2015 Fiscal Year Research-status Report
Development of antimicrobial packaging system foreseeing enhanced storage stability of lotus root (Nelumbo nucifera)
| Project/Area Number |
15K07452
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| Research Institution | University of Tsukuba |
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Principal Investigator |
Neves Marcos 筑波大学, 生命環境系, 助教 (10597785)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Keywords | Food Engineering |
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| Outline of Annual Research Achievements |
The overall purpose of this research is to enhance the storage stability of lotus root. In order to achieve this goal, in the first year of the project, on one hand we focused on the development of composite films, as a primary step to produce films with enhanced properties, foreseeing their application as packaging material for lotus root. On the other hand, we are also looking into the development and characterization of Oil-in-Water nanoemulsions loaded with natural antimicrobial and/or antioxidant compounds, for optimum antimicrobial and antioxidant activities.
As for the first major task in our project "Task 1: Development of antimicrobial W/O/W nanoemulsions", we has investigated the encapsulation of two antimicrobial compounds, nisin and carvacrol, into Oil-in-Water nanoemulsions, and monitored their antimicrobial activity against Bacillus subtilis, an undesirable food pathogen. The experimental results indicated that a reduction of nearly two log cycles (around 100 times) on B. subtilis population was achieved upon treatment with O/W nanoemulsions loaded with both antimicrobial compounds, compared to the blank (10 mM phosphate buffer).
Regarding the second major task of this project "Task 2: Development of edible coatings and nanocomposite films", we have been investigating the effect of various compositions (consisting of chitosan and nanoclay) on the mechanical properties, and gas barrier characteristics, foreseeing their application as base material for packaging of fresh-cut lotus root.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The major task planned for the first year (FY 2015) "Task 1: Development of antimicrobial W/O/W nanoemulsions" had to be changed somewhat, because we preferred to start the investigation by developing Oil-in-Water emulsions, which for simpler formulation and evaluation of their physicochemical properties, as compared to multiple emulsions such as Water-in-Water-in-Oil, which are more time-consuming to formulate and characterize.
On this regard, during the first year of the project we develop Oil-in-Water emulsions loaded with antimicrobial compounds (nisin and carvacrol), and also investigated their storage stability and antimicrobial activity against Bacillus subtilis and Escherichia coli. The encapsulation of those compounds into O/W nanoemulsions resulted in enhanced antimicrobial activity against spores of B. subtilis, but the synergistic mechanism is not well understood yet.
Seemingly, we had initially planned to purchase in the first year of the project an automatic film casting machine, foreseeing its use in experiments planned for "Task 2: Development of edible coatings and nanocomposite films". Even though we decided not to purchase this equipment in the first year, we have already started this task as planned, where the composite films were prepared by casting, a different technique. Instead, we decide to use part of the budget initially allocated for that equipment, and payed for publication fees for an article relating to these experiments, which was published on March 2016.
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| Strategy for Future Research Activity |
Starting from the second year of the project, we are going to start soon another major task of this project "Task 3: Antimicrobial coating / film applied to fresh-cut lotus root". For this purpose, we still may need to purchase an equipment for automatic coating of the fresh-cut lotus root samples, to be treated with different coating materials, whether they may be antioxidant and/or antimicrobial compounds. In this task, upon optimizing the composition for the edible coatings, the antimicrobial O/W nanoemulsions will be incorporated into those coatings, and the quality parameters of fresh-cut lotus root will be monitored during storage under different conditions, under refrigeration or at room temperature, with or without the application of vacuum packaging.
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| Causes of Carryover |
The sum of 20,506 Yen was carried over to the second year of the project. This budget had been initially planned for purchasing standard reagents for analysis, but this purchase had to be cancelled because that specific reagent was not available.
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| Expenditure Plan for Carryover Budget |
The remaining budget from the first year 20,506 Yen will be used to purchase the standard reagent as soon as it is available in the market.
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