Vitamin K Isn't Destroyed By Freezing, Contrary To General Consensus

[burtlancast]

The current general scientific academic consensus, even among alternative health advocates, seems to be that Vitamin K may be destroyed by freezing.

I was curious to learn to which extend this loss occurred, so i went on a scientific hunt: but once i pinned it down, it seems this is a scientific myth: vitamin k is barely affected by freezing (barely is meant in a not statistically significative way).

Even, in some plant species, freezing actually increases vitamin K content.

I think that's quite important to know this, considering the many health applications of this vitamin.

Study in meats from fishes:

Vitamin K is a heat-resistant vitamin but is destroyed in the presence of light and alkali (Leskova et al., 2006), and atmospheric oxygen (Ottaway, 2010). Our results also showed vitamin K to be resistant to freezing.

https://www.researchgate.net/public...m_Kamenskii_1901_and_Sander_lucioperca_L_1758

Study in plants:

it was concluded that there was no appreciable loss of vitamin K activity in the foods preserved by any process or when stored for 15 months.

Comparative Vitamin K Activity of Frozen, Irradiated and Heat-Processed Foods


Does freezing kill vitamin K?

 

[Broken man]

Thank you.

 

[Tristan Loscha]

nice.

 

[boris]

Good to know, thanks! Now I can go back to freezing liver and greens without the feeling of missing out

 

[GelatinGoblin]

Could be compression leading to higher Vitamin K content, kinda like how boiled spinach has 'more' oxalic acid than raw spinach, but it shows that only because of the extreme compression of spinach.
Edit: compression of Spinach when boiled

 

[Tristan Loscha]

Tangentially related,HEAT and FREEZE stability of Alpha Tocopherol,another important Fat-Soluble,in Cow Milk:


Effects of Frozen and Other Storage Conditions on Alpha-Tocopherol Content of Cow Milk
C Vidal-Valverde 1 , R Ruiz, A Medrano
Affiliations

PMID: 8326025 DOI: 10.3168/jds.S0022-0302(93)77484-6

Abstract

The effect of temperature and length of storage on the stability of alpha-tocopherol in UHT milk was studied by HPLC. The effect of water activity conditions during storage of milk powder on the stability of the same vitamin was also studied. Losses of alpha-tocopherol occurred in UHT milk after 1 mo of storage at 30 degrees C; losses increased as storage time increased. In general, when the storage temperature changed from 30 to 40 degrees C, decrease in alpha-tocopherol content was greater. Short periods of frozen storage of the UHT milk (up to 60 d) had no effect on alpha-tocopherol content. However, frozen storage from 4 to 8 mo produced losses in alpha-tocopherol. When water activity was increased, the alpha-tocopherol content in milk powder decreased significantly after 2 mo of storage at 20 degrees C.

 

[Rafael Lao Wai]

Awesome. I don't really freeze leafy greens, but I do freeze liver. Ray has said that he once tried to determine the amount of vitamin K in liver, and, although he didn't get an exact amount, he said it was at least a couple mg per kilo, so at least 200 micrograms per 100 grams, which adds up if the person is already eating some leaves, so very good to know the vitamin K is there wrt liver.