How much to feed fish daily

[Atrumblood]

I get your skepticism. It's funny because I said to myself, someone will question that statement. Freezing causes a rupturing of cells and a loss of quality. The slower the freeze the worse it is (home freezer). The food industry has moved to flash freezing which produces smaller ice crystals in the cell walls, reducing rupturing, and maintaining moisture and nutritional content. Not an old wives' tale. No where across any food manufacture or in the FDA Food Code will you find a thaw refreeze cycle permitted after the initial freeze on the finished product. There's no study on something like a cube of mysis that's been frozen, thawed, frozen, and thawed again that I'm aware of. It's just not best practice. My insight comes from 30 1/2 years of QA work and regulatory inspection across just about type of food manufacturer. It's really a basic food manufacturing concept.

Quick quote from a health and nutrition site:
For example, freezing and thawing meat more than one time might cause color and odor changes, moisture loss, and increased oxidation of its fat and protein.

Oxidation is a process in which electrons are transferred from one atom to another. When this occurs in meats, it can lead to a significant deterioration in quality.

Thanks for all the information.

Can you define: "quality" in this case?

From the information I've gathered so far, quality seems to not be a definition of amount of nutrients available but rather taste, texture, appearance.

Many of those studies also involved testing of foods that had been thawed then heated then refrozen. Which would reduce the quality in terms of providing micro organisms an ideal environment to thrive.

However when it comes down to the actual quantity of nutrients contained in the same mass of food being thawed and frozen again while being kept between 2-8°C was not touched on in enough detail to draw conclusions from.

Thoughts on that?

 

[vetteguy53081]

I have never used an auto feeder for anything other than dry pelleted food. Is this an option for frozen foods? Does your auto feeder turn off your pumps to prevent uneaten food from getting filtered out before your fish can get to it?

I use feeder for dry pellets and flakes as a supplement in my absence. Pumps remain running. My unit drops food 11a-1p-3p-7p

 

[jmichaelh7]

There is that one theory heavy in heavy out .

 

[vtecintegra]

Can you define: "quality" in this case?

Common industry definition, or what some call a "text book" definition:
Typically, the term food quality represents the sum of all properties and attributes of a food item that are acceptable to the customer. These food quality attributes include appearance (size, shape, gloss, color), consistency, texture, flavor, and nutritional content.

Heating and microbes are an entirely different topic. All I was saying, is that thawing and refreezing fish food is not a good idea. You may be reducing the nutritional value of the food you're feeding. The food industry doesn't do it, for valid reasons.

 

[Atrumblood]

Common industry definition, or what some call a "text book" definition:
Typically, the term food quality represents the sum of all properties and attributes of a food item that are acceptable to the customer. These food quality attributes include appearance (size, shape, gloss, color), consistency, texture, flavor, and nutritional content.

Heating and microbes are an entirely different topic. All I was saying, is that thawing and refreezing fish food is not a good idea. You may be reducing the nutritional value of the food you're feeding. The food industry doesn't do it, for valid reasons.

I've still not been able to locate a study done on nutrition specifically. All I can find and maybe this is due to my searching for the wrong keywords, are studies focusing on appearance, taste, texture, smell, and other sensory qualities. What I cannot find is details as to how and what nutrients are affected.

I am specifically looking for how thawing and refreezing affect the nutritional bioavailable carbohydrates, protein, fat, mineral, and amino acid content of meats and vegetables, but I will concede this discussion to you and your expertise for now until I can find the relevant data.

Either way, I thank you for the information you have given me.