2. RAW MATERIALS FOR RICE NOODLES
The basic ingredients used to develop rice based
noodles include flour and water, along with
additional ingredients i.e. salt, oil to improve the
quality of final product. Raw materials are judged
by determining their physicochemical properties
and processing parameters. It is important that
raw materials possess appropriate functional and
processing properties in order to develop a quality
product [1, 15].
2.1 Rice Flour
Rice flour is obtained from fine milling of rice
kernels. Rice flour may be made from either
brown rice or white rice [16]. It is energetic and
basic food consumed on a regular basis and has a
very high digestibility value. Rice flour comprised
of about 0.4–0.8% fat, 7% protein and 78%
carbohydrates[17]and provide substantial amount
of B vitamins; thiamin, niacin and riboflavin [18].
Different type of products are made from rice
flour, such as bread, noodles, cakes, and other
conventional products developed in the homes or
in the industries, across the world [1, 10]. Different
types of noodles consumed in the Asia-Pacific
region. Each noodle is preferred and consumed in
different culture within different region of Asia.
Hence, it is not easy to discuss flour specifications
or quality, without recognizing the type of noodle,
method of production, production environment,
existing facility and regional preferences [1].
The flour physicochemical properties would
facilitate the understanding of its possible uses
and applications [11]. Brown rice variety had the
highest protein concentration (8.16%) and lowest fat
concentration (0.07%). However, white rice variety
has high amylose concentration (27.71%), while
brown rice variety has low amylose concentration
(3.36%). On the other hand, white rice had 25.0%
amylose, 8.0% protein and 2.2% fat concentration
[19].Rice flour is categorized according to the
presence of amylose concentration, as either high
amylose (25-33%), intermediate amylose (20-
25%), low amylose (12-20%), very low amylose
(2-12%) and waxy (1-2%). On the basis of cooking
properties, rice is categorized into two groups;
waxy and non-waxy rice. Waxy rice is mostly
composed of amylopectin and produces chewy and
sticky structure; whereas non-waxy rice contains
10-20% amylose and produce firm noodle [20].
The quality attributes of rice grains are
appearance, cooking and eating properties as well
as nutritional value [21]. Rice varieties containing
high amylose concentration, high gel consistency
and low gelatinization temperature are appropriate
for making rice noodles [7]. Rice flour having
intermediate amylose concentration produce soft
texture noodles. Such noodles lead to high solid
loss in cooking water. Noodle made from very
low amylose concentration flour lead to very
poorly textured noodles and is therefore not used
in preparing noodles [22-23]. The granule size of
rice starches may vary from 3 to 8 µm and is much
smaller from granules obtained from other starch
sources. The use of larger granule size (> 20 µm)
for noodles making showed higher processing
ability and quality attributes [24]. Rice flour
starches exhibited weaker resistance toward shear
forces and do not form strong gel. It also loses
thickening power and viscosity significantly during
cooking process. The gelling property of rice starch
is dependent upon rice varieties, amylopectin and
amylose concentration, as well as the duration of
the ageing [25]. Physical modification of flour such
as addition of water and heat treatment improves
the eating and cooking properties of rice noodles
[7].
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