Does Frequent Replenishment with Fresh Monoenoic Oils Permit the Frying of Potatoes Indefinitely?
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- 作者：A. Romero ; C. Cuesta ; and F. J. Sá ; nchez-Muniz
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：1999
- 出版时间：March 1999
- 年：1999
- 卷：47
- 期：3
- 页码：1168 - 1173
- 全文大小：68K
- 年卷期：v.47,no.3(March 1999)
- ISSN：1520-5118
文摘
The frying life of two monoenoic oils, extra virgin olive oil (EVOO) and high oleic acid sunflower oil(HOSO), used to fry potatoes following a domestic frying model, by replenishing the oil in the fryerwith fresh oil after each use to maintain the oil volume/fresh potato ratio, was studied by measuringpolar content (PC) and triglyceride oligomer (TO) content. A combination of column and high-performance size-exclusion chromatography was used. Changes in the PC and TO content of bothoils according to the number of frying uses were adjusted to linear, logarithmic, and power equations.While all three equations reflected the alterations quite accurately (p < 0.001), the logarithmic andpower equations defined them best. Frequent replenishment of both frying oils with fresh oil produceda stabilization of PC and TO levels after 20-40 uses. According to the linear adjustment equation,321 ± 33 frying operations with EVOO and 290 ± 40 with HOSO would be needed to raise PC to25%. To reach the 10% TO level set for discarding oil used in frying, EVOO and HOSO would haveto be used 319 ± 35 and 241 ± 37 times, respectively. Using the power adjustment, however, thetheoretical frying life of both oils would be much higher (at least 4460 frying uses before reachinga 25% PC and 538-1552 uses for the EVOO and 249-1319 uses for the HOSO to reach a 10% TOlevel). The frying life of EVOO and HOSO would be extended almost indefinitely (at least 170 000uses) when the logarithmic adjustment was applied. These data suggest that frequent replenishmentof used monoenoic oil with fresh oil permits one to fry sets of fresh potatoes a very high number ofoccasions.Keywords: Column chromatography; deep frying; frying life; extra virgin olive oil; high oleic acidsunflower oil; HPSEC; polar content; triglyceride oligomers