PUY TRilMH SAIM XUAT CHE HOA TAIM TU CHE CUPIMG PHE LIEU
D o V a n Chuong^
TOMTAT
Che cupng la loai che phe lieu chie'm ty le cao nhat (63,0%) trong tong so che phe lieu. Mac dii la loai che phe lieu nhung trong che cupng ham lupng chat hoa tan rat cao (28,8% so vai chat kho). Xac dinh chat lupng che cupng thu gom a Cong ty TNHH che Hoai Trung, Phii Thp bang phuong phap cam quan va hoa hpc da cho thay chat luong che cupng khong thua kem nhieu so voi che OP mot loai san pham che den co chat luong tdt nhat trong cac mat hang che den xuat khau cua Viet Nam. Ket qua nghien ciiu cho thay, voi ty le che g/ml nuac la 1/8 trich ly 2 lan trong khoang thoi gian 10 phiit a nhiet dp dun soi cho hieu suat trich ly cao nhat. Sau do, dich trich ly dugc co dac giam ap a nhiet dp 50- 60''C, dich che co chat lupng tdt nhat ve mau sac nuac pha cung nhu mui thorn dac trung ciia che. De tao ra san pham bot che hoa tan, tien hanh say phun dich che co dac co dp Bx tir 10- 12 va nhiet dp say phun phii hop nhat la 170''C. San pham che hoa tan thu dugc co dp am khoang 1,5%. San pham che hoa tan dugc san xuat tii che cupng phe lieu co chat luong tuong duang nhu che hoa tan dugc san xuat tii che thanh pham. Hieu suat trich ly ciia che cupng so voi ham lugng ban dau ciia no la 65,5%.
Tir khoa: Che hoa tan, che cudng, sin xuat I. DAT VAN DE
T h e o sd lieu c u a Hiep h d i C h e Viet N a m , h a n g nam tdng san p h a m c h e d e n c u a Viet N a m d u g c s a n xuat va xuat k h a u k h o a n g 80.000 tan [4]. D e l a m dugc sd san p h a m c h e d e n n a y c h i i n g ta c a n k h o a n g 86.022 tan c h e d e n b a n t h a n h p h a m ( T d n g t h u hdi binh quan d a t 93%) [2], n h u vay sau k h i s a n g p h a n loai sd c h e b a n t h a n h p h a m (BTP) nay, e a c d o a n h nghiep d a phai loai b d ra g a n 6.022 t a n c h e p h e pham. T r o n g dd c h e e u g n g c h i e m k h o a n g 63,0%, c h e rau la 24,0%, cdn c h e b u i (dust) c h i cd 13,0% [3].
Nhiing loai c h e p h e p h a m ( p h e lieu) n a y hien nay chii yeu lam p h a n b d n , vira l a n g phi vira g a y d n h i i m mdi trudng. T h u c te c h o thay, n h i i n g loai c h e p h e pham nay chiia r a t n h i e u c h a t h d a tan, la t h a n h p h a n chii yeu quyet dinh n e n c h a t l u g n g t r o n g s a n p h a m che den. Bai bao trinh b a y c a c k e t q u a n g h i e n ciiu xay d u n g qui trinh c d n g nghfe s a n x u a t c h e h d a t a n tir c h e c u d n g p h e lieu, k h d n g n h i i n g tiet k i e m va t h u dugc d a n g k e m d t n g u d n san p h a m t h u c p h a m ed gia tri dinh d u o n g c a o m a c d n g d p p h a n g i a m thieu 6 n h i i m m6i t r u d n g d o b u i c h e va tanin c h e g a y ra.
U. VAT UEU VA PHUONG PHAP NGHIEN CUU 1. Vat lieu nghifin cuu
- Che eugng phe lieu cua Cdng ty TNHH Che Hoai Trung, huyen Thanh Ba, tinh Phii Thg.
2. TTiiet bi nghien cuu
- Cae loai thiet bi trich ly, ed dac bang phuong phap dun sdi, Igc cua Viet Nam.
- Thiet hi c6 quay chan kh6ng Buchi- R114 eiia Thuy Si.
- Tii say, can phan tich eiia Diic va Trung Qudc.
- Thiet hi say phun BUCHI MINI SPRAY DRIER B-191 ciia Cong hda Lien bang Diic.
- Thiet bi phan tich do am che hda tan Preeisa XM-60eiiaThuySi.
3. Phuong phap nghien cuu
- Xac dinh chat lugng che phe lieu dira theo TCVN 1454- 1993 [Ij; xac dinh do am cua che theo phuong phap say den trgng lugng khdng doi TCVN 5613-1991 [1]; xac dinh ham lugng chat hda tan theo TCVN 5610-1991 [5]; xac dinh ham lugng tanin theo phuong phap Leventhall [5]; ed dac dich che bang phuong phap giam ap b nhiet do thap tren thiet hi co quay chan khong Buchi- R114 ciia Thuy Si.
- San xuat che den hda tan bang phuong phap say phun tren thiet bi BUCHI MINI SPRAY DRIER B-191 ciia Cong hda Lien bang Due.
III. KET QUA VATHAO LUAN
1. Chat lugng che cudng phe Ueu
a. Cac chi tieu cam quan ciia che cudng 'Truong Dai hpc Kinh t l - Ky thuat Cong nghiep
KHOA HOC CONG NGHE
Loai che
Che cudng
OP (DC)
Bang 1. Chi tieu cam quan cua che cuong Chi tieu cam quan
Ngoai hinh Mau nau den hoi vang hoac dd, kich thude 1,0- 3,0 cm.
Canh che ddu, xoan chat mau nau den.
Mau nude Nau do cd vien vang Nau do ro vien vang.
Huong
Huong thom dac trung mill hoa qua nhe.
Huong thom dac trung mill hoa qua
Vi Chat diu cd hau
Chat diu ed hau.
Ket luan Loai tdt
Loai tdt Khi kiem tra danh gia chat lugng che cudng phe
lieu bang phuong phap cam quan, cd so sanh vdi san pham che OP, la mdt trong nhiing loai san pham tdt nhat cua san pham che den xuat khau, chiing ta thay rang mac du ngoai hinh ciia che eugng kh6ng phu hgp vdi sd thich ngudi tieu diing, do mau sac hoi vang hoac dd (thudng san pham che den phai ed mau sac nau den), nhung ngi chat (huong, vi, mau nude) ciia che eugng phe lieu rat tdt, khdng thua kem nhieu so vdi che OP thanh pham.
b. Cac chi tieu hoa hoc ciia che cuong
Ham lugng tanin va ham lugng chat hoa tan (CHT) trong che deu phan anh len chat lugng cua che. Dac biet ham lugng CHT cang cao thi chiing to che cd chat lugng cang tdt.
Qua bang 2 cho thay ham lugng tanin va CHT eiia che eugng phe lieu gan tuong duong vdi che OP, chiing td ham lugng CHT eiia che eugng rat Idn.
Dieu nay cung hoan toan logic khi ta danh gia chat lugng che cudng bang phuong phap cam quan so vdi che OP.
2. Qui trinh san xuat che hda tan a. Qua trinh trich ly dich che
Da tien hanh trich ly 2 lan vdi cae ty le ehe/nudc (g/ml) la: 1/6, 1/7, 1/8 va 1/9. Thi nghiem cho thay, sau khi trich ly 10 phiit thi ndng do chat hoa tan (do Bx) khong tang niia, ket qua trich ly duge the hien d bang 3.
Bang 3: Ham lugng chat hda tan va the tich dich Igc thu dugc b cac ty le che/ nude va nhiet do trich ly khac nhau
Bang2.C]
Loai che
Che cupng Che OP (d/c)
li tieu hda hoc eiia che Chi tieu hda D6 am
(%)
7,23 7,65
Ham lugng
tanin (% CIQ
7,03 8,86
eugng
IOC
Ham lugng CHT (%CK)
28,80 29,60
Ty le
1/6 1/7 1/8 1/9
Lugng che
(g) 50 50 50 50
Lugng nude 2
lan (ml)
600 700 800 900
Ndng do chat hda tan (Bx) theo nhiet d6 tuong ling
fC)
70 2,2 2,1 1,9 1,9
80 2,2 2,1 2,0 2,0
90 2,5 2,2 2,0 2,0
100 2,9 2,2 2,0 2,0
Dun soi 3,2 2,8 2,5 2,2
Lugng dich trich ly (ml) theo nhiet do tuong ling
(°C) 70
436 537 660 728
80 422 536 631 722
90 420 528 602 716
100 408 500 594 694
Dun soi 364 434 526 636 Sd lieu bang 3 cho thay:
- Vdi ciing mot ty le, khi nhiet do trich ly cang tang thi hieu suat trich ly (do Bx) cang tang va phuong phap dun sdi cao nhat.
- Ciing ty le nud'c ban dau nhu nhau, nhung khi nhiet dp trich ly tang thi the tich thu duge sau trich ly cang giam, dac biet the tich dich cdn lai theo phuong phap dun sdi la nhd nhat, dieu nay rat thuan Igi cho
qua trinh c6 dac sau nay.
De xac dinh hieu suat trich ly ddi vdi cac mlu trich ly d cac nhiet do khac nhau va ty le nude khac nhau, sau khi thu dugc lugng dich trich ly d cac miic nhiet dp va dun soi tien hanh dinh lugng len ciing mot the tich la 800 ml, sau dd do do Bx de nit ra hieu suat qua trinh trich ly (Bang 4).
Bang 4. So sanh hieu qua ciia qua trinh trich Iv
Ty le
1/6 1/7 1/8 1/9
Luang che
(g)
50 50 50 50
Nong dp CHT (dp Bx) sau khi dinh miic len 800 ml a cac
m l u trich ly a nhiet dp 70''C
1,3 1,4 1,6 1.7
SO^C 1,3 1,5 1,6 1.8
go'c
1,4 1,5 1,7 1,8
100"C 1,4 1,5 1,7 1,8
dun soi 1,5 1,6 1.8 1,8
Luang dich trich ly con lai
theo phuang phap dun soi
(ml)
364 434 526 636
Ket qua cho thay phuong phap dun s6i da cho
dich cd ham lugng chat hda tan cao nhat. Trong dd, ty le 1/8 va 1/9 la mSu ed ham lugng chat hda tan cao nhat, tuy nhien nen ehgn ty le 1/8 vi lugng dich cdn lai 526 ml thuan tien cho viec c6 dac hon so vdi ty le 1/9 lugng dich cdn 636 ml.
b. Qua trinh co dac
Da thuc hien c6 dac giam ap d nhiet dd thap: Su dung thiet bi e6 quay chan kh6ng Buchi CPhuy Si).
Lugng dich cho vao c6 dac la 250 ml, nhiet do eo dac dugc thuc hien d cac thang nhiet la 50°C, 60°C, 70°C.
Ket qua qua trinh c6 dac dugc the hien d' bang 5.
Bang 5. KA qua qua trinh eo dac dich che
Nhiet dp CO dac
fC)
50 60 70
Thai gian CO dac (Phiit)
60 40 20
Lugng dich dau
(ml) 250 250 250
Lupng dich con
lai(mD 60 60 60
CHT sau CO dac (Bx)
10 10 10
Nhan xet chat luong dich che
Dich che mau nau do, miii thom tu nhien manh, CO miii Caramen nhe.
Dich che mau nau do, miii thom tu nhien yeu, Ip miii Caramen.
Dich che mau nau hoi sam, mat miii thom tu nhien, miii Caramen manh.
Nhu vay, e6 dac d nhiet do khoang 50 - 60° C la tdi iru nhat, vi dich che sau c6 dac co ban vSn giir dugc cae tinh chat cam quan cua che la mau nude va huong thom cua che.
c. Qua trinh say phun dich che
* Anh huong nong do chat hoa tan ciia dich che CO dac den qua trinh say phun
Ndng do chat hda tan ciia dich che cd anh hudng den qua trinh say phun (Bang 6) cho thay ndng do chat hda tan ciia dich che cd Bx tir 10-12 la phii hgp cho qua trinh say phun.
Bang 6. Anh hudng cua nong do chat hda tan tdi qua trinh say phun
Nong dp chat hoa tan (Bx) 9
10 11 12 13
Hien tugng xay ra trong qua trinh say
Lugng dich loang, ham lugng chat hoa tan khong dii phun de tao san pham.
Ham luong chat hoa tan vira du de thiet bi phun tao san pham.
Ham lugng chat hoa tan vira du de thiet bi phun tao san pham.
Ham luong chat hoa tan \ara du de thiet bi phun tao san pham.
Ham lupng chat hoa tan cao, gay tac duong ong hiit thiet bi khong phun dugc.
*Anh huong ciia nhiet do dau vao den thdi gian say va gia tri cam quan cua bot che hoa tan.
Tien hanh say phun 100 ml dich che cd do Bx la 11, vdi cac dai nhiet do say khac nhau cho thay khi nhiet do say cang tang thi thdi gian say cang giam va chat lugng hot che hda tan ciing khac nhau (Bang 7).
Say phun che d nhiet do dau vao 170°C la tdi uu nhat vi chat lugng hot che hda tan duge danh gia bang phuong phap cam quan la tdt nhat va thdi gian say ngan nhat.
Bang 7. Anh hudng cua nhiet do va thdi gian tdi qua trinh say phun
Nhiet dp dau vao CQ
150 160 170 180 190
Thai gian say (phiit)
35 30 25 20 15
Gia tri cam quan Bot che min co mau vang sang.
Bot che min co mau vang sang.
Bot che min co mau vang sang.
Bot che min c6 mau nau sam.
Bot che CO thoang dang hat nho, mau nau sam.
KHOA HOC CONG NGHE
3 Tinh toan hieu suat trich ly cua che hda tan Da dua 500 g che eugng phe lieu cd do am 8,5%
vao trich ly 2 lan bang phuong phap dun s6i, moi lan 10 phiit vdi 4000 ml nude sdi (ty le che/ nude la 1 g/
8 ml), sau dd e6 dac giam ap o nhiet do 60°C trong 40 phiit. Sau khi say phun da thu dugc 86,3 gam che hoa tan cd do am 1,5%.
- Lugng chat kh6 trong 500 gam che la: G^ i= 500 - (8,5 x500)/100 = 457,5 g
- Ham lugng CHT cua che cudng (bang 2) la 28,8% so vdi chat kh6.
- Vay lugng CHT trong 500 g che eugng la: 457,5 X 28,8/100 = 131,76 g.
- Hieu suat trich ly CHT thu duge la: (86,3/
131,76) X 100 = 65,5%. . .
4. Thiet lap qui trinh san xuat che hda tan Tren co sd cac ket qua thu dugc, xin de xuat qui trinh san xuat che hda tan tir che eugng d so dd 1.
CHE CUONG
PHE LIEU Lam sach tap chat: Tap
chat la, tap chat sat
Trich ly bang nude dun s6i: 2 lan, 10 phiit/lan
C6 dac giam ap nhiet do
50- 60°C, do Bx 10-12 Dich che thu duoe Loe tho va loe tinh
Say phun dl70°C Bot che hoa tan thu duac
r o fto am 1.5%
Bao quan bot che hda tan
P ••• ' :
IV. KET LUAN
So dd 1. Qui trinh san xuat che hda tan tir che cuong phe lieu
TAI UEU THAM KHAO
1. Ddi vdi che phe Ueu chi can trich ly 2 lan, thdi gian trich ly khoang 10 phiit; phuong phap dun s6i cho hieu suat trich ly cao nhat; trong phuong phap dun sdi thi ty le che/nud'c (g/ml) 1/8 la tdi mi.
2. Co dac bang phuong phap giam ap b nhiet do thap khdng nhiing cho thdi gian cd dac nhanh nia chat lugng rat tdt, dac biet 6 nhiet do SO^C va 60°C.
3. Ndng dd dich che ed do Bx tir 10- 12 va nhiet do 170°C la tdi uu nhat. Do am cua che hda tan sau qua trinh say phun khoang 1,5%.
4. Hieu suat trich ly cua che cudng so vdi ham lugng ban dau cua nd la: 65,5%.
(1) Bg N6ng nghiep va PTNT, Vu Khoa hoc - Cong nghe va Chat lugng san pham (2001). Tuyen tap Tieu chuan Nong nghiep Viet Nam; Ha Npi 2001.
(2) D5 Van Chuong (2002). Ky thuat san xuat che den- Tdng e6ng ty Che Viet Nam- Ha Ngi, 2002.
(3) Dd van Chuong (2008). Bao cao de tai nghien ciiu khoa hgc cap Bd "Nghien ciiu tan dung che den phe Ueu de san xuat che hda tan, nu6i trdng nam va lam phan bdn, nham lam tang hieu qua kinh te va giam thieu 6 nhiSm moi trudng". Ha Ngi, 2008.
(4) Tran Van Gia (2008). Bao cao tinh hinh san (5) Vu Thy Thu va CS (2001). Cac hgp chat hoa xuat va tieu thu che cua Viet Nam nam 2007. Hiep hgc ed trong che. Nha xuat ban N6ng nghiep. Ha hdi Che Viet Nam, Ha Ngi, 2008. Ngi, 2001.
UTILISING WASTE STEM TEA TO PRODUCE INSTANT TEA
Do Van Chuong Summary
Stem tea (twig tea) makes up the highest proportion of 63% among kinds of refused tea. Although stem tea is waste one, the proportion of soluble substance in it is very high (28.8% compared to dried substance).
Therefore, utilising this waste tea to produce instant tea, which is the ingredient for food or beverage, is very neccesary. By organoleptic and chemical technique, the quality of stem tea collected at Hoai Trung Tea Ltd. Company (Phu Tho) is measured. The result shows that the quality of stem tea is not much worse than OP tea (a kind of best black tea for export in Viet Nam). The highest extraction efficiency can be reached up when the proportion of tea and water is 1/8, extract 2 times within 10 minutes at boil temperature. After that, extracted juice is steamed at 50-60°C. Then the tea juice has the best quality in terms of colour and favour. To produce soluble tea powder, spray/freeze drying of the concentrated brew at 10-12 Bx, 170°C. The received instant tea has the humidity of about 1.5%. The instant tea which manufactured from waste stem tea has the same quality as the one which produced from processed tea.
Extraction efficiency of stem tea compared to the initial one is 65.5%.
Key words.- Instant tea, stem tea, produce.
Ngudi phan bien: PGS.TS. Ngo Xuan Manh
