Short-Term in Vivo Digestibility of Triglyceride Polymers, Dimers, and Monomers of Thermoxidized Palm Olein Used in Deep-Frying
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- 作者：M. José ; Gonzá ; lez-Muñ ; oz ; Sara Bastida ; and Francisco J. Sá ; nchez-Muniz
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：1998
- 出版时间：December 1998
- 年：1998
- 卷：46
- 期：12
- 页码：5188 - 5193
- 全文大小：62K
- 年卷期：v.46,no.12(December 1998)
- ISSN：1520-5118
文摘
Palm olein used to fry potatoes 40 and 90 times was tested in a short-term in vivo digestibilityexperiment. Total alteration, expressed as polar content, reached 26.4 g/100 g of olein, and theamount of triglyceride polymers, triglyceride dimers, and oxidized triglycerides increased severalfold,as a result of repeated frying use of the olein. True digestibility of used and unused whole palmolein and that of the nonoxidized triglycerides and different polar compounds was tested after 1 gof palm olein/100 g of body weight was administered to young adult Wistar rats by means of anesophageal probe. Luminal fat was obtained 4 h later, and its polar and nonpolar fractions wereseparated and quantified using column chromatography. Thermoxidized and hydrolytic compoundswere quantified by high-performance size exclusion chromatography and compared to the compoundsadministered. The true digestibility coefficient of palm olein used in frying 90 times was 30% lowerthan that of unused palm olein. True digestibility of triglyceride polymers and dimers of unusedpalm olein was quite high (>50%). After 90 uses, digestibility of dimers was significantly lower (p< 0.01), being ~30%. Nonoxidized triglyceride hydrolysis was negatively affected by the presenceof large amounts of thermoxidized compounds. The amount of monoglycerides and free fatty acidsfound in the luminal fat also decreased as a consequence of the arrest of pancreatic lipase activityby thermoxidized compounds formed through repeated frying.Keywords: Column chromatography; deep-frying; digestibility; HPSEC; in vivo; oxidized triglycerides; palm olein; polymers; rats