1994 Fiscal Year Final Research Report Summary
Study on quality preservation of fresh agricultural products under controlled atmosphere conditions.
| Project/Area Number |
04454102
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
農業気象・生物環境制御学
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| Research Institution | Utsunomiya University |
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Principal Investigator |
SHIGA Tohru Utsunomiya University Faculty of Agriculture Asociate Professor, 農学部, 助教授 (30089932)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Takahiro Utsunomiya University Faculty of Agriculture Assistant Professor, 農学部, 助手 (50221990)
IMOU Kenji Utsunomiya University Faculty of Agriculture Asociate Professor, 農学部, 助教授 (40184832)
NAKAJIMA Yoshihiro Utsunomiya University Faculty of Agriculture Asociate Professor, 農学部, 助教授 (10008055)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Environmental gas controll / CA storage / quality preservation / fresh agricultural products / respivation rate |
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| Research Abstract |
This research discusses the effects of controlled atmospheric conditipns during storage for quality preservation of fresh shiitake, strawberries, asparagus and other agricultural products.
Decreasing O_2 concentration to 1% and/or increasing CO_2 to 20% during storage will reduce the respiration rate of fresh shiitake more than normal air. Both the lower O_2 concentration and the higher CO_2 concentration lower the respiration rates. PPO activity, the enzyme active in the browning reaction, increase in normal air but decreases in gas treatment during storage. Increasing the CO_2 concentration has a greater effect on the PPO activity in fresh shiitake than decreasing the O_2. From a total assessment, the CA conditions in 10% and 5% O_22 with 20% CO_2 could preserve the quality of fresh shiitake better than other treatments.
Strawberries are found to tolerate high CO_2 concentrations, that is the higher the CO_2 atmospheres reduces the respiration rate, hence extends the shelf life. Keepin
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g strawberry in a very low 1% O_2 and/or a very high 20% CO_2 causes a reduced respiration rate. The high CO2 concentration causes a respiratory quatient (RQ) is not equal to 1 which means that anaerobic respiration has occured. The high CO_2 concentration prevents the reduction pf L-ascorbic acid content during storage. Strawberries can tolerate 20% CO_2 and that is effective for preventing fungal infection.
Decreasing oxygen has a greater efect on reducing respiration rate of asparagus spears during storage than treatment with increasing CO_2. The higher the CO_2 concentration in combination with 10% O_2 the lower the occurrence tip elongation. Asparagus spears stored under CA conditions can reduce chlorophyll degradation more than those stored in normal air. Treatments in low O_2 and/or high CO_2 also reduce the lightening and yellowing of the normal gray-green color. Low O_2 and/or high CO_2 treatments preserve the percentage of sucrose up to 20 days longer than thpse in normal air. In overall data, the L-ascorbic acid content in asparagus spears drastically decreased in 5 days of storage.
The prediction of the respiratory behavior of the various products fitted very well with the Arrhenius and Gore equations The high temperature dependence decreases the effect of temperature change on respiration rate. The Q_<10> of products commonly present a higher value in low temperature and a lower value in higher temperature.
The measurement system established in this study has been well verified in its accuracy in measuring the respiration rate in agricultural products, especially in closed system. Moreover, the data from these system will be advantageous in designing CA and/or MA in present and future postharvest handling. Less
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