Milk Science
Online ISSN : 2188-0700
Print ISSN : 1343-0289
ISSN-L : 1343-0289
Volume 66, Issue 2
Displaying 1-5 of 5 articles from this issue
Original Papers
  • Yasuhisa Ano, Hiroyuki Nakayama
    2017 Volume 66 Issue 2 Pages 89-96
    Published: 2017
    Released on J-STAGE: August 07, 2017
    JOURNAL FREE ACCESS

     Recent epidemiological studies suggest that certain dairy products may reduce the risk of cognitive decline in the elderly and prevent Alzheimer's disease. We previously demonstrated that intake of a dairy product fermented with Penicillium candidum, i.e., Camembert cheese, suppressed the deposition of β-amyloid (Aβ) and inflammation in the brain of Alzheimer's disease model mice. Previous studies suggest that peripheral inflammation is induced in these mice owing to Aβ deposition in the peripheral nervous tissue and that peripheral inflammation is associated with inflammation in the brain and cognitive decline. In the present study, the effects of a dairy product fermented with P. candidum on myeloid dendritic cells (DCs) and immune responses in the peripheral lymph node of Alzheimer's model mice have been investigated. The extract from Camembert cheese suppressed the inflammatory responses of myeloid DCs in vitro. Intake of Camembert cheese reduced peripheral inflammation and increased regulatory T cells in the mesenteric lymphoid nodes of Alzheimer's disease model mice. Taken together, dairy products fermented with P. candidum might be beneficial in the prevention of inflammation in both brain and peripheral tissue inducing cognitive decline.

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  • Keiichi Matsuura, Takanobu Gotou, Kyosuke Kawaguchi, Seiichi Mizuno, N ...
    2017 Volume 66 Issue 2 Pages 97-106
    Published: 2017
    Released on J-STAGE: August 07, 2017
    JOURNAL FREE ACCESS

     The antihypertensive peptides, Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), were first isolated from Lactobacillus helveticus fermented milk; however, there are few reports on the antihypertensive effects of cheese. The objective of this study was to quantify the amounts of VPP and IPP in various cheeses and to discuss the potential of these antihypertensive effects. Fifteen European-type cheeses were selected and analyzed for these two antihypertensive peptides using an LC-MS analysis. The Dutch cheeses, Reypenaer and Old Amsterdam, contained high amounts of VPP/IPP, 19.9/0.9 and 10.5/0.9 mg in 100 g of cheese, respectively. The Swiss cheeses, Emmental and Gruyere, also contained VPP/IPP at 8.0/1.1 and 5.2/1.2 mg in 100 g of cheese, respectively. Notably, some French-type Blue cheeses prepared with Penicillium roqueforti contained the highest amounts of both peptides (13.3/31.0 mg in Bleu d'Auvergne and 9.9/19.2 mg in Bleu des Causses in 100 g of cheese). The ratio of VPP to IPP was higher in Dutch and Swiss cheeses than in Blue cheeses. To understand the release of these peptides in Blue cheese, proteolytic enzymes, neutral protease I (NPI) and leucine amino peptidase (LAP), previously identified as crucial proteolytic enzymes for IPP processing in Aspergillus oryzae, were searched in Penicillium using BLAST. A homolog with similarity to NPI of A. oryzae was detected in extracellular metalloproteinase-4 of Penicillium subrubescens with 36% identity. Moreover, LAP of A. oryzae was identical to an unknown protein of P. roqueforti. These observations suggest that proteases of Penicillium with homology to A. oryzae NPI and LAP might be involved in the processing of antihypertensive peptides during Blue cheese ripening.

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  • Tatsuya Kosugi, Ai Iwasawa, Yuichi Shimomura, Shu Kogawa, Soichi Ishid ...
    2017 Volume 66 Issue 2 Pages 107-115
    Published: 2017
    Released on J-STAGE: August 07, 2017
    JOURNAL FREE ACCESS

     The aim of this study was to clarify the effects of low level β-carotene feeding on properties of the cream obtained from the cow's milk. In the test farm where the breeding condition was controlled, lactating cows (Holstein) were fed with two types of feed with low level β-carotene contents for two weeks (Farm trial). Estimated β-carotene contents per Dry matter (DM) in feed were 12.8, 10.0 and 9.8 mg/kg-DM, respectively. The cream was prepared from each milk with the conventional method and their β-carotene contents, color, and flavor were evaluated. Then we collected milk from two farms in Hokkaido and prepared cream (Field trial). Estimated β-carotene contents in their feed were 13.4 and 10.6 mg/kg-DM. The relation between β-carotene contents and color or flavor of the prepared cream was examined, and liquid cream stability of each cream was also evaluated. In both trial, low level β-carotene feeding reduced the β-carotene contents and b* value in L*a*b* color system as an indicator of whiteness of the cream. The result of a sensory analysis showed the cream with lower b* value was whiter. The cream obtained from cows with low level β-carotene feeding had more fresh flavor. The freshness was possibly due to an increase in hexanal and decrease in hexanoic acid as flavor compounds. In field trial, the cream obtained from low level β-carotene feeding had higher liquid cream stability than another.

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  • Tomoki Nakano, Motoko Ueki, Ryu Mizoguchi, Masahiko Takeshita, Yuo Ari ...
    2017 Volume 66 Issue 2 Pages 117-123
    Published: 2017
    Released on J-STAGE: August 07, 2017
    JOURNAL FREE ACCESS

     The present study aimed to clarify the effects of heating and salts on the aggregation and solubility of casein under acidic conditions. The turbidity of whole casein solution increased with increasing temperature (50-90℃) and pH (3.30-3.50). Addition of NaCl to whole casein solution caused suppression of the turbidity. Addition of >30 mM NaCl to the unheated casein solution at pH 3.30-3.50 caused insolubilization of casein, and the insolubilized casein was solubilized by heating with decreasing pH. Casein was insolubilized at <25 mM NaCl by heating with increasing pH. In the absence of NaCl, the insoluble casein formed by heating comprised only αS1-casein and β-casein, while insoluble form of the other casein constituents increased by heating at >10 mM NaCl. The effects of Ca, Mg, phosphate, and citrate on the solubility of casein at pH 3.45 and its changes when heated were also examined. The behavior of casein toward heat and salts under acidic conditions is markedly different from that under neutral conditions.

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Reviews
  • Takayoshi Aoki, Rei Mizuno, Toshiaki Kimura, Shunichi Dosako
    2017 Volume 66 Issue 2 Pages 125-143
    Published: 2017
    Released on J-STAGE: August 07, 2017
    JOURNAL FREE ACCESS

     Numerous studies have been performed on casein micelles because they have characteristic structure and biological functions, and play important roles in processing of milk. More than twenty models have been proposed since Waugh proposed the first model of casein micelle in 1958. In this review, models of the casein micelle were divided into three groups of early stage, submicelle, and nanocluster modeles, and then their characteristics were described. Submicelle models of Slattery, Schmidt and Walstra had been accepted by many researchers. However, since Holt proposed the nanocluster model in 1992, most of the proposed models were modified nanocluster ones. We made discussions on the electron micrographs which played a key role in proposing the nanocluster models. Finally, we described whether it is possible to explain the changes in casein micelles during processing milk using the submicelle model of Schmidt, nanocluster models of Holt, Horne, and Dalglesish & Corredig. It is impossible to explain all phenomena which occur in casein micelles during processing of milk using any models. Further studies on casein micelles are needed.

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