الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
This investigation was carried out on some milling by - products of hard
red winter wheat(T.aestivum ) introduced from U.S. A. and obtained from
EL-Hoda and EL-Marwa mills ( North Cairo flour mills Co. ) •
The physical and chemical characteristics of wheat kernels and wheat
milling by - products in addition to flour streams, diagram flour grade 2,
commercial flour grade 2, patent and 72 0/. flour extraction were studeied. The
rheological properties of some flour streams and of mixing exhaust or bran ( in
the percentages of 10, 20, 30 ,and 40 %) with wheat flour 72 % extraction
rate, also, mixing bran flour ( 10 , 20 , 30 , and 40 % ) with exhaust flour were
studied. These blends were used to produce pan - bread which was
organolipticaUy evaluated .
The physical properties : -
The physical properties of hard red winter wheat kernels ( T.aestivitm” )
indicate that hectoliter weights were 80.7 and 79.5 kg I HL while 1000 kernel
weight were 37.2 and 28.69 for EL - Hoda and EL -Marwa mills • The
difference in 1000 kernel weight could be due to the source and time of
importing wheat kernels .
:fhe chemical properties of wheat kernels and wheat by - produts:-
Data concerning the chemical properties of wheat kernels and wheat bypreduets
show that the kernels had 11.5 and 11.9 % moisture content.
]~L-Marwa kernels and it’s by- products had higher ratios of moisture content
~”hich could be attributed to it’s higher water absorptie& during condi1ioaing.
Also, EL - Marwa Kernels ash content ( 1.99 %) was. higher than that of EL -
Hoda mill (1.68 0/0 ) • Coarse bran had highest ash coatent ( 5.82 and 6.05 Ok
} comparing with other mill fractions while red dog had the lowest ash content
(3.54 and 3.78 %).
Crude protein content of hard red winter wheat kernels ranged between
11.99 to 12.36 % • EL- Hoda mill wheat germ. had lower crude protein content
” 17.89 0/0) than that produced from EL- Marwa mill (25.06 %) which could
be attributed to less purity and bran conta niin:ation ’.•
Lipids content of wheat kernels ranged between (1.66 to 1.7 0/0 ) and
wheat germ. characterized by it’s higllest lipids content ( 11.33 - 11.67 % ).
In general the results indicate that most of the lipids content are found in the
germ and in the outer layers of kernel which produce shorts, coarse and fine
bran.
Sugars content results showed that hard red winter wheat content 2.47 -
2.62% sugars while wheat miJIiog by - products (fine and coarse bran, red
and white dog and wheat germ characterized by it’s high total soluble sugars
content. High reducing sugars maybe due to longer conditioning time and
humidity which increase the activity of alpha amylase. Also, -high. suagrs
content could be attributed to the presence of aUeurone cells and wheat germ.
particles.
phytate posphorous content of wheat kernels ranged between 0.30 to 0.35
Ok while, wheat kernels by - products hadlliigher phytate phosphorous
content ( 0.91- 1.24 0/0). High phytate phosphorous content could be
attributed to the presence of alleUl”Olle cells and wllest germ partides. Also,
there is positive relationship betweeD ash aad playtate pIaosphorous CODtent•
rhe chemical composition of wheat flour grade 2 streams: _
Moisture contents of final flour of break stages and final flour of
’eduction streams ranged from 9.0 to 13.4 % and 12.9 to 14.8 % for EL-Hoda
md EL- Marwa mill respectively while , the final product ( 72 % flour)
neisture cootents were 13.9 and 14.2 % for the same mills.
Ash contents of flour streams which mixed to make diagram Oour grade
, in both EL-Hoda and EL- Marwa mills ranged from 0.66 to 2.44% and 0.59
[) 2.23% respectively . Ash content of these streams was higher than that of
latent flour ( 0.45 and 0.46 %) and white Oour 72 % extraction (0.50 and
.53 % ) •
The protein content of :Oour streams from EL-Hoda and EL- Marwa
liDs ranged from 9.24 to 14.26 % and 10.95 to 16.97% while patent :Oour had
.63 and 10.74 % and Oour 720/. extraction had 10.69 and 11.39 % protein
entent •
There is a positive relationship between protein and ash content for the
s lme stream and also, a positive relationship between protein and gluten
c )otent of the same stream except the Ooor mill· streams which contains
n )oglutenous protein from the aleurone layer cells..
Total lipids content for both EL-Hoda and EL- Marwa mills indicate
at Dour streams grade 2 had high values ( 4.33 - 3.66 % ) and ( 1.33 -4.66 %)
bile patent and 72 % eItradioD flour bad (1.33 - 1.06 %) and ( 1.33 %)
r spectively.
Flour streams whicb bas less falling number was high in its ash content.
1ls0,faUing number reflects the alpha amylase activity. Exhaust flour had the
highest alpha amylase activity than aU other streams.
Bran and KLM flour characterized by it’s high reducing and total soluble
ugars in addition to it’s high cc - amylase (low falling number). Also, patent
nd 72 % flour characterzed by it’s low non reducing and total sugars than
hat of other mill streams.
Results indicate that copper contents were relatively constant- iDspite of
difference in ash contents. Phosphorous, calcium and potassium forms the
lajority of minerals content of both flour and by - products.
’he rheological properties of some milling streams:-
be farinograph characteristics of some milling streams:-
The farinogram of some milling streams obtained from EL-Hoda mill
. ldicate that exhaust Oour had the higher values for water absorption, dough
stability and Valorimeter value while it’s douch weakening was the lowest one.
m the other side, patent flour had the lower rheological properties which may
e due to its low protein ( 9.63 % ) and gluten ( 26.9 % ) content.
EL-Hoda diagram flour grade 2 bad high dough stability and
a10rimeter value and low degree of softraing than the commercial flour grade
2 which could be attributed to the proteia and eluteD q_tity and quality.
Although commercial flour grade 2 contains higher gluten ( 39.2%)
an diagram flour grad 2 (32.8 % ) its rheological properties is lesser than
hat of diagram flour grade 2 • This may be due to that commercial flour
onsist bran flour and exhaust flour which the first distroys the g1utenious
atrix network and weakened the rheological properties •
m chracteristics of EL-Marwa millin streams:
The results show that diagram flour grad 2with its low ash ( 1.02°k)
nd high gluten (37.4°../0) content showed true dongh strength. The dough of
M flour had high degree of softening ( 100 B. U) and low valorimeter
alue ( 46 ) comparing with patent and 72 % extraction flour dough. Dough
oftening ofKLM flour may be attributed to it’s low gluten content ( 16.97 %).
flour high ash (2.23 % ) content affect on its rheological
h of some flour streams obtained from EL -Hoda and
1- Marwa mills :-
Results show that diagram flour grad 2 had higher strength properties
n that of the commercial flour grade 2 in both EL - Hoda and EL-Marwa
• High strength properties could be due to the quantity and quality of its
.gh gluten content . Exhaust flour had the highest dough strength ( area ]OS
mZ
) and extensibility ( 277 mm) and the lowest proportional number.
Bran. and KLM Oours obtaiaed •.•.•• die two ••• bad tile lowest area
other fIoun which may be attribllted to less gIateo contents ( 5.04 and
2.44 %).
On the other side mixing bran flour at ratios 30 and 40 % show
increment in dough stability and valorimeter values while degree of softening
increased. Such trend could be due to high water absorption of hemicellulose
( pentosane ) content of bran flour and to its particle effect on gluten shearing.
Extensograph test proved that dough extensibility, resisitance to
extension, proportional number and strength values were decreased as the
added bran flour ratio increased . Bran flour addition weakened the dough
strength due to it’s low gluten content inspite of its high protein content.
The rheological characteristics of mixing bran Dour with exhaust flour:
Farinograph test showed that as mixed bran flour ratio increased. water
absorption ratio, dough arrival time , development time, stability and
valorimeter values were decreased while softening was increased. Also, bran
flour addition weaken the dough due to gluten dilution beside bran particles
effect on gluten shearing.
All of the extensograph parameters were gradually decreased as the
added bran Dour ratios increased • Therefore , addition of bran flour to
exhaust Bour weakened dough strength due to its low gluten content.
The organoleptic evaluation of pan - bread :-
A- Pan bread produced from wheat Bour 72 %and exhaust flour :
Sensory evaluation showed that pan bread produced from blend
containing 10 % exhaust Dour had bighest weight, ”olome, specific ”olome and
score coapariDg with control and other blends.
B- Pan bread produced from flour 72 % and bran flour:
It is obvious that the suitable blend to produce pan bread was 90 Ok
wheat flour and 10 % bran flour. It had high specific volume and total bread
score comparing with other bread blends but lesser than 100%wheat flour.
c- Pan bread produced from exhaust flour and bran flour:
The results indicate that increasing bran flour percentage increased pan
bread weight while, volume and total score decreased. pan bread which
contains 10 °kbran flour is prefered than others ( 20 , 30 and 40 % bran flour)
due to its moderate amount of bran flour.