Ultrasound and ozone techniques show potential for improving cassava starch extraction processes. The study investigated using ultrasound-assisted extraction and ozone treatment to extract starch from cassava tubers. Optimal extraction conditions were determined using response surface methodology. Ultrasound-assisted extraction achieved 8-11% higher starch yields than conventional wet extraction. Ozone is a powerful disinfectant and oxidizer that could potentially replace chemicals used for bleaching and whitening cassava starch.

1. INNOVATIVE NON-THERMAL PROCESSING
TECHNIQUES (ULTRASOUND AND OZONE)
IN CASSAVA STARCH INDUSTRIES
Dr.T.Krishnakumar
Scientist (Agrl.Process Engg.)
ICAR-CTCRI

2. Starch
• Starch is most abundant carbohydrate reserve in
plant tubers and seed endosperm
• Main location of starch synthesis and storage in
cereal is endosperm
• Starch provides 70 to 80 % of the calories
consumed by human worldwide
• Starch is major source of diet made up of
amylose (20-30 %) and amylopectin (70-80 %)
with a ratio of 1:3

3. Principal carbohydrates in the human diet.

4. Different types of starch
S.No Starch
Amylose
(%)
Amylopectin
(%)
Granule
Size
(Micron)
Shape
1. Corn 25 75 5-20
polyhedral to
sub-spherical
2. Potato 20 80 50-75
Smooth round
oval shape
3. Rice 20 80 3 -8
irregularly
shaped
polygons
4. Cassava 18 82 15-40
Smooth
irregular sphere
5. Wheat 25 75 22-36
Smooth round
shape
Commercially starches are produced from Maize,
Cassava, Wheat, Rice and Potato.

7. • In India, it is cultivated about 0.20 M ha with a
total production of 8.13 MT and a overall
productivity of 34.37 Metric Tonnes per hectare
• Total starch and sago production are
2.5 Lakh Tonnes and 1.5 Lakh Tonnes
respectively
Area and Production details of Cassava in India

8. Area and Production details of Cassava in India

10. Amylomaize (High Amylose Starch)
Retrogradation of starch takes place by
amylose content
By Genetic Engineering techniques waxy
starches are developed from Rice, Maize
and Potato.
 Waxy starches have less retrogradation
results in a good pasting properties
Waxy starch
Mainly for improving gel strength,
resistant starch and bioplastics

12. It is a sound waves with frequencies higher
than 20 kHz
It ranges from 20 kHz to 200 MHz
Human ear can hear up to 20 kHz
Ultrasound

13. Bats navigate using ultrasound

14. Ultrasound

15. Ultrasound

16. Application of Ultrasound
Type of application determine the intensity and
the frequency of sound waves
Low Power, High Frequency (1W/cm2
, >100 kHz) –
Monitor Products or Processes
 High Power, Low Frequency (10- 1000 W/cm2
, 20 to 100
kHz) – alter the properties of material or facilitate the
progress of a process

17. Applications of Ultrasound in Food Processes
Emulsification
Homogenization
Extraction
Crystallization
Low temperature pasteurization
Particle size reduction
Viscosity alteration
Modification of product

18. Mechanism of Ultrasound in Food Processes

19. Ultrasound -Assisted Extraction (UAE)
19
 Sound waves with frequency ranges from 2 x 104
to 2 x 109
kHz.
 Ultrasonic waves at high intensity passed into the liquid media
which results in alternating high pressure (compression) and low
pressure cycles (rarefaction).
Sound motion in liquid medium

20. Ultrasonic Assisted Extraction (UAE)
20
During the low pressure cycles, high intensity
ultrasonic waves create small vacuum bubbles in the
liquid
Cavitation collapse as the pressure increase again,
hot spots will appear, creating high temperature and
pressure area with high speed impinging liquid jets
and strong hydrodynamic shear forces.
Cavitational effects of these waves facilitate the
release of extractable compounds and enhance mass
transport by disrupting the plant cell walls (Vinatoru,
2001; Melecchi et al., 2006).

21. Advantages of Ultrasonic Assisted Extraction (UAE)
21
 Less extraction time
Reduce the use of solvent
Enhancement of Extraction yield
Improve the quality of extracts
Promising alternative to conventional extraction method

22. Conventional wet extraction of cassava starch

23. 23
RESEARCH STUDY

24. Background details for the study
 Cassava is an important tuber crop has high starch content (25-
30%)
 Cassava starch has its unique physicochemical and functional
properties, therefore it finds wide applications in food, paper,
textile, adhesives etc. (Moorthy, 2001)
 One kg of cassava flour can be produced from 3 kg of cassava
tubers
 One kg of cassava starch can be produced from 4 kg of cassava
tubers
 One kg of tapioca sago can be produced from 5 kg of cassava
tubers
 Maximum extractable starch from cassava tubers of 28 % starch
by chemical method was found to be 22.80 % (Sajeev et al.,
2012)
 Maximum cassava starch extraction by commercial wet method
was found to be 18.98 % (Sajeev et al., 2012)
24

25. 25
Optimization of Ultrasound-Assisted Extraction of
Cassava Starch using Response Surface
Methodology Using bath and probe type sonicator

26. Objectives
26
• To develop a simple and standardized technique to obtain a
maximum extraction yield of starch from cassava tubers by
ultrasound assisted extraction compared with conventional wet
extraction.
• To optimize the ultrasound assisted extraction process conditions
(ultrasonic temperature, ultrasonic power, extraction time and
solid-liquid ratio) for obtaining maximum extraction of yield of
cassava starch using response surface methodology technique.

27. Comparison of Bath type and Probe type Sonicator
S.No Bath type sonicator Probe type sonicator
1. Weak sonication (20 -40
W/L)
Strong sonication (20,000
W/L)
2. Non-uniform
distribution
Uniform distribution
3. Produce less energy Produce high energy
(1000 times higher energy
input per volume)

28. MATERIALS AND METHODS
Raw material:
28

29. MATERIALS AND METHODS
29
Dependent Variables:
•Size, shape and structure of starch granule
•Starch colour
•Amylose content
•Gelatinization/Pasting temperature
•Retrogradation of starch
•Viscosity
•Swelling volume
•Solubility
•Pasting stability

30. Factors Levels
Extraction Time (min) 15, 30, 45 (3)
Extraction Temperature (°C) 30, 40, 50 (3)
Sonication Power (W) 250, 300, 350 (3)
Solid-Liquid Ratio (g/ml) 1:10, 1:20, 1:30 (3)
Selected factors for probe sonicator
Selected factors for bath sonicator
Factors Levels
Sonicator power (W) 50, 75,100 (3)
Sonication time (min) 10, 15, 20 (3)
Solid-Liquid Ratio (g/ml) 1:10, 1:20, 1:30 (3)

31. MATERIALS AND METHODS
31
Bath Sonicator (Make: Life-Care, 33±3 kHz, 240 V)

32. MATERIALS AND METHODS
32
Probe Type Ultrasonicator
(Make:Sonics, 30 ± 3 kHz frequency,
heating strength of 750 W,
Input voltage 230 V)

33. Factors and levels Used in the Box-Behnken design for
probe type
33
Independent Symbol Variables
Factor level
-1 0 +1
Extraction temperature X1 (°C) 30 40 50
Ultrasonic power X2 (W) 250 300 350
Extraction time X3 (min) 15 30 45
Solid-liquid ratio X4 (g/ml) 10 20 30

34. Factor 1 Factor 2 Factor 3 Factor 4 Response 1
A:Extraction Time B:Extraction Temp C:Ultrasonic Power D:Solid-Liquid Ratio Starch Yield
min deg c W g/mL %
-1 0 0 -1
0 0 -1 1
0 -1 0 -1
1 0 1 0
-1 0 -1 0
-1 1 0 0
0 1 1 0
-1 0 0 1
0 1 0 -1
0 0 -1 -1
1 1 0 0
0 -1 0 1
0 1 -1 0
0 0 0 0
1 0 0 -1
-1 0 1 0
0 1 0 1
1 -1 0 0
0 0 1 1
0 0 0 0
-1 -1 0 0
0 -1 1 0
1 0 0 1
0 -1 -1 0
0 0 0 0
1 0 -1 0
0 0 0 0
0 0 1 -1
0 0 0 0Experimental Design for Probe type

35. • The maximum experimental starch yield (83.20 %) which
was 8.20 % higher than that obtained with the
conventional wet extraction method (75 %)
• The optimal conditions were sonication power of 63.32
W, sonication time of 15.59 min and solid to solvent ratio
(SS) of 19.19 g/ml) with a desirability value of 0.76
Results for bath type sonication:

36. • The maximum experimental starch yield (86.25 %) which
was 11.25 % higher than that obtained with the
conventional wet extraction method (75 %).
• The optimal conditions were found to be : Extraction
temperature of 41°C, Ultrasonic power of 287.43 W,
Extraction time of 27.48 min and Solid-liquid ratio of
1:19.9 g/ml) were determined with a desirability value of
0.992.
Results for probe type sonication:

37. • In India, sago is to be manufactured only
from the tubers of tapioca
• On an average, the yield of sago is 200 kg
per tonne of tapioca tubers processed
• For Processing 200 kg of 5,000 litres of
water (5 m3
) is required
SAGO

38. SAGO
S.No Parameters Value
1. Moisture content (%) 12.00
2. Energy (Kcal) 350.00
3. Starch (%) 98.00
4. Protein (%) 0.20
5. Fat (%) 0.05
6. Crude fibre (%) 0.18
7. Iron (mg/100g) 1.30
8. Calcium (mg/100g) 10.00
9. Ash (%) 0.30
10. pH 6.0

39. • Sago is classified into two types viz. Roasted
sago (commercial sago) and boiled sago
(Nylon sago)
• Commercially available in different grades
viz., super fine, milky white, best, pearl and
broken.
• Size generally ranges from 2 to 4.5 mm
Types of SAGO

40. • Traditional processed food product of India and
commonly used as a food (known as khichadi)
during festive season and fasting in western and
central part of India (Maharashtra and Madhya
Pradesh) and used as baby food (West Bengal)
• Used as a food thickener in several food
preparations and in South India, it is used to make
Kheer by adding milk
• Provides slightly higher energy (350 Kcal) than
cassava starch (347 Kcal)
Uses of SAGO

41. • 70% of the sago produced in India is from Tamil
Nadu
• 90% of the tapioca produced in Tamil Nadu is
processed into sago and starch
• 450 sago and starch industries are located in Tamil
Nadu
SAGO

42. • SAGOSERVE (Salem Starch
and Sago Manufacturers Service
Industrial Co-operative Society
Ltd) was started in 1981 under
the Tamil Nadu Co-operative
Society Act 196.
• Starch market in Tamil Nadu is
semi-organized
• 60% of the sago produced in
Tamil Nadu is marketed through
SAGOSERVE
SAGOSERVE

43. Hindu on December 11, 2011

44. The Covai Post

45. Business Standard Newspaper

48. Oct 9, 2015 by The Hindu

49. The Hindu Newspaper

51. T Next Newspaper

52. • In the peeling process the complete thin outer skin and thick inner skin are
removed, these parts are usually not edible and also render the final product not
only with undesirable colour but also with toxic hydrogen cyanides.
• In order to make the colour desirable many industries are using bleaching
chemicals making the product even more toxic

53. Bleaching Agents
Calcium hypochlorite
Sodium hypochlorite
Acids
Sulphuric acid
Hydrochloric acid
Phosphoric acid
Artificial Whitening Agents
2-B-Con or Tinopal
Chemicals Used in Sago Processing

54. Ozone
• Ozone is a triatomic form of oxygen
(O3).
• In 1997, ozone was Generally
recognized as safe (GRAS) for food
contact applications in the United
States (U.S. Food and Drug
Administration, 1997).
• FDA approval of ozone as a direct
additive to food in 2001.

55. Ozone
• Most people can detect about 0.01 ppm of
ozone in air where it has a very specific sharp
odor
• Ozone is a pale blue gas, slightly soluble in
water

56. Stability:

57. Why ozone?
• Most powerful oxidizer available
• Instantly destroys microbes
• Environmentally friendly
• Stops mold spores

58. Application of Ozone in Food Industries
• Ozone is a powerful disinfectant due to its
oxidizing capacity.
• Bleaching/whitening
• Food surface hygiene
• Sanitation of food plant equipment
• Waste water treatment
• Lowering BOD and COD

59. Ozone is better or Chlorine ???
• Ozone is known to kill bacteria in water 500 times
faster than chlorine.
• Ozonation helps fruit and vegetables stay fresh up to
three times longer than chlorine.
• Oxidizing agent of ozone is 1.5 times stronger than
chlorine
• Chlorination produces harmful disinfectant by-
products.

60. Ozone as a disinfectant
10 times more effective than chlorine
 25 times more effective than HOCl (Hypochlorous Acid)

2,500 times more effective than OCl- (Hypochlorite)
 5,000 times more effective than NH2Cl (Chloramine)

61. Life Cycle of Ozone
• Generation, oxidation, and return to oxygen.
• The atmospheric air is concentrated to 90% +
with oxygen concentrators and concentrated
oxygen is then passed through an electrode
inside the ozone generator, using corona
discharge process, creates ozone molecules (O3)
from the oxygen molecules (O2).

62. Whitening of Cassava Starch
• Consumers prefer white colour
• Some manufacturers resort to the ill-advised
practice of adding chemicals like
• Bleaching agents (such as calcium hypochlorite,
sodium hypochlorite,etc.,).
• Acids (such as hydrochloric acid, sulphuric acid
& phosphoric acid, etc).
• Artificial & Optical whitening agents (such as
2-B-Con or Tinopal) are added to impart an
artificial brilliant white colour to their improperly
manufactured starch.

63. • The chemically treated starch overcomes the
handicap of colour but it is not good for the
health of the consumer and attracts the Food
Adulteration Act.
• Ozone – An Organic and Green Technology for
Natural Oxidation
Whitening of Cassava Starch

64. Schematic Diagram of Ozone Apparatus

67. Disadvantages of ozonation
• Relatively high equipment costs
• Requires large amounts of energy
• Ozone is less soluble in water, compared to
chlorine, and, therefore, special mixing
techniques are needed.