الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
SUMMARY
Tannins affect food taste and qUality, inhibit digestive
enzymes, bind protein and lead to decrease nut~i~-
tional varue of foodo This research was carried out to
study tannins in broad beans, dates (Samani, Zaghloul,
and Siwi varietie$)and tea (Ceylon and Indian). The study
included some treatments to bind o~ remove t~ins from
tae materials used. This study included the following
points:
10 The a.e’CeL·mination of moisture, sugars,protein and
amino aeids content in the used materials and thei.r
treatments,
2-, ~he determination of phenols and tannins using five
metnods.
30 Fractionation anQ ~dentification of tannins and
quantitative determination of separated tannins.
4. Inhibition effect of tannin fractions on trypsin,’
pepSin and amylase enzymes.
50 Dece.cmfnata on of antimicrobial activity of tannin
i’ractions on ll)scherichia C.?li, Bac111usj’ycoid ,
Sarcina Lutia, Nocardia!E, .§~ecbaromy~es_ ce~ev1siae
and Aspergi~~ua niger.
Tae obtained results §WJlDlarized”as’follo.ws£’: ~~.’..:’:~”
l~ Steeping bro~d bean for 16 hrs led- to increase in
’the moisture content also baking process increased ~
the moisture conten-c also baking process increased
the moistu.re content in broad beans, while adding
milk powdcz- to the baked broad beans (BBB) reduced
it. ’.~.~.
Treated dates had; moisture content moBe than.
’the fresh dates. Ceylon tea contained moisture
(6.91%) slightly higher than Indian tea (6.6?%)~
20 Bread bean~ contained manitol glucose, fruc.tose sucrose and oJ: marcose and raffinoseo The steepi.D.gpz-ocee.a
lead ~o increase the concentration o~ sugars from ’.’
ana 00116 for manuit;al, glucose, sucrase and or
•..~. maltose and raffioose respectively. ~ose appered
ai’C€j’ steeping :for 8 and 16 hr-s , The baking process
causeci ~he decrease of glucose, fructose and sucrose
and! or mal to se and disappear of mannose.
_ill studied dates varieties contained lJlB.Ditol.
Slucose) fructose, sucrose and/or maltose While raffinose
was fOWld in IISiwin dates. SOakiI:J.iof dates led
~o increase glucose from 44.085 to 49.98% and decreased
slightly raffinose and sucrose and/or maltose.
Indian ana Ceylen tea contained manitol, glucose,
sucrose ~d/or maltose and raffinose with concentration
of 0.060, 2.102, 0.330 and 0.042% for Indian tea and
0.080, 1.946, 0.423 and 0.035% for Ceylen tea respectively.
Fructese was found in Indian tea but mannose
(0.098) and trihalose (0.008%) were only found in ,
Oey.Lcn ”tea •
.5D Brxad beans had. 23D321% Protein which decroased to
··.·r’·
22.81 allQ 22.660 by steeping for 8 and 19 hrs~
respectively, also decreased to 22.500%.by baking
procoss but increased by adding 2% milk powder to
23.1000 St~eping and baking procoss increased some
amino acids and r-educed othar amine acids, The
adaac Lon or milk powder didnot increase all maino acids •
.IISamanylt, ”Zagh.Loul,” and ”8iwin dates had
}0810, 4.300 and j.336% protein contents which
dacr~ased to a.?OO, 4.077 and 3.115% by seaking ~ne
da.ces in. boiling water for two min. The soaking r....
’trea”ClC.e!1{;S did.mo,t reduce all amino acids but few
~ino acids had increased or appeared~
Indian and ceylon tea contained 20.000 and 19.099%
pro{;ein respectivelyo
4. Falin-Denis (FD) and prussian blue methods were
used for determination of total phenols, prussian .
blue arid tam1in~rotein precipitation methods for
total tannin aeterillination, l,2~diphenol, FD, vanil~
lin-del and prussi’Qn bLue inethods for non-tannin
phenol determination, and 1,2-diphenol, FD, vanillin
-HOl and weight me~hods for determination of low
anu aiga molecutar weight tannins. The results of
~revious methods indicated ~hat:
Q.o B~oad. beans
.ill phenols decreased, generally by steeping
for 8 and 16 hrs but total tannins increased from
O.~22 to 0.470 by steeping for a hrSD «hen
c..s”ternnedby prussian blue methods ,also HilI1WT
increased by steeping for 16 hrs from 0.034 and
0.05.2 .co 0.040 and 0.064 when determined by’FD
raYJ.Q varll.lin-HCL methods respectively!
The LMWT increased in baked broad beans (BBB)
to 0.215% when compared with BB by using FD method
wnile F.MWT and non-tannin phenols decreased to
0.560 and 0.076%. respectively. The addition of
milk powder to BBB led to decrease of all phenols.
Tha anthocyanidin of BB decreased from 0.366 to
0 ..5.50 and 0.30’::>% by steeping for 8 a.n~.16 hrs ,
.” :. respectively and increased by baking of broad
bean seeds to 0.4-30%. The addition ~.fmilk powder
improved ”the quality by decreasing th~”anthocy- .: ~-I.
auidin and total phenols to 0.360 and· 0.54-5% when.
bo Date fru.its
Total phenOls, total tannins and LYWT decreased
by boiling in water, while non-tannin phenols,
HdWT and anthocyanidin increased. Total phenols
decreased from 10686, 1.925 and 1.900 to 1.425,
1.699 and 10707, and LMWT decre~ed from 0.110.
0.197 and 00311 to 00012, 0.070 and 00105% for
”” •. • II I •
Sanam., ?aghloll1 and Siwi. fresh and treated dates
respectively when determined by FD metnod. also
~o~al tannins decreased from 0.400, 10100 and
0.670% to 0.306, 0.697 and 0.~9% for Ssman1.
Zaghloul aud Siwi fresh and treated dates, respe~-
Lively when determined by prussian blue metho~.
The .non-tannin phenols inereased from 1~166t
lo56 Q.L.d 1,,295 to 1.201, 10590 and 1.’89 :for fresh
and treated dates of Samani, Zagh10ul and Siwi
varieties, respectively when determined by FD method,
~lso ~WT increased from 00023, 00069 and 0.030 to
0.053, 0.095 and 0.051% for the same previous
order, respectively when determined by FD meth0C!:e.,.
The statistical analysis revealed ~hat there is
no~ significant difference between FD and prussian
blue methods in determination of total phenols,
olso there is not significant difference between
dates var~eties before and af~er treatment. Total
cannins had high significant difference when
~dt~r~ned by prussian blue and tannin-protein
precio.itation methods..’
There is significant difference betweenpr-used an blue and any of other methods when detertining
non-tannin phenols. There is not any-signify
icant a.ifference between the different varieties
of da~es w~d ~he1r treatments~·
In the case of LMWT, there is not any significant
d.ifference between the different· methods used.
F vest indicated high significant difference
~ong the differeAt date varieties and their treat-
illents. LoS.D. test indicated that Siwi dates has
highest value of LMWT and there is high significant
.~ • r . difference between 8iwi dates and each. of Zaghloul
and Bamani dates~
S~atistical analysis revealed that the traated
dates has significant decrease in ~t ThU ~mean;.
~nat soaking da~es in bOiling water for 2 min lead
.
to reduce the ~VT which in turn im~rove the taste
of the datie s, Also Siwi dates has the highest
average o.r H.riWT content and soa.k.iJlg ..Jn boiling
wa~er had not significant effect on·HMWT
Co Tea
There was not significant difference in total
ph~nols between Indian and Ceylon tea andolso
between pz-uss.i.an blue and FD methods. Total tannins
did not indicate significant difference between t
tne two varieties or between the used methods.
TU0re was high significant difference between all
the used methods except the difference between 1,2
-uiper-d and PD. methods which was signi~icant.
Ceylon tea contained higher concentration of
LmWT.than Indian teawith significant d~~ree. So
the 4S~ringent taste which is related ·to LMWT is
hi6her in ceylon tea than lndian teao .There was .’
nov significant dif’.fe~ence between the used methods
or bet~’weenthe vareties of teao”
An thocyanidin results indicated ~hat.the cooaent-
J:’atiou ot: flavan coapounds in Indian tea is JaiP,er
than in ceylon teao The addition of milk powder
to ”teabeverage led to decrease all phenol fractions
(non-tannin phenols, LMWT, and BMWT)~
5. By soJ?a.rationof tannins in broad beans ·’”(BB) on paper
chroilla~ograpay, it qas fOQnd that: of •• ~
a. Broad beans
··.·r·
By increasing steeping time of BB~ the m~~er
~ • > •
OI separated spots decreased and the baking process
decr-eased the number of separated spots from 19 tp 80
Hl’viWT
The BE contained 21 spots, BBS 8 contained 13
S?ots, BBS 16 contained 11, BBB contained 26 and
~ffiBB contained 1? spotSD”
b. Date fruits
LMwTof .Samar.l.idates were separated to 8 spots,
of Za6h1ou1 dates were separated to 8 s,ilots and of
S i.wi dates were spar-aced to ? spots.
By treating dates they were sepa~ted to 3., ,
&~~ 3 spots for tr~~ted samani, Zaghloul and S~wi.
repectively.
H1lliT of aamani, Zaghloul and Siwi dates were
S~yorated to 10,8 and 19 spots and decreased by
t~oating to 7,6 and 8 spots respectively.
ell Tea
LIi:h’lT of Indian ’teawere separated to 12 spots
and C~y1on tea were Separated to 12 spots. HMW~
of Indian and Ceylon tea were separated to 12 and
11 spo~s resp~ctive1y.
60 Inhibi~i~n of enzymes by tannins
ao The ~rypsin enzyme was inhibited by LMWT of all
L::=”::0.::::i als VI;:’th different percentages. The’ steeping
ai BE and addition of milk powder to BBB led to
UVC4’Case the inhibition .;tfect o:fta.n.nin OD. ~a.6 ..
~~sted enzymes. Also in the dates treated with”
boiling water, the inhibi~n eff~ct or LUWT •
rne trypsin enzyJII-’!\,as inhibitAd by LilrlWT ot ceylon
than Indian tea.
ffiJf.~Tof steepi~ broad bean see da had inhibittnn
effect on ”ChA enzynu~ leSS than BB, but the addi tian
0:: mi.Lk powder ltUl . to increasA this i.nb.lbi t:1.on
effecl;.
3A~T o~ aate fruits have. Inhibiton etreet on
~he enzyme and this inhibition was decreased by
~reating the dates with boiling water. Also, HYW~
of the two tea varieties had innibition effect on
”Ch~ -c’-yp.ti:in enzyme.
o , Pep s Ln enz yma
LMWT of steeping BBS had higher inhibition effect
” ” on pepsin enzyme. also the baking process revealed
inhibition effect on the enzyme but the addit.ion of
llIilk powder reduced the inhibition effect •
LMWT of date frQits had some inhibition effect
on pepsin enzyme except LMWT of Siwi dateso Also
Indian and Ceylon tea had high effect on tha
~nzJme inhibi~ion •
HMWT of BBB 16 had inhibition effect (82.00%)
Les s than BB (100%) and BBS 8 (100%): ~ By processing
BB to produce BBB its HMWT had less inhib1tion
~ff~ct (64.90%) than BB also MBBB decreased the
inhibition of enzyme to 62000%
”H~WT of treated dates had ~~ibi~iou e£fect on
enzJ~e less tcan the fresh dates! Also ~ of
~ey10n~~a had high inhibition effect (100%) than
- IfF -
I~dian tea. (60.00%) 0
Co oe-Aillylaseenzyme
ste,;;pj.ugbJ:cad beaas led’ to decrease in the
iru~ibi~ion effect of &-amylase. Baking of BB increased
the inhibition of ~amylcse but When milk
powder was add~d the inhibition effect 9£ ~-amyl~
ase e~3J~e decreasedQ
:u.iWT of the treated dates had less’; inhibition
effect than that of fresh dates, on the enzymeo
UiWTof’ Indian and Ceylon tea had ·the maximum
illilibition on ~-amylase enzyme!
EW~VT of BBS 8 and BBB 16 ~ed to decrease the
inhibition from 97% of BE to 71.66 and 66% respectivelYt
also the addition of mil~ powder. to BBB
l;d to decrease the inhibition of ~amylQse
enzyze from 97000 to 95.00% 0
.fuiJ.WT of’dates head to deorease in.the inhibition
effect of ~-amylase by treating from 40 and 27.% to
10% for eaca of Zaghloul and •Siwi ’dated. while in
’Samani’ dates the inhibition increas~d f~om 11 to
20%••
HMWT in Indian teachad inhibition effect (54%)
~ore ~han in Ceylon tea (190370%)
70 By s~Qding the difect of tannin fractions-on some
illicr~o~banisms(~•c•herichia coli, Bacillu,..:s mycoid, J
Sa.r:’cinaIlltia;Nocardia sp!, saccharom.yces cere171s-iaf”’;0
ana Asoergillu~ ni~er)o ,It was found that:
LMWT of BB had antimicrobial effect on Eo c-oli
~~~ S-.,..lu~ti.a-.- only.. LMWT of BBS 8 had inhibit on effect
on tine growth of B. mycoid, S.,! 1utia_, and Sac,_
cere~iae , bQ~ the steeping for 16 hra prevented the
inhibition effect and only So lutia was inhibited,
BBBhad inhibition effects 011 E.coli and Bomycoido
The add.i,tion of milk pa.der to BBB Led to low
Lnh.Lb L1;wn effect on Eo mycoid and ~_ lU1iia..
~’\VT of BB had inhibition effect on A. II!Ycoid and
BB2 (3 had lc’,’! iuhibit:l.on o:ffec-t on l!.:-- !DYcoid and
S•• lQt~§. out the sueepang for 16 hours prevented all
innioi tion effdcts. Two organisms (~~:·,-mycoid and !.!
nig;er) were i~ibi ted by HMWT of BBB rFoul Medammes)
but the addi~ion of milk powder (MBBB) led to remove
tile inhibi tioe. effecto
Lil£~”T of ”Samani II· dates had low inhibition on S-ac’o
carevisiea and Ao . niger and by trealing .’Samani’ dates
tne inhibition was found with -Eo-co-li, Nocardia s-P. and
it.. niger ..
LJitiWT of ”Zagh.Loul,” dates had low inhibition effect
on Sac. cerevisiae .., this effect didnot change by treating
Doiling watero LMWTof ”Siwi” dates had inhibition
er rec c on Sac •• cerrviaiae’ and A. niger and by treating
E. coli and Sac. carlVisiae. were inhibited.
HM~ of ’Samani’ dates had ligh inhibition ~fect
on 40 niger but by treating the dates.no inhibi tn’.on
cccur-ad;
F~WT of Zaghloul dates had low inhibition effect
on A••uie;aT. and by treating E.~. :!!niger was inhibited
’-;;,yffilIWT of • Siwi’ dates and by boili.,og in water
fOl’ 2. lllin. tc.Ls inb.ibi tn on was removed b.llt E~.col.i -was
in”nibi ted.
LMWT of Indian tea had aigh inhibition effect on
E~coli and So lutia but its HMWT had the inhibition
&ffec~ on -Eo’-coli only,
LUWT of Ceylon tea had inhibiton effect on ~
~”. S.lu.lia SJ.1.d Nocaria ~. t While HMWTinhibited
Tn.e ,;>henoliccompounds had inhibition effect on
difi’e.r:’ent (nicroorgonisms depending on the phenoi
CO~D.pound.s~
It may be ”concluded that for binding or removing
vannins ~he follOWing treatments may be recommended:
Broad bean should be steeped bafor baking and prptein
source may be added to the broad beant( Foul Medammes ).
Da.-t;es containing ~igh It:vel of tannins in matillr@
s~ag0 (~~alal stage) such as ’Siwi’ variety and to
reaQce the as~ringent ~aste Dates may b’ treated by
~~~)ing in boiling water for two minuteso
Tea had. high tannin con:teuj; ~ and the addi tien of
mi.Lk)revent nne effect of tanaino