Food Chemistry

(Sean Pound) #1
4.4 Polysaccharides 317

Table 4.24.


Shape, composition, and properties of different starch granules


Source

Shape

a

Diameter Crystallinity Gelatinization Swelling Amylose

Amylopectin

(μm)

(%)


temperature

at 95

◦C


b

◦(


C)


Percentage Polymeri-

Iodine

Polymeri-

(%


c)

sation

binding

sation

degree

constant

d

degree

e

Cereal

Wheat

l,p

2–38


36


53–65


21


22–28


2100


0.


21


19–20


Rye

l

12–40


57–70


28


0.


74


26


Barley

l

2–5


56–62


22–29


1850


26


Corn

p

5–25


62–70


24


28


940


0.


91


25–26


Amylomaize

20–25


67–87


52–80


1300


0.


11


23


Waxy corn

p

39


63–72


64


0–1


20–22


Oats

5–15


56–62


27


1300


20


Rice

p

3–8


38


61–78


19


14–32


0.


59


Waxy rice

55–65


56


1


Millet

p,s

4–12


}


69–75


g

}


22


g

Sorghum

p,s

4–24


21–34


Waxy sorghum

68–74


49


Legumes

Horsebean

s,o

17–31


64–67


32–34


1800


1.


03


23


Smooth pea

n(si)

5–10


33–35


1300


1.


66


26


}


57–70


h

Wrinkled pea

n(c)

30–40


63–75


1100


0.


91


27


Roots and tubers

Potato

e

15–100


25


58–66


23


3200


0.


58


24


Cassava

semi-s,s

5–35


38


f

52–64


17


1.


06


a
l = lenticular, p = polyhedral, s = spherical, o = oval, n =

kidney-shaped, e

l = elliptical, si =

simple, c = compound.

b

Weight of swollen starch, based on its dry weight; loss of soluble polysaccharides is considered.
c
Based on the cum of amylose and amylopectin.
d

mg iodine/100 mg starch.
e
Cleavage degree of polymerization, determined by degradation of branches with pullulanase or isoamylase.
f
Tapioca.
g

Millet.
h

Pea.
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