Comparison of various analytical techniques for the determination of essential fatty acids in hardened fats

Zmachinski, Helen; Waltking, Arthur E; Miller, James D.

doi:10.1007/bf02682405

Cited by 15 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The molar absorption factor suggested by McGee has been used to make our findings comparable with others (34). This method gave good reproducibility and good agreement between calculated and experimental data.…”

Section: Methods Materials and Proceduressupporting

confidence: 63%

See 1 more Smart Citation

Rapeseed oil in a two‐component margarine base stock

Zalewski

Kummerow

1968

J Americ Oil Chem Soc

View full text Add to dashboard Cite

A two-component margarine base stock with liquid oil as one component allowed for a lower trans fatty acid content and at the same time provided for a higher essential fatty acid level than a one-component base stock. Transesterification softened a two-component margarine base stock and resulted in a steeper solid fat index curve, but did allow for a lower trothS fatty acid level in a margarine base stock. The high content of erucic acid in rapeseed oil did not change the physical properties of a margarine base stock and provided a good hardstock when this oil was hydrogenated. The use of a hydrogenated rapeseed oil ensured interchangeability of liquid oils in blends and rearranged blends, also seemed superior to soybean hardstocks in this respect.

show abstract

Section: Methods Materials and Proceduressupporting

confidence: 63%

“…This method gave good reproducibility and good agreement between calculated and experimental data. The molar absorption factor suggested by McGee has been used to make our findings comparable with others (34).…”

Section: % Of Solidssupporting

confidence: 55%

Rapeseed oil in a two‐component margarine base stock

Zalewski

Kummerow

1968

J Americ Oil Chem Soc

View full text Add to dashboard Cite

show abstract

“…On the other hand, the lipoxygenase oxidation has been applied to the determination of cis, cis-methylene interrupted PUFA content of oil and fat products (6)(7)(8)(9). PUFA content can be calculated from the UV absorption at 234 nm corresponding to conjugated diene.…”

mentioning

confidence: 99%

Formation of conjugated diene and triene products in lipoxygenase oxidation of C18, C20, C22 PUFAs

Toru

Wakasa

Miyashita

1987

J Americ Oil Chem Soc

View full text Add to dashboard Cite

The determination of conjugated diene formation revealed that the tool % conversions of all cis-6,9,12-oetadecatrienoic acid [y-linolenic, 18:3(n-6)], all cis-5,8,11,14eicosatetraenoic acid [arachidonic, 20:4(n-6)], all cis-5,8, ll,14,17-eicosapentaenoic acid [20:5(n-3)], and all cis. 4,7,10,13,16,19-docosahexaenoic acid [22:6(n-3)] into conjugated diene products by soybean lipoxygenase-1 at pH 9.0 were 84, 86, 60 and 40% of that of all cis-9,12-octadecadienoic acid [linoleic, 18:2(n-6)], respectively. On the other hand, the conversions of all cis.9,12,15-octadecatrienoic acid [a-linolenic, 18:3(n-3)], all cis-5,9,12-octadecatrienoic acid (c5,c9,c12-18:3), and trans.5,cis-9,cis-12-octadecatrienoic acid {t5,c9,c12-18:3) were equal to that of 18:2(n-6). The lowering of the conjugated diene formation in the oxidation of 18:3(n-6), 20:4(n-6), 20:5(n-3), and 22:6(n-3) by the lipoxygenase was thought to be caused by the further oxidation of conjugated diene monohydroperoxides to yield conjugated triene products. For this reason, the conventional lipoxygenase method gave erroneous values for cis, cis-methylene interrupted polyunsaturated fatty acids (PUFA) in oils containing a large amount of 20:5(n-3) and 22:6(n-3) such as fish oils. However, by changing the pH of reaction mixtures from 9.0 to 11.0, the secondary oxidation of conjugated diene monohydroperoxides was completely inhibited, and the PUFA values in fish oils obtained by this improved method were in good agreement with those obtained by a GLC method.

show abstract

“…For the lipoxidase determinations on marine oils (including fresh water fish oils), 200 to 300 mg of sample was weighed into a nitrogen-purged flask and diluted to 100 ml with hexane. An aliquot (1 ml) was taken for saponification, usually overnight, as described by Zmachinski et al (15). The enzymic incubation and determination of resulting hydroperoxide conjugation were performed as previously described for the reference lipids.…”

Section: Methodsmentioning

confidence: 99%

Reaction of lipoxidase with polyenoic acids in marine oils

Beare-Rogers

Ackman²

1969

Lipids

View full text Add to dashboard Cite

Eight samples of raw oils from fresh water and marine fish, and two from marine mammals, were examined for polyenoic fatty acids susceptible to the action of lipoxidase. The results agreed well in most instances with gas chromatographic data and indicated that only one peroxide group was formed in polyenoic fatty acids with more than one ostensibly suitable 1,4‐pentadiene system. Four commercially available preparations of polyenoic fatty acids showed varying degrees of susceptibility to lipoxidase, indicating the probable presence of artifacts formed in purification steps. The marine polyenoic acids were suitable substrates for lipoxidase.

show abstract

Comparison of various analytical techniques for the determination of essential fatty acids in hardened fats

Cited by 15 publications

References 11 publications

Rapeseed oil in a two‐component margarine base stock

Rapeseed oil in a two‐component margarine base stock

Formation of conjugated diene and triene products in lipoxygenase oxidation of C18, C20, C22 PUFAs

Reaction of lipoxidase with polyenoic acids in marine oils

Contact Info

Product

Resources

About