how starch can be modified into different valuable products.

1. MODIFICATION &
BIOCONVERSION OF
STARCH
SHEETAL HANDU

2. BIOCONVERSION
The conversion of organic materials suchas plant and animal waste
into usable products or energysources bybiological processes
agents.
Source: Hermitica Bioconversion

3. WHY BIOCONVERSION?
Source: Hermitica Bioconversion

4. FACTSAND FIGURES
• According to FAO, nearly 1.3 billion tones of foods including fresh
vegetables, 66 fruits, meat, bakery and dairy products are lost along the
food supply chain.
• The annual amount of urban FW in 70 Asian countries could rise from 278
to 416 million tones from 2005 to 2025.
• FW is traditionally incinerated with other combustible municipal wastes
for generation of heat or energy.
• It should be realized that FW indeed contains high level of moisture and
this may lead to the production of dioxins during its combustion.
• In addition, incineration of FW can potentially cause air pollution and loss
of chemical values of FW.
• Total sugar and protein contents in FW are in the range of 35.5–69% and
3.9–21.9%, respectively.
• FW has been used as the sole microbial feedstock for the development of
various kinds of value-added bioproducts, including methane, hydrogen,
ethanol, enzymes, organic acid, biopolymers and bio- plastics
Source: Esra Uckun Kiran et al, 2014

5. BIOPRODUCTS FROM
STARCHWASTE
 LACTIC ACID
PROTEIN SYNTHESIS
AMYLOLYTIC ENZYMES
ETHANOL PRODUCTION
METHANE PRODUCTION
HYDROGEN PRODUCTION
XYLITOL
 ASTAXANTHIN

6. CONVERSION OF WASTE POTATO
STARCH INTO LACTIC ACID
FERMENTATION AND RECOVERY PROCESS FOR LACTIC ACID PRODUCTION(Tsai et al)
United States Patent.
• To provide an efficient process for producing lactic acid of sufficient
purity to make a degradable plastic of lactide polymers and copolymers
from a renewable biomass material in a sufficiently short process time to
render the entire method economically viable.
• To provide a process for converting industrial food waste to glucose and
lactic acid by the use of both enzyme and microbiological action, wherein
the processing time to produce over 90% glucose is reduced to less than
10 hours and the subsequent process time is less than about 48 hours to
produce lactic acid from the glucose.

7. POTATO WASTE
HOMOGENISATION
STARCH SEPERATION UNIT
STARCH SLURRY
LIQUIFICATION/ SACCHARIFICATION
LIQUIFIED STARCH
FERMENTATION
CELL SEPERATION- CELL MASS/CELL FREE BROTH
CRUDE LACTIC ACID
VACUUM EVAPOURATION
CONCENTRATED LACTIC ACID
PURIFICATION- EXTRACTION
PURIFIED LACTIC ACID

8. 1. A flow diagram of the preferred process of converting the potato
waste to high purity lactic acid.
2. The potato waste is fed to the homogenizer which can be a
hammer mill or Rietz mill, to produce a potato waste homogenate.
3. Separation of the potato starch from other components of the
homogenate, is performed in the optional starch separation unit
which includes a shaker screening and a settling tank or a
centrifugal separator.
4. The starch slurry is pumped to the liquefaction unit to produce a
liquefied starch. At pH 5 alpha-amylase is added with stabilising
material calcium chloride.
5. After mixing above components the material is heated at 90-130ºC
at 15psi for 15min.This process reduces microbial activity.
6. The material is then cooled at 50-70ºc at pH below 6.5.
7. After the temperature is lowered, glucoamylase is added in the
mixture .The incubation time is 4-8hrs for conversion of 90%
glucose.

9. 8. The potato hydrolysate is passed through filtration device
wherein the solids are separated from glucose- containing
filtrate.
9. The filtrate containing glucose is added with nutrients to
facilitate fermentation of glucose to lactic acid.
10. The fermenter is fed with microbial inoculum (mixed culture of
L.delbrueckii subsp. lactis, L. casei, L. helveticus) and nutrients
(trypticase peptone, yeast extract, tryptose and sodium acetate)
11. During fermentation, a sodium hydroxide solution is added to
the fermenter for pH control.
12. The fermentation broth containing cell mass and sodium lactate,
is processed by a cell separator which can be a centrifuge to
produce a cell-free broth containing sodium lactate solution and
a cell mass concentrate.
13. The cell mass concentrate is recycled to the fermenter and part of
it goes to waste.

10. 14. The cell-free broth is fed to the electrodialysis to generate a
sodium hydroxide solution (which is recycled for fermentation
pH control), and a crude lactic acid which is further concentrated
in a vacuum evaporator at 60°—70° C.
15. The concentrated crude lactic acid produced from the vacuum
evaporator is further processed in the purification process to
produce a purified lactic acid.
16. The purification process is done by extraction. The crude lactic
acid with an extractant (such as a tertiary amine in a water-
immiscible organic solvent) and back-extracting the lactic acid
from the extractant using a concentrated alkali solution (such as
sodium hydroxide) resulting in a lactate salt (e.g., sodium
lactate).
17. The lactate solution can then be processed by electrodialysis to
recover the alkali solution and a purified lactic acid.
18. The purified lactic acid is fed into the polishing unit, which may
include treatment by ion exchange resins and activated carbon.
19. The polished lactic acid is further concentrated in the final
evaporation to generate the final product, a high purity lactic
acid.

11. APPLICATION OF PLA
1. Bags for salads.The fast food
chain such as McDonald’s is using
PLA cups for packaging salads.
2. Coca-Cola is another company
that is looking to implement PLA
into its operation.They are
currently developing a PET “Plant
Bottle” that will contain 25% PLA
(Kalkowski).
3. Some of the most common uses
include plastic films, bottles, and
biodegradable medical devices
(e.g. screws, pins, rods, and
plates that are expected to
biodegrade within 6-12 months.
4. PLA constricts under heat and is
thereby suitable for use as a
shrink wrap material.
SOURCE: creativemechanism.com; PLA:A Critical Analysis

12. FUNGAL BIOMASS PROTEIN PRODUCTION
FROM STARCH PROCESSING WASTEWATER
• Bioconversion of wastes is a natural way of recovering useful
resources.
• Biotechnology can facilitate this natural recycling process.
• Biotechnological treatment of food processing wastes, which exist in
huge quantities, can produce a valuable end-product, e.g. microbial
biomass protein (MBP).
• The manufacturing of starch products from wheat, corn and potato
involves significant usage of water.
• This voluminous water usage results in the generation of substantial
quantities of wastewater. The vast quantities of starch processing
wastewater (SPW) have higher biochemical oxygen demand (BOD),
levels than town sewage, are highly polluting, and can impose heavy
loads on the environment or be expensive in terms of sewer disposal.
• The SPW, with a relatively high percentage of carbohydrates, cellulose,
protein and plant nutrients, represents an important energy-rich
resource.
Source: Bo Jin et al, 2002

13. STARCH HYDROLYSIS
• Microfungi of A. oryzae and R. oligosporus
possess a high amylolytic enzyme activity.
• The amylase enzymes are preferred for use in
fermentation for human or animal
consumption, and have been extensively used
in fermentation industries to produce
traditional beverages and fermented foods.
PROTEIN SYNTHESIS
• The fungal biomass contained more
than 45% protein and appreciable
quantities of amino acids.
• Safe for human and animal
consumption.
• Microfungi have a number of properties which make them important both scientifically
and industrially.
• They play an important role in the food industries, are known to have a wide range of
enzymes, and are capable of metabolising complex mixtures of organic compounds
occurring in most wastes.
• Cultivating microfungi to yield biomass protein is particularly attractive because:
1. Microfungal cells contain reasonably high levels of protein;
2. Microfungi contain a lower amount of nucleic acid than yeasts and bacteria.
3. Food produced from fungi is traditionally eaten in many parts of the world.
• Fungi can be grown using almost any waste products that contain carbohydrates, such as
confectionery and distillery waste, vegetable waste and wood processing effluents.
•The enzyme-producing fungal species of Aspergillus oryzae and Rhizopus oligosporus
were used for starch hydrolysis and protein synthesis.
Source: Bo Jin et al, 2002

15. ETHANOL PRODUCTION
• Without thermal sterilization, acidic condition is needed
to prevent microbial contamination and putrefaction
PRE-
TREATMENT
• a-amylase, b-amylase, glucoamylase and pullulanase
(catalyze the hydrolysis of a-1,6-glucosidic linkages) is added
• Small fermentable sugars (e.g. maltose, amylose,
glucose, and fructose) can be produced
SACCHARIFI-
CATION
• The fed-batch culture has been commonly employed for
the production of high concentration reducing sugars
which can be further fermented to ethanol (Compared to
batch culture, fermentation were both improved
significantly using fed-batch configuration, e.g. the glucose
bioconversion yield reached 92% of its theoretical value).
PROCESS
CONFIGURA-
TION
Source: Esra Uckun Kiran et al, 2014

16. HYDROGEN PRODUCTION
Hydrogen (H2) is used as compressed gas and has a high energy 225 yield
(142.35 kJ/g). FW rich in carbohydrate is suitable for H2 production.
• Hydrogen production potential of carbohydrate-based waste was
reported to be 20 times higher than that of fat-based and protein-
based waste.
• H2 yield was found to increase at lower C/N ratio.
SUBSTRATE
COMPOSI-
TION
• FW itself can be a source of H2-producing microflora. Lactic acid
bacteria are the most abundant species in untreated FW.
• Heat treatment is effective for suppressing lactate production
and increasing H2/butyrate production.
PRE-
TREATMENT
• The optimum pH for H2 production from organic waste ranged
from 4.5 to 6.5.The accumulation of fermentation products, i.e.
CO2, increases the acidity and then inhibits the microbial growth.
• Such fermentation products can be removed by simple gas
sparging and addition of alkaline.
PROCESS
CONFIGURA
TION
Source: Esra Uckun Kiran et al, 2014

17. METHANE PRODUCTION
The production of biogas, particularly methane via anaerobic processes is an
acceptable solution for waste management because of its low cost, low
production of residual waste and its utilization as a renewable energy source.
• Single-stage anaerobic digestion process has been employed for
municipal solid waste treatment.
• As all of the reactions take place in a single reactor, the system
encounters less frequent technical failures and has a smaller
investment cost.
• The anaerobic digestion can be wet or dry. Compared to wet
anaerobic digestion, dry anaerobic digestion provides lower
methane production
Single-
stage
anaerobic
digestion
• Two-stage anaerobic digestion has often been used for producing
both hydrogen and methane in two separate reactors.
• In the first stage, fast-growing acidogens and hydrogen
producing m/o are enriched for the production of hydrogen and
volatile fatty acid (VFAs).
• In the second stage, slow-growing acetogens and methanogens
are built-up, whereVFAs are converted to methane and carbon
dioxide.
Two-
stages
anaerobic
digestion
Source: Esra Uckun Kiran et al, 2014

18. Xylitol is a sugar alcohol derivative of xylose, valuable as a sugar substitute. Xylitol is
equivalent to sucrose in sweetness, but unlike sucrose it is anticariogenic and metabolized
by an insulin-independent pathway. Xylitol is used to make mint, candies, toothpaste.
Conventionally produced by a chemical process from birch wood chips and is relatively
expensive at about $7 kg.
It has been suggested that a bioconversion process could offer a more economical
alternative. Numerous yeasts convert xylose to xylitol,particularlyincluding species of
Pichia and Candida.
Astaxanthin is the carotenoid pigment that gives salmon their characteristic color. The
pigment is important for consumer acceptance and also may have health benefits. For
farm-raised salmon, astaxanthin is an expensive feed supplement.
The red yeast Phaffia rhodozyma is a natural source of astaxanthin that has been
commercially developed as an aquaculture feed supplement.
Five naturally occurring strains of P. rhodozyma have been tested for growth and
carotenoid production on a standard laboratorymedium and on media containing only
clarified corn residues in distilled water. Source:Timothy D et al,2002

19. BIBLIOGRAPHY• FERMENTATIONAND RECOVERY PROCESS FOR LACTIC ACID PRODUCTION(Tsai
et al) United States Patent.
• https://www.creativemechanisms.com/blog/learn-about-polylactic-acid-pla-
prototypes
• PLA: A Critical AnalysisCasey Kingsland Mohawk College of AppliedArts and
Technology
• www.hermiticabioconversions.com
• Bioconversion of food waste to energy:A review, 2014.Esra Uckun Kiran, Antoine P.
Trzcinski,Wun Jern Ng,Yu Liu. Advanced Environmental BiotechnologyCentre,
Nanyang Environment &Water Research Institute.
• Bioconversions of maize residues to value-added coproducts using yeast-like fungi,
2002.Timothy D. Leathers Fermentation Biotechnology Research Unit, National
Center for Agricultural Utilization Research, Agricultural Research Service, United
States
• A comprehensive pilot plant system for fungal biomass protein production and
wastewater reclamation (2002) Bo Jin, X.Q.Yana, Q.Yu, J.H. van Leeuwen