MODIFIED RHEOLOGICAL PROPERTIES OF STARCH FROM TRIPLOID CASSAVA FOR INDUSTRIAL USE

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MODIFIED RHEOLOGICAL PROPERTIES OF STARCH FROM
TRIPLOID CASSAVA FOR INDUSTRIAL USE
M.T. SREEKUMARI, S. N. MOORTHY AND K.
ABRAHAM        CENTRAL TUBER CROPS RESEARCH
INSTITUTE, TRIVANDRUM, INDIA
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• POLYPLOIDY BREEDING is an ideal tool for the
  genetic improvement of cassava due to
• Vegetative propagation
• Amenability for hybridization
• Low chromosome number
• Sterility not affecting the economic produce

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• PRODUCTION OF TRIPLOID CASSAVA
• Selection of desirable cultivars
• Induction of tetraploidy by colchicine
  treatment
• Identification and screening of tetraploids for
  flowering
• and fertility
• Raising pollination block
• Hand pollinations between diploids (2n36) and
  induced
• traploids (2n72)
• Seedling evaluation and identification of
  triploids (2n54)

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• CTCRI possesses 320 triploid hybrids
• Majority of them have
• Compact plant type
• Higher yield
• Higher dry matter and starch content
• Shade tolerance
• Early harvestability
• The triploid hybrid SREE HARSHA released from
• CTCRI Is the first of its kind in the world

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• Cassava starch
• Nature
• Easily extractable
• Pure white colour
• Good viscosity
• Good Clarity
• Applications
• Food
• Textile
• Paper
• Adhesive

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OBJECTIVE To study the rheological properties
of native starch from tripolid cassava in
comparison with the respective diploid
and tetraploid parents and assess the scope for
its direct use for industrial purposes.
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MATERIALS AND METHODS Material Freshly
harvested tubers of diploid, triploid, tetraploi
d plants of four varieties of cassava viz., 1.
M4 Popular local variety, very good
cooking quality 2. OP-4 Profusly
flowering and seed setting 3. Sree
Visakham Released hybrid of CTCRI 4. Sree
Sahya Released hybrid of CTCRI
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• Methods Starch was extracted and following
  characters
• were studied.
• Swelling volume
• Standard procedure followed
• Gelatinizing starch (1) in distilled water
• Centrifuging at 2000 rpm and noting the value
  of the sediment
• Solubility
• Determined by noting the percentage of material
  going into
• the solution while swelling freely.

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• Viscosity
• Determined using Rapid Visco Analyzer by
  adopting
• standard procedure
• Following parameters were read out from the
  graphs
• Peak viscosity
• Trough viscosity
• Final viscosity
• Pasting temperature
• Breakdown value
• Set back viscosity

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Table 1. Solubility and swelling volume of native
starches from different ploidy types of cassava

• Swelling volume is affected by ploidy level
  difference
• Increased swelling volume of M-4 (3n) and
  decreased
• swelling volume in OP-4 (3n)
• Swelling volume of diploids found to be in
  between
• tetraploids and triploids

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Table 2. Viscosity data of the native starches of
the three ploidy types of four
cassava varieties
_at_Viscosity unit cP
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• Results indicate
• Noticeable increase in peak viscosity in
  triploids of M-4
• Sree Visakham and Sree Sahya.
• A reverse effect in OP-4
• Peak Viscosity of tetraploids and diploids
  nearly same
• No effect of ploidy change on the trough
  viscosity except
• for M-4
• Higher breakdown viscosity for M-4 triploid
• Low breakdown viscosity in OP-4
• No regular pattern of setback viscosity
  however variation
• was evident in different ploidy types
• Pasting temp. lowered in M-4 triploid and
  elevated in OP-4
• triploid

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• Conclusion
• Obvious difference in starch properties of
  different cultivars.
• Triploid cassava possess higher yield coupled
  with higher
• dry matter and starch content
• Notable changes observed in starch properties
  of 2n, 3n
• and 4n plants
• Starch modification was prominent in M-4
  triploid
• Lower Viscosity of OP-4 is advantageous
• Viscosity modification was achieved without
  chemical
• treatment

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• Conclusion (Contd.)
• M-4 2n and 3n are ideal for edible and
  industrial use
• respectively
• Popularization of M-4 3n is warranted
• More emphasis on the production of an array of
  triploids
• for the direct use of starch
• Modified viscosity properties can be useful in
  various
• applications
• The structural characteristics of the starch
  of 3n plants
• need further investigation

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Thank You