UP

1
UPs part of WP 2 The Whole Gory Story (but
fortunately for all concerned in a very shortened
form)
2
Extraction of sorghum with aqueous ethanol (70)
sodium hydroxide and sodium metabisulphite
yields pure kafirin Addition of Sodium
Hydroxide improves the yield of kafirin, also
makes it more soluble, less prone to gelation
gives it better film forming properties
No NaOH
With NaOH
3
Method for casting free-standing films with
aqueous ethanol
4
A plasticiser combination of equal parts
Glycerol, Polyethylene glycol 400 and Lactic
acid found to be satisfactory for making kafirin
films
Brittle film
Plasticised film
5
Glacial Acetic Acid, Lactic Acid and Aqueous
Isopropanol identified as alternative food
compatible solvents for kafirin
6
Extraction of sorghum with Glacial Acetic Acid
after pre-soaking with Sodium Metabisulphite
gives high yield of pure kafirin
7
Kafirin can be extracted from both white and red
sorghum bran
8
Free-standing films can be made from kafirin
extracted from sorghum bran
9
Tannic acid (a Hydrolysable Tannin) and Sorghum
Tannin (Condensed Tannin) can cross-link with
kafirin
10
Kafirin films with modified properties can be
made from kafirin cross-linked with tannic acid
or with sorghum tannin  Modified films have
increased tensile stress and decreased tensile
strain and oxygen permeabilityWater barrier
properties unaffected

SCT
TA
11
Kafirin films made with different levels of
Glycerol, Polyethylene Glycol 400 and lactic
acid   Principal Component Analysis showed that
the most effective Plasticisers for kafirin films
are the Associated Moisture, Glycerol (G) and
Polyethylene Glycol (PEG)   Lactic Acid (LA) is
an essential component of plasticised kafirin
films, but probably as solvent rather than a
plasticiser
12
Glucono delta-lactone (GDL) when present with
lactic acid was found to have potential as a
kafirin film plasticiser
GDL ( relative to protein wt) Stress (N/mm2) Strain ()
0 28.6 2.6
21 15.4 13.8
42 9.7 23.1
13
Journal papers   Emmambux, M.N. and Taylor,
J.R.N. 2003. Sorghum kafirin interaction with
various phenolic compounds. J. Sci. Food Agric.
83 402-407. Da Silva, L.S. and Taylor, J.R.N.
2004. Sorghum bran as a potential source of
kafirin. Cereal Chemistry 81
322-327. Emmambux, M.N., Iannace, S. and
Stading, M. 2004. Cereal biopolymer films,
coatings and other industrial products.
Chemical Technology (1) 27-31 Taylor, J.,
Taylor, J.R.N., Dutton, M.F. and De Kock, S.
2004. Identification of kafirin film casting
solvents. Food Chemistry (In press). Emmambux,
M.N., Stading, M. and Taylor, J.R.N. 2004.
Sorghum kafirin film property modification with
hydrolysable and condensed tannins. Journal of
Cereal Science (In press) Da Silva, L.S. and
Taylor, J.R.N. 2004. Physical, mechanical and
barrier properties of kafirin films from red
and white sorghum milling fractions. Cereal
Chemistry (In press) Gao, C., Taylor, J.,
Wellner, N., Byaruhanga, Y.B, Parker, M.L.,
Mills, C. and Belton, P.S. (2004). Effect of
preparation conditions on protein secondary
structure and biofilm formation of kafirin.
Journal of Agricultural and Food Chemistry (In
press)
14
Deliverables   D4 Kafirin protein from sorghum
bran, Report Extraction of kafirin from red
and white sorghum milling fractions. L S da
Silva, December 2002 D5 Screening of
food-compatible non-ethanol kafirin extraction
methods. J Taylor, December 2002. D6 Casting
of free-standing kafirin films and investigation
into film preparation and film properties using
food compatible non ethanol solvents. J Taylor
December 2002 D16 Modified kafirin films
(cross-linked, plasticised and combined
cross-linked and plasticised) J Taylor, August
2004 D17 Sorghum kafirin film property
modification with hydrolysable and condensed
tannins. M N Emmambux, M Stading and J R N
Taylor, August 2004 D21 The physical
properties, including biodegradability of
modified kafirin protein films. J Taylor, M N
Emmambux, H van Eck, Y B Byaruhanga and J R N
Taylor, August 2004 (actually part of WP3)
15
Exhibitions   Sorghum Protein Films. Science at
the World Summit on Sustainable Development,
CSIR, Pretoria, August 2002   Sorghum and
Sorghum Protein Biofilms. University of Pretoria
Open Day, May 2003.   Out of Africa Sorghum the
Sustainable Cereal. Royal Society Summer
Science Exhibition, London, July 2003