New Technology for Improving the Functionality of Fish Muscles Using Koji Fermentation

• Main Authors: Ming-Chu Lu, 呂明珠
• Other Authors: Shann-Tzong Jiang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/57247261735551325170

碩士 === 國立海洋大學 === 食品科學系 === 90 === Abstract To improve the quality and functionality of mackerel minces and consequently increase the utilization of this species, the minced mackerel was fermented with Monascus purpureus CCRC 31499 and Monascus sp. CCRC 31746. The medium with 3% rice powder and 2% yeast extract at pH 5.0 was the most suitable for the growth of these strains. When the minced mackerel was used to replace the nitrogen source, a medium with fish meat to 3% rice powder solution ratio of 3:7 was employed. The growth of Enterbacteriaceae, Staphylococcus and Pseudomonas were significantly inhibited, when fermented at 25oC on the medium preheated at 65oC for 30 min and with pH 5.0, shaking at 120 rpm during 7 days fermentation. During fermentation, the anka plate counts increased from 104 to 106 cfu/ml, while the pH of Monascus purpureus CCRC 31499 and Monascus sp. CCRC 31746 increased from 4.9 and 5.0 to 5.2 and 6.4, respectively. Hunter a value of anka significantly increased (p<0.05). The total sugar rapidly declined, but the reduce sugar increased at early stage and then decreased. The activities of both amylase and acidic proteases were detected after 1 and 2 days fermentation, respectively and further increased during fermentation. No significant difference in neutral proteases was observed (p>0.05). The activities of amylase and acid proteases in those fermented with Monascus sp. CCRC 31746 were significantly higher than those fermented with Monascus purpureus CCRC 31499. The VBN of those fermented with anka were still lower than the safety limit of food regulation (< 25mg/100g) after 7 days fermentation. Comparing with the control samples, no significant differences in organoleptic flavor, moisture content, crude fat, crude protein and ash was obtained during fermentation (p>0.05), but the free amino acid increased significantly (p<0.05), especial glutamic acid and lysine. The data of amino-nitrogen, free amino acid and SDS-PAGE indicated severe hydrolysis of muscle proteins occurred during fermentation. The increases in peptides and free amino acid during anka fermentation would substantially improve the digestion efficiency, flavor, taste and nutritional value of the fermented fish.