10 replies to this topic

[Florin1980]

I'm very curiosly if someone have a procedure to determinate the percentage of ice for the frozen fish.
I have something, but it's not very official :

the frozen sample are weights (P1 ) and after that the product passes unde the cold running water untill the ice is departed, so the resulting product ( P2 ) is weighting again and we apply the following formula :


((P1-P2)/P1)x100 =% ice

[Anish]

Dear Florin,

Yes, the calculation part is correct - But, there is a standard procedure by codex -
a) measure initial weight of the frozen material which is taken from frozen temperature storage (-15+/- 5 deg)
b)After weighing the frozen material, you have to transfer it to a sieve with mesh size 3mm max) - Initial weight of the sieve should be recorded before placing the material.
c)Place the sieve with the frozen material in a water bath of 25deg (the water bath should contain water which is 10times the weight of the frozen material)
d)Wait till all the ice has been removed.
e) Incline the sieve so that all the water is completely drained. Remove excess water with clean towel
f) weigh it and calculate.

If I get a copy of soft copy of the procedure, will forward you.

Regards,
anish

I'm very curiosly if someone have a procedure to determinate the percentage of ice for the frozen fish.
I have something, but it's not very official :

the frozen sample are weights (P1 ) and after that the product passes unde the cold running water untill the ice is departed, so the resulting product ( P2 ) is weighting again and we apply the following formula :


((P1-P2)/P1)x100 =% ice

Edited by Anish, 03 February 2011 - 11:08 AM.

[Charles.C]

Dear Anish / Florin,

Actually, I think the previous method was originally due to A.O.A.C. ?

Other methods also exist, eg de-glazing in a refrigerator / open air; packed in sealed bags or not, defrosting by spray.

Basically, all the methods are empirical. The choice may relate to things like whether your fish is whole, filleted, glazed block, semi-block, or IQF presentation. Or if you wish to maximise the chance of a numerically low or high “net weight” result.?

Rgds / Charles.C

[Florin1980]

No, I refer only to determinate de percentage of ice, because you might be misled by the total water content.
I found a STAS used in Romania :

The frozen sample is weight (P1 ) ,the product is left for 2 hours at 20 C, then proceed to remove the layer of ice by hitiing ( i know it seems a little bit medieval style ) so the resulting product ,which is P2 , is weighting and we apply the formula :

((P1-P2)/P1)x100 =% ice

[Charles.C]

Dear Florin,

If you look at the maths / terminologies, you will find that we are basically talking about the same thing. A frequent practical problem is how to measure "ice" but not include "drip loss". Or the opposite.

In practice, buyer / seller (should) typically agree on a particular method, eg as posted by Anish. IMEX, does not typically involve beating the fish.

Rgds / Charles.C

added - I think you are referring to the (%)loss in weight within procedures primarily intended to measure what is described as "deglazed weight". Standard procedures for this do exist, particularly for IQF or semi-blocks (lightly glazed frozen units of several fish). Two popular methods involve (a) cautiously "bathing" the product in a downward fine spray of water so as to remove the surface ice only while maintaining the fish in a frozen condition or (b) similar concept but submersing the product within a tank of water and testing for glaze removal by hand/feel followed by withdrawal and rapid drying. As can be imagined the procedure is typically not that accurate. But should be better than hitting.

[hygienic]

Hi :

I am asking , if we can use the same determination method (equation) to determine the percentage of Ice in frozen Poultry ? or only for fish ?

Hygienic

[Charles.C]

Dear hygienic,

Both the methods mentioned in my previous post were AFAIK developed for seafood (see attachment, 7.3.2 / Annex B). The concept should be general but no idea about implementation for chicken, sorry. Anybody ?

 Deglazed weight, Codex.pdf   101.95KB   92 downloads

Rgds / Charles.C

[Florin1980]

Thank you,Charles.It is very usefull.

[Florin1980]

About food safety and health care, I'm very curious about your position against the products based on vegetable fats.Our producers floaded the market with this kind of products without specify the origin of the vegetable fat.

[Charles.C]

Dear Florin1980,

About food safety and health care, I'm very curious about your position against the products based on vegetable fats.Our producers floaded the market with this kind of products without specify the origin of the vegetable fat.

Regarding "origins", do you mean country or type of vegetable ?

Can you give an example of product referred above ? What type of fat used was used before?

(I'm guessing you mean the current label just says "vegetable fats" with no other information )

Rgds / Charles.C

[Florin1980]

Dear Florin1980,


Regarding "origins", do you mean country or type of vegetable ?

Can you give an example of product referred above ? What type of fat used was used before?

(I'm guessing you mean the current label just says "vegetable fats" with no other information )

Rgds / Charles.C

I refer strictly at the origin of the vegetable fat type. As you know, the legislation requiering to name the country or if is in EU you might write on the label "Origin :EU" - but you have to name the importer or the distributor. The products are sold with an attractive comercial brand in the front of the label ( because the labelling legislation permitted ) and to the second label it;s write : "product based on vegetable fats" - not speciffy the origin of the fats - trans fats hidrogenated fats,nehydro fats,etc.
The products is very cheap, invaded the market because they make good money and looks like cheese.
Srry for my english