碩士 / 國立海洋大學 / 水產食品科學研究所 / 83 / This study aimed to investigate the effect of endogenous cathepsin B on the deterioration (modori) of minced fish products. The crude cathepsins B+L activity of the mackerel meat, after leaching, and after grinding with 2.5 % NaCl were 6.02, 5.23 and 4.07 units/g for the hydrolysis of Z-Phe-Arg-MCA (benzyloxycarbonyl-phenylalanyl-arginine-4-methyl-7-coumarylamide), respectively. Cathepsins B+L in surimi without salt still had 82 % activity remained, while the purified cathepsin B had 80% activity remained even after 8 weeks storage at 40℃. These phenomena suggested that cathepsins B+L or only B in mackerel muscle were very difficult to remove through washing process and very stable during frozen storage. According to the SDS-PAGE, no degradation on myosin heavy chain (MHC) was observed on the samples without cathepsin B after 5 hr incubation at 25℃, pH 5.5~7.5 or at 40℃, pH7.5. Degradation of MHC was observed on the samples after 5 hr incubation at 40℃ or only after 1 hr incubation at 55℃ under pH 5.5~7.0. The degree of the degradation on MHC of surimi samples with crude cathepsins B+L under pH 5.5~7.5 increased with the duration of incubation at 40 and 55℃. The MHC of surimi with purified cathepsin B were slightly degraded after 5 hr incubation at 25℃ and obviously degraded after 1 hr incubation at 40℃ under pH 5.5 or 6.5, or at 55℃ under pH 5.5~7.5. However, no degradation on muscle protein was observed on the samples with E-64 (L-trans-epoxysuccinyl-leucylamido-4-(guanidino) butane). The gel strength of kamaboko made by the surimi ground with purified cathepsin B decreased significantly from 649 (pH 7.0) and 611 g.cm (pH 6.5) to 315 and 383 g.cm after 2 hr incubation at 55℃ under pH 7.0 and 6.5, respectively. High residual cathepsins Bor B+L activities of the minced mackerel meat after leaching or grinding with 2.5 % NaCl or after 8 weeks storage at -40℃, degradation of the muscle proteins and decrease in the gel strength of kamaboko by purified cathepsin B and the inhibition of the degradation by E-64, suggested that the cathepsin B might play an important role in the deterioration of minced fish products.
| Identifer | oai:union.ndltd.org:TW/083NTOU3084006 |
| Date | January 1995 |
| Creators | 李百齡 |
| Contributors | , 江善宗, 曹欽玉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 72 |
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