ANNEX VIU.K.DETERMINATION OF THAW LOSS(Drip test)
1.Object and scopeU.K.
This method shall be used to determine the amount of water lost from frozen or quick-frozen chickens during thawing. If this drip loss, expressed as a percentage by weight of the carcase (including all the edible offal contained in the pack) exceeds the limit value laid down in point 7, it is considered that excess water has been absorbed during processing.
2.DefinitionU.K.
Drip loss determined by this method shall be expressed as a percentage of the total weight of the frozen or quick-frozen carcase, including edible offal.
3.PrincipleU.K.
The frozen or quick-frozen carcase, including edible offal present, is allowed to thaw under controlled conditions which allow the weight of water lost to be calculated.
4.ApparatusU.K.
4.1.Scales capable of weighing up to 5 kg and accurate to at least 1 g.U.K.
4.2.Plastic bags large enough to hold the carcase and having a secure means of fixing the bag.U.K.
4.3.Thermostatically controlled water-bath with equipment capable of holding the carcases as described in points 5.5 and 5.6. The water-bath shall contain a volume of water not less than eight times that of the poultry to be checked and shall be capable of maintaining the water at a temperature of 42 ± 2 °C.U.K.
4.4.Filter paper or other absorbent paper towels.U.K.
5.MethodU.K.
5.1.Twenty carcases are removed at random from the quantity of poultry to be checked. Until each can be tested as described in points 5.2 to 5.11, they are kept at a temperature no higher than – 18 °C.U.K.
5.2.The outside of the pack is wiped to remove superficial ice and water. The pack and its content are weighed to the nearest gram: this weight is M0.U.K.
5.3.The carcase, together with any edible offal sold with it, is removed from the outer wrap, which is dried and weighed to the nearest gram: this weight is M1.U.K.
5.4.The weight of frozen carcase plus offal is calculated by subtracting M1 from M0.U.K.
5.5.The carcase, including the edible offal, is placed in a strong, waterproof plastic bag with the abdominal cavity facing towards the bottom, closed end of the bag. The bag must be of sufficient length so as to ensure that it can be fixed securely when in the water-bath but not so wide as to allow the carcase to move from the vertical position.U.K.
5.6.The part of the bag containing the carcase end edible offal is completely immersed in a water-bath and remains open, enabling as much air as possible to escape. It is held vertically, if necessary by guide bars or by extra weights put in the bag, so that water from the bath cannot enter it. The individual bags must not touch each other.U.K.
5.7.The bag is left in the water-bath, maintained at 42 ± 2 °C throughout, with continuous movement of the bag or continuous agitation of the water, until the thermal centre of the carcase (the deepest part of the breast muscle close to the breast bone, in chickens without giblets, or the middle of the giblets in chickens with giblets) reaches at least 4 °C, measured in two randomly chosen carcases. The carcases should not remain in the water bath for longer than is necessary to reach 4 °C. The required period of immersion, for carcases stored at – 18 °C is of the order of:U.K.
| Weight class (g) | Weight of carcase + offal (g) | Indicative immersion time in minutes |
|---|
| Chickens without offal | Chickens with offal |
|---|
| < 800 | < 825 | 77 | 92 |
| 850 | 825 — 874 | 82 | 97 |
| 900 | 875 — 924 | 85 | 100 |
| 950 | 925 — 974 | 88 | 103 |
| 1 000 | 975 — 1 024 | 92 | 107 |
| 1 050 | 1 025 — 1 074 | 95 | 110 |
| 1 100 | 1 075 — 1 149 | 98 | 113 |
| 1 200 | 1 150 — 1 249 | 105 | 120 |
| 1 300 | 1 250 — 1 349 | 111 | 126 |
| 1 400 | 1 350 — 1 449 | 118 | 133 |
For carcases over 1 400 g, an increase of seven minutes for each additional 100 g is required. If the suggested period of immersion is passed without reaching + 4 °C, in the two carcases which are checked, the thawing process is continued until they do reach + 4 °C in the thermal centre.
5.8.The bag and its content are removed from the water-bath; the bottom of the bag is pierced to allow any water produced on thawing to drain. The bag and its content are allowed to drip for one hour at an ambient temperature of between + 18 °C and + 25 °C.U.K.
5.9.The thawed carcase is removed from the bag and the pack containing offal (if present) is removed from the abdominal cavity. The carcase is dried inside and out with filter paper or paper towels. The bag containing the offal is pierced and, once any water has drained away, the bag and thawed offal are dried as carefully as possible.U.K.
5.10.The total weight of thawed carcase, offal and pack is determined to the nearest gram and expressed as M2.U.K.
5.11.The weight of the pack which contained the offal is determined to the nearest gram and expressed as M3.U.K.
6.Calculation of resultU.K.
The amount of water lost through thawing as a percentage by weight of the frozen or quick-frozen carcase (including offal) is given by:
((M0 – M1 – M2)/(M0 – M1 – M3)) × 100
[7. Evaluation of result U.K.
If the average water loss on thawing for the 20 carcases in the sample exceeds the percentages given below, it is considered that the amount of water absorbed during processing exceeds the permissible limit.
The percentages are, in the case of:
air chilling: 1,5 %,
air spray chilling: 3,3 %,
immersion chilling: 5,1 %.
other chilling method or a combination of two or more of the methods defined in Article 10: 1,5 %.]