For the prevention of texture softening of pickled ume apricot fruit, the effect of treatment with CaCl₂ solution before salting was studied. The changes in its composition of pectic substances consisting of the water soluble(W-P), the hot-water-soluble(HW-P), the hexametaphosphate-soluble (HP-P), and the HCl-soluble(HCl-P)was measured during salting with or without Ca-salt. The results were obtained as follows: (1)During salting of the fresh fruit, a remarkable decrease of HClP and an increase of W-P accomparied softening the texture. (2)The treatment with CaCl₂ before salting increased HP-P and HCl-P, decreasing W-P, and kept the texture well hardened. (3)During salting without Ca-salt, a decrease of the Ca-content in the ethyl alcohol-insoluble substance (AIS)of the pickled product was found, while with Ca-salt, the Ca-content was increased. (4)The amount of Na in the AIS was also increased during salting. As a result of our experiments, the following reaction mechanism of Ca-salt to hold hard texture was presumably proposed: (1)During salting, a part of permiates into the tissues of ume apricot and causes the ion exchange reaction with Ca or Mg ions combined with pectic substances, which changes HP-P and HCl-P to W-P to some degree, and make the texture softer. (2)During salting with Ca-salt, the Ca ions, being increased in its amount in the tissue might form much more additional cross-linkages between or amoung the pectin molecules, which increase HP-P and cause the increase of the hardness of texture.

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Changes in the amino acid composition of fried Kamaboko(FK)prepared from frozen surimi of sardine, Sardinops melanostictus, by irradiation under air at 3 kGy and by subsequent storage were examined. The amino acid content of FK and its extractives was determined by amino acid analyzer. The total bacterial count(TBC)of the samples was measured. The results obtained were as follows; (1)None of 18 amino acids of irradiated FK differed significantly from unirradiated ones. Irradiation brought about the formation of a very amall amount of methionine sulfoxide and sulfone. (2)During 21 days storage at 30°C, the decrease in the total amino acid content(TAAC)of irradiated and unirradiated FK about 5.8 and 4.8%, respectively. TBC of the both samples and amino acid content of their extractives increased rapidly. (3)In storage at 10°C, no apparent change was observed in TAAC of unirradiated FK during 21 days storage. However, a rapid increase in TBC of unirradiated FK and in amino acid content of its extractives was recognized. During 56 days storage irradiated FK showed a very little change of TAAC and of amino acid content of its extractives, and a slight increase in TBC. It turned out that the changes in amino acid composition of FK by irradiation and storage were almost the same degree as that of FK which was made from frozen ground surimi of Alaska pollack reported in the previous paper.

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Phenylalanine ammonia-lyase(PAL)activity in a plum fruit(Prunus salicina Lindl.)variety 'Sordum' was assayed by using crude enzyme solutions extracted from acetone powders prepared from the plum with buffer solution(pH8.8). The relationship between inhibition of increase of pulp color and PAL activity in the fruit during storage at 30°C was examined. (1) PAL activity was detected in plum fruit, and the maximum activity was found at around pH8.8 and in the range of 45 and 50°C. (2)The trend of change of anthocyanin pigment contents was similar to that of PAL activities during maturation on the tree, and both of them increased remarkably at the end of the harvest period. These results indicate that PAL activity is greatly responsible for the formation of anthocyanin pigment. (3)During storage at 3°C, anthocyanin pigment contents did not change. At 20°C, they started to increase from the biginning of the storage, especially increased rapidly after storage for 9 days. At 30°C, although they increased gradually, they were repressed to low level compared with those at 20°C. In fruit transferred to 20°C from 3 or 30°C, and in fruit transferred to 30°C from 20°C, anthocyanin pigment contents increased during storage. (4)During storage, the tendency of change of PAL activities was similar to that of anthocyanin pigment contents in fruit stored at 3, 20 and 30°C, and in fruit transferred to 20°C from 3 or 30°C. These results also indicate that PAL activity is concerned with the formation of anthocyanin pigment. But, in fruit transferred to 30°C from 20°C, PAL activities decreased unlike the change of anthocyanin pigment contents. From these experiments, the inhibition of increase of pulp color at 30°C may be caused by the decrease of PAL activity.

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Utilization of agricultural waste such as Job's-tears husk, peanut shell, lawn grass and rice bran was studied for cultivation of oyster mushroom(Pleurotus ostreaus(Jacg. ex Fr) Quél.)in order to solve the scarcity of sawdust. (1)Practical yield of mushroom was not obtained unless rice bran was added to the substrate. (2)The optimum water content of Job's-tears husk, peanut shell and lawn grass substrates in the presence of 16% of rice bran were 50, 60 and 65%, respectively. (3)Incorporation of 16% of rice bran with the basic ingredient significantly improved the yield. Peanut shell and lawn grass were considered as good as sawdust for the cultivation of oyster mushroom. (4)The substrate composed of rice bran and porous stone gave yields that ranged from 82 to 92% of dry rice bran weight. These results indicate that Pleurotus ostreaus is able to fruit by utilizing rice bran only. (5)Porous stone used was easily recovered and able to employ for re-cultivation.

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The ultrastructure of albumen of fresh chicken and duck shell eggs that were boiled at 100°C or 70°C for 30min and then frozen and thawed, was studied by the use of a TE microscope operated at 80kV. The fluid separated from thawed albumen was collected by draining and centrifugation (2850×G, 20min)of the albumen, and nitrogen and sugars of the fluid were analyzed. After ovomucin was removed from fresh albumen by dilution(1:4)or with 1N HCl(pH5.50), the effects of heat ing and freezing on the ultrastructure of modified chicken and duck albumen were studied by the same method described above. Differences between the micrographs of fresh chicken and duck albumen were evident, but fibrous structures of heavy electron density were occasionally observed in both of them. The fibrous structure was not found in chicken and duck albumen from which ovomucin was removed. Protein matrix of albumen without ovomucin might be easily condensed into clumps or clusters in heating and freezing and when ovomucin was removed with acid, distinct condensation was caused and electron dense spheres were formed. The condensed spheres in chicken albumen were larger than those in duck albumen and protein matrix almost disappeared in chicken albumen, heated at 100°C for 30min. The fluid separated from chicken albumen heated at 70°C, contained much protein, whereas in the fluid of duck heated at 70°C, most of nitrogen was in non-protein type. Paper chromatograms showed that free sugars in the chicken and duck fluid were qualitatively different from the dialyzable sugars of fresh chicken albumen, reported previously. Hexosamine and uronic acid in duck fluid were more than those in chicken fluid.

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The evaluation of protein denaturation in steamed soybeans was attempted by various extraction methods. Soybeans were steamed at atmospheric pressure for 0-60min. Nitrogen extractabilities with buffers containing a protease, carbohydrases and denaturing agents, and by mechanical dispersing were measured. Sodium dodecyl sulfate gel electrophoresis of the extracts and microscopic observations of the extraction residues were also carried out. The water extractability of the protein decreased with steaming time and reached the lowest level of 20% by 10min steaming. The extractability with the buffer containing trypsin also decreased with the time but the lowest level was 40% at 10min steaming and the extractability recovered by further steaming; the extractability of the beans steamed for 60min was similar to that of the nonsteamed soybeans. The band patterns analyzed by the electrophoresis of the protease-extracted protein from steamed soybeans were different from the pattern of the protease extract from nonsteamed soybeans, which showed that the proteins extracted from steamed beans were denatured. It was suggested that the denaturation of the protein in the steamed soybeans could be evaluated by the extraction with trypsin. The protein was also well extracted with concentrated denaturing agent but the difference of the extractability accompanied by the length of the steaming time was not observed. Carbohydrases and mechanical dispersing had little effect on extraction of the protein.

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The permeation rate and the permeability of juice components during the concentration of Satsuma mandarin juice by means of reverse osmosis were studied. DDS plate-and-flame module fitted with three kinds of RO membrane made from different materials(cellulose acetate, composite membrane, polyacrylonitrile)were used. At operating pressure of 70kg/cmcm², the efficient concentration obtained from the single strength juice was limited to about 30°Bx. As a feed juice, clarified juice was more desirable in view of permeation rate. The higher the content of pulp in the feed juice, the lower the permeation rate. When the flow rate of feed juice was increased in the case of unclarified juice, permeation rate was increased. High operating pressure was more effective for clarified juice in increasing permeation rate. The rejection percentages of acid, potassium and vitamin C were slightly lower than that of sugar. The permeability of the volatile components of Satsuma mandarin juice into permeate during concentration to 30°Bx was examined. Monoterpene and sesquiterpene hydrocarbons were almost perfectly retained in the concentrated juices by use of the three membranes. However, monoterpene alcohols, aliphatic alcohols and aliphatic aldehydes were partially permeated through cellulose acetate membrane, but they were mostly retained by the other two membranes.

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The "Sunki", one of the Japanese pickles produced in Kiso district, Nagano pref. is pickled without salt under a lower temperature by the action of lactic fermentation, then dried and preserved throughout the year. Sunki-pickling method is considered to be available for preserving green vegetables. In this report, the author intended to make Mizuna(Elatostema involucratum Franch. et Sav.)into reserving food by means of Sunki-pickling method. Crude protein, amino acid composition and free amino acids were analysed and the following results were obtained. (1)The contents of crude protein and tasty amino acids in the leaves are rich comparing to those in the stem. (2)It was found that Mizuna could be made into reserving food by means of Sunki-pickling method. But the content of free amino acids in the Sunki-pickles decreased compared to that in fresh one, so the taste is inferior to fresh one. (3)Crude protein in Mizuna Sunki-pickles contained proper essential amino acids.

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