Changes of viable counts and microflora of ground pork stored at 5°C for 20 days under modified atmosphere packaging with O₂, CO₂, N₂, air, vacuum, free oxygen absorber or stretch were compared. Viable counts of ground pork stored under CO₂, free oxygen absorber and vacuum packaging were 10¹ to 10⁶ CFU/g lower than those stored with O₂, N₂, air and stretch packaging. At the initial stage, the dominant microflora in ground pork were Micrococcus, Staphylococcus, Acinetobacter and Yeast. The dominant microflora in the latter stage were Lactobacillus for CO₂ and vacuum packaging, Pseudomonas for O₂, air and stretch packaging, Lactobacillus and Serratia for free oxygen absorber packaging or Psedomonas and Brochothrix for N₂ packaging. VBN and pH values of ground pork packaged with CO₂, free oxygen absorber and vacuum on the 14 th day of storage were lower than those packaged with O₂, N₂, air and stretch packaging. It was suggested that storage under CO₂, free oxygen absorber and vacuum packaging was effective to extend the microbiological shelf life of ground pork.

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The relation between cell wall polysaccharide constituents and hardness of Koumezuke (salted small mume fruit) were investigated. 1) The cell wall polysaccharides of small mume fruit consisted of 35-45% pectin, 30-37% hemicellulose and 25-28% cellulose. An increase of pectin content, and a decrease of hemicellulose II (soluble in 17.5% NaOH) and cellulose content were observed during maturation. 2) When mume fruit was salted with Ca (OH)₂, pectin and hemicellulose I (soluble in 5% NaOH) in the cell wall showed decrease, but cellulose and hemicellulose II showed an increase. And the increase of pectin was observed in the fruit salted without Ca (OH)₂. 3) In the cell wall pectin of Koumezuke, a decrease of the methoxyl group and increases of ash and Ca content were observed during salting. These increases were remarkably observed in the Koumezuke which maintained fruit hardness by salting with Ca (OH)₂. 4) Three main pectin fractions in fresh small mume fruit and Koumezuke were eluted by 0.10-NaOH, 0.30 M and 0.20 M-phosphate buffer on DE AE-cellulose chromatogram.

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Geen onion (Allium fistulosum L.) and spinach were held at 1, 5, 10, or 15°C for 5-40 hrs as pre-cooling and the periods of shelf-life after transferring to 25°C were determined, respectively. The shelf-lives of green onions at 25°C after pre-cooling at 1°C for 10 hrs, 5°C for 10-20 hrs, and 10°C or 15°C for 5-20 hrs were longer than that of the control. Pre-cooling of spinach at 5°C for 10-40hrs and 10°C for 10-20 hrs extended the shelf-life at 25°C. Pre-cooling at 1°C for 10-40hrs did not extend the shelf-life of 4 cultivars garland chrysanthemum (Chrysanthemum coronarium L.) after transferring to 25°C. Contents of sugars in green onion and spinach did not show apparent changes during storage at 1°C and 20°C. Contents of chlorophyll in green onion, spinach, and garland chrysanthemum decreased slightly and the free amino acid content increased slightly during storage at 1°C. During storage at 20°C, chlorophyll contents in three leafy vegetables decreased rapidly and the free amino acids showed rapid increase with yellowing.
Contents of chlorophyll and free amino acid in garland chrysanthemum grown with organic fertilizer were higher than those in chemical ones. The changes during storage were almost similar.

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The laboratory model-modified air system controlled atmosphere (MASCA) storage facility which is being developed as an economical CA was improved to develop a practical CA facility for vegetables. The practical MASCA facility consists of a modified air generator, CA room, O₂ and CO₂ analyzer and sequence program. A pressure control unit was equipped to the generator to select the desired O₂ concentration in modified air. A commercial prefabricated walk-in cooler (5.72 m³) was used as a CA room. To make the room gas-tight, a stainless steel sub-door was fixed inside the door board. The sequence program was improved from the aspect of saving energy. 600 kg of cabbage was stored for 4 weeks to evaluate MASCA to extend storage life and to estimate storage cost, etc. The practical MASCA storage facility functioned as it had been designed. The MASCA can be applied to vegetables because it has some advantages in facility investment, operation cost and maintenance, and it has a wide application for commodities and good retention of freshness.

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A gas separation membrane-modified air system (GSM-MAS) ·CO₂ evolution analyzer was developed to determine the effects of low oxygen atmosphere on the respiration of harvested fruits and vegetables. The equipment was composed of gas separation membrane-modified air generator, gas tight chamber, O₂ and CO₂ sensors. The equipment produces the desired low oxygen atmosphere and determines the respiration rate by measuring the rate of carbon dioxide evolution from plant materials. The GSM-MAS · CO₂ evolution analyzer well controlled the atmosphere within the range of optional oxygen concentration, and the results suggested that the analyzer provides a useful means to study the effects of low oxygen atmosphere on the respiration of fruits and vegetables. The respiratory response of spinach to a low oxygen atmosphere is also discussed.

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