초록
재동결 명태육의 냉동변성에 미치는 축합인산염처리의 영향을 밝히고져 북양산 냉동명태를 해동하여 fillet로 만든 후 sodium polyphosphate 및 sodium polyphosphate: sodium pyrophosphate(1:1, w/w) 용액에 농도별, 시간별로 침지처리하여 동결저장한 후 해동하였을 때의 육중에 흡수된 인산염량, free drip, expressible drip, drip중의 total solid, total nitrogen 및 DNA함량, 해동시의 fillet의 관능적품질 및 가열조리시 중량감소 등을 실험하여 육질변성의 정도를 비교 검토하였다. 1. 해결전 처리에 의한 육중의 인산염흡수량은 침지시간보다 처리액농도에 더욱 많은 영향을 받았으며, 본 실험 조건하의 전처리육의 인산염함량은 모두 FAO/WHO의 허용기준량이하였다. 2 Drip의 발생량은 육중의 인산염량와 역상관계를 나타 내었고 drip감소에 가장 효과적인 처리조건은 $10\%$, sodium polyphosphate액에 5분간 침지한 것으로 무처리때의 drip 량의 약 $14\%$ 였다. 3. Drip중의 total solid, total nitrogen 및 DNA 함량은 대체적으로 drip량에 비례하는 결과를 나타내었으며, 특히 DNA 감소에 미치는 축합인산염처리의 효과는 컸다. 4. 해동한 fillet의 관능적품질은 고농도처리액에 처리한 것은 광택이 있고, 육질은 강성이 있어 양호하였으나, 저농도액에 처리한 것 및 무처리의 것은 광택과 강성이 좋지 못 하였다. 5. 가열조리시의 감량은 고농도처리액에 장시간 처리한 것은 감량제어의 효과가 다소 있는 듯하였으나, 저농도액에 처리한 것을 그 효과를 인정할 수 없었다.
The present study was ,conducted to evaluate the effects of condensed phosphates on the refeezing damage of Alaska pollack muscle. The fillets were dipped in such solution as 5 and $10\%$ sodium polyphosphate, 1 and $5\%$ mixture of sodium polyphosphate and sodium pyrophosphate (1:1, w/w) for 1 and 5 minutes, respectively, before refreezing. And fillets were frozen at $27^{\circ}C\~28^{\circ}C$ and stored for 15 days at $-18^{\circ}\~-20^{\circ}$. The degree of denaturation was estimated by determining amounts of drip relased, content of total solids, nitrogen, and DNA in the drip an cooking-weight-loss. Phosphorus absorbed in the muscle was also determined. Phosphorus absorbed in the fillets treated with loft solution of sodium polyphosphate for 5 minutes amounted to 101 mg/100g muscle as $P_2O_5$. The absorption was dependent on tile concentration of treating solution rather than on the dipping time. The increase of phosphorus absorption seemed to affect to reduction of drip. Among the treating conditions, $10\%$, 5 minutes and $10\%$ 1 minute with sodium polyphosphate appeared most effective ones on drip reduction. The effect of $5\%$, minutes with the mixture of sodium polyphosphate and sodium pyrophosphate did not show so benefitable effect in refrozen fillets. As a tendency total solids, nitrogen, and DNA in tile drip varied proportionally to the amount of drip released. And the content of DNA was lower than the amount. Treatment, at higher the concentration and longer the dipping time, resulted in the lower cooking-weight-loss and the better quality on organoleptic test of thawed fillets.