碩士 / 國立臺灣海洋大學 / 食品科學系 / 104 / Due to polyphenol oxidase enzyme melanosis, microorganism and lipid oxidation, shelf life of shrimp under normal storage conditions is very short. In general, sulfite was used in shrimp to prevent from enzymatic browning and inhibiting microbial growth. However, over used by food processors is the major concern. In addition to this, consumers now concern the impact of chemical additives on the human body. There is a growing trend using natural substances or physical methods to replace sulfite in food. Nisin is one kind of bacteriocins, which secreted from Lactococcus lactis subsp. Nisin can inhibit the growth of bacteria. The US Food and Drug Administration in 1988 officially had included it as GRAS level of preservatives. So far it has been widely used in food preservation. To achieve our goals, this study divided Pacific white shrimp (Litopenaeus vannamei) intro following groups: control group (Control), ice group (ICE), 12.5 g / L sodium metabisulfite (SMS) with flake ice group (ICE_S), nisin broth with flake ice group (ICE_N) and 6.25 g / L SMS mixed nisin broth with flake ice group (ICE_S_N) and stored in 10-day. Following results were obtained: First, the minimum inhibitory concentration of nisin broth standard to Streptococcus thermophilus is 50 ppm. seanwhile the the minimum inhibitory concentration of nisin in the nisin fermented broth was found to be 47.22 ppm. Second, the antibacterial effect of three Gram-negative bacteria of nisin mixed 20 mM EDTA solution from high to low was V. parahaemolyticus, P. fluorescens and Sal. enterica. Third, shrimp with flake ice added sodium metabisulfite can reduce the pH rise, and the maximum of storage was 8-day. Fourth, the flake ice with sodium metabisulfite group can retard the melanosis. Fifth, sodium metabisulfite mixed with nisin broth can inhibit the growth of microorganisms, in which synergistic effect was observed. Based on our findings, nisin could be used to replace part or all of sulfite in the future.
| Identifer | oai:union.ndltd.org:TW/104NTOU5253037 |
| Date | January 2016 |
| Creators | Liang, Zheng-Rong, 梁正融 |
| Contributors | Hsiao, Hsin-I, 蕭心怡 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 73 |
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