Dept. Fish Processing Technology, Faculty of Fisheries and Marine Science, Sam Ratulangi Univ., Manado, North Sulawesi, Indonesia.
OSU Seafood Research & Education Center Experiment Station, Dept. of Food Science and Technology, Oregon State Univ., Astoria, OR, U.S.A.
J Food Sci. 2018 May;83(5):1200-1207. doi: 10.1111/1750-3841.14126. Epub 2018 Apr 16.
Brine injection of natural proteases, dried egg white (EW), and dried potato extract (PE), was investigated as a means to prevent softening during cooking of Pacific whiting fillets. Treatments included fillets injected with Water (W), 3% sodium chloride and 3% sodium tripolyphosphate brine (B), B with 0.1% xanthan gum (B ), B with 1%, 2%, or 3% EW (B ), B with 1%, 2%, or 3% PE (B ) or non-injected (NI). Non-injected Pacific cod (Cod) was also utilized as a reference for texture analysis. Fillets were subsequently cooked using cooking protocol 1 (90 °C for 20 min) or cooking protocol 2 (60 °C for 30 min then 90 °C for 20 min). Cooked fillet pH, moisture, total protein, total extractable protein (TEP), total non-extractable protein (TNEP), texture profile analysis (TPA), and electrophoretic pattern (SDS-PAGE) were measured. Cooking protocol 2 significantly reduced moisture, increased total protein, TEP and TNEP. Loss of moisture suggested cooking protocol 2 promoted proteolysis. Electrophoretic evaluations of the fillets treated with the cooking protocol 2 confirmed proteolysis was enhanced by cooking protocol 2 and myosin band integrity was protected in fillets containing natural protease inhibitors. For TPA, there was no significant difference between protease inhibitor types although means for B did trend higher than B . However, PCA analysis clearly demonstrated B and B fillets were most similar to Cod. Results demonstrated brine injection with protease inhibitors prevented fillet softening during cooking.
Texture softening in fish has typically been addressed by diverting product to lower-value minced applications where ingredients can be blended-in to counteract softening caused by enzymes. Investigations demonstrate feasibility of brine injection of protease inhibitor ingredient, dried egg white, to preserve protein integrity during cooking. Dried potato extract required a suspension aide, xanthan gum, in order to become sufficiently suspended in the brine for injection. Dried potato extract was able to inhibit protease activity, however, the suspension aide negatively impacted protein-protein interactions during cooking. An alternative suspension aide is therefore required for dried potato extract.
研究了天然蛋白酶、干蛋白（EW）和干土豆提取物（PE）的盐水注射，作为防止太平洋无须鳕鱼片在烹饪过程中变软的一种方法。处理方法包括用 W（水）、3%氯化钠和 3%三聚磷酸钠盐水（B）、B 中添加 0.1%黄原胶（B ）、B 中添加 1%、2%或 3%EW（B ）、B 中添加 1%、2%或 3%PE（B ）或未注射（NI）处理的鱼片。未注射的太平洋鳕鱼（Cod）也被用作质地分析的参考。鱼片随后按照烹饪方案 1（90°C 20 分钟）或烹饪方案 2（60°C 30 分钟，然后 90°C 20 分钟）进行烹饪。测量了煮熟鱼片的 pH 值、水分、总蛋白、总可提取蛋白（TEP）、总不可提取蛋白（TNEP）、质地剖面分析（TPA）和电泳图谱（SDS-PAGE）。烹饪方案 2 显著降低了水分，增加了总蛋白、TEP 和 TNEP。水分的损失表明烹饪方案 2 促进了蛋白质水解。用烹饪方案 2 处理的鱼片的电泳评价证实，烹饪方案 2 增强了蛋白质水解，并且在含有天然蛋白酶抑制剂的鱼片中原肌球蛋白带的完整性得到了保护。对于 TPA，虽然 B 的平均值有上升趋势，但不同类型的蛋白酶抑制剂之间没有显著差异。然而，PCA 分析清楚地表明，B 和 B 鱼片与 Cod 最为相似。结果表明，在烹饪过程中用含有蛋白酶抑制剂的盐水注射可防止鱼片变软。
鱼类质地变软通常通过将产品转移到低价值的细碎应用中来解决，在这些应用中可以混合配料来抵消酶引起的软化。研究表明，在烹饪过程中，用蛋白酶抑制剂、干蛋白（EW）的盐水注射来保持蛋白质的完整性是可行的。干土豆提取物需要使用悬浮助剂黄原胶，才能在盐水注射中充分悬浮。干土豆提取物能够抑制蛋白酶的活性，然而，悬浮助剂在烹饪过程中对蛋白质-蛋白质相互作用产生了负面影响。因此，需要一种替代的悬浮助剂来用于干土豆提取物。
