Starch and Liquid glucose from potato

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Starch and Liquid glucose from potato


Introduction

Potato is rich in starch with 14-16 starch
content. Although potato starch is costlier when
compared to maize and cassava, because of its
superior properties it is preferred for special
applications in pharmaceutical, textile, food and
paper industries. The demand for potato starch is
because of its unique properties (Talburt and
Smith, 1987). The advantage of using potatoes for
starch production is that substandard potatoes
not suitable for table or processing can be used
for starch production. Glucose syrup is a
food syrup, made from the hydrolysis of starch. Ma
ize is commonly used as the source of the starch
and the syrup in this case is called "corn
syrup", but glucose syrup is also made from other
starch crops, including potatoes, wheat, barley, r
ice and cassava.
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Objectives

After completing this lesson, you will be able to

Understand the process of making potato starch
and liquid glucose and its importance.
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Potato Starch

Potato starch is superior to cereal starches in
many ways. It has large granule size (5-100um),
its lipid content is low, it has higher water
binding capacity and high solubility, besides
having low protein content and it helps in
avoiding foam building and colour formation. It
also has higher phosphorus content and higher
swelling volume.
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Method for preparation of potato starch
Take 1kg big size potatoes Peel it Cut into
small pieces Dip in water after putting 1
potass. metabisulphite Grind in a grinder Sieve
it in a tub through muslin cloth with the help of
water Let the starch settle on the surface of
tub Decant the starch 2-3 times with water till
the water is clear Dry it in oven at 80C/
sunlight on tray till fully dry Grind till fine
powder is obtained. Sieve it to get fine
powder About 50 to 100g of potato starch will be
formed which can be stored in airtight containers
for future use.
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Uses of Potato Starch

Potato starch may be utilized in several
industries. In food industry it may be used as
thickener in sauces, gravy, puddings, soups, etc.
As softening agents in cakes, breads, biscuits
and cookies. As ingredient in custard, cream,
candies and chewing gums. In textile industry it
gives the finished cloth a smooth surface and
better feels and hence is preferred in warp
sizing. In paper industry it is useful in coating
smooth white paper because of its unusually
strong binding power for white pigments and
clays. In pharmaceutical industry it is used for
preparation of dextrins, adhesives, glues, drugs,
dressing materials, binder for tablets, etc.
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Liquid Glucose

Liquid glucose is a solution of glucose suspended
in liquid and sold in jars or tubs. Many
companies manufacture glucose in powdered form to
which water can be added to make liquid glucose,
to make transportation of this product
easier. Liquid glucose is available from a
variety of sources, depending on how one intends
to use it. This monosaccharide is produced
through the processing of starches such as corn,
wheat and even potato. Liquid glucose is an
extremely pure form of glucose which has a
concentrated flavor. In cooking, liquid glucose is
used as a sweetener in a range of foods. This
product does not crystallize, sweetens evenly,
helps to preserve food, and has a very low
freezing point, making it appealing for things
like candy and ice cream. European recipes tend
to call for liquid glucose more commonly, and it
is more readily available in European stores for
this reason. In medicine, liquid glucose is used
when a patient has dangerously low blood sugar.