Abstract
Domestic pear has been reported that it contained a pretense, which used for tenderizer of meat, however no researches for optimum level of the enzyme with maximum tenderness effect have been studied. Thus, this study was peformed to determine the optimum level of a protease for meat tenderness. Moisture contents (％) of domestic pears was determined. A pretense was homogenized in a mixer and centrifuged at 10,000 G for 1hr. After taken the supernatant, dialysis was conducted to remove salts and sugars, and freeze-dried. Then, various level (0.05, 0.1 and 0.2％) of the purified pretense were added to pork loins (3cm thickness). Then, pork samples were boiled at 80 for 12 min in a water bath to reach the interval temperature of 71 and chilled in an ice. Moisture contents (％) of domestic pears ranged from 87.2 and 87.8％. No differences in cooking loss of pork meats were observed (p>0.05) among various levels of a pretense. After centrifugation, the protein concentrations of a protease showed from 5.96 $\mu\textrm{g}$/fmL to 7.25 $\mu\textrm{g}$/mL. Increased level of a pretense up to 0.1％ reduced (p<0.05) the shear value (kg/g), however no further reduction of shear value was observed at the level of higher than 0.1％ of the purified pretense. The approximate molecular weight of the pretense analysed by sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was 30 kDa. These results suggest that the optimum level of a pretense for the maximum effect of meat tenderness is above 0.1％. Further research will be peformed to determine the effect of various domestic pears and ingredients, such as salt and phosphate, on meat tenderness.
본 연구는 국산 배에서 단백질 분해효소를 분리, 정제하여 단백질 효소의 농도별 돈육 등심에 대한 연화 정도를 측정하여 가장 적당한 농도를 찾고자 실시하였다. 단백질 함량은 5.96 $\mu\textrm{g}$/mL와 7.25$\mu\textrm{g}$/mL을 나타냈었으나 투석한 경우는 신고가 0.19$\mu\textrm{g}$/mL, 추황이 0.24$\mu\textrm{g}$/mL를 나타내 투석할 경우 오히려 단백질 함량이 감소하였다. 투석한 단백질 분해효소를 첨가하지 않은 대조구와 각각 0.05%, 0.1% 및 0.2%를 첨가한 후 81$^{\circ}C$에서 가열한 후 냉각한 돈육 등심의 전단력은 신고에서 6.24, 5.69, 5.37 및 5.58을 추황에서 5.44, 4.92, 4.65 및 4.80을 나타냈다. 신고와 추황의 정제된 단백질 분해효소를 0.1% 첨가했을 때 가장 낮은 전단력을 보였고 첨가하지 않은 것에 비해 각각 14%와 15%의 감소를 나타냈다. 전기영동에 의한 단백질의 분자량은 약 30kDa을 나타냈다. 연도에 최대 효과를 줄 수 있는 적정함량은 0.1% 이상이라 사료된다.
