Progress 10/01/11 to 09/30/14
Outputs
Target Audience: The target audience includes the scientific community, including researchers and externsion specialists, and commercial aquaculture producers of freshwater prawn. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Manuscripts are in preparation for publication in scientific journals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Prawns were purchased from two commercial producers and were obtained from aquaculture ponds at Virginia State University (VSU). Sediment and water samples were obtained along with the prawns, and production data were provided by the growers. Major ion content of prawn tissue, sediment and water samples was analyzed as well as proximate and amino acid compositions and food quality attributes of prawn meats. Size and productivity were consistent with reports from other areas with similar soil characteristics, but lower than areas with higher native fertility. Prawn composition was similar to other reports, 80% moisture, 89% protein (dwb), 6% ash (dwb) and 4% lipid (dwb). Noticable color variation was found and is attributed to differing water clarities. Microbial contamination was consistent with other reports, andwas higher for the head than the tail. Typical storage options include packaging in ambient air and under vacuum. Though access to modified atmosphere packaging (MAP) systems may be limited for small-scale producers, this technology offers potential benefits for shelf-life extension. Fresh prawns obtained from VSU were chill killed in chlorinated water. Samples of six fresh tails were packaged in sealed containers either in air, 50% CO2-N2 (mixed-MAP), 100% N2, or under vacuum and were then refrigerated. Samples were evaluated weekly for 4 wk. Post-storage, 3 tails from each pack were cooked (2 min) in boiling water. Spoilage indicators (visual and odor) increased slowest among mixed-MAP samples. Physical and quality attributes and functional properties differed between raw and cooked meats. Texture differences between raw and cooked meats and between packaging methods were foundsuggesting that such changes may not be apparent to consumers until after cooking. Fast freezing of muscle foods reduces ice-crystal damage during frozen storage. Direct contact immersion (DCI) freezing, wherein solute (typically sodium chloride, NaCl) is used to reduce the freezing point of water, is an affordable technology for small-scale producers. Sodium absorption can lower product quality.Inclusion of sugar may reduce sodium absorption, but alsomay also impact quality. Trehalose (TRE) has unique physical properties that may be beneficial for DCI freezing. Tails and meats from fresh prawns from VSU were either frozen on trays (slow) or frozen using DCI (fast) in one of four solutions of differing NaCl content and with or without TRE. Biphasic water-ethanol solvent was necessary to ensure TRE solubility at low NaCl levels. Quality attributes of meats or of meats from tails frozen in no- and moderate-salt DCI solutions often showed slight, but improved performance relative to fresh meatcompared to those frozen in high-salt solutions with or without TRE. No marked textural differences were found.
Publications
- Type:
Journal Articles
Status:
Other
Year Published:
2013
Citation:
Poster Presented at 1890 ARD Research Symposium
Bragg, S., Y. Xu, E. Sismour, S. Pao and A. Atalay. 2013. Nutrtional, textural and microbiological quality attributes of freshwater prawn Macrobrachium rosenbergii grown in Virginia. 17th 1890 Research Symposium, April 6-10, Jacksonville, FL.
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: The target audience at this stage of study is the scientific community. This includes Food Scientists, and aqua culturist, and other interested parties. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? More studies on effects of these treatments on qualities and safety will be investigated.
Impacts
What was accomplished under these goals?
The ‘Year 2’ study objective was to investigate the effect of different processing methods on nutritional, safety and quality characteristics of freshwater prawn.In the present investigation we compared both methods using calcium chloride to replace a portion of sodium chloride and using trehalose in lieu of glucose.The results showed that the presence of calcium chloride and trehalose, alone or in combination, did not significantly reduce sodium concentrations in freshwater prawn tail meats. Trehalose was present in freshwater prawn tail meats in low concentrations, with no significant difference among treatment and control group.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2013
Citation:
Sismour, N., Xu, Y., Pao, S., Atalay, A. and Kim, C. (2013). Biological, biochemical, and microbiological characteristics of Malaysian prawn Macrobrachiumrosenbergii grown in Virginia. International Journal of Fisheries and Aquaculture (Ready for submission to Virginia Academy of Science).
Bragg, S., Xu, Y., Sismour, E., Pao, S and Atalay, A. (2013). Nutritional, Textural, and Microbiological Quality Attributes of Fresh Water Prawn Macrobrachiumrosenbergii Grown in Virginia.17th1890 Research Symposium, April 6-10, Jacksonville, FL.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Physical, chemical, and mcirobiologcial attributes of Malaysian prawn Macrobrachiumrosenbergii grown in Virginia were evaluated. Sizes varied among three producers, though tail meat yield was similar: 34-38% for females and 32-33% for males. Prawns from one producer exhibited robust pigmentation whereas prawns from the other producers were generally pale with little color except for the claws. Proximate and amino acid compositions, major element concentrations, and microbial profiles were comparable between producers. Amino acid concentrations in Virginia-grown prawn were generally lower compared to prawn grown in Kentucky, but the rank order was similar. No Salmonella spp., Escherichia coli, or Listeria monocytogenes were found. The conclusions drawn in the present study are that prawns tested werehigh in digestible protein and low in lipid, ash and carbohydrate. The microbiological quality of tested prawn was considered acceptable. Tested prawn showed consistent composition between producers, except for crude lipid concentration and color. They were similar in size to prawns grown in ponds constructed in acidic, low-productivity soils elsewhere in the eastern US coastal plain, but they were smaller and amino acid concentrations in tail muscle were similar to or lower compared to prawn grown in ponds located in soils with higher natural productivity. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The overall goal of this project was to investigate the production conditions and post-harvest processing and packaging methods influencing on the nutritional, safety, and quality characteristics of small-scale producing freshwater prawn (Macrobrachiumrosenbergii). In current study, our investigations onphysical, chemical, and mcirobiologcial attributes of Malaysian prawn Macrobrachiumrosenbergii grown in three Virginia locations are an integral partand play very critical and important roles in achieving long-term term outcome measures for the project.The results from this study will lay the groundwork needed to develop a production and postharvest management manual for Virginia prawn producers to use.
Publications
- Edward N. Sismour,Yixiang Xu , Steven Pao, AsmareAtalay and Chyer Kim. (2013). Biological, biochemical, and microbiological characteristics of Malaysian prawn Macrobrachiumrosenbergii grown in Virginia. International Journal of Fisheries and Aquaculture .
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