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DUONG NGHICH CHUYEN
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ng nghch chuyn
ng nghch chuynBch khoa ton th m Wikipedia
ng nghch chuyn (i khi c gi l ng nghch o) l hn hp ca glucoza v fructoza, thuc bng cch phn tch sucroza. So vi sucroza, ng nghch chuyn ngt hn v cc sn phm ca ngi m nhiu hn, cng nh t b kt tinh hn. Do ng nghch chuyn thng c dng trong qutrnh lm bnh[1].
V mt k thut, sucroza l ng i disacarit, ngha l gm hai phn t ng n (monosacarit), c thl fructoza v glucoza. S phn tch sucroza c tin hnh bi phn ng thy phn. Vic thy phn c thtin hnh n gin bng cch gia nhit dung dch sucroza, nhng thng thng s dng cht xc tc thcy qu trnh chuyn i. Cc cht xc tc sinh hc c s dng gi l sucraza (ngun gc ng vt) vinvertaza (ngun gc thc vt). Sucrasza v invertasza l cc dng enzyme glycosit hydrolaza. Cc cht axitnhnc chanh cng thc y qu trnh chuyn i sucroza.
Mc lc
1 Phn ng nghch chuyn2 ng nghch chuyn3 Thi gian bo qun4 Cc v d5 Tham kho
5.1 Ch thch5.2 Tham kho chung
6 Lin kt ngoi
Phn ng nghch chuyn
Khi nim 'nghch chuyn' xut pht t vic o nng dung dch ng bng phn cc k.
C12H22O11 (sucroza, quay cc ring = +66.5) + H2O (nc, khng quay cc) C6H12O6(glucoza, quay cc ring = +52.7) + C6H12O6 (fructoza, quay cc ring = -92)tng hp: +66.5 chuyn thnh -39
Phn ng thy phn l phn ng ha hc trong mt phn t b phn hy bng nc. Nng sut thy phnsucroza thnh glucoza v fructoza t khong 85%, nhit phn ng c th duy tr 50-60 C (122-140 F).
ng nghch chuyn
Dung dch ng c th d dng nghch chuyn khi thm 1 g axit citric hoc axit ascorbic, tnh trn 1 kgng. C th dng nc chanh ti (10 ml/kg).
Thi gian bo qun
ng nghch chuyn c hot nc thp hn hot nc ca sucroza, v vy n c tc dng bo quntt hn, ngha l cc sn phm s dng ng nghch chuyn c hn s dng di hn.
Thi gian bo qun khi s dng ng nghch chuyn l khong 6 thng, ty theo iu kin bo qun.Dung dch ng nghch chuyn c kt tinh c th tr v trng thi lng bng cch un nh.
Cc v d
Ko toffeeMt ong
Tham kho
Ch thch
1. ^ Hubert Schiweck, Margaret Clarke, Gnter Pollach Sugar" in Ullmanns Encyclopedia of Industrial Chemistry2007, Wiley-VCH, Weinheim.
Tham kho chung
Carbohydrates (http://biology.clc.uc.edu/courses/bio104/carbohydrates.htm). Carbohydrates. Truycp ngy 1 thng 5 nm 2006.Making simple syrup is an exercise in chemical reactions(http://web.archive.org/web/20070714004114/http://www.bakers-exchange.com/articles/2000/april.html). A Word from Carol Kroskey. Bn gc (http://www.bakers-exchange.com/articles/2000/april.html) lu tr ngy 14 thng 7 nm 2007. Truy cp ngy 1 thng 5nm 2006.Frequently Asked Questions - Cookies (http://techserv.aibonline.org/faqs/cookies.html). AIBInternational. Truy cp ngy 1 thng 5 nm 2006.
Lin kt ngoi
Invertase (http://greenwoodhealth.net/np/invertase.htm)Making sugar sweeter (http://www.csiro.au/resources/ps20m.html), an educational experiment inchemistry.
Ly t http://vi.wikipedia.org/w/index.php?title=ng_nghch_chuyn&oldid=19562046
Th loi: Monosacarit Cht to ngt Khoa hc thc phm Xiro Cht ngt
Trang ny c sa i ln cui lc 04:42 ngy 9 thng 9 nm 2014.Vn bn c pht hnh theo Giy php Creative Commons Ghi cng/Chia s tng t; c th pdng iu khon b sung. Xem iu khon S dng bit thm chi tit.Wikipedia l thng hiu ng k ca Wikimedia Foundation, Inc., mt t chc phi li nhun.