Wednesday, February 19, 2014


You are not serious about your health until you juice combinations of fruits and vegetables, according to those that pray at the Church of Blended Plants. You exchange recipes online and discuss the best juicers and blenders on the market and tell the world of nature’s wonders. But will juicing elevate your health beyond the capabilities of the original ingredients?

Juicing is a relatively new concept, with the popularity growing over the last 30 years. The great thing is that you can develop your own creative formulas and in an instant you have a tasty and nutritious drink that you can down in seconds before you go to work, or sip while you check emails.
Don’t forget the pulp
Well-known Australian Food Coach Judy Davie has her  favourite juice. She says it is perfect for keeping her “regular”, even if she doesn’t include the pulp. Well, she probably eats lots of other fibre foods too.

Now, one criticism about juicing is that the fibrous pulp is often discarded and plant fibre is excellent for your insides. Judy reserves the pulp for using in muffins. Smart idea. Those healthy bacteria in your intestines get particularly upset if you don’t include their favourite food (they eat the fibre to produce protective compounds and nutrients in your large intestine).

Enzyme hoax
Some people will tell you that juices contain enzymes, or even “live” enzymes (do they socialise and swap orchard stories?). As an enzyme is a protein and all consumed proteins encounter protease enzymes in the small intestine, it makes no difference if they are alive or semi-conscious because they are all going to be chopped up into small chains of amino acids. It may sound like a horrible death, but that is the cruelty of nature I’m afraid. Enzymes are proteins. We eat them. They die. Then their amino acids get made into human proteins we can use and bingo!, they’ve become useful to us.

Another favourite line is that juices “detox” the body. Nope, and that’s a definite. What detoxifies your body are the lungs, liver and kidneys and they work around the clock doing a fabulous job for eight or ten decades, with luck, providing you give them good care. Detox anythings are a scam. Eating well is normal, leaving your body to do its own detoxification and “cleansing”.

Drinking vs chewing
Enjoy your homemade juice but don’t make that the only way you get two fruits and five veggies inside you. One clear benefit from eating fruit and veg the traditional way (ie chewing) is that it takes longer than drinking. Chewing food takes time, and taking time over food means that you are better able to control your appetite and less likely to overeat.

Commercial juices from the supermarket are likely to be devoid of fibre, possibly be more dilute than comes out of your juicer, and won’t contain the love and flavour of your homemade version. Fruit juices are generally 12% sugar (12g per 100mL), which is the same as a regular soft drink, so it becomes a very easy way to drink quite a few Calories as juice. Knocking back 300mL (10oz) of juice will give you 145 Cals/600 kJs, about the same as eating three medium apples. The juice won’t make much of dent in your appetite, eating three apples will.

What does it all mean?
Juices and juicing can be a neat way to get nutrients from fruit and vegetables, especially if you are in a hurry. Juicing can also be a refreshing drink that you are confident is “good for you”. Try and include the whole food where possible to avoid peeling. For example, the  peel of an apple has 60-100% of its antioxidant flavonols.

Just don’t rely on juicing to get all your fruits and vegetables, and don’t think you have moved up to a higher plane, because all those non-juicers who just chew their plant food will be equally wholesome and well.

Should you wash mushrooms ?

 I have often read that you should never wash a mushroom because it quickly absorbs water and you get squishy mushrooms. Yet there are plenty of voices out there saying that you can wash a mushroom. I write a lot as a consultant to the Australian mushroom industry, so I needed to find the “truth”.

My kitchen became a laboratory. I plonked 150g (5 oz) of whole button mushrooms in cold water and waited 5 minutes. With another lot I waited 10 minutes. After being submerged in water for the designated time I drained off the water and dried the mushrooms with a clean tea towel. Then I re-weighed the mushrooms. After 5 minutes in water there was a gain of 4 grams (2.6% gain) and 6 grams after 10 minutes (4% gain).

Now, I imagine if you did wash your mushrooms to clean off any residual ‘dirt’ you can do it in less than 5 minutes with 0% gain. The mushrooms were then cooked and their brief swim didn’t affect the eating quality.

Then, I read that Robert Wolke, Professor of Chemistry at the University of Pittsburgh had done the very same experiment about a decade ago and found a 2.7% weight gain after soaking mushrooms for 5 minutes. How’s that for brilliant, reproducible kitchen science?

I should warn you that I did the very same experiment with sliced mushrooms. Oh dear! They gained 27% of their weight in water within 5 minutes. Still edible after cooking, but not so good. Why the difference? The sliced mushroom have their inside flesh exposed and this is the part that absorbs water quickly. The “skin” of the whole mushroom is essentially impervious to water as you would expect from a food designed to grow in rain, fog and dew. In fact, the extra weight gained with the whole mushroom might be because I didn’t dry off all the external water.

Of course, you could just brush any visible dirt from a mushroom. I wasn’t suggesting that you need to wash them. Anyway, now you know the truth too. You can give your mushrooms a quick rinse before cooking. Trust us. Quote us. Robert and I are scientists.

Wolke RL. What Einstein Told His Cook. WW Norton & Co. 2002 (p268)