Componen of Stalk Sweet Sorghum

7/31/2019 Componen of Stalk Sweet Sorghum

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4 .1 . Com ponen t s o f sw eet so rgh um stemj u ice

The stem juice of sweet sorghum is rich in fermentative sugar and is a desirable

alcoholic fermentation material. It is difficult to measure the juice Sugar content inthe process of production. The sugar content is commonly expressed with juice brix

degree, but the relation between sugar content and brix degree has not been very

cleared The objective of this study was to find out their relation and tell the sugar

content by means of the measurement of juice saccharine more accurately, which

may provide a theoretical basis for crop breeding and fermentation. In addition to

fermentative sugar, other kinds of sugars are also found in the stem juice of sweet

sorghum. The acquirement of the contents of different sugars is beneficial to the

enhancement of alcohol production rate. There are also some ammonia acids and

minerals in the juice, measuring their contents enables us to use sweet sorghumbetter with multi-purpose.

The current research determined the sugar content and brix degree of different

varieties in different growth stages. The results gave a scientific basis for thearrangement in the varieties and their sowing dates, so as to prolong the

fermentation period and increase the efficiency of the alcoholic fermentation device

usage. Therefore, this study has a practical instructive meaning for sweet sorghum

breeding as well as the cultivation or fermentation, and the materials and methodsas follows:

A. Materials and Their Sources

RIO US: recommended variety;

Shennong No.2: Shenyang Agricultural University;

6AX1022: Liaoning Academy of Agricultural Science;

Jitian 2: Jilin Academy of Agricultural Science;Longshi 1: Heilongjiang Academy of Agricultural Science;

6AXN249: Shenyang Agricultural University;

B. Field Experiment

a. Field planning

Randomized blocks and triplication have been applied, among the triplication, the

same material placed in different row.

b. Plot area and density

Plot area with 10 m long row, 0.7 m row distance, 5 ridges in one replication. Thedensity of longshi 1 and Jitian2 are 8000 plants per Mu, others 4500.

c. Seeding and fertilization

Sowing in May 7 . Base manure was spread 30t/ha, ammonia phosphate 112. 5kg/haand urea 300kg/ha.


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d. Field management

Appropriate intertilling, continuous operation, weeding by hand and intertill bymachine.

C. Measurement Methods

At different period, two plants as a sample in each plot were randomly chosen for

measuring their stem weights, and then juice of the stems were extracted by IJ -305

squeezer, and finally measuring glucose fructose sucrose content by high

performance liquid chromatography, starch and total sugar content by another one

spectrophotometry, Amino acid content by high speed amino acid analyzer, crude

protein content by nitrogen and protein analyzer, total Phosphorus content by

ammonia Vanadate and ammonia molybdenum spectrophotometry, mineral elementcontent by atomic absorption spectrometry.

4.1.1 Brix degree in sweet Sorghum stem

A. Changing Law of Brix Degree of juice in sweet sorghum stem

The research shows that the brix degree of juice in sweet sorghum stem is lower

before heading stage. After that, with the grain forming, the brix degree straightlyincrease towards its maximum at harvest stage. For whole

Tab.4.1.1 Brix Degree of different Varieties at different period

time (D/M)variety

26/8 5/9 13/9 4/1010/1015/10 29/10

RIO 12.2 15.5 16.8 17.0 17.0 15.5 14.5

Shennong No.2 11.5 12.7 15.3 14.5 14.5 13.0 9.0

6AX1022 12.2 15.0 17.2 14.3 14.5 14.0 11.0

Jitian 2 10.1 12.8 15.8 15.5 14.0 14.0 12.2

Longshi 1 14.5 16.3 18.0 13.0 14.0 12.5 11.5

6AXN249 8.4 10.8 15.7 15.0 12.5 11.2 9.8

Stem or each section of the stem, its brix degree rises as the plant growing it is the

period within heading the first ten days and the third ten days that the degree

increases distinctly. From Tab.4.1.1, it is known although among the six varieties,

the brix degree changing law and the maximum degree period are not same, thepresent time of the maximum value is highly according to the harvest stage.

Therefore, sweet sorghum should be harvested at the grain maturing stage in whichboth high sugar content and grain yield can be obtained.

B. Analysis on Brix Degree of Juice in internodes and Whole Stem

From Tab.4.1.2, it can find that the brix degrees are different in every internodes,the tendency is low-high-low from top to low position, and most


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Tab.4.1.2 internode brix degree of different varieties (1990.8.26)

internode variety

2 4 6 8 10 12 14

14.214.515.014.514.013.0

13.514.514.314.012.612.711.5

Rio

13.013.213.814.213.512.5

10.211.512.513.413.011.2

10.511.511.712.011.510.0 9.5

Shennong No.2

16.315.014.212.011.0

15.014.015.313.0

15.315.011.310.5

6AX1022

12.311.111.510.0 8.5

13.010.510.3 8.6 9.0

13.512.612.512.3

Jitian 2

13.711.211.110.610.0

15.015.816.016.1

12.413.014.0

Longshi 1

15.516.414.2

8.2 10.1 9.5 9.0

7.0 8.3 8.0 8.2 7.5

6AXN249

14.014.313.011.0 9.5 8.7

Varieties highest brix degrees are occurred at 4 to 6th internodes from the top. In

order to exactly measure the brix degree of stem, the juice for test should beextracted from whole stem.

Varieties highest brix degrees are occurred at 4 to 6th internodes from the top. In

order to exactly measure the brix degree of stem, the juice for test should be

extracted from whole stem theoretically. However, it is impossible to extract the

stalk juice on field. The purpose of this trial is to find a way of testing brix degree by

one internode to present the one of whole stem, Through testing the brix degree of

each internode of a stem (as shown in Tab. 4.1.3). it is known that the brix of some

internodes can not present the one of whole stalk, because the brixes are differentfor each internode. The average brix degree for all internodes are suggested to be asthe one of whole stalk.

C. Comparison of Brix Degree of Different Varieties in the Same Period

Variance analysis of test results in different three days indicates that the difference is

significant between brix degrees of different varieties. The test shows that the brix

degree of Longshi 1 is the highest and the one of 6AXN249 is the lowest. There RIO,


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6AX1022, Shennong No.2 and Jitian 2. in the midst of them. Statistics analysis

shows before September, the brix degree of Longshi 1 is the highest, but with the

growing of plants, at the beginning of September, the difference becomes smaller

until no any gap between them. Thus, for prolonging the period of ethanol productionfrom sweet sorghum, the order of seeding time are Longshi 1, Shennong No.2.

Tab.4.1.3. Comparison between Internodal Mean Brix Degree (IMBD) and WholeStalk Brix Degree (TBD)

Time (D/M)

| 26/8 | 5/9 | 13/9Variety

Plot q r s q r s q r s

MBD 14.2 13.3 13.4 15.7 15.8 16.3 18.5 17.5 17.1Rio

TBD 12.8 10.6 13.2 15.5 15.5 15.5 16.0 18.0 16.5

IMBD 12.0 12.8 13.7 14.0 15.4 11.2 14.6 17.2 12.3Shennong No.2

TBD 12.3 10.1 12.0 14.0 12.5 11.5 16.0 18.0 12.0

IMBD 14.3 13.0 10.7 16.0 17.2 14.2 18.3 18.5 17.86AX1022

TBD 13.5 11.6 11.5 16.0 16.0 13.0 17.0 19.0 15.5

IMBD 10.3 12.7 11.3 11.6 15.8 11.4 13.8 18.9 16.3Jitian 2

TBD 10.2 10.1 10.0 12.0 14.5 12.0 12.0 18.5 17.0

IMBD 15.7 13.1 15.4 17.4 17.0 19.3 16.5 20.2 19.4Longshi 1

TBD 14.5 14.0 15.0 15.0 15.5 18.5 16.0 19.0 19.0

4.1.2 Analysis of Total Sugar Content in Juice of Sweet Sorghum

There are plenty of sugar in the juice of sweet sorghum stem. However, how many

kinds of sugars exist in the juice is still a question. Based on our results, it was not

sufficient to regard the sum of sucrose, glucose and fructose as the total sugar

content traditionally. The test by enthrone spectrophotometry shows the following

kinds of sugars are existed in the juice of sweet sorghum, stem: xylose, ribose,

arabinose, fructose, sorbose, galactose, mannose, sucrose glucose, polyglucose and

glucoses. Of course, the total sugar content is much more than that of sucrose,

glucose and fructose. Based on the test results as shown in Tab.4.1.4, the variance

and the multiple comparison have proved both the variety and test time have a

significant influence on sugar content. So in order to prolong the period of ethanol

production and get more sugar, it is suggested that not only the varieties should becombined with but also the different harvest time should be planned.

4.1.3 Relationship between, Total Sugar Content and Brix Degree

It has been doubted if the brix degree equals to sugar content. The experiment

confirmed that the sugar content usually larger than brix degree. Variance analysis

also indicates that sugar content (Y) of all varieties have a significant(!y) or

extremely significant (!y !y) Line correlation with brix degree (X). Their linecorrelations can be respectively described as Tab 4.1.5.


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Tab.4.1.4 Total sugar content of different variety in different period

Time (D/M)Variety

4/10 10/1015/10 25/10 29/10

Rio 22.14 19.44 16.92 16.20 16.20

Shennong No.2 20.52 19.04 16.63 14.11 10.82

6AX1022 16.13 19.26 16.02 13.29 10.81

Jitian 2 21.24 16.20 15.95 10.29 13.86

Longshi 1 16.67 18.68 12.96 7.96 10.26

6AXN249 20.52 17.96 13.07 11.52 10.67

Tab.4.1.5 Line Correlation between Sugar Content and Brix Degree

Variety Equation R

RIO Y= -7.712+ 1.660X 0.89

Shennong No.2 Y= -4.714+ 1.662X 0.97

6AX1022 Y= -5.624+ 1.601X 0.90

Jitian 2 Y= -11.080+ 2.008X 0.97

Longshi 1 Y= -14.176+ 2.283X 0.94

6AXN249 Y= -9.549+ 2.052X 0.97

Tab.4.1.5 shows the sugar content with brix degree has a positive correlation. Based

these equations, we can predicts the sugar content by measuring the brix degree

easily. In order to use equation more convenient, we dealt with total sugar content

(y) and brix degree (x). Table 4.1.6 shows the mean Y and mean X of the 6 varieties

at different periods. Variance analysis appears extremely Significant between Y andX, Our aim is this equation can be used in other varieties besides the tested ones.

The line-correlation is:

y= -10.24+ 1.974x

Tab.4.1.6 Mean total sugar content and mean brix degree

timetime (D/M) 4/10 10/10 15/1025/10 29/10

brix degree 14.9 14.4 13.4 11.2 11.3

total sugar content 19.54 18.43 15.26 12.2 12.1

4.1.4 Contents of some main sugars


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A. Glucose content

Glucose is dextrose hose being present in all plant organs and tissues. Glucose has

two crystals: one is ? -glucose separated out from alcohol or water solution under

room temperature, with melting point of 146C and [? ]200+ 112.2 C; another is ? -

glucose separated out from hot pyridine solution of 148 to 150 C, [ ? ]200+ 18.7C.

D-glucose is the only form in natural world with a saccharinely of 0.69 times as muchsucrose.

Glucose is the primary material of plant photosynthesis. For C4 species, besides the

Calvin cycle of glucose formation, there is also a four-carbon pathway for CO2fixation in mesophyll cells, therefore they have great potential for CO2 assimilation.

Sweet sorghum is a C4 crop, with lower CO2 compensation point, higher light

saturation point and weak photorespiration, and consequently has a higher biological

yield.

Glucose is a substrate of respiration and also a component of sucrose, starch andcellulose.

As a reducing sugar, glucose can be fermented by saccharomycete. In fermentation,

acetic aldehyde and CO2 are produced through decarboxylation of pyruvic acid

formed from the dehydrogenation of glucose, then acetic aldehyde is

dehydrogenated and alcohol is produced. The whole process is under anaerobic andenzymatic conditions, which is known as alcohol-producing fermentation.

Glucophosphate ester can be transformed into fructophosphate ester by isomerase.

Glucose can form starch either with ADPG (or UDPG) as offering under

amylosucurose, or with glucophosphate ester as offering under phosphatase

transferring glucose to an introducer. Cellulose is formed through times oftranslocation of glucose unit to the glucose chain from GDPG under transferase.

Tab.4.1.7 Glucose content of different Varieties (%) 1989

Time (D/M)Variety

27/9 6/10 12/10 T*

Rio 1.0 2.2 1.70 4.2

Shennong No.2 2.3 2.1 2.4 3.2

6AX1022 2.2 1.9 2.7 4.8

Jitian 2 3.4 3.1 4.0 5.6

Longshi 1 2.1 1.7 1.8 5.4

T: sampled on October 6 and measured on October 12

From Tab.4.1.7, samples were obtained for different varieties in different growth

stages. The juice was extracted and was to be analyzed for glucose content. The


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variance analysis showed that both varieties and growth stages affected glucosecontent very significantly.

The multiple comparison results using SSR method showed that Jitian-2 was highest

in glucose with 1.762 difference from the lowest Rio; the glucose content of Jitian 2

had significant difference with that of Longshi 1 and 6AX1022, very significant with

that of Shennong No.2 and Rio; there is no significant difference among 6AX1022,longshi 1, Shennong No.2 and Rio. As for the growth stages, October 6 sampling,

then stored until October 12 for extraction and analysis showed highest glucose

content, Very significantly different from other stages, while there is no significant

difference among the latter.

In summary, varieties were an very important factor determining the glucose

content, there were differences in glucose among varieties; there were no significant

differences in that among growth stages, but the stored sample after harvest gaveobviously higher glucose content.

B. Fructose content

Fructose is a hexose with reductive character. ? -pyranofructose is its free type, and

? -furanofructose the combined type. The natural fructose is all levulose, ? -D-

fructose with [? ]200 -63.6C, ? -D-fructose with [? ]20

0-133.5C. Fructose is a

colorless crystal with strong hygroscopicity. It is sweetest among the sugars, with a

saccharinity of 1.15 to 1.5 times as much as sucrose, so it can be used as nutrientand as preserving agent.

Fructose can be combined with saccharomycete. It is first transformed into

fructophosphate ester, and then enter the EMP pathway. The sucrose synzyme

existing in high plants can use uridine diphosphate glucose (UDPG) as the offering of

glucose to form sucrose with fructose. It can also be synthesized under sucrose

phosphate using UDPG as offering of glucose and 6-p-fructose as receptor. The first

product of above reaction is phosphorescence that is then hydrolyzed to sucroseunder phosphate.

In plant photosynthetic tissue sucrose phosphoresce is more active, while in non-photosynthetic tissue sucrose synzyme is mere active.

Tab.4.1.8 shows Fructose contents of 5 varieties, Rio.Shennong No.2, 6AX1022,

Jitian 2, Longshi 1, in 4 growth stages, September 27, October 6, October 12 and

October 6 sampling but October 12 measuring, were analyzed. The results indicated

that varieties were not important determinant for fructose content. Of the 5

varieties, only Jitian 2 was significantly different in fructose content from Rio,

whereas there was no big difference among others. However, growth stages affected

fructose content very much. October 6 sampling but October 12 measuring got ahighest fructose content, very significantly different from other stages among which

no significant difference was found. Like glucose, fructose increased very significantlyafter storage. This means that storage exerts a large effect on fructose content.

Tab.4.1.8 Fructose content in stem juice (%) 1989

Variety Time (D/M)


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27/9 6/10 12/10 T*

Rio 0.8 1.7 1.4 3.6

Shennong No.2 1.9 1.7 2.0 2.6

6AX10226 1.8 1.5 2.3 4.4

Jitian 2 2.6 2.4 3.0 4.3

Longshi 1 1.8 1.5 1.6 4.8

T: Sampled on October 6 and measured on October 12

C. Sucrose content

Sucrose is a widely existed disaccharide in natural world, and it is a non-reducing

sugar. It is found in all photosynthetic plants, but is more in cane and beet so it is

popularly called cane sugar on beet sugar sucrose plays an important role in plant

physiology, it is not only the main product of photosynthesis, but also the main form

of storage and accumulation of carbohydrate, sucrose is also the transportation formof carbohydrate within plant.

Sucrose is disaccharide, when hydrolyzed, one molecule D-glucose and one molecule

D-fructose are produced sucrose can be looked as a product of? -hydroxyglucoside

and ? -hydroxyfrucoside losing one molecule of water. The mixture of glucose and

fructose formed from sucrose hydrolysis is defined as invert sugar.

There is no hydroxyl group of glucoside in sucrose molecule, so sucrose cannot be

changed to open chain structure. Therefore sucrose has no multiracial effect, can not

form osazone. It has no reductive effect, is non-reducing sugar sucrose is dextrose

with [? ]20 0=66.5C. Saccharomycete can ferment sucrose.

Tab.4.1.9 Sucrose content in stem juice (%) 1989

Time D/M)Variety

27/9 6/10 12/10 T*

Rio 6.9 9.0 5.7 7.0

Shennong No.2 3.6 5.9 5.5 9.6

6AX1022 3.4 7.2 5.5 9.2

Jitian 2 2.2 3.7 7.4 2.8

Longshi 1 7.5 6.9 9.4 10.0

T: Sampled on October 6. and measured on October 12

Tab.4.1.9 shows the sucrose content of the tested varieties. It could the seen from

the variance analysis and multiple comparison that varieties and growth stages had

no significant effect on sucrose, and the content is relatively stable. Thus sucrosecontent does not greatly influence the fermented sugar and total sugar content.


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D. Pooled analysis of glucose, fructose and sucrose

From Table 4.1.10, Rio, Shennong No.2, 6AX1022, Jitian 2 and Longshi 1 were

analyzed for sugar contents on September 27, October 6, October 12, and October 6

sampling but October 12 measuring. From Fig 1, we can know the differences amongthe 3 kinds of sugar contents.

From the above 3 factors randomized block experiment, conclusions were made as

follows:

a. October 6 sampling and then stored until October 12 showed very significantly

higher in sugar content than September 27, October 6 and October 12, indicating

that storage could increase sugar content. The other 3 stages had no significant

differences in sugar content, meaning that sugar content was stable during that

period.

b. sucrose content was very significantly different with glucose and fructose, while

glucose content was not obviously different from fructose. This mean that sucrose

prevailed over glucose and fructose in the stem sap of sweet sorghum.

c. Sucrose, glucose and fructose contents showed great significant difference for Rio,

Shennong No.2, 6AX1022 and Longshi 1, but no significant difference for Jitian 2.

d. The glucose content in Jitian 2 varied significantly with those of the other 4

varieties.

e. The fructose content showed no significant variance among the studied varieties.

Tab.4.1.10. Glucose, Fructose, sucrose content in stem juice of different varieties at

different period (%) 1989

Time (D/M)

27/9 6/10

variety GlucoseFructose Sucrose GlucoseFructoseSucrose

Rio 1.0 0.8 6.9 2.2 1.7 9.0

shennong No. 2 2.3 1.9 3.6 2.1 1.7 5.9

6AX1022 2.2 1.8 3.4 1.9 1.5 7.2

Jitian2 3.4 2.6 2.2 3.1 2.4 3.7

Longshi 1 2.1 1.8 7.5 1.7 1.5 6.9

Time (D/M)

12/10 T*

variety GlucoseFructose Sucrose GlucoseFructose sucrose

Rio 1.7 1.4 5.7 4.2 3.6 7.0

shennong No. 2 2.4 2.0 5.5, 3.2 2.6 9.6


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6AX1022 2.7 2.3 5.5 4.8 4.4 9.2

Jitian2 4.0 3.0 7.4 5.6 4.3 2.8

Longshi 1 1.8 1.6 9.4 5.4 4.8 10.0

* T: Sampled on October 6 and measured on October 12

Fig .4 .1 .1 Glucose , Fru c tose and suc rose con ten t i n s t em j u i ce

4.1.5 Starch content


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Starch is a material of white and colorless, existing in granule forms of spherical or

oval depending on plant types. It consists of amylose and amylopectin, and in most

case the former accounts for 10 to 20% and the latter 80 to 90% It transfers into D-

glucose by complete hydrolysis and into maltose by partial hydrolysis.

The water solution of starch of dextrose with [? ]200 =201.5 to 205 C. The mean

specific weight is 1.5.

Looking at the structure of starch, we know that at the end position of the

polyglucoside chain there is free semi-acetalhydroxyl. But starch generally does not

present reductive character, because there is only one semi-acetal hydroxyl in everyhundreds or even thousands of glucose units.

Tab.4.1.11 Starch content of stem juice (%) 1990

Time (D/M)Variety

4 /10 10/10 15/1025/10 29/10

Rio 0.32 0.27 0.16 0.03 0.07

Shennong No.2 0.99 0.23 0.37 0.06 0.02

6AX1022 0.30 0.16 0.12 0.09 0.07

Jitian 2 0.45 0.43 0.14 0.11 0.09

Longshi 1 0.26 0.29 0.04 0.02 0.06

6AXN249 0.41 0.45 0.37 0.03

Starch is the main storing form of sugar and energy in plants existing with great

amount in seeds, fruits, root and stem tubers, and with small amount in leaves and

stems.

Starch can not be fermented by saccharomycete directly, it needs to be dextrinized

and saccharified, turning into fermentable, and then can be used to produce alcohol

through fermentation.

Starch content was measured for 6 varieties, Rio, Shennong No.2, 6AX1022, Jitian 2,

Longshi 1 and 6AXN249, at 5 growth stages, October 4, October 10, October 15,

October 25 and October 29 (Table 11). Variance analysis and multiple comparison

results showed that varieties had little affect on starch content, among the 6

varieties only Shennong No.2 and 6AXN249 exhibited significant difference. Growth

stages affected starch content greatly starch content on October 4 was highest, very

significantly different from those on the other stages except October 10. starch

content on October 10 had no significant difference with those on October 4 and

October 15, but had significant difference with these on October 25 and October 29.

There were no significant differences in starch content among October 15, October

25 and October 29.

From the above analysis, we know that starch is very low in stem juice, it contributes

in alcohol production with small amount so the stem juice of sweet sorghum is a

good saccharine source. Therefore, the alcohol production with sweet sorghum stem


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as raw material does not require complicated technology and expensive equipments,

also the production period is short because of some procedures being left out. It is alow cost and easily operated alcohol producing method.

As for starch content, early October is the best time for harvest when starch amount

is high. starch can be utilized to produce alcohol through fermentation after

saccharigation. Although starch content is not high, it is still important for a largeproduction scale so the starch has also certain value in alcohol production.

4.1.6 Relation between total sugar and glucose, fructose and sucrose in stem juice

According to the preceding discussion that the total sugar in the juice includes some

penthouse, hexose and polysaccharide. of these sugars, glucose, fructose, sucroseand starch have examined in order to learn some internal regularities.

Tab.4.1.12 and Tab.4.1.13 showed sugar contents of 5 varieties measured in 1989.

The results in Table 4.1.12 were measured on October 12 immediately after

sampling, and those in Table 4.1.13 were measured on October 12 after 6 days

storage. From these tables we know that glucose, fructose and sucrose are the ma inparts of sugars in the juice, the sum of these 3 sugars is near to the total sugar

amount but they are not the same thing, especially different sugars should not be

simply summed up theoretically. So, the estimate of total sugar should be made by

direct measurement or calculated according to the brix degree using the formula

described earlier.

Table 4.1.12. Sugar Content in Stem Juice (%) 1989.10.12

Variety Rio Shennong No. 26AX1022 Jitian2 Longshi 1


Glucose 1.7 2.4 2.7 4.0 1.8Fructose 1.4 2.0 2.3 3.0 1.6

Sucrose 5.7 5.5 5.5 7.4 9.4

Table 4.1.13. Sugar Content in Stem Juice (%) 1989

Variety Rio Shennong No. 26AX1022 Jitian2 Longshi 1


Glucose 4.2 3.2 4.8 5.6 5.4

Fructose 3.6 2.6 4.4 4.3 4.8Sucrose 7.0 9.6 9.2 2.8 10.0

It is known that the transformation from glucose to sucrose under enzyme is a

simple process. Furthermore, sugar and starch contents are different among

varieties, so considerations should be made on choosing higher glucose and fructose

or higher sucrose. Perhaps it is better to select higher glucose and fructose sweet

sorghum considering that the transformation from glucose to sucrose or starch, and


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then starch and sucrose turning into glucose in the process of fermentation allconsume energy.

Componen of Stalk Sweet Sorghum

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