牛乳蛋白質の発癌性ヘテロサイクリックアミンに対する結合性

牛乳中の各種蛋白質、即ち whole casein, αs-casein, β-casein, κ-casein, β-lactoglobulin A, β-lactoglobulin B, α-lactalbumin, lactoferrin, lactoperoxidase を分離精製し、これらの蛋白質が発癌性ヘテロサイクリックアミンである 3-amino-1, 4-dimethyl-5Hpyrido[4, 3-b]indole (Trp-P-1) と給合するか否かについて実験を行った。さらに我々自身で分離調製した蛋白質と比較検討する為にSigma社製のα-casein, β-casein, κ-casein, β-lactoglobulin A, β-lactoglobulin B, α-lactalbumin, lactoferrin, lactoperoxidase ついても同様の実験を行った。凍結乾燥した蛋白質2mg, Trp-P1 20μgを0.4mlのpH7.4, 50mM燐酸バッファーに溶解し、37℃で10分間振盪し反応させる。つづいて、日本ミリポアリミテッド製のUFC3LGC00を用いて反応液中の非結合型 Trp-P-1 を限外濾過により分離し、この Trp-P-1 を HPLC 法により測定する。HPLC は日立 L-6000ポンプ・L-4000UV 検出機に GL-Science 製 Inertsil ODS-2(4.6×150mm)カラムを使用し、acetonitrile-H2O-triethylamine 50:50:0.05 で展開した。254nmに於ける吸収を SIC System Instruments 製Labchart 12で記録する。Whole casein:54.04%, αs-casein:40.02%, β-casein:56.24%, κ-casein:33.75% で反応液中の Trp-P-1 を比較的に高い割合で結合した。Sigma 社製の α-Casein:59.46%, β-casein:40.43%, κ-casein:23.75% で類似の傾向を示した。β-Lactoglobulin A:23.61%, β-lactoglobulin B:17.87%, β-lactoglobulin A・Sigma:15.78%, β-lactoglebulin B・sigma:3.65% であった。Lactoperoxidase:15.20%, lactoperoxidase・Sigma:6.41%, lactoferrin-a:22.53%, lacteferrin-b:6.92% であったが、α-lactalbumain, α-lactalbumin・Sigma, lacteferrin・Sigma は Trp-P-1 と結合しなかった。The binding ability of bovine milk proteins with mutagenic heterocyclic amine was investigated. Binding was determined with 2 mg of protein and 20 g of 3-amino-1, 4-dimethyl-5H-pyrido[4, 3-b]indole (Trp-P-1) in 0.4 ml of pH 7.4, 50 mM phosphate buffer, at 37°C, in a shaker for 10 min. The unbound Trp-P-1 in protein-free ultrafiltrate was prepared using Ultrafree UFC3LGC00 and was analyzed by HPLC method. The binding of whole casein, αs-casein, β-casein and κ-casein were 54,03, 40.02, 56.24 and 33.75%, respectively. β-Lactoglobulin A, β-lactoglobulin B, lactoperoxidase, lactoferrin-a and lactoferrin-b were 23.61, 17.87, 15.20, 22.53 and 6.92% respectively. However, α-lactalbumin could not bind Trp-P-1 in this experiment. The binding of these milk proteins which were prepared by ourselves were compared with purchased proteins. They showed similar tendency to our proteins

ミンクの成長における真皮コラーゲン線維の走査型電子顕微鏡観察

ミンクの成長における真皮コラーゲン線維の形態学的変化を、走査型電子顕微鏡(SEM)を用いて研究した。SEM観察から、真皮コラーゲン線維は、出生直後、皮膚成長期、皮膚成熟期の3つの段階を経て変化することが示された。出生直後のミンク真皮はプレート状物質が中心であり、プロテオグリカンや糖タンパク質とコラーゲン線維が密接に結合してプレート状物質を形成したものと考えられる。ミンクの成長に伴い、真皮コラーゲン線維は、比較的細い、曲がりくねった線維がランダムに絡まり合った様子に変化した後、規則正しい三次元的ネットワークを示した。コラーゲンの三次元的ネットワークは、成熱した真皮に観察され、そのときのコラーゲン線維の配向状態は、真皮の深さの程度により異なった。すなわち、真皮上部のコラーゲン線維は皮膚表面に対して斜めに配向し、一方真皮中部から下部では、比較的太いコラーゲン線維が皮膚表面に対して平行に配向した。各々のコラーゲン線維は、さらに、分岐・合流して、三次元的ネットワークを形成した。真皮・表皮接合部およびコラーゲン線維と皮膚付属器宮の間には、細い弾性線維のネットワークが存在した。Morphological changes in dermal collagen fibers in growing mink were investigated using a scanning electron microscope (SEM). The SEM view of dermal collagen fibers varied throughout the newborn, growing and mature skin phases. The reticular layer of newborn mink dermis was plate-like, and appears to be composed of fine collagen fibers, proteoglycans and glycoproteins. With mink growth, randomly entangled dermal collagen fibers, which were relatively fine and curled or waved, showed regularity of the three-dimensional network. A three-dimensional network of thick collagen fibers was observed in the mature mink dermis, and the fiber arrangement altered in relation to the depth from the epidermis, i. e., in the upper dermis, many fibers were arranged diagonally to the skin surface, whereas in the mid and deep dermis, thick fibers were conspicuously arranged parallel to the skin surface. The collagen fiber network was formed by repeated branching and anastomosis of the fibers. There were thin elastic fibers in the dermal-epidermal junction and between the collagen fibers and skin appendages

バヒアグラスの生草および乾草の揮発性成分

粗飼料中の香気成分の種類とその量的分布を知るために、バヒアグラスの生草と乾草の揮発性成分を、ガスクロマトグラフ・マスペクトロメーター(GC-MS)および水素炎イオン化検出器のガスクロマトグラフ(FID-GC)によって分析した。揮発性成分中の各化金物の面積%および飼料中の各化合物のppb濃度は、正ペンタデカンを内部標準に用いてクロマトグラフ用データ処理装置によって算出した。それによって、バヒアグラス生草の揮発性成分から25化合物を同定し、それらの面積%およびppm値は、それぞれ総計78.2および22.0であった。この生草の揮発性成分は、量的にアルコール類、エステル類、ケトン類が多かった。一方、バヒアグラス乾草の揮発性成分から26化合物を同定し、それらの面積%およびppm値は、それぞれ総計79.4および12.0であった。この乾草の揮発性成分もまた、アルコール類、エステル類、ケトン類が多かった。両者の揮発性成分は、質的にほとんど同じであったが量的に若干の差があった。In order to elucidate the qualitative disposition and the quantitative distribution of the aromatic constituents in roughage, the volatile constituents of the green forage and hay of bahiagrass were analyzed by a combined gas chromatograph-mass spectrometer (GC-MS) and a FID-gas chromatograph (FID-GC). The area percentage of each compound in the volatile constituents and the parts per billion (ppb) concentration of each compound in the materials were calculated on a data processor for FID-GC using n-pentadecane as the internal standard. As a result, 25 compounds were identified from the volatile constituents of the green forage of bahiagrass; their area percentages and ppm values totaled 78.2 and 22.0, respectively. The volatile constituents of this green forage were quantitatively rich in alcohols, esters, and ketones. On the other hand, 26 compounds were identified from the volatile constituents of the hay of bahiagrass; their area percentages and ppm values totaled 79.4 and 12.0, respectively. The volatile constituents of this hay were also rich in alcohols, esters, and ketones. Both volatile constituents were qualitatively about the same, but were somewhat different quantitatively

Toughness Variations among Natural Casings: An Exploration on Their Biochemical and Histological Characteristics

We investigated the mechanical, biochemical, and histological properties of hog and sheep casings produced in different countries to elucidate the responsible factors for the toughness quality of natural casings. The toughness and collagen characteristics of sheep and lamb casings were also investigated to elucidate the effect of animal slaughter age on the relationships between connective tissue and the mechanical properties of natural casings. The results showed that the main component of hog and sheep casings was collagen with many layers of sheets. The contents of collagen, elastin, and proteoglycan in hog and sheep casings were similar. The toughest Chinese casings (p p p p < 0.01). Therefore, the high thermal and structural stability of collagen in aged animals may contribute to the enhanced mechanical properties of casings

Long-term storage under pressure in deep sea improved the microbiological safety and physical properties of whale meat

This study aimed to clarify the effects of deep-sea pressure storage on the quality of whale meat, especially microbiological safety and physical properties, to examine the effectiveness of deep-sea storage for long-term aging of whale meat. Microbiological safety, physical properties, color and appearance, water content, water activity, and pH of whale meat were examined after storage in the deep sea at depths of 2200–6000 m (22–60 MPa) for 4 months. During storage under high pressure at a depth of >4000 m (40 MPa), the growth of aerobic bacteria was inhibited in whale meat. The toughness of whale meat stored in deep sea at a depth of >4000 m became significantly tender than that before deep-sea storage. Long-term storage of whale meat under high pressure and low-temperature conditions in the deep sea at a depth of >4000 m was clarified to improve the microbiological safety and tenderness of whale meat