Is Frozen Wheatgrass
As Good As Fresh Wheatgrass?
It might even be better. Let me explain.
Freeze and defrost a whole tomato and it will look lot less appetising than it did. Clearly, something irreversible is going on. Plant cells are enclosed in a ridged cellulose cell wall. It is this cell wall that gives plants their overall rigidity - compare a carrot to a chicken breast. When we freeze fruit and vegetables the water they contain turns to ice and expands. This bursts the cells open and destroys the overall structure. Defrosted fruit and vegetables have lost their 'bite'. This is true for pretty much all fruit and vegetables, even the ones sold frozen in the supermarket.
Animal cells are enclosed in a flexible lipid membrane instead of a ridged cell wall and are much less susceptible to cell bursting.
What does this mean for the health value of frozen fruit and vegetables?
Broadly speaking, there are two reasons your Mum made you eat all your vegetables: fibre and vitamins.
Fibre, the indigestible part of your vegetable diet, is more or less unchanged by freezing even though is is the cellulose cell walls that burst that make up most of this fibre.
Vitamins are organic compounds required in our diet in tiny amounts because we can not synthesise them ourselves and need them for essential functions. The wikipedia entry on vitamins is well worth reading. Freezing does not directly affect vitamins. If you leave fruit and vegetables sitting around, many of the vitamins they contain will slowly become oxidised by free radicals. This is the reason that the anti-oxidant vitamins are good for your health, they get oxidised on your behalf.
The best time to eat vegetables is at the moment they are picked. From that point onward, they loose their anti-oxidant power. The rate of this loss is slowed by cooling. That is part of the reason that food stays fresh for longer when it is kept in the fridge and will last even longer when frozen. So, in terms of health benefit, if you don't have the opportunity to eat your vegetables on the day they are harvested, you are better off eating from frozen. Research on the question started a long time ago, Am Journal Public Health Nations Health, 1932 has been well documented in the media: by the BBC and lots of others, ivillage, explanations.
So, what does this mean for wheatgrass? The same rules apply. The fresher the better. Our wheatgrass is cut, juiced and rapidly frozen all at the same time. The wonderful antioxidant benefit of wheatgrass is protected by its freezing temperature. Once you receive the wheatgrass juice all you need to do is make sure that you keep it frozen until you are ready to drink it. All the other important health giving properties of wheatgrass juice like its chlorophyl and alkalinity ar perfectly preserved.
Didn't I say that frozen wheatgrass juice might even be better? To explain let me answer another question first: why isn't grass a natural part of our diet? Grass cells have a particularly tough cell wall. Try eating plain wheatgrass and a couple of days latter you will see that not much has happened to the grass while it was in your body. Humans lack the natural ability to extract the nutrients from grass.
I may not be a cow but I have wheatgrass juicer!
Ruminants, the specialised grass eaters, like cows and sheep have two tricks up their sleeves. Firstly, they regurgitate partially-digested grass (cud) to re-chew it over and over again. This slowly breaks down the extra tough cell wall in grasses to release the nutrients. And secondly, they cultivate specialised microbes in their fore-stomach, which produce enzymes that break down the cellulose cell wall.
A wheatgrass juicer does this job for us: it bursts the nutrients out of wheatgrass cells so that we can absorb them. But inevitably, some intact cells slip through. Freezing the wheatgrass juice unlocks these last cells. Having said that, this is probably only a minor benefit and not worth doing unless you have some other reason to freeze the wheatgrass.