soluble solids in given juice sample. Pol % juice (apparent
sucrose) was measured from the same juice by using
Polarimeter and Purity was calculated as Pol/Brix×100.
Reducing sugars were measured from cane juice using Lane &
Eynon (original) method [7]. The turbidity of the clear juice
was determined according to the method of GS7-21 (2007).
The concentration of calcium in clear juice were determined
using EDTA method [7]. Brix%, Pol%, reducing sugar%,
Purity%, Turbidity, TSS and TDS were calculated before and
after the clarification.
D. Statistical analysis –
Data were analyzed using analysis of variance (ANOVA).
The Duncan’s Mean separation procedure was used to
compare the four treatments and untreated mixed juice (UMJ)
sample.
Regression analysis was carried out to model the relationship
between turbidity vs pH, mud volume vs pH and CaO vs pH
of the juice. Scatter plots were generated to identify the pattern
of the data. The linear, quadratic and cubic forms were fitted
using OLS method, and the best fit form were selected based
on the magnitude of adjusted R2 and the significance of the
model components at 5 % probability level.
SAS (Ver 9.1) and Minitab (Ver 17) software were used for
the data analysis.
III. RESULTS AND DISCUSSION
Turbidity, reducing sugar, Brix, Pol, Purity, Mud Volume,
calcium oxide and color were measured to study the individual
performances of the each treatments (T1(initial pH),
T2(pH=6.5), T3(pH=7.5), T4(pH=8.5)). Lime was added to
increase the pH to 6.5, 7.5, and 8.5 during clarification.
However, the pH values were slightly dropped after heating to
6.25, 7.04, and 8.30, respectively.
International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
16
The response of each treatment conditions to select main
quality parameters are described separately as below.
Table - 2 Average Physical and Chemical characteristics data
obtained from clarification test (n=5)
Treatment
No.
pH
Turbidity
(IU)
Pol %
Brix %
Purity %
TSS
(mg/L)
TDS
(mg/L)
RS %
CaO
(ppm)
Mud
Volume
(ml)
UMJ
(Untreate
d mixed
juice)
218.76a
15.07b
17.56b
85.78ab
11750a
158360b
0.399c
T1
5.44
(Initial
pH)
153.66b
17.13a
20.14a
84.98b
12140a
192700a
0.584a
0 c
0 d
T2
6.5
64.42c
17.08a
19.44a
87.9a
10430a
186710a
0.514b
2445b
60c
T3
7.5
3.64d
17.27a
19.66a
87.83a
10470a
188940a
0.559a
2715ab
270b
T4
8.5
6.12d
17.34a
19.66a
88.19a
10590a
190970a
0.540ab
2945a
364a
TSS = Total Suspended Solids, TDS = Total Dissolved Solids, RS
= Reducing Sugar
*For each clarification parameter and CJ composition, figures
with the same letters are not significantly (P > 0.05) different.
Average physical and chemical characteristics data obtained
from clarification test are shown in table 2.
Turbidity
Turbidity value of juice samples were decreased as the
increase of pH values from initial pH 5.44 (T1) to pH 7.5 (T3),
but turbidity value was begun to increase again when the pH
increases to 8.5. Therefore pH 7.5 shows the lowest turbidity
value.
Juice turbidity mainly caused by suspended impurities. Thus,
turbidity removal is considered as primary objective and
therefore turbidity measurement can be used as a high degree
of confidence measurement to measure the efficiency of
clarification [8]. Lime was added to neutralize the juice and
form insoluble lime salts such as Calcium Phosphates.
Colloidal matters such as pectins, hemicelluloses, proteins and
coloured compounds are absorbed by the precipitated ions and
some colloids are flocculated by heat. Therefore turbidity of
treated juice samples decreased compare to UMJ, due to
removal of impurities. And also T1 and T2 were shown
significantly high values of turbidity compared to T3 and T4.
Since low liming pH in the process leads to limitation of
reaction with existing phosphate content and reduction in
catching impurities. But excess lime to 8.5 pH gave adverse
effect on turbidity. Therefore, liming to a certain pH is
necessary to achieve lower turbidity. Among the tested
treatments liming to pH 7.5 (T3) with heating is suggested in
cold liming process to achieve lower turbidity in clarified
juice. Further, regression analysis revealed that the quadratic
model (R2 = 99.2 %, p <0.001) best fitted to explain the effect
of pH on turbidity of juice (Equation 01). The fitted line plot
and the 95% confidence Interval (95% CI) for turbidity and
pH is depicted in Fig. 1 and it revealed that the data are
randomly spread about the regression line and majority of data
points are within the confidence limit.
Turbidity = 1721 - 425.6 pH + 26.32 pH2 (1)
Fig. 1 Effect of pH on the turbidity of clarified juice.
Reducing sugar
The reducing sugar percentage was also significantly affected
by the pre liming pH value. The pH adjustment of sugar cane
juice via the addition of MOL is a critical step during the
clarification process to avoid sucrose inversion by hydrolysis
in acidic conditions (≤ pH 4) and alkaline degradation (≥ pH
8) [13]. Sucrose mostly hydrolyses to make reducing sugars,
glucose and fructose, which are available in the form of
fructosyl oxocarbenium cation and D–glucose at the extreme
acidic and alkaline juice conditions.
According to Table 2, highest value of reducing sugar was
recorded in the T1 (pH = 5.44) due to hydrolysis of available
sucrose in to reducing sugars in acidic conditions. And also
reducing sugar value was begun to reduce again when the pH
rises to 8.5 (T4) due to alkaline degradation. Therefore, liming
to a certain pH is necessary to maintain optimum level of
reducing sugar in the given sugarcane juice sample.
Pol/Brix/Purity
Sucrose is most stable ~ pH 8.3, whereas glucose and fructose
(invert sugars) are most stable at severe acid conditions such
as pH 3-4, thus balancing both sucrose and invert sugars at
optimum level is a real challenges to sugar industries [9]. In
the above paragraph, the variation in Glucose and Fructose
(Reducing Sugar) was analysed at different pH levels, whereas
International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
17
the variation in Sucrose (Pol %) at different pH levels is
analysed in this paragraph.
Since some of the dissolved non sugars removed from the
mixed juice (MJ), the pol of the Clarified Juice (CJ) samples
(T1, T2, T3 and T4) significantly exceeds that of the UMJ
sample. And also brix value of Clear Juice (CJ) samples (T1,
T2, T3 and T4) significantly exceeds that of the UMJ due to
increase of dissolved ions with introducing liming. However,
the ratio of pol to Brix (Purity %) of the treatments T1 to T4 is
not significantly different from that of the UMJ.
However there are no significant difference between
treatments (T1 to T4), for pol % and Brix %, while purity of
T1 significantly lower compared to other treatments.
Mud Volume
(a) (b)
Fig. 2. (a) Before clarification (b) After Clarification
After treating with different pH values, Precipitation of
various calcium phosphates forms are occurred in sugarcane
juice samples. Equation 2 is shown the dicalcium phosphate
form of precipitation. Secondary reaction takes place to form
intermediate calcium phosphate phases due to the creation of
unstable and insoluble dicalcium phosphate in water.
Therefore the most stable compound of the calcium phosphate
phases are shown in Equations 3, 4, 5 and 6 [3],[10].
Ca2+ (aq) + (aq) CaHPO4(s) (dicalcium phosphate) (2)
Ca2+ (aq) + (aq) Ca(H2PO4)2(s) (monocalcium phosphate) (3)
3Ca2+(aq) + (aq) Ca3(PO4)2(s) (tricalcium phosphate) (4)
2CaHPO4(aq) + 2Ca3(PO4)2(aq) Ca8H2(PO4)4(s) (octacalcium phosphate) (5)
Ca3(PO4)2 + 2Ca2+ + + H2O Ca5(PO4)3OH(s) + 2H+(aq)
(hydroxyapatite) (6)
Type of calcium phosphate phase which is formed during
clarification process is depend on the concentration of calcium
and phosphate, pH and the nature of the particle interface [3].
Therefore settling rate and final mud volume are differed with
pH values of the treatments. Final mud volume was increased
with the increase of pH liming and it was highest in treatment
4 (pH=8.5). That leads to highest juice clarity.
Regression analysis revealed that the cubic model (R2 = 99.4
%, p <0.001) best fitted to explain the effect of pH on
deposited mud volume (ml) (Equation 7). The fitted line plot
and the 95% confidence Interval (95% CI) for mud volume
and pH is depicted in Fig. 3 and it revealed that the data are
randomly spread about the regression line and majority of data
points are within the confidence limit.
Mud volume = 13805 - 6240 pH + 916.0 pH2 - 43.29 pH3 (7)
Fig. 3. Effect of pH on the deposited Mud volume after Clarification
CaO
When the pH liming increases, the mud volume increases but
it was observed that the residual concentration of calcium also
increased with the pH. Introduced Ca2+ ions in to juice
samples react with P2O5 to form a calcium phosphate
precipitation, but some amount of Ca2+ ions are remained in
the clarified juice due to limited amount of natural occurring
P2O5 in the sugarcane juice. Therefore calcium oxide content
of clear juice increased with increased levels of liming pH
according to the above Table 2. Therefore higher calcium
level in the clarified juice obtained with higher pH (pH ~ 8.5)
result in an increase in scale formation in the evaporators.
The regression analysis revealed that the cubic model (R2 =
93.9 %, p <0.001) best fitted to explain the effect of pH on
CaO (ppm) of clarified juice (Equation 8). The fitted line plot
and the 95% confidence Interval (95% CI) for CaO and pH is
depicted in Fig. 4.
CaO = - 131455 + 53651 pH - 7142 pH2 + 316.5 pH3 (8)
International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
18
Fig. 4. Effect of pH on CaO content in clarified juice
Color
The formation of colourants produced during factory
processing is mainly due to sugar degradation reactions.
Reducing sugars, such as glucose and fructose, formed by the
inversion of sucrose, play an important role in the formation of
colour. These sugars degrade due to changes in operating
conditions such as pH and temperature to form highly reactive
intermediates, which undergo condensation and
polymerisation reactions to form highly coloured polymers
[11]. According to the Fig. 2, clarified juice color was
darkened with the increase of pH liming from T1 to T4.
Colourants such as caramels and melanoidins are pH
insensitive; therefore their colour does not change across pH
5.44–8.5. But flavonoids and phenolic compounds (i.e., colour
precursors) are highly pH sensitive. Therefore, these types of
compounds are lightly coloured at pH 5.44 (lower liming pH)
and darken greatly at pH 8.5 (highly alkaline conditions) [11].
This is because at pH 8.5, the ionization of these compounds is
almost complete. Hence, these compounds are more highly
coloured in their anionic form than in their neutral form.
That’s the reason behind the color variation of clarified juice
which is mentioned in Fig. 2.
Main juice quality parameters and mud volume were
separately analyzed to identify the individual performances of
the each treatments (T1 (5.44), T2 (pH=6.5), T3 (pH=7.5), T4
(pH=8.5))., However, turbidity measurement can be used as a
high degree of confidence measurement to measure the
efficiency of clarification since turbidity removal is the
primary objective of the juice clarification process. Therefore,
the variation of other key parameters with turbidity is further
elaborated using the contour graphs.
Effect of pH on turbidity and pol in juice
In order to achieve high clarification efficiency, the turbidity
value should be low. Thus according to table 2, the lower
turbidity values are recorded at 7.5 pH (3.64 IU) and 8.5 pH
(6.12 IU). When analyzing this lower turbidity with pol in
juice parameter, pol in juice value should be a higher one. The
darkest green color represents the highest pol in juice
according to the contour graph mentioned in Fig. 5. By
considering these two phenomena’s, the most suitable region
with best pH range is between 8.0 to 8.5 (pol % > 17.3%). But
the pH range from 7 to 8.0 can also be taken in to
consideration since it shows less variation in pol in juice >
17.25 %.
Fig. 5. Contour Plot for variation of Pol % and Turbidity with pH of
juice
Effect of pH on turbidity and reducing sugar in juice
In order to achieve high clarification efficiency, the turbidity
value should be low. According to table 2, the lower turbidity
values are recorded at 7.5 pH (3.64 IU) and 8.5 pH (6.12 IU).
When analyzing this lower turbidity with reducing sugar
parameter, reducing sugar value should be low. The darkest
blue color represents the lowest reducing sugar according to
the contour graph mentioned in figure 6. By considering these
two phenomena’s, the most suitable region with best pH range
is between 7.0 to 8.5. Even though the pH 8.0 to 8.5 shows
much better reducing sugar value than the value showed in pH
range of 7.0 to 8.0, this cannot be considered since the
reducing sugar started to invert at high pH. As a conclusion,
the best pH range is 7.0 to 8.0 by considering both Fig. 5 &
Fig. 6.
pH
Turbidity of Juice (IU)
8.58.07.57.06.56.05.5
1 40
1 20
1 00
80
60
40
20
>
–
–
–
–
< 17.1 0
17.1 0 17.1 5
17.1 5 17.20
17.20 1 7.25
17.25 1 7.30
17.30
Pol in Juice
International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
19
Fig. 6. Contour Plot for variation of reducing sugar % and Turbidity
with pH of juice
Effect of pH on turbidity and purity in juice
By considering the purity of the juice, the best juice purity
gives when the pH is between 8.0 to 8.5, according to figure 8.
But when compare with the reducing sugar and pol in juice
parameters, the optimum pH range is 7.0 to 8.0 with respect to
Fig. 5, 6 & 7.
Fig. 7. Contour Plot for variation of purity % and Turbidity with pH
of juice
Turbidity, reducing sugar, calcium oxide, Mud Volume, Brix,
Pol, Purity and color were measured to study the individual
performances of the each treatments (T1(initial pH),
T2(pH=6.5), T3(pH=7.5), T4(pH=8.5)). However, turbidity,
reducing sugar, calcium oxide and purity are more influential
in indicating the juice clarification efficiency than the rest.
Over liming to pH ~ 8.5 can result in highly alkaline
conditions and it was recorded separation of highest mud
volume from the mixed juice. Although an alkaline
environment can reduce sucrose losses due to inversion, but it
would exacerbate scaling in the evaporators due to increase of
residual Ca2+ ions in the clarified juice. As well as it promotes
the formation of colourants (dark brown) and initiates to
decrease reducing sugar due to the alkaline degradation of
glucose and fructose. On the other hand deficit liming can
cause the acidic conditions (pH = (5.44 - 6.5)) and it was
recorded lowest level of residual Ca2+ in the clarified juice. So
it is a good sign for the retardation of scale formation in the
evaporators. But under deficit liming, no clear mud separation
was observed with each treatment (T1 & T2). Furthermore,
each treatments showed higher turbidity values and lower
deposited mud volumes of the juice under the acidic
conditions (pH = 5.44 & pH = 6.5).
IV. CONCLUSION
Since over liming and deficit liming are not good, neutral
liming to pH~7.5 should be considered for sugar clarification
process. Liming to pH 7.5 gave a lowest turbidity value.
Although the precipitated mud volume at pH 7.5 (270 ml) is
slightly lower than the precipitated mud volume at pH 8.5
(370 ml), but it is significantly higher than the precipitated
mud volume at pH 6.5 (70 ml). In addition, the amount of
residual Ca2+ ions in the clarified juice at pH 7.5 is clearly
lower than the amount of Ca2+ ions remaining in the clarified
juice at pH 8.5. Thus 7.5 pH is selected as the best performed
pH out of tested pH values.
Among tested treatments, T3 (pH =7.5) is the best for turbidity
improvement of the clarified juice while T4 (pH 8.5) is second
best. In contrast T4 is deposited significantly high mud
volume than T3. It is expected to obtain high turbidity and
higher mud volume with low sugar inversion at optimum pH.
Therefore the results suggest optimum pH range lie around pH
7.5 to 8.5. Conducting similar experiment by using pH range
around 7.0 to 8.4 at 0.2 increments is suggested to validate the
optimum pH.
V. REFERENCE
[1] Prati, P. and Moretti, R., (2010). Study of clarification
process of sugar cane juice for consumption. Ciência e
Tecnologia de Alimentos, 30(3), pp.776-783.
[2] Nour Eldien, W., H . M. Ali, E., Sohily, A. and Hamad
E.A, M., 2017. Evaluation and Optimization of Hot
Liming Process in Kenana Sugar Factory, White Nile
State, Sudan. International Journal of Scientific and
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[3] C.D. Thai, C., 2013. Studies on the clarification of juice
from whole sugar cane crop. Ph.D. Queensland University
of Technology.
[4] Asfaw, G.(2015). Optimization of Pre-Liming and
Sulphitation pHof Cane Juice onAsfaw, G., 2015.
Optimization of Pre-Liming and Sulphitation pHof Cane
Juice on Clarification. Degree of Master of Science.
Addis Ababa University School of graduate studies.
pH
Turbidity of Juice (IU)
8.58.07 .57.06.56.05.5
1 40
1 20
1 00
80
60
40
20
>
–
–
–
–
–
–
< 0.52
0.52 0.53
0.53 0.54
0.54 0.55
0.55 0.56
0.56 0.57
0.57 0.58
0.58
RS_1
pH
Turbidity of Juice (IU)
8.58.07.57 .06.56 .05.5
1 40
1 20
1 00
80
60
40
20
>
–
–
–
–
–
–
< 85.0
85.0 85.5
85.5 86.0
86.0 86.5
86.5 87.0
87.0 87.5
87.5 88.0
88.0
Purity_1
International Journal of Engineering Applied Sciences and Technology, 2021
Vol. 6, Issue 1, ISSN No. 2455-2143, Pages 14-20
Published Online May 2021 in IJEAST (http://www.ijeast.com)
20
[5] Nocony Reece, N., 2003. Optimizing aconitate removal
during clarification. Master of Science. Louisiana State
University and Agricultural and Mechanical College.
[6] Doherty, W., 2011. Improved Sugar Cane Juice
Clarification by Understanding Calcium Oxide-
Phosphate-Sucrose Systems. Journal of Agricultural and
Food Chemistry, 59(5), pp.1829-1836.
[7] Gupta, S.K. (2005). System of technical control for cane
sugar factories in India. 2nd ed. Sugar Technologists’
Association of India, pp.33–37.
[8] Mkhize, S.C.(2003). Clear juice turbidity monitoring for
sugar quality. Sugar Milling Research Institute,
University of Natal, Durban, South Africa.
[9] Eggleston, G. and Amorim, H.(2006). Reasons for the
chemical destruction of sugars during the processing of
sugarcane for raw sugar and fuel alcohol production.
International Sugar Journal, 108(1289), pp.271-282.
[10] William, D. and Darryn, R., 2008. Some aspects of
calcium phosphate chemistry in sugarcane clarification.
In: Conference of the Australian Society of Sugar Cane
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