bao ca cao invertase

7/31/2019 Bao CA Cao Invertase

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I. T VN Trong tnh hnh hin nay, khi m mc cnh tranh cng ln th vn cht lng

cng phi c quan tm v ch trng. Ca cao l cy trng v ang mang li thu nhprt ln cho b con nng dn mt s vng Ty Nguyn, Nam Trung B v ng BngSng Cu Long, nhng theo mt s thng tin gn y cho thy cht lng ht ca cao Vit

Nam ang gp phi mt s tr ngi ln nh mc ln men cha cao, axit cn thpcho d n c du hiu ci thin dn v cht lng. Xut pht t thc t hin nay v datrn cc nghin cu trc chng ti tin hnh th nghim b sung enzyme vo trongqu trnh ln men ht ca cao, vi mong mun s iu khin c qu trnh ln men theong hng, ci thin c cht lng sn phm v mang li hiu qu kinh t.

II. NI DUNG V PHNG PHP NGHIN CU1. i tng v vt liu nghin cu

- S dng ch phm enzyme invertase.- S dng qu ca cao chn k thut, khi lng t 0,5 1 kg thuc dng

forastero v trinitario, hi t vn kinh doanh ca Cty EAKMAT.

2. Ni dung- Nghin cu liu lng enzyme invertase thch hp cho ln men ht ca cao.- Nghin cu thi im b sung invertase thch hp cho ln men ht ca cao.

3. Phng php nghin cu- Th nghim 1: Nghin cu liu lng enzyme invertase thch hp cho ln men,

s dng 3 cng thc vi mi cng thc l 25kg ht ti v tin hnh 2 ln nhc.CT1 liu lng enzyme 40ppm, CT2 liu lng enzyme 60ppm, CT3 liulng enzyme 80ppm v C1 i chng (tt c u ln men 6 ngy vi 2 lno).

- Th nghim 2: Nghin cu thi im b sung invertase thch hp cho ln men,

s dng 3 cng thc vi mi cng thc l 25kg ht ti v tin hnh 2 ln nhc.CT4 b sung enzyme ngay t u (0 gi), CT5 b sung enzyme sau 24 giln men, CT6 b sung enzyme sau 48 gii ln men v C2 i chng (tt cu ln men 6 ngy vi 2 ln o).

- Ch tiu theo di: Nhit ln men, hm lng nht, hm lng v, im sln men (CTS), pH, TA, th nm. s liu thc nghim c x l theo phnmm thng k Excel v Sas.

- a im thc hin: Phng th nghim sinh ha v cng ngh sinh hc VinKHKT NLN Ty Nguyn.


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III. KT QU NGHIN CU1. Kt qu xc nh liu lng enzyme invertase thch hp cho ln men ca cao

Bng 3.1 Nhit khi ht trong qu trnh ln men ht ca cao

trn gia di trn gia di trn gia di trn gia di trn gia di trn gia di trn gia di

CT1 25.5 27.0 26.4 28.1 26.9 26.0 33.4 30.2 27.6 39.5 34.9 28.7 42.1 39.1 35.3 41.9 40.1 37.7 43.8 44.5 42.3

CT2 25.5 27.0 26.4 28.1 27.0 26.1 33.2 29.9 27.4 38.2 35.7 31.5 39.3 36.3 32.9 41.6 41.2 39.4 42.8 43.1 41.9

CT3 25.5 27.0 26.4 26.8 26.3 25.7 31.9 29.0 27.0 39.3 34.8 30.1 39.2 35.3 32.2 38.5 35.5 34.3 43.8 43.9 40.8

C1 25.5 27.0 26.4 28.0 26.5 25.5 35.2 31.8 28.1 39.4 35.4 31.6 40.5 36.1 31.6 42.1 41.9 40.0 42.5 41.9 39.4

MT

CTNgy 5 Ngy 6

26.8 24.6 23.4 24.1 22.8 21.3 21.4

Ngy 0 Ngy 1 Ngy 2 Ngy 3 Ngy 4

Bng 3.2 Tc thot dch nht (hm lng cm nhy) trong khi ln men

28.05

9.138.256.29

10.62

0.00

5.0010.00

15.00

20.00

25.00

30.00

Ngy 0 Ngy 1 gy 2 Ngy 3 gy 4 gy 5 gy 6

%

T1

T2

T3

C1

Bng 3.3 Hm lng v v CTS sau khi ln menCng thc Hm lng v % CTS (cut test score)

CT1 15,33 839,17aCT2 15,87 892,50aCT3 14,70 872,50a

C1 16,23 872,50a* Ghi ch : Cc s trn cng mt ct i theo sau bi cc ch ci ging nhau th khng khc nhau c ngha thng k, p > 0,05 ;LSD0,05 = 50,85 theo trc nghim Sas)

Qua kt qu th nghim 1 cho thy, mc nh hng ca iu kin mi trngn qu trnh ln men ht ca cao l rt ln, trong qu trnh ln men do nhit mi trngrt thp v n tc ng cn tr qu trnh ln men, lm cho cc phn ng sinh ha xy rakhng mnh, nht l phn ng chuyn ha ru thnh axit din ra yu nn nhit khiht ln men khng tng cao (bng 3.1), hu nh nhit khng c s chnh lch ln ccCT v nhit cao nht ch khong 43,9oC khi bc sang ngy th 6 ca qu trnh lnmen.

Tuy nhin, cng trong iu kin ny th hm lng nht thot ra cng tng icao, kt thc qu trnh ln men th hm lng nht cn li khong 6,29% (CT3) n10,62% (C1) so vi lng nht ban u l 28,05% v c xu hng hm lng cn lithp dn theo chiu tng ca liu lng enzyme (bng 3.2). Nguyn nhn l do khi b sungenzyme invertase th n xc tc phn hy ng khng kh (Saccharose) thnh ccng kh ( Glucose + Fructose) phn t nh hn, do n d phn hy vchuyn ha hn so vi ln men khng b sung invertase. iu c ngha rt quan trng


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trong vic nh gi cht lng ca cao thnh phm cng nh nh gi mc ln men caht ca cao, bi khi dch nht thot ra cng nhiu th hm lng v cn li sau khi ln mencng thp, trn bng 3.3 cho thy hm lng v CT3 (14,7%) thp nht v cao nht lC1 (16,23%).

Kt qu xc nh im s ln men (CTS) bng 3.3 khng thy s khc nhau gia

cc CT. Nguyn nhn, l do nhit khi ht trong khi ln men khng cao v khng c schnh lch ln nn cc phn ng ha sinh bn trong ht (oxy ha anthocyanin thnhquinonic v anthocyanin di chuyn ra ngoi) din ra yu v khng c khc bit nhiu.

Bng 3.4 Kt qu kim tra pH TACng thc pH TA (ml NaOH 0,1 N/g)

CT1 4,90a 1,32aCT2 5,09a 1,23abCT3 4,98a 0,91bC1 4,97a 1,24ab

LSD0,01 0,30 0,34* Ghi ch : Cc s trn cng mt ct i theo sau bi cc ch ci ging nhau th khng khc nhau c ngha thng k p < 0.05, theotrc nghim Sas

Bng 3.5 Kt qu th nm hng v ca caoCng thc Hng ca cao V chua V ng V cht Hng tri cy

CT1 3,13a 2,75a 3,25a 2,88a 1,38bCT2 4,38a 2,88a 2,88a 2,63a 2,38aCT3 3,63a 2,88a 3,38a 2,88a 1,50abC1 4,25a 3,13a 2,75a 3,13a 1,63ab

LSD0,01 2,08 0,72 1,74 0,94 0,94

* Ghi ch : Cc s trn cng mt ct i theo sau bi cc ch ci ging nhau th khng khc nhau c ngha thng k, p < 0,05 theotrc nghim Sas)

Cht lng cui cng ca ht ca cao ln men c nh gi thng qua pH TAv th nm, y l mt trong hai ch tiu quan trong nht thng c cc nh thu mua,ch bin trn th gii kim tra nh gi cht lng ht ca cao. Kt qu xc nh pHcho thy CT2 cao nht 5,09, v tip n l CT3 4,98, C1 4,97 v thp nht l CT1 4,9nhng khi x l thng k th khc bit ny khng c ngha. Trong khi c s khc nhauc ngha gia cc CT khi kim tra TA (xem bng 3.4), CT1 c TA cao nht 1,32 vthp nht l CT3 0,91, trong khi CT3 v C1 khng c s khc bit.

Kt qu th nm trn bng 3.5 khng thy c s khc nhau gia cc CT v hngca cao, v chua, v ng, v cht, ring v hng tri cy th c s khc bit c ngha gia

cc mu th nghim v cho im cao nht l CT2 2,38, thp nht l CT1 1,38, cn giaCT3 v C1 khng khc nhau.Nh vy, qua kt qu thu c TN1, cho d iu kin mi trng cha l tng

ln men nhng chng ti xc nh c liu lng enzyme thch hp nht bsung vo qu trnh ln men ht ca cao vi quy m nh l 60ppm (CT2). Vi kt qu ny,chng ti c c s tin hnh nghin cu cc th nghim tip theo.

2. Kt qu xc nh thi im b sung invertase thch hp cho ln men ca cao


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Bng 3.6 Nhit khi ht trong qu trnh ln men ht ca cao

t r n g i a d i t r n g i a d i tr n g i a d i tr n g i a d i tr n g i a d i tr n g i a d i tr n g i a d i

C T 4 2 4.6 2 4.5 2 4. 4 2 5. 4 2 5.0 2 4. 2 2 8.2 2 6. 8 2 5.4 3 5. 8 3 2. 3 2 9. 3 3 6. 4 3 2.2 2 9.2 3 7. 2 3 5.0 3 2.7 4 2. 7 4 2. 6 3 9.3

C T 5 2 4.6 2 4.5 2 4. 4 2 7. 2 2 6.4 2 5. 3 3 3.5 3 1. 0 2 7.9 3 8. 0 3 3. 5 2 8. 9 3 9. 8 3 4.7 3 0.2 4 2. 9 4 0.3 3 6.3 4 3. 1 4 4. 1 4 2.2

C T 6 2 4.6 2 4.5 2 4. 4 2 6. 1 2 5.1 2 4. 4 2 9.5 2 8. 0 2 6.1 3 8. 9 3 2. 8 2 9. 0 4 0. 3 3 7.9 3 4.0 4 3. 8 4 0.3 3 7.6 4 1. 6 4 2. 3 4 1.0

C 2 2 4 .6 2 4.5 2 4. 4 2 6. 1 2 5.1 2 4. 3 2 9.9 2 7. 4 2 5.4 3 7. 3 3 1. 9 2 7. 8 3 8. 6 3 4.4 3 0.8 4 1. 6 4 0.5 3 5.8 4 3. 0 4 2. 7 4 1.2

M T

CT

19.4 20.6

N g y 0 N g y 1 N g y 2 N g y 3 Ng y 4

26.4 22.2 22.2 22.1 20.8

N g y 5 N g y 6

Bng 3.7 Tc thot dch nht (hm lng cm nhy) trong khi ln men

27.81

15.58

12.26

7.72

12.24

13.99

6.27

13.82

10.01 8.0913.77

15.47

5.84

0.00

5.00

10.00

15.00

20.00

25.00

30.00

ngy 0 ngy 1 ngy 2 ngy 3 ngy 4 gy 5 gy 6

%

T4

T5

T6

C2

Ti khu vc daklak vo nhng ngy cui thng 11 u thng 12 ca cao cho thuhoch tng i nhiu, nhng ngy ny thi tit thng rt mt v ko theo nhng cnma nh nn nhit y trung bnh khong 21,9oC, khng thun li cho qu trnh lnmen theo chiu hng c li. Do , trong sut qu trnh ln men nhit khi ht cc th2, th 3 v th 4 c xem l thi im chuyn ha ru thnh axit acetic mnh nht tng nhit, nhng chnh nhit mi trng qu thp nn nhit khi ht trong giai on

ny rt thp, cao nht ch t 40,3oC (bng 3.6) v c s chnh lch ng k v nhit gia cc lp trn, gia v di trong cng mt khi ht, cng xung di th nhit cnggim v khi n ngy 6 th nhit mi tng ln c khong 43 oC tng i thp, dbo cho kt qu ht ca cao sau khi ln men cht lng khng cao.

Bng 3.7 cho thy khng c s khc nhau ln gia cc mu CT v C2, chng tkhng c s nh hng ca thi im b sung enzyme n tc thot dch nht ca khiht trong qu trnh ln men, thm ch y mu C2 c hm lng nht cn li cn thphn so vi cc CT khc.

Bng 3.8 Hm lng v - im s ln men (CTS)Cng thc Hm lng v % CTS

CT4 13,07b 766abCT5 15,29a 745bCT6 15,25a 776aC2 14,24ab 747b

LSD0,01 1,51 28,24

* Ghi ch : Cc s trn cng mt ct i theo sau bi cc ch ci ging nhau th khng khc nhau c ngha thng k, p < 0,01 theotrc nghim Sas)


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Hm lng v ht sau khi ln men cao hay thp phn nh phn no mc phnhy thnh phn lp cm nhy ca ht trong khi ln men din ra cao hay thp, hay ni cchkhc l phn nh cc phn ng sinh ha din ra bn ngoi v ht mc mnh hay yu.Bng 3.8 ch ra gia cc CT v C2 khc nhau c ngha v hm lng v, CT4 hmlng v thp nht (13,07%), tip n l C2 (14,24%), gia CT5 v CT6 khng c s

khc bit. Mt khc, v im s ln men (CTS) ca cc CT v C2 khng cao, bi iukin mi trng ln men cha thch hp nn cc phn ng sinh ha bn trong ht din rakhng mnh v cao nht l CT3 (776), k n l CT1 (766), gia CT2 v C2 khng khcnhau.

Bng 3.9 Kt qu xc nh pH TA sau khi ln menCng thc pH TA (ml NaOH 0,1N/g)

CT4 4,71a 1,81abCT5 4,63a 1,85abCT6 4,94a 1,71bC2 4,77a 2,12a

LSD0,01 0,32 0,41* Ghi ch : Cc s trn cng mt ct i theo sau bi cc ch ci ging nhau th khng khc nhau c ngha thng k, p < 0,05 theotrc nghim Sas)

Bng 3.10 Kt qu th nm hng v ca cao sau khi ln menCng thc Hng ca cao V chua V ng V cht Hng tri cy

CT4 3,00 4,13 3,88 3,38 1,88CT5 2,75 4,00 3,75 3,63 1,50CT6 3,38 4,00 3,63 3,88 1,88C2 3,75 4,00 3,50 3,75 2,00

LSD0,01 1,90 1,18 1,96 1,44 1,57

Cng t cc kt qu thu c trn cho thy phn no cht lng ln menkhng cao v khi tin hnh kim tra pH th cho kt qu rt thp v khng c s khcnhau gia cc CT nhng TA li c s khc bit c ngha, C2 c TA cao nht 2,12 vthp nht l CT6, cn CT4 v CT5 khng thy khc nhau (bng 3.9), chng t khi b sungenzyme invertase vo trong khi ln men th lng axit cn li trong ht ca cao thnh phmthp hn so vi ln men bnh thng trong cng mt iu kin. Tuy s khc bit ny lcha ln c th phn bit c r rng thng qua th nm, nn kt qu th nm bng 3.10 cho thy gia cc CT v C2 khc nhau khng c ngha thng k.

Nh vy, bc u chng ti cng tm thi xc nh c thi im b sungenzyme invertase thch hp nht vo trong qu trnh ln men ca cao l sau 48 gii ln men

(CT6).Kt lun:- Liu lng enzyme invertase thch hp nht b sung vo trong ln men ca cao

vi quy m va v nh l 60ppm.- Thi im b sung enzyme invertase thch hp nht l sau 48 gi ln men.- Khi s dng enzyme invertase vo trong ln men ca cao lm cho lng axit cn

li thp hn so vi ln men bnh thng.


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- Cht lng th nm cha thy s ci thin ng k khi s dng enzymeinvertase so vi mu i chng.

ngh:- Tip tc tin hnh theo di th nghim cc ln nhc tip theo.- Th nghim tin hnh vi khi lng ht ca cao ln men ln hn v s dng

nhiu khong liu lng enzyme hn, a ra c kt qu chnh xc nht.- Tin hnh kt hp thm vi mt s cc th nghim v s ln o, thi gian ln

men, v kt hp vi cc loi enzyme khc.- Cn tm hiu thm c ch tc ng ca mt s loi vi sinh vt cng nh cc loi

enzyme c sn trong ni ti ca khi ht cc giai on ln men khc nhau.

bao ca cao invertase

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