Nutritional Content of Fresh vs Processed

[Melody]

So my latest quest is to find out the difference in nutritional content between fresh, cooked, dehydrated, dried and powdered. I know that the more a food is processed the less nutritional value it contains, what I want to know is how much of a difference there is.

The thing is, I often have a choice. I can feed fresh Shrimp or Shrimp Flakes. I can use peas in my homemade foods or I can use pea powder, etc. Fresh is always better, but I wonder how much better?

If its a large difference, how much real nutrition are the fish getting from processed foods? All they are is processed seafood, vegies, etc - powder paste, dried out and vitamin fortified. Most go into the food as powder and are then further processed to make the food. HBH lists their vegies as 'powder', for example, carrot powder, pea powder, etc, so its already thoroughly processed going in. Are they getting any nutrition from the ingredients listed or just the synthetic vitamins added?

Some things I simply can't provide fresh, like Spirulina, but others are quite easily obtained. My second best sub for fresh would be freeze-dried I suppose, like Krill.

I'll be doing a search for data, but I thought I'd run it by you first in case you already know where I can find this type of information. Even if I have the information regarding a few of the commonly used ingredients, we can gain a general idea of just how much of the nutrition is sourced from real food.

It would also blow a lot of these powdered health food additives/drinks out of the water, but that's not the point ;) .

[Danzig]

i hope this isnt too far off topic, but i have found the following link helpfull not only for the human comsumption but i use it as somewhat of a guide as to which fresh fish to feed my fish. It shows mercury toxicity comparisons between common supermarket fish.Albeit it is American im sure it is similar for Canada.

http://www.nrdc.org/health/effects/mercury/guide.asp

[Melody]

Its certainly something that should be factored into the equation. Overall the human-grade food that we would be using would have to meet higher standards than fish meals and the like, but there's more than meets the eye even when it comes to what we eat. Its amazing what we leave up to the 'powers that be' to keep safe for us. :wideeyed: Excellent point, thanks!

[Melody]

The challenge so far is weeding out the commercial information from the unbiased information. BIG difference between the two at times. One says the powders are right up there with fresh vegies, while the others are talking about drastic reductions. Guess who says they're almost as good as fresh? ;)

So far I'm finding information regarding vegies and fruit most. Seafood items will take some diggiing to get by the commercial hype I suspect.

Its an interesting read overall so I'll spend some time on it and let you know what I find out. If anyone has anything to contribute, I'd love to hear it.:smile:

[CACAdmin]

The challenge so far is weeding out the commercial information from the unbiased information.

I tried to search out some info and for the most part all I got was the commercial info which of course will support the product they're selling. Tough to find unbiased info. Good luck and be sure to let us know what you find out.

[Melody]

Anyone remember the Mr. Rogers episode where they visited a fish food factory? I can still see those big sheets of fish flakes :D .

Heat is a big factor it would seem. Higher temps mean more nutrient loss, which most people who cook already know. Most flake foods are 'baked' at high temp's.

Freeze drying retains a lot of nutrients. Dehydrated fresh foods are also very high in nutrients as the drying process utilizes very low heat and air circulation.

Encapsulation processes seem to hold promise on the processed fish food flake/pellets level, being processed at a lower heat and utilizing gelatinized starches. Unfortunately, its also expensive as a rule. Then again, so are the self-proclaimed 'premium' foods that are little more than hype, powder, synthetic vitamins and preservatives.:rolleyes:

So if the food is dried with as little heat as possible, such as dehydration or freeze drying, it retains remarkably more of its naturally sourced nutrition content. All methods utilizing heat, especially high temperatures, destroy a great deal of the nutritional content.

In order to judge the nutritional content retained from natural sources, we have to know the process used by the manufacturer. Not only do we need to know the process involved in producing the food for market, but also how the ingredients were produced, such as vegetable powders.

Since few of the brands actually manufacture their own food, a lot of the processes can be nailed by finding out who does. Most don't like to mention when they don't manufacture their own food though - they like to make you think they make it with their own bare hands. How bad would it look to say its made by the same people who make their competitors' food?

I'll keep digging :smile: .

[Melody]

I'm finally making some headway by researching the individual processes involved. I often hear the term 'spray dried' in regards to fish foods, including egg and seaweed. The following article describes the process very well:

Spray-Drying
Innovative Use of an Old Process (http://www.foodproductdesign.com/archive/1997/0597DE.html)
By Ronald C. Deis, Ph.D.

[Melody]

In regards to powders, most vegetable/fruit powders are the result of high-heat drum drying as well, according to what I've found. This process "destroys most of the antioxident & Phytonutrient content". I have come up with a couple of products designed for humans which are made from low-heat dehydration. This is commercially sourced information and should be taken at face value, although the claims for products designed for human consumption are more tightly controlled.

So again, it depends on the process used. For animals I'm guessing they would use the most efficient method (both time & cost efficient), which would be high heat. Since they're already using drum-drying for the flakes, it stands to reason that they'd do the same for vegetable powder. However, they don't necessarily produce their own ingredients so its not a given by a long shot.

I've decided to write to a Petfood mag I subscribe to and see if they'll enlighten me at all. Worth a shot anyways.:smile:

[Melody]

I attended a very interesting Pet Food seminar that was aired yesterday. They touched on the processing methods as the topic was the trend towards more healthy & 'unconventional' pet foods. Even they acknowledge that they need to know how the ingredients they purchase are processed, before they can come to any conclusions regarding the nutritional value of said ingredient.

They're obviously becoming aware of these things primarily for the profit potential of marketing towards the educated & health-conscious consumer, but its still good to see progress in this regard. They also need to be more aware of things like nutritional content because more and more people are either making their own foods to avoid the over-processed commercial versions, or they're paying more for human grade pet dinners.

They do need tougher regulations for pet food, that's for sure. The term 'natural' can be used by the industry, for example, even if they also use synthetic ingredients for processing the fresh.:rolleyes: