Qhov sib txawv tseem ceeb ntawm enzymatic thiab nonenzymatic browning yog tias cov enzymatic browning muaj enzymes xws li polyphenol oxidase thiab catechol oxidase whereas lub nonenzymatic browning tsis koom nrog tej yam enzymatic.
Cov ntsiab lus enzymatic thiab nonenzymatic browning yog qhov tseem ceeb heev hauv kev piav qhia cov zaub mov browning. Lawv txawv raws li lawv cov mechanism ntawm kev ua. Khoom noj khoom haus browning yog txheej txheem ntawm tig cov zaub mov xws li txiv hmab txiv ntoo thiab zaub rau hauv cov xim xim av vim yog cov tshuaj lom neeg uas tshwm sim hauv cov zaub mov. Qhov no muaj ntau yam cuam tshuam rau kev lag luam zaub mov, tshwj xeeb tshaj yog hais txog tus nqi.
YEnzymatic Browning yog dab tsi?
Enzymatic browning yog cov txheej txheem ntawm cov zaub mov tig xim av vim muaj cov tshuaj enzyme-catalyzed uas tshwm sim hauv cov zaub mov. Peb tuaj yeem pom qhov no hauv txiv hmab txiv ntoo, zaub thiab nqaij nruab deg thiab. Nws cuam tshuam rau saj, xim thiab tus nqi ntawm cov khoom noj. Cov tshuaj tiv thaiv no suav nrog cov enzymes xws li polyphenol oxidase thiab catechol oxidase. Cov enzymes no tsim melanin thiab benzoquinone los ntawm ntuj phenols. Lwm lub npe rau cov txheej txheem no yog "oxidation ntawm zaub mov". Cov txheej txheem no yuav tsum tau txais cov pa oxygen.
Daim duab 01: Enzymatic Browning
Enzymatic browning pib nrog oxidation ntawm phenols los ntawm phenol oxidase rau hauv quinones. Cov quinones no muaj zog electrophiles uas ua rau muaj kev cuam tshuam rau nucleophilic tawm tsam los ntawm lwm cov proteins. Cov quinones no tuaj yeem ua polymerize ntawm ntau cov tshuaj tiv thaiv. Thaum kawg, nws ua rau cov xim xim av xim ntawm cov khoom noj khoom haus. Yog li ntawd, yog tias peb xav tau inhibit cov txheej txheem no, peb yuav tsum tsom mus rau kev cuam tshuam cov kev ua ntawm polyphenol oxidase. Txawm li cas los xij, qee zaum qhov browning no muaj txiaj ntsig zoo thiab. Piv txwv li, nws tsim cov xim thiab tsw hauv kas fes, cocoa taum thiab tshuaj yej.
Nonenzymatic Browning yog dab tsi?
Nonenzymatic browning yog cov txheej txheem ntawm cov zaub mov tig xim av vim muaj tshuaj lom neeg cov tshuaj tiv thaiv uas tsis catalyzed los ntawm ib qho enzyme. Nws kuj tsim cov xim xim av hauv cov khoom noj. Muaj ob lub ntsiab ntawm cov tshuaj tiv thaiv no ua caramelization thiab Mallard cov tshuaj tiv thaiv.
Daim duab 02: Tsis yog Browning
Caramelization cuam tshuam nrog pyrolysis ntawm qab zib. Yog li ntawd, cov txheej txheem no yog qhov tseem ceeb hauv kev ua noj kom tau txais ib qho nutty tsw thiab xim av. Nyob rau hauv cov txheej txheem no, volatile tshuaj tso tawm ua tus yam ntxwv caramel tsw. Hauv Mallard cov tshuaj tiv thaiv, cov tshuaj tiv thaiv tshuaj tshwm sim ntawm pawg amine ntawm cov amino acid dawb thiab cov pab pawg carbonyl txo cov suab thaj. Tsis tas li ntawd, qhov tshuaj tiv thaiv no tshwm sim nrog qhov sib ntxiv ntawm cov cua sov. Cov piam thaj reacts nrog cov amino acid ua ntau yam tsw thiab tsw. Li no, cov tshuaj tiv thaiv no yog lub luag haujlwm rau kev tsim cov tsw tom qab peb ua zaub mov. Ntxiv mus, qhov tshuaj tiv thaiv no yog qhov tseem ceeb hauv kev tsim cov khoom qab zib rau cov zaub mov tiav. Hom amino acid uas koom nrog cov tshuaj tiv thaiv txiav txim qhov tsw ntawm cov khoom kawg.
Qhov txawv ntawm Enzymatic thiab Nonenzymatic Browning yog dab tsi?
Enzymatic browning yog cov txheej txheem ntawm cov zaub mov tig xim av vim muaj cov tshuaj enzyme-catalyzed uas tshwm sim hauv cov zaub mov. Nws suav nrog cov enzymes xws li polyphenol oxidase thiab catechol oxidase. Ntxiv mus, nws pib nrog oxidation ntawm phenols los ntawm phenoloxidase rau hauv quinones uas tom qab ntawd polymerized muab cov xim xim av xim. Nonenzymatic browning yog cov txheej txheem ntawm cov zaub mov tig xim av vim muaj tshuaj lom neeg cov tshuaj tiv thaiv uas tsis catalyzed los ntawm ib qho enzyme. Nws tsis koom nrog kev ua haujlwm enzymatic. Ntxiv rau qhov ntawd, nws koom nrog cov tshuaj tiv thaiv ntawm amine pawg ntawm cov amino acid dawb thiab cov pab pawg carbonyl txo cov suab thaj. Cov nram qab no infographic nthuav qhia qhov txawv ntawm enzymatic thiab nonenzymatic browning nyob rau hauv daim ntawv tabular.
Summary – Enzymatic vs Nonenzymatic Browning
Food browning yog txheej txheem tseem ceeb heev uas peb tham hauv kev lag luam khoom noj. Muaj ob txoj hauv kev uas nws tuaj yeem tshwm sim; Lawv yog enzymatic thiab nonenzymatic browning. Qhov sib txawv tseem ceeb ntawm enzymatic thiab nonenzymatic browning yog tias cov enzymatic browning muaj enzymes xws li polyphenol oxidase thiab catechol oxidase whereas lub nonenzymatic browning tsis koom nrog tej yam enzymatic.
