响应曲面法优化气调包装冷却猪肉气体比例的研究

Optimization of gas ratio in MAP chilled pork by RSM

为确定气调包装冷却猪肉最佳气体比例，首先设计单因素试验，通过测定细菌总数，肉色，pH值和电导率。综合分析并确定较好的气体比例，再采用中心复合设计响应面优化设计法，放置在7℃条件下贮藏，通过测定细菌总数，L，a，pH值，电导率，分别建立CO2，O2 2个因素依次与细菌总数值，L，a，电导率之间的回归模型．结果表明，当CO2，O2，N2的气体比例为39％，37％，24％时，细菌总数较低；当CO2，O2，N2的气体比例为33％，39％，28％时，亮度较好；当CO2，O2，N：的气体比例为43％，37％，20％时，肉色较红；当CO2，O2，N2的气体比例为37％，41％，22％时，pH值较低；当CO2，O2，N2的气体比例为32％，40％，28％时，电导率较低．当CO2为32％～43％，O2 为37％～41％，其余比例用相应N２补足100％时，冷却猪肉在贮藏期间可以保持很好的品质．

The objective of this study was to optimize the gas ratio of modified atmosphere packaged （MAP） chilled pork stored at 7 ℃. Single factor experiment and Central Composite Design （CCD） of the Response Surface Methodology were used to determine the better gas ratio by testing the total num- ber of bacteria, flesh-colored, pH and conductivity. In this study regression models were built among CO2, 02 and total bacteria,L , a , pH, electrical conductivity. The results showed that as gas ratio was 39% CO2 ＋ 37% O2 ＋ 24% N2 the level of total bacterial count was the lowest; while it was 33% CO2 ＋39%O2 ＋ 28% N2, the level of light value was minimum ; when it was the 43% CO2 ＋ 37% O2 ＋ 20% N2, high level red value was achieved; as gas ratio was 37% CO2 ＋ 41% O2 ＋ 22% N2, low level pH was realized ; while it was 32% CO2 ＋ 40% O2 ＋ 28% N2 , the level of electrical conductivity was the lowest. Therefore, Response Surface Methodology could be welled in the optimization of the gas ratio. When the gas ratio was CO2（33% -46% ）, 02（34% -40% ）, and the rest ratio using N2 as supplement, the specimens could keep the good quality during storage.