三浦 孝之

ABSTRACT: Wild boar meat containing radioactive cesium (Cs) of approximately 1,000 Bq/kg (134Cs+137Cs) was processed into bacon, sausage, and ham. To understand the concentration and quantity change of radioactive Cs, the processing factor (Pf) and food processing retention factor (Fr) were calculated. The radioactive Cs quantity in the meat did not reduce during smoking. The dehydration-related meat mass reduction during smoking without decrease of radioactive Cs led to Cs condensation in the bacon compared with the raw rib meat before processing, resulting in a Pf of 1.18. Soaking in liquid, such as pickling in liquid and desalting or boiling in water, effectively removed radioactive Cs by leakage into water. Therefore, the Fr value of the boiled ham produced from a loin meat block through three liquid-soaking processes was 0.27. The Pf value of the boiled ham was 0.30 due to meat block mass reduction after boiling as a result of dehydration, along with protein thermal denaturation-related muscle tissue shrinkage. The steamed ham Fr value was 0.53, because the removal of radioactive Cs was less efficient by steaming than by boiling. The Pf value of the steamed ham was 0.54, almost the same as the Fr value, because the mass decrease rate was the same as the radioactive Cs decrease rate by steaming. The Fr and the Pf values of the boiled sausage, whose processing did not include soaking in the pickling liquid, were 0.64 and 0.62, respectively. Steaming the sausage meat did not remove radioactive Cs during the dehydration-related mass reduction, leading to Fr and Pf values of 1.01 and 1.17, respectively. This study found that processing into boiled ham was the most effective measure for reducing radioactive Cs quantity and concentration in raw meat. Processing into bacon and steamed sausage showed no Cs quantity reduction, with the moisture loss resulting in Cs condensation compared with the raw material.

To determine the impact of traditional koji molds on chemical characteristics of soft-type natural cheese, novel surface mold-ripened cheeses with Aspergillus oryzae and Aspergillus sojae were studied by non-targeted metabolite profiling. Comprehensive water-soluble and volatile metabolite profiles of koji cheese were evaluated among five Aspergillus strains and other mold-ripened cheeses. Time-course changes in the metabolite profiles and degrading enzyme activities were also compared with those of an industrial Penicillium candidum starter culture. Koji cheeses differed from Camembert, Brie, and blue cheeses in higher lactic acid, amino acid, and acetoin levels and lower methyl ketone and volatile fatty acid levels. Time-course analysis revealed the associations of rapid accumulations of glutamic, aspartic, and 3-methylbutanoic acids and 3-methylbutanal with higher proteolytic activity, and methyl ketone and fatty acid derivative suppressions with lower lipolytic activity. Ethyl butanoate, diacetyl, and malic acid also characterized koji cheeses as strain-dependent metabolites. This study highlighted the key compositional difference derived from cheese ripening with Aspergillus strains. The findings could help quality improvements of koji cheese product.

More than 2,000 varieties of cheese currently exist in the world, and cheese manufacture continues to flourish. To develop the cheese ripening process, additional ingredients are used during cheese production. In this study, the effect of sake lees as an additional ingredient on the fermentation of cheese using Aspergillus oryzae (koji mold), known as koji cheese, was investigated. Aspergillus oryzae is used in the fermentation of Japanese traditional foods, such as sake and soy sauce, given its strong enzymatic activities, as well as in cheese production (i.e., koji cheese). Sake lees, a by-product of the fermentation of rice with A. oryzae and yeasts in the sake brewing process, contains various metabolites, such as amino acids. Here, supplementation with sake lees enhanced the activities of lactic acid bacteria and affected the color of the cheese. Metabolome analysis revealed that sake lees altered the balance of carbohydrates and fatty acids in the cheese. Remarkably, supplementation with sake lees enhanced the production of umami-enhancing γ-glutamyl (kokumi-active) peptides. This study suggests that a new type of cheese can be produced using A. oryzae and sake lees, and information on the synergistic effects of A. oryzae and sake lees will aid the development of cheese production.

© 2016 Elsevier Ltd The inactivation efficiency of a two-stage system with low-pressure CO2 microbubbles (two-stage MBCO2) on Escherichia coli in physiological saline (PS) and commercial sterilized bovine milk (CBM), and aerobic bacteria in unpasteurized bovine milk (UBM) was investigated. Furthermore, protease-resistance of casein and the free amino acid contents in the treated milk were measured. The number of surviving E. coli cells in PS and CBM by the two-stage MBCO2 decreased with increasing pressure in a mixing vessel or increasing temperature in a heating coil. A 3-log reduction in aerobic bacteria in UBM was achieved by two-stage MBCO2 after 1 min with the heating coil at 45 and 50 °C. Casein in UBM treated with only mixing vessel of two-stage MBCO2 was easier to be decomposed by thermolysin, although the casein warmed with the heating coil was difficult to be decomposed by thermolysin and papain. In addition, most of the free amino acid contents in UBM were decreased by the two-stage MBCO2. Therefore, it was suggested that limited inactivation of aerobic bacteria, and change of protease-resistance of casein and free amino acid contents in UBM were induced by two-stage MBCO2.

The application of cooking water abundant in phenolic compounds, obtained from cooking three types of beans (black soybean, yellow soybean and adzuki bean) and chestnut inner shell, to functional cheese product manufacturing was evaluated. Total phenolics in the cooking water were estimated by the Folin-Ciocalteu colorimetric method and showed a wide range, from 24.4 to 761 mu g/mL. The antioxidant activity of extracts was determined by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and oxygen radical antioxidant activity (ORAC) assays. Results of both antioxidant assays showed similar trends in total phenolic content; DPPH values ranged from 24.6 to 309.3 mu mol TE/mL, while ORAC values ranged from 30.6 to 325 mu mol TE/mL. High estimated residual phenolic values were observed for cheese curd made with chestnut inner shell, yellow soybean, adzuki bean and black soybean extracts; 96, 87.2, 84.9 and 82.3%, respectively.

Active acid phosphatase (AcP), 37 kDa, was completely separated from the purified lactoferrin fraction of bovine milk (LF-rich fraction). The N-terminal amino acid sequence of the 37 kDa molecule had 84% homology with bovine uteroferrin (Uf)-like protein. The 37 kDa molecule has an optimum pH range of 4.5-5.0 and an optimum temperature of 60 degrees C. The AcP activity of the iron removal 37 kDa molecule (iron-depleted LF-rich fraction) was approximately half that of the iron-containing sample (LF-rich fraction). The activity increased in a time-dependent manner on tryptic digestion. These profiles correspond to the mammalian purple acid phosphatase (PAP) family (Uf, Type-5 and tartrate-resistant acid phosphatase: EC3.1.3.2). It seems reasonable to propose that the active molecule in the LF-rich fraction is an undocumented bovine PAP-family protein. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.

ナチュラルチーズの種類は1000 以上とされるが、製造に必要な原材料は乳、凝乳剤、乳酸菌等の微生物および塩のみである。とくに乳酸菌はナチュラルチーズ製造時に重要な働きを示すだけでなく、製品の品質に及ぼす影響が大きい。Lactococcus 属、Leuconostoc 属を主体とした乳酸菌スターターは製造工程において原料乳のpH 低下および良好な凝乳反応を促し、乳酸菌由来のタンパク質分解酵素はチーズのテクスチャーや風味に多大な影響を示す。さらに乳タンパク質の分解産物であるアミノ酸はアミノ基転移酵素（AT 酵素）による異化作用を受け、セミハード・ハードタイプチーズの特徴的な芳香成分生成に関わる。Lactococcus 属のAT 酵素は良く研究されており、分子量38-43.5 kDa のサブユニットが2-4 量体を形成している。 またLactobacillus 属のLb. paracasei subsp. paracasei からもAT 酵素活性が示され、これらの酵素および菌株がチーズの品質に及ぼす影響について研究が進められている。

Fermented milks of Asia probably originated in the Middle East before the Phoenician era. The Old Testament mentions that fermented cream existed in Mesopotamia in c. 1300. BC, and laban rayed and laban khad were manufactured perhaps as early as 5000. BC. The skills of making fermented milk were introduced to Russia and other European areas by the Tartars, and to central Asia by the Huns and Mongols. The 'Silk Road' contributed to the early development and spread of fermented milks. Various methods have been used for the manufacture of traditional fermented milks. The bacteria essential for fermentation originate from fermentation vessels, raw milk, the alimentary tract of animals, and plants. Warm raw milk from the cows, sheep, goats, water buffaloes, camels, or horses of the nomads was turned into clabber or curd by indigenous bacteria, by means of traditional fermentation. The aim of this article is to introduce the common traditional fermented milks of Asia, such as dahi, kumys, yakult, and some Mongolian products.

The aim of this study was to determine the principal active molecules in the acid phosphatase (AcP) fraction of skim milk origin using immunostaining and AcP staining. The AcP fraction was separated from skim milk at 0.38 m NaCl using carboxymethyl cellulose chromatography at pH 5.2. The molecular mass of the active molecule in AcP fraction was estimated to be 80 kDa by immunostaining and AcP staining. The 80 kDa protein was analyzed by a protein sequencer, using the automated Edman degradation method; the first thirteen N-terminal amino acid sequence obtained were shown to be APRKNVRWXTIXQ. For that amino acid sequence, there was 84% (11/13 residues) homology with the amino acid sequence of bovine lactoferrin (LF). The AcP fraction and commercial LF showed a similar AcP activity profile, having an optimum pH of 4.5 and temperature of 60 degrees C. Thus, the AcP fraction from bovine skim milk was isolated and the principal active molecule present was tentatively identified as LF (C) 2009 Elsevier Ltd. All rights reserved.

ミルク成分によるカテキンの渋味抑制効果を採点法および 2 点試験法を用いて評価した。カテキン-ミルク成分混合試験区は6.26 mg/mL カテキン溶液に対し，全乳，9％スキムミルク，4.5％ラクトースあるいは3.8％クリームを等量ずつ混合して調製した。これらのうち，ラクトース以外の試験区で46-58％の渋味減少効果が認められた。次にカテキン-ミルク成分混合試験区において遊離カテキンの量を高速液体クロマトグラフィー（HPLC）を用いて測定した。試験区はカテキンに対し 9％スキムミルク，4.5％ラクトースおよびホエイを混合し調製した。これら試験区を酸沈澱によって除たんぱくした後，得られた上清みに含まれる遊離カテキン量を測定した。スキムミルク混合試験区では遊離カテキンは約95％程度の減少を示したが，ラクトースおよびホエイ混合試験区では5-25％程度の減少であった。さらに，同モル濃度の各種カゼイン（α, β, κ）が遊離カテキン量へ及ぼす影響を調べたところ，βカゼインが最も遊離カテキン量を減少させた（約35％減少）。これらの結果はカテキンの渋味はミルク成分によって抑制されることを示している。

Myostatin, a member of the TGF-beta superfamily, is a negative regulator of skeletal muscle mass. We have recently demonstrated that decorin binds to myostatin in vitro, and that immobilized decorin within the collagen matrix prevents myostatin-mediated inhibition of myoblast proliferation. However, little is known about other ECM molecules that bind to myostatin and modulate its activity. Thus, in the present study, we investigated the interaction of several other ECM molecules with myostatin. We here show that fibromodulin, fibronectin and laminin bind to myostatin in the presence of Zn(2+) with a dissociation constant (K(D) ) of 10(-10)similar to 10(-8) mol/L. Fibromodulin shows the highest affinity for myostatin among them. These results suggest that these ECM molecules may modulate myostatin activity like decorin does.

Myostatin, a member of TGF-beta superfamily of growth factors, acts as a negative regulator of skeletal muscle mass. The mechanism whereby myostatin controls the proliferation and differentiation of myogenic cells is mostly clarified. However, the regulation of myostatin activity to myogenic cells after its secretion in the extracellular matrix (ECM) is still unknown. Decorin, a small leucine-rich proteoglycan, binds TGF-beta and regulates its activity in the ECM. Thus, we hypothesized that decorin could also bind to myostatin and participate in modulation of its activity to myogenic cells. In order to test the hypothesis, we investigated the interaction between myostatin and decorin by surface plasmon assay. Decorin interacted with mature myostatin in the presence of concentrations of Zn2+ greater than 10 mu M, but not in the absence of Zn2+. Kinetic analysis with a 1:1 binding model resulted in dissociation constants (K-D) of 2.02 x 10(-8) M and 9.36 x 10(-9) M for decorin and the core protein of decorin, respectively. Removal of the glycosaminoglycan chain by chondroitinase ABC digestion did not affect binding, suggesting that decorin could bind to myostatin with its core protein. Furthermore, we demonstrated that immobilized decorin could rescue the inhibitory effect of myostatin on myoblast proliferation in vitro. These results suggest that decorin could trap myostatin and modulate its activity to myogenic cells in the ECM. (c) 2005 Elsevier Inc. All rights reserved.