Qhov sib txawv tseem ceeb ntawm hydrolytic thiab oxidative rancidity yog tias hydrolytic rancidity yog hais txog cov ntxhiab uas tsim thaum triglycerides undergo hydrolysis thiab tso tawm cov roj fatty acids dawb, whereas oxidative rancidity yog cov tshuaj tiv thaiv ntawm cov roj nrog oxygen.
Rancidification yog cov txheej txheem tshuaj uas suav nrog kev ua tiav lossis tsis tiav oxidation lossis hydrolysis ntawm cov rog thiab roj thaum raug huab cua, lub teeb, lossis ya raws lossis los ntawm kev ua haujlwm microbial uas ua rau muaj qhov tsis hnov tsw thiab tsw. Yog li ntawd, cov tshuaj tiv thaiv no uas tshwm sim hauv cov zaub mov tuaj yeem ua rau muaj ntxhiab tsw thiab tsw. Raws li hom kev ua, muaj peb hom rancidification li hydrolytic, oxidative, thiab microbial rancidity.
Hydrolytic Rancidity yog dab tsi?
Hydrolytic rancidity yog kev txhim kho ntawm cov ntxhiab tsw ntxhiab thaum lub hydrolysis ntawm triglycerides, tso lawv cov fatty acids dawb. Qhov no yog tshuaj lom neeg cov tshuaj tiv thaiv qhov twg lipid feem ntau reacts nrog dej. Cov tshuaj tiv thaiv no tshwj xeeb yog xav tau lub catalyst. Tsis tas li ntawd, cov tshuaj tiv thaiv tshuaj no ua rau tsim cov rog dawb thiab glycerol.
Tsis tas li ntawd, qee cov roj ntsha luv luv uas muaj nyob hauv lipids (piv txwv li butyric acid) tuaj yeem ua rau malodorous (lub ntsiab lus, lawv tuaj yeem muaj cov ntxhiab tsw tshwj xeeb). Tsis tas li ntawd, thaum luv-chain fatty acids tsim nyob rau hauv lipids, cov fatty acids no muaj peev xwm ua raws li catalysts lawv tus kheej, uas tuaj yeem ua kom cov tshuaj tiv thaiv ntxiv. Yog li ntawd, peb tuaj yeem sau npe hom tshuaj tiv thaiv no ua cov txheej txheem autocatalysis.
Oxidative Rancidity yog dab tsi?
Oxidative rancidity yog cov txheej txheem tshuaj uas cov roj degraded los ntawm oxygen hauv huab cua. Feem ntau, unsaturated fatty acids muaj ob daim ntawv cog lus ntawm carbon atoms. Ob daim ntawv cog lus no tuaj yeem raug tshem tawm los ntawm cov tshuaj tiv thaiv dawb radical, qhov twg cov tshuaj tiv thaiv cleavage kuj muaj cov pa oxygen molecular.
Feem ntau, oxidative rancidity tuaj yeem ua rau tso tawm malodorous thiab volatile aldehydes thiab ketones. Txij li cov tshuaj tiv thaiv no yog cov tshuaj tiv thaiv dawb radical, lawv tuaj yeem ua rau lub hnub ci. Feem ntau, oxidation tshwm sim nyob rau hauv unsaturated fats.
Piv txwv li, peb feem ntau khaws cov nqaij hauv tub yees lossis hauv lub xeev khov; Yog tias tsis yog, oxidative rancidity tuaj yeem tshwm sim. Txawm li cas los xij, txawm tias peb khaws cov nqaij hauv lub tub yees, cov roj polyunsaturated tseem tuaj yeem ua rau oxidize; yog li ntawd, cov rog yuav maj mam ua rancid. Cov txheej txheem oxidation rog no tuaj yeem ua rau rancidity, uas pib tam sim ntawd thaum cov tsiaj tua tsiaj, thiab cov rog ntawm cov nqaij ntshiv tau raug rau cov pa oxygen. Ntxiv mus, cov tshuaj tiv thaiv tshuaj no feem ntau txuas ntxiv thaum lub tub yees ntawm qhov ceev heev vim tias cov nqaij yog qhov kub thiab txias.
Daim duab 01: Txoj Kev Yooj Yim ntawm Oxidative Rancidity
Peb tuaj yeem tiv thaiv cov zaub mov kom tsis txhob muaj oxidative rancidity los ntawm kev siv lub teeb-pov thawj, siv qhov chaw tsis muaj oxygen nyob ib ncig ntawm cov zaub mov thiab los ntawm kev ntxiv cov tshuaj antioxidants. Cov tshuaj antioxidants no feem ntau yog siv los ua cov tshuaj tiv thaiv kom ncua kev loj hlob ntawm rancidity. Muaj qee cov tshuaj antioxidants ntuj uas peb siv tau thiab; Cov no suav nrog ascorbic acid thiab tocopherols.
Qhov txawv ntawm Hydrolytic thiab Oxidative Rancidity yog dab tsi?
Rancidity los yog rancidification yog tsim los ntawm ib qho tsis kaj siab tsw vim tag nrho los yog ib nrab degradation ntawm lipids. Qhov sib txawv tseem ceeb ntawm hydrolytic thiab oxidative rancidity yog tias hydrolytic rancidity yog hais txog cov ntxhiab tsw uas tshwm sim thaum triglycerides raug hydrolysis thiab tso tawm cov roj fatty acids dawb, qhov oxidative rancidity yog cov tshuaj tiv thaiv ntawm cov roj nrog oxygen.
Cov infographic hauv qab no teev qhov sib txawv ntawm hydrolytic thiab oxidative rancidity hauv daim ntawv tabular.
Summary – Hydrolytic vs Oxidative Rancidity
Rancidity los yog rancidification yog tsim los ntawm ib qho tsis kaj siab tsw vim tag nrho los yog ib nrab degradation ntawm lipids. Muaj peb txoj hauv kev ntawm rancidity li hydrolytic, oxidative, thiab microbial rancidity. Qhov sib txawv tseem ceeb ntawm hydrolytic thiab oxidative rancidity yog tias hydrolytic rancidity yog hais txog cov ntxhiab uas tsim thaum triglycerides raug hydrolysis thiab tso tawm cov roj fatty acids dawb whereas oxidative rancidity yog cov tshuaj tiv thaiv ntawm cov roj nrog oxygen.
