The Lane-Eynon method is the Japanese official method for measuring lactose in milk products containing sucrose. This method includes titration procedure which must be completed within a definite time at boiling temperature, and the visual detection of its end point is also difficult. To remove these defects an improved method was developed. Sample solution (10ml) is mixed with an excess amount of copper (II) solution containing strong alkali (5ml of Fehling's soln. A+7ml of Fehling's soln. B), and the mixture is boiled for 2min. The copper (II) which is equivalent to reducing sugar is reduced to copper (I). After the boiling procedure, an excess amount (4g) of potassium iodide crystal is added to the mixture. To avoid oxidation of potassium iodide by air, sodium carbonate (40ml, 4%) and hydrochloric acid (8ml, 6.7N) are added successively to the mixture. Carbon dioxide thus liberated is effective in removing oxygen from the solution. The mixture is kept in dark for about 5 min. The liberated free iodine which is equivalent to the remaining copper (II) is titrated with sodium thiosulfate solution (0.05 N) by use of starch as an indicator. The blank test is carried out in the same way by using water as a sample. With the difference between the resulting titre of the sample and that of water, the amount of lactose can be known from a calibration curve which is prepared previously by use of samples containing known amounts of lactose. In this method, the operation was more convenient and the visual detection of the end point was easier than the Lane-Eynon method, since the titration was carried out at room temperature and free from time restriction. The method described here is suitable for practical use judged by reproducibility, recovry and accuracy.

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Relationships between 51 abstract terms and 54 concrete terms for oder-description were evaluated by three types of panel. On the assumption that the abstract terms were explanatory factors of the concrete terms, the response pattern matrix was analyzed by non-parametric multi-dimensional scaling (quantification theory III) and cluster analysis was done on the scores from the first to the fifth axis obtained by quatification theory III. Concrete terms were separated into 23 groups as a whole, but terms that coincided with classification among three types of panels and the sum of the three data sets, were only 17, less than the result obtained by the analysis of similarity matrix. It was considered as a reason that the terms were classified more distinctly and more closely, as compared with the former analysis. The resolution 1 and 2 of sample score (concrete terms) and category weight (abstract terms) obtained by quantification theory III, were profiled two-dimensionally, respectively. When they were overlapped together, the abstract terms explained well the concrete terms to which they corresponded at the positions.

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Fifty-one abstract terms and 54 concrete terms for odor-description were separated into 13 and 23 groups as result of analysis of similarity matrix and response pattern matrix, respectively. Contributions of 13 groups of abstract terms to the characterization of 23 groups of concrete terms were elucidated. (1) The groups of concrete terms signified as "disagreeable odor" were contributed by the group of abstract terms; 'stink and/or nauseous'. (2) Characterization of the groups of concrete terms "animal and/or fatty", was due to the groups of abstract terms; 'extensive', 'round and/or gentle' and 'sweet and/or warm'. (3) The concrete terms grouped as "smoky" were largely contributed by the groups of abstract terms; 'pungent' and 'dry'. (4) On the groups of concrete terms signified as "high volatile", panels responded to the groups of abstract terms; 'pungent' and 'active and/or lively'. (5) The concrete terms grouped as "vegetable" were characterized by the groups of abstract terms; 'extensive', 'round and/or gentle', 'light and/or refreshing' and 'active and/or lively'. (6) The groups of concrete terms signified as "dry odor" were contributed firstly by the group of abstract terms; 'dry', and secondly by 'flat and/or featureless'.

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A detailed study was carried out on triterpene alcohol acetates contained in chicle resin which is used as a chewing gum base. As a result, we have newly identified ψ-taraxasterol acetate, taraxasterol acetate, eupha-7, 2, 4-diene-3β-ol acetate and tirucalla-7, 2, 4-diene-3βol acetate mainly based on 1H-NMR spectra, in addition to α-amyrin acetate, β-amyrin acetate and luperol acetate which have been previously reported. Each of these newly identified compounds is a cyclic triterpene synthesized via dammarenyl cation formed through a ring-closure reaction of all-trans-epoxysquarene which is a chain-type triterpene.

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Experiments to detect typical off-flavor of raw milk with tin-oxide semiconductor gas sensors were carried out. The sensors used were Taguchi gas sensor: TGS 822, TGS 71N and TGSS-100 of Figaro Engineering Ind.. Each sensor was mounted on the measuring circuit, SR^# 1 (Figaro), in which detected electric resistance of the sensor was converted to a corresponding voltage signal (0-5V). To overcome some defects of human sensory test, and to make the sensory test automatic, suitability of the sensors and an extraction method of odor were investigated. It was found that the stable measurement was possible with a procedure as follows; mixing a sample with gas in a definite ratio in a narrow tube continuously, heating at a definite temperature while passing through the tube soaked in a water bath, removing the sample from the mixture and inspecting gas which contains odor. In this process, using nitrogen gas containing 0.2% v/v of O² in final inspecting gas makes sensitivity much higher than using air. With two sensors which have different characteristics for odor materials, the classification of off-flavor was possible. At the optimum conditions of this method, sensitivity level of off-flavor detection could be almost same as that of human sensory test.

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Continuous production of kiwi fruit and persimmon vinegar were developed using fixed cells on woven cotton fabrics. The fabrics were packed in a column and inoculated with Acetobacter aceti. Acetobacter cells were easily fixed on the cotton fabrics and grew well. When the synthetic medium was used to the fermentation, the acetic acid productivity was achieved to be 49.7g/l·h at acetic acid concentration of 45g/l, and the maximum productivity based on the total volume of column including fabrics was 13.7g/l·h. When the kiwi fruit- and persimmon-wine were used, the acetic acid productivity decreased a little, but was still preserved on the level of 7.4g/l·h and 5.2g/l·h, respectively, on the total column volume basis at 45g/l acetic acid concentration. The surface culture by the growing cells fixed on the woven cotton fabrics was superior over the submerged culture involving aeration, from the viewpoint of the higher productivity and of the higer energy efficiency.

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The scale-up effects of a horizontal rotary column reactor were studied using a pilot scale reactor, the volume of which was 5.3 times that of a bench scale reactor. The rotary column, consisting of a wire-mesh cylinder, is divided into five sections in the axial direction and into eight sections in the periphery direction with punched plates to prevent fibrous immobilized β-galactosidase clumping together. Further, we searched for reaction conditions which produced 70 to 80% lactose-hydrolyzed skim milk (at 7°C) after 16 to 20h of the reaction. The results were as follows: (1) The rate of lactose-hydrolysis in the pilot scale reactor was the same as that in the bench scale reactor at rotational speeds above 21rpm. This shows that the degree of mixing in the scale-up rotary column reactor is comparable to the bench scale reactor. That is, simple scale-up rules for an isothermal reaction apply to the rotary column reactor. (2) The ratio of hydrolyzed lactose in reconstituted skim milk was constant at circulation flow rates of above 600l/h. (3) The ratio of hydrolyzed lactose after 16 to 20h of the reaction reached a maximum with 12 to 13% (w/w) reconstituted skim milk. (4) The ratio of hydrolyzed lactose decreased with an increase of the lactose load. The lactose load (mass of lactose in reconstituted skim milk/mass of immobilized β-galactosidase) was required to be kept between 20 and 34 to obtain a ratio of 70 to 80% hydrolyzed lactose after 16 to 20h of the reaction.

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We studied ways of washing fibrous immobilized β-galactosidase (IMG) in a horizontal rotary column reactor and a horizontal washing machine. In the horizontal rotary column reactor, IMG was washed by stirring as the column rotated and by air bubbles entering through orifices in the hollow shaft. In the horizontal washing machine, IMG was lifted up to the top of the drum by rotation and was washed by the impact of its falling onto the surface of a buffer solution which was about 1/4 volume of the drum. The results were as follows: (1) In the bubbling method, hydrolysis of lactose in skim milk and washing of IMG were repeated in the horizontal rotary column reactor. The amount of protein attached to IMG was under 22μg/mg (IMG (dry)) till the 6th processing, but it increased rapidly after that. (2) The packing density of IMG in the horizontal rotary column reactor must be kept under 0.008g/cm³ to fluidize IMG completely. In this case, however, an enormous quantity of the buffer solution was needed, which was undesirable for practical operation. (3) Washing of IMG in the horizontal washing machine and hydrolysis of lactose was carried out for 36 cycles. The packing density of IMG in the washing machine was 0.024g/cm³. The amount of protein attached to IMG was kept under 20μg/mg almost every time and 71 to 80% of lactose was hydrolyzed during processing. From the above results, we found that the horizontal washing machine has a higher washing efficiency than the bubbling method in the horizontal rotary column reactor.

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Three groups of rabbits were given water, normal oolong tea or strong oolong tea. There were no significant differences in the various indices for lipid metabolism and those related to the liver and pancreas functions in the blood serum among the groups of animals at 130 days of the experimental period. It was suggested that chronic consumption of oolong tea was in no way harmful at least in this animals species at the dosages employed in the present study.

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Metabolism of nomilin was studied as to obtain fundamental knowledge for diminishing the bitterness of limonoid in citrus fruits. ¹⁴C-nomilin (375000cpm) was injected into the albedo of Yuzu (Citrus junos Sieb. ex Tanaka) fruit with a syringe (marking circle of 1.4cm in diameter) and the metabolites were extracted with ethyl acetate and identified by using TLC method. The recovery of total radioactivities of ¹⁴C-nomilin in the injected part of peel was 19.5% and that in the other part of fruit except seeds was 71.4%. After long incubation the ratio increased of metabolites of nomilin to the other limonoids. However, the recovery of the total limonoids showed no significant difference between the two experiments. In the fruit of Yuzu (except seeds), nomilin was found to be metabolized into other limonoids such as nomilinic acid, deacetylnomilin and a trace amount of obacunone.

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The lipid peroxidation suppressing ability of whole lipid extracted from commercially purchased squid mantle muscle of three common squids, i.e., Japanese common squid (Todarodes pacificus), flying squid (Ommastrephes bartrami) and short-finned squid (Illex argentinus), was evaluated by the progress of peroxide value (PV) and carbonyl value (CV) of purified sardine oil with or without addition of whole lipid fraction at 10% level. Every whole lipid extracted from the three species of squid markedly suppressed the peroxidation of purified sardine oil. The whole lipid of I. argentinus showed the strongest suppressive activity of the three. Neither differences in compositions of lipid and fatty acids nor content and composition of tocopherols in the mantle muscle could sufficiently account for their antioxidative ability. The addition of purified phospholipid fraction, fractionated from the whole lipid of I. argentinus, to purified sardine oil at the concentration of 5% (w/w) markedly suppressed the peroxidation of sardine oil.

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Five groups of spent layer hens (about 17-month-old White Leghorn, commercial strain) with 10 birds in each were fed a commercial-type broiler ration supplemented with DL-α-tocopheryl acetate (ATA) at a level of 0, 500, 750, 1000 or 2000mg/kg of feed, respectively, for the last 10 days prior to slaughter. Results demonstrated that α-tocopherol supplementation to spent layer hens resulted in deposition of greater amounts of α-tocopherol (α-Toc), mainly on their egg yolks and incorporation of dietary α-Toc into the skeletal muscular tissue and subcellular membranes. However, the concentration of α-Toc in the meat of the spent layer hens was significantly less than that in broilers. Thus, the spent layer hen meat suffered more from lipid oxidation during refrigerated storage than that from broilers even when fed the diet supplemented with 2000mg of ATA per kg of feed. The relatively higher molar ratios of polyunsaturated fatty acids (PUFA)/α-Toc and/or PUFA> 18:2 (PUFA with three or more double bonds)/α-Toc in the spent layer hen muscle and subcellular membranes appeared to contribute to the greater susceptibility of the spent layer hen meat to lipid oxidation.

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Changes in pH, and ethanol and reducing sugar contents during the growth of Saccharomyces servazzii and Debaryomyces hansenii in YM broth (yeast and malt extract) were studied under two different fermentation conditions; fermentation in air and fermentation in an atmosphere composed of 2% oxygen and 98% nitrogen gas. In addition, volatile constituents released in the head space gas by S. servazzii were analyzed by gas chromatography and mass spectrometry. During the fermentation, reducing sugar was utilized by the growing yeasts, the pH of the broth dropped and ethanol was formed. However, ethanol production by D. hansenii was low. The growth of both yeasts was faster in the fermentation in air than that in the artificial gas containing 2% oxygen. As the fermentation advanced, pH of growing broth of D. hansenii rose slowly. In the early stages of the fermentation, the growth of S. servazzii was faster than that of D. hansenii. In the advanced stage, however, cell number of D. hansenii excelled that of S. servazzii. Volatile constituents released during growth of S. servazzii were mainly composed of acetaldehyde, ethyl acetate, ethanol, n-propanol, iso-amyl acetate and iso-amyl alcohol.

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