Polysaccharides

1
Polysaccharides

• 1.Starch
• 2.Modified Starch
• 3.Glycogen
• 4.Cellulose
• 5.Hemicellulose
• 6.Pectic Substance
• 7.Gums

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1.Starch

• (1) Structure
• Amylose alpha-D-(1?4) glycosidic bond
• Amylopectin alpha-D-(1?6) glycosidic bond
• (2) Characteristic
• Gelatinization
• Viscosity enhancement
• Gelation and retrogradation
• Properties of starch from Taiwan

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Gelatinization ??

• ?? ????????????????,??????????????????? random
  coil,???????????????
• ??????????????,??????????,?????????????20,???????
  ???? (birefringence)?
• ??????????????
• ???????????????????????????????,?????????????????

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???????(differential scanning calorimeter, DSC)
--??????????

• ???? ? 1 2 ?,? DSC ????1????,???? 54 C,????
  69 C,???? 86 C,??G ???????????????
• ?? ? 1 1 ?,???????????????(M1
  ????),????????????????,???????????????????????????
  ???????20-30 C???????????M1???????????
• ????? 35 ? 80 ?????????????? M2
  ??,???????-?????????????? ?
• ?? ? 1 4 ?,M2 ??? 98 C,????????? DSC
  ??,?????? G ??,? M2 ??

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??? DSC ???
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DSC

• ?????????? 32 ? 67 ?,? DSC ???????,?????????????
  ???32,
• ?????? 20 ?,???????,?????????????
• ???????????????????
• DSC????????????????????????????????????

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Viscosity enhancement

• ???????????????????????????????
• ????????????????,????????????,???????????,????????
  ??????
• ??????????(scanning electronic microscope)????????
  ???????????,???????????????????

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????????

• ????
• ?5-8 starch solution??????????
• ?35 C ??????? 1.5 C??????95 C
• ?95 C ?? 60 min
• ????????95 C ????35 C
• ???35 C ??1 hr
• ????
• ???????????????
• ?95 C??????????????????
• 95 C???????????????????????
• ??(setback) ???????35 C ????
• 35 C?????????????????????????

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????????
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Gelation and retrogradation

• ??????????????????,???????????????????,???????????
  ???????,???????
• ???????????????,??????????????????????????????
• ????????,????????,?????????,???????????????
• ????????????,??????????????

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2.Modified Starch

• ?????????????????????????,????????????
• (1) ???(pregelatinization)??
• (2) ?????
• (3) ???(Stabilized) ??
• (4) ??(Cross-linked) ??
• (5) ????

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(1) ???(pregelatinization)??

• ?????????????????????????????,??????????
• ??
• ?????????
• ???????

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(2) ?????

• ??????????????,????????????,?????????????????
• ??
• ??????
• ??????
• ????????
• ????????????,???????
• ????? 40???????????????25-55 C ???6-24
  h,??????????NaOH???,?????????

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(3) ???(Stabilized) ??

• ??????????????????????????,???????
• Glucopyranse??????? OH,????(degree of
  substitution, DS) ??0-3
• ?????????? DS lt 0.1
• ??????????? -OH ??,????????????????????,??????????
  ,?????
• ????????????????,??????????????????????

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(3) ???(Stabilized) ??-- examples

• A. OH????? (DS 0.005-0.1)
• ????????????????50 C ?????
• ?? ?????????????????????????????????????-?????
• B. ?????? (DS gt0.25)
• ???????- (ortho-)??(pyro-)???????,???????
• ?????????DS gt 0.07 ????????????-??????????????

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(4) ??(Cross-linked) ??

• ?????????????????????OH ?????
• ????????????????????
• ??????????????,?????????????
• ??????????????????????????
• ?????? ?????-OH???????
• ??????????????????
• ??????????????????????

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(5) ????

• ????????????,???????????????
• ???????????
• ????
• ???????????????
• ????????????

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3.Glycogen

• Homopolysaccharides
• ??? amylopectin??,??alpha-D-(1?4) ?alpha-D-(1?6)
  glycosidic bond,????????????

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4.Cellulose

• Beta-D-(1?4) glucopyranose ????,up to 12,000
  glucose unit
• homopolysaccharides
• ?????????
• ????????????????,????????,??????????
  micro-crystalline cellulose
• ???
• ?????? (carboxymethyl cellulose, CMC)
• ?????

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4.Cellulose CMC
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4.Cellulose CMC

• DS (degree of substitute) 0.7-1.0
• ????????????
• ??????
• ???????
• ????????
• ???????
• ???

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4.Cellulose methyl cellulose
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4.Cellulose methyl cellulose

• DS (degree of substitute) 1.64-1.92???????
• ???????????????????????
• ??????????????
• ???????????
• ????????
• ?????????
• ?????????
• ???

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5.Hemicellulose
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5.Hemicellulose

• Hemicellulose ?????????????????????
• ??beta-D-(1?4) xylopyranose???????,?????????????be
  ta-L-arabinofuranose???,?150-200 units
• ??????????4-?????????D-?L-????????

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5.Hemicellulose

• ?????????,?????????????,??????????
• ??????????,??????
• ???????,????????????????????????????????

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6.Pectic Substance

• ???alpha-D-(1?4) galacturonic acid
  ???,????alpha-D-(1?6) ??rhammose,????fructose,
  xylose ?? galactose? beta-(1?4) ????????
• ??????????????,?????(degree of esterification,
  DE)??DE 100 x (????galacturonic
  acid)/(?galacturonic acid)

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6.Pectic Substance--??

• (1)????(protopectin)
• ?????????????????????????,????
• (2)???? (pectinic acid)
• ?????????????????????
• ???????????????????????
• (3)???(pectic acid)
• ??????????????????

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????????

• ??? 0.2-0.4 ?????????????????????
• ?? pH ??? 2.0-3.5 ??? 60-65 sucrose?,????????????
  ??
• ????1???????????????
• ????? 30 ?? 50 ?,??????????
• ????? 50 ?? 70?,??????????

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????????

• ???????????????,???????????????????????????
• ????10-20 ????????????
• ???????? pH 2.5-6.5 ?????,?????????? pH ???? pH
  2.7-3.5

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7.Gums

• ????????????,???????????????????,?????????????
• (1)???? (guar gum)
• (2)???? (locust bean gum)
• (3)???? (gum arabic)
• (4)??? (gum tragacanth)
• (5)??? (seaweed gum)
• (6) 1,6 ???
• (7) ??? (xanthan gum)

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(1)???? (guar gum)

• ??????????,????????,???12,????? 220,000 ???
• ???????????????????,??????? 1 ??
• ???????? pH ?????,???????????????????
• ???????????????????

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(2)???? (locust bean gum)

• ????????????????,???? 1 4,??????,?????
• ???????,???????????????????,?????????????????

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(3)???? (gum arabic)
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(3)???? (gum arabic)

• Acacia ????????,?????????????,???
  250,000-1,000,000 ???
• ?????????????????,??? 50 ?????,????????
• ?????????
• ???????? pH ???????,?? pH 6-8 ??????
• ??????????????????????
• ?????????????

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(4)??? (gum tragacanth)

• Astragalus??????,??????????D-gluconic acid,
  D-galactose, D-xylose, L-????, L-???
• ???????????????60-70,???800,000???????????840,000
  
• 0.5?????????? ?,?????????

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(5)??? (seaweed gum)?? (agar)

• ??????(agaran)?????(agaropectin)
• ?????beta-D-?????(1?4)?3,6??- alpha-L-galactopyran
  ose???????
• ?????5-10??????gluconic acid????
• 1.5 agar?30 C??,?????85 C
• ??????????????????
• ?????????,?????????

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(5)??? (seaweed gum)??? (carrageenan)

• ???????kappa (k), lambda ( ), mu ( ), iota ( )?
  nu ( ) ,?????????????????
• ??????????????????
• ????????????
• ????????????????,???????
• ????????????????,???????,???????????????

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??? (carrageenan)
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(5)??? (seaweed gum)??? (alginate)

• ???????? (G)?????? (M)???
• ???M/G?????????????
• ??????????????????????????,??????????????
• ?????????
• ?????????,pH 4-10 ????????
• pH 5-10 ?????????????

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??? (alginate)
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(6) 1,6 ???

• ??????????,?alpha-D-glucopyranose????????
• ???????,????????????????
• ?L. mesenteroides ???????95 (1?6)??,???(1?3)?
  (1?4)??
• ??????????

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(7) ??? (xanthan gum)
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(7) ??? (xanthan gum)

• ?Xanthomonas??????????,???????????????????
• ????????,???????????????
• ????,? 60-70 C ?pH 6-9 ????????
• ??????????????????
• ????????????,?????????????????

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??????

• ?????????????????????????????
• ???? ??????????????
• 1.???????????
• ??? cellulose ? hemicellulose ?????????????
• 2.??????
• ????????????????????????

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????????

• ????????????????????????
• ????????????????????,????????????????????????????,
  ?????????????????
• ??????????????????????,??????????????,????????????
  ???

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???????????

• ???????????????,??????????????????????????,???????
  ?
• ??????,?????????????,???????????????,?????????,???
  ??????????????(????)

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???????????

• ?????????????????????,??????????????????????,?????
  ???????,???????,????????
• ???????????????,????????????????????????
• ????????????????????????????????????,???????,?????
  ???????

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???????????

• ?????????????????????
• ????????,?-COOH??????????,???????????,?????????
• ???????????,????????????????????????????????,?????
  ??

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????????

• ??????????????
• ?????????????????????????????
• ?????(???)???????,??????????????,?????????????????
  ?????,????????????????,?????????????????????
• ???????????,????????????????????,?????????????????
  ??????????