Low Toxin Studies Pasteurisation and retinoic acid

[Peater]

I found this study:

Influence of thermal and other manufacturing stresses on retinol isomerization in milk and dairy products - PubMed

An analytical procedure, based upon HPLC, has been used to determine the degree of isomerization of retinol (vitamin A) in various dairy products. In raw milks, which are not subjected to thermal processing, there was no conversion of the predominant all-trans-isomers to cis-isomers in samples...

pubmed.ncbi.nlm.nih.gov

An analytical procedure, based upon HPLC, has been used to determine the degree of isomerization of retinol (vitamin A) in various dairy products. In raw milks, which are not subjected to thermal processing, there was no conversion of the predominant all-trans-isomers to cis-isomers in samples from various species. Pasteurized milks with mild heat treatment (high quality milk) had an average 13-cis: all-trans ratio of 2.6%, while pasteurized milk treated for 15 s at temperatures ranging from 72 to 76 degrees C had an average ratio of 6.4%. Milk subjected to more severe heat treatments had a higher degree of isomerization (UHT milk, 15.7%; sterilized milk, 33.5%), consistent with increased thermal conversion of the retinol isomers. In pasteurized and UHT cream, the increase in 13-cis-isomer was also a consequence of heat treatment (pasteurized cream, 3.0%; UHT cream, 14.4%). The presence of cis isomers in fermented milk suggests that fermentation processes, directly or indirectly, can induce cis-trans isomerization. In the cheeses analysed, the extent of retinol isomerization ranged from 7.6 to 35.0%. Our results confirm the importance of individual isomers in evaluating the vitamin A status of dairy products.

You get all that healthy Accutane this way. I wonder if that is why Ray noticed an improvement in spots after drinking milk? I don't recall all the details but I think he said he fell asleep with a light shining on him, and woke up with a few spots. He theorised that the light had depleted available vitamin A. (From memory)

 

[mosaic01]

It seems the study is talking about 13-cis-retinol, not 13-cis-retinoic acid.

13-cis-Retinol

13-cis-Retinol | C20H30O | CID 9904001 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

Isotretinoin

Isotretinoin | C20H28O2 | CID 5282379 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

But it shows how easily heat affects retinol conversion.

Apparently, it is called "neovitamin A". Not to be confused with 13-cis-retinoic acid.

 

[Peater]

Thanks for clarifying that @mosaic01 - is neovitamin A where 13-cis-retinoic acid comes from?

 

[Elchupanibrain]

Thanks for clarifying that @mosaic01 - is neovitamin A where 13-cis-retinoic acid comes from?

i think so… if you oxidize Retinol you get retinoic acid

 

[Peater]

i think so… if you oxidize Retinol you get retinoic acid

Thanks. If they didn't measure for retinoic acid it could be there then, I suppose. I don't know if pasteurisation is done in an anaerobic environment.