| Summary: | 碩士 === 國立臺灣大學 === 食品科技研究所 === 84 === In this study, two kinds of squid products, shredded squid
and dried squid, were investigated for the formation of
cholesterol oxidation products(COPs) during process, storage,
an cooking .
The eight major oxidized cholesterols in the eluates were
quantified by capillary gas chromatography which included
7α-hydroxycholesterol (7α-OH),7β-hydroxy-cholesterol(7β-OH)
7-ketocholesterol (7-keto), cholestan- 5α,6α-epoxy-3β-ol(α-
epoxide), cholestan-5β,6β-epoxy-3β-ol(β-epoxide),cholestane
3β,5α,6β-triol (Triol), 20α-hydroxycholesterol (20-OH) and
25-hydroxycholesterol(25-OH).
The fresh squid which was used to process dried shredded
squid contained three COPs namely 7β-OH,α-epoxide,and
β-epoxide. Total cholesterol oxidation products(TCOPs) content
increased during processing from 0.55ppm initially to 1.88ppm
in the final products. Among the COPs, α-epoxide and 7β-OH
contents were higher than others.
Dried shredded squid showed an increase of cholesterol
oxide contents accompanied by a remarkable concurrent decrease
in polyunsaturated fatty acids. The contents of TCOPs in air
package were significantly higher than in vacuum package. Light
was found to have a significant influenc oxidation during low
temperature storage but only showed a slight influence during
high temperature storage due to the capacity of autoxidation.
On the effect of temperature, it was shown that the TCOPs
levels at 5℃ was higher than at 35℃.
During roasting of dried squid, cholesterol decreased
appreciably. COPs (mainly C-7 and epoxide types) began to
increase accompanying the oxidation of lipids.
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