Effect of 6.0% polyphosphate treatment on microbial growth and
composition of microbial flora of three representative seafoods were
investigated.
Polyphosphate treatment washed off microorganisms by 1 log in
peeled shrimp (10⁷ to 10⁶ and 10⁶ to 10⁵) and cooked crab meat (10⁶
to 10⁵) and by 2 logs in red snapper fillet (10⁶ to 10⁴). Phosphate
treatment more readily washed off Pseudomonas sp. and Moraxella sp.
and Lactobacillus sp., Corynebacterium sp. and Acinetobacter sp. were
the most difficult to wash off. Polyphosphate also raised pH from 7.1
to 7.5 in cooked shrimp, from 7.7 to 8.2 in cooked crab meat and from
6.6 to 7.5 in red snapper fillet. The alkaline pH of up to 9.0,
however, had no effect on the growth rates of Pseudomonas I, II and
III sp., A. putrifacien sp., Micrococcus sp., Moraxella sp., Flavobacterium-
Cytophaga sp., Acinetobacter sp., and Lactobacillus sp.
Microbial growth was inhibited immediately following phosphate
treatment. The phosphate induced lag period was almost 4 days at 1.1°C
for shrimp and crab meat but was not observed in red snapper fillet.
The degree of inhibition by phosphate depended on the initial
number and kind of bacteria, especially those belonging to genera
Pseudomonas, Moraxella, Lactobacillus and Corynebacterium. If still
present in phosphate-treated seafoods, Pseudomonas sp. and Moraxella
sp. quickly outgrew all others at 1.1°C. Lactobacillus sp. and
Corynebacterium sp. became the predominant microorganisms when
Pseudomonas sp. and Moraxella sp. were absent. / Graduation date: 1983
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27445 |
| Date | 20 August 1982 |
| Creators | Petchsing, Urairatana |
| Contributors | Lee, Jong S. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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