Blended greens

Question
QUESTION: What I like to do every weekend is...chop an assorted amount of vegetables,
fruits and throw them in 7 ziplock bags in the freezer, for the next one or
two weeks. Every night, I then take one of the bags of chopped up assorted
veggies and fruits, and blend them into a smoothie, so that I can drink them
the following day.

My question is, am I affecting the nutritional value or quality of the
vegetables and fruits when I either preserve them in the freezer for one or
two weeks, or blend them up into a smoothie to drink the following day.

I have heard on multiple occasions that blending the fruits doesn't do
anything to the nutritional value except for destroying about half the fiber.

I also heard that blending the smoothies in advance...for example, if I were to
blend a whole bunch of veggies and fruits on Sunday, and consume the
smoothies throughout the week is a bad idea because the smoothie will
spoil(even in the freezer) or the nutrients will significantly oxidize and
"deplete" throughout the week.

Thanks for the advice. Many thanks.

ANSWER: Hi Andrew

Thanks for an interesting question. I am not as concerned about the freezing of the veggies, as about the smoothie mix that you are keeping for a day or longer.

Usually, when freezing vegetables, blanching is recommended. This 'sets' the vegetables in a sense and helps to retain vitamins and appearance. If you are planning to use the produce for smoothies, retaining color probably isn't very important to you.

After blanching, the veggies are removed from the boiling water and plunged into ice water to stop the cooking process. They can then be dried in a spinner, before freezing them. The more delicate the vegetable, the shorter the blanching period. You will be able to find tables with blanching times for the different veggies on the internet. To prevent browning or oxidization in fruits, ascorbic acid or lemon juice are often used.

Blanching deactivates the enzymes that usually cause loss of color, flavor and nutrients. It also destroys microorganisms on the surface of vegetables. So, for the best retention of nutrients, this technique can be used if you have the time and patience.

When it comes to storing smoothies and fresh vegetable juice, this isn't recommended. As soon as the fresh produce is blended or juiced, oxidization begins to destroy nutrients. It is always better to drink a smoothie or a glass of vegetable juice as soon as possible.

Andrew, something else you may want to keep in mind is that juicing gives you far better access to nutrients than blending (as in the case of smoothies). You can read more about this at http://www.best-juicing.com.

With juicing, you may be losing fiber, but you are gaining so much in the sense of all the nutrients that are extracted from the fiber. For instance, it is claimed that when you eat a raw carrot, your body can access only about 1% of the beta carotene in it. The rest remains trapped in the fiber. However, when you run a carrot through a juice extractor, your body can access more than 90% of the beta carotene! That is a massive difference.

When blending veggies into smoothies, you won't get nearly the same nutritional advantage, but you will retain more of the fiber. So, making use of both techniques seems to be the way to go health-wise. There are also certain fruits that don't juice well, such as bananas. These do very well in smoothies.

So, I would say that freezing the veggies is OK, but try to freeze just enough for each day's smoothie. And, if possible, also consider adding juicing for health to your nutrition program.

Congratulations for taking care of your nutritional needs in this way! You can expect to see major dividends in the long run in terms of health and vitality.

Regards
Rika Susan



---------- FOLLOW-UP ----------

QUESTION: i forgot to add, but does this apply to avocadoes and guacamole as well?
i make homemade guacamole all the time and i totally forgot that it was a
fruit/veg as well, thus it is also vulnerable to the oxidization process as soon
as it is opened and mashed?

surely the grocery stores or producers must put some sort of ingredient in
their guacamoles to presrve the nutrients of their avocadoes?

is there some sort of book i can pick up on this subject?

once again, your answer has helped me tremendously.

Answer
Hi Andrew

Yes, you will have a problem with oxidization in guacamole as well. Use the same tips I gave in the previous answer to reduce oxidization. Minimizing exposure to air is the most important thing. So cover the guacamole with plastic wrap and seal it as tightly as possible. You can also add a dash of lime juice or lemon juice. The citric acid acts as an antioxidant. You can also use this in smoothies and veggie juice and you can also add a teaspoon or two to mashed avocado. Brushing this over the surface of a cut  apple is also effective. Some folks also recommend covering the guacamole with a thin layer of pureed tomatoes as a way to prevent oxidization.

Hope these tips help you. Happy, healthy eating!

Best wishes
Rika Susan

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