A pressure swing adsorption-modified air system (PSA-MAS) ·CO₂ evolution analyzer was developed to determine the effects of low oxygen atmosphere on respiration of harvested fruits and vegetables. The respiration rates of cauliflower, celery, komatsuna, lettuce, broccoli and cabbage were measured with the PSA-MAS·CO₂ evolution analyzer and the gas separation membrane-modified air system (GSM-MAS) ·CO₂, evolution analyzer which was previously developed, The respiration rates were determined by measuring the rate of CO₂, evolution from vegetables under air, 1 % O₂, 4 % O₂, 7 % O₂ and 10% O₂ atmospheres at 10°C. The respiration rates were lower under the low oxygen atmosphere as compared to the air control in all vegetables. Distinctive differences in the respiratory response after exposure to low oxygen conditions were observed among commodities. These differences were divided into three groups. The first group showed that the respiration rate decreased immediately after exposure to a low oxygen condition and then the respiration rate stabilized to a steady, remained constant until the end of treatment. The second group showed that after exposure to the low oxygen condition, the respiration rate decreased slightly slower than the first group but then the respiration rate settled down to a steady rate and remained constant until the end of treatment. The third group showed that the respiration rate gradually decreased until the end of treatment after exposure to a low oxygen condition. Vegetables of the first group included cauliflower and celery. Vegetables of the second group included komatsuna and lettuce. And vegetables of the third group included broccoli and cabbage. There was a linear correlation between the oxygen concentration in the atmosphere and the respiration rates of cauliflower and lettuce. Compared to the air control, the respiration rates of cauliflower and lettuce were considerably decreased even at a 10% oxygen atmosphere. In other vegetables, however, respiration rates were slightly decreased under 7 % or more oxygen conditions. Below 7 % oxygen level, respiration rates were obviously reduced at the lower oxygen levels as compared to the air control.

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This study was conducted to find the suitable storage conditions for immature black soybeans (Glycine max Merr. 'Tamba kuro') served as a vegetable snack. Immature black soybeans with pods and stems were packaged in a polyethylene bag with and without perforation (Perforated Polyethylene Bag, PPB and Non-perforated Polyethylene Bag, NPB), and in a laminated film (“Canz” film) bag with and without 100% Nitrogen (Laminated film + N₂ Bag, LNB and Laminated film Bag, LB), which has a high gas-barrier property. The black soybeans packaged in these plastic bags were stored at 1 °C for 21 days or at 20 °C for 7 days. The gas concentrations in the bags stored at 1 °C showed higher levels of carbon dioxide in LB and LNB than in NPB, and lower levels of oxygen in LNB than in LB during storage for 7 days. The black soybean quality, which was evaluated by the color of pods, stems and seeds, and the taste of seeds, was maintained well in all bags during the storage at 1 °C for 7 days. After storage at 1 °C for 14 days, the green color of pods and stems faded in PPB and NPB, and the color on the seed surface turned to deep purple in LB, where as the quality was maintained relatively well in LNB. Starch content in the seeds had a tendency to decrease slightly in all bags during storage at 1 °C. Especially. the decreasing tendency was more conspicuous in PPB and NPB than in LB and LNB. Sucrose content in the seeds stored in PPB and NPB tended to increase as days of storage at 1 °C increased. Amino acid contents were found to be higher in seeds stored for 7 days at 1 °C than 20 °C in each bag. And it was observed that alanine was accumulated markedly in seeds packaged in LB and LNB during the storage at 1 °C for 7 days.

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The Influence of oxygen and storage temperature on ascorbic acid content, browning index (O.D. 430nm), Hunter colorimetric value, dimethyl sulfide (DMS) and sensory acceptance of aseptic packaged satuma mandarin (Citrus unshiu Marc.) juice were investigated during storage for 3 months at 20°C and 37°C. The single-strength juice (13° Brix) concentrated by the reverse osmosis membrane method was aseptically packaged into a can (3 L volume) and bag-in-box type flexible pouch (3 L vol.) consisting of ethylene vinylacetate copolymer/viniridene oriented nylon / polyethylene (oxygen permeability ; 0.2ml /container·day). The hot-packed canned juice was used as the control. Storage temperature and oxygen, including dissolved oxygen in the juice and permeable oxygen, had profound effects on the juice quality. The ascorbic acid content, Hunter L* value and sensory acceptance declined with the increase of storage temperature and oxygen concentration, while the browning index and DMS developed. Sensory evaluation showed that the aseptic package containers have maintained the juice quality better than the hot-packed can used as the control.

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Cell wall polysaccharides from fresh and salted mume were fractionated, and the quality of glycoprotein bound to the polysaccharide and amino acid composition were investigated. The content of glycoprotein in hemicellulose- I fraction was the highest and that in pectic substances, cellulose and hemicellulose- II fractions became successively lower in this order.
For each fraction, the composition ratio of each amino acid to the total amino acids was different, however, hydroxyproline, glutamic acid and aspartic acid were common to all the fractions. A difference in amino acid composition was found between the Control (brined with NaCl solution) and the Ca-added group (brined with NaCl solution and calcium hydroxide), and especially the behavior of hydroxyproline was quite different. The hydroxyproline of the Control group increased in the pectic substances fraction while it decreased in the hemicellulose-I fraction. On the contrary, hydroxyproline content of the Ca-added group, which presented quite a hard texture, increased in hemicellulose- II and cellulose fractions.
From these results, it was suggested that the increase of the hydroxyproline content in hemicellulose- II and cellulose fractions, whose affinity to the cell wall is stronger than pectin and hemicellulose- I fractions, contributes to the strength of the cell wall structure, in the case where the hardness of mume texture is maintained by the addition of calcium hydroxide.

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