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A previous study showed the ability of old-style cheese starters to produce large amounts of γ-aminobutyric acid (GABA). This work reports the identification of GABA-producing strains and the effect of the main cheese matrix parameters (NaCl, glutamic acid, pH, oxygen) having an influence on GABA production. Out of a total of 50 individual bacterial strains contained in two old-style cheese starters, nine were able to produce GABA and were identified as either Lactococcus lactis ssp. lactis or L. lactis ssp. lactis biovar diacetylactis. Strains ULAAC-A13 and ULAAC-A23 were able to produce up to 500 mg of GABA per 100 mL of fermented milk containing 2% NaCl and 367 mg per 100 mL of glutamate. Moreover, the low residual glutamate concentration indicates the almost total conversion of glutamate into GABA. GABA was also detected in four commercial cheeses at concentrations varying from 10 to 97 mg of GABA per 30 g of cheese and at a concentration of 29 mg of GABA per 30 g of a cheese slurry ripened with ULAAC-A old-style starter. In that cheese slurry, GABA concentrations were above the levels previously proven to be effective for lowering blood pressure in humans. Both individual GABA-producing strains or the old-style starters containing the GABA strains seem to be promising for GABA production in hard or semi-hard cheeses with prevailing conditions for GABA production. Keywords Gamma-aminobutyric acid. Glutamate. Lactococcus lactis 1 Introduction Lactic starters used for cheesemaking, mainly lactococcal strains, are responsible for the acidification of cheese milk to the desired pH during manufacturing. In addition,

Old-style cheese starters were evaluated to determine their ability to produce cheese aroma compounds. Detailed analyses of the aroma-producing potential of 13 old-style starter cultures were undertaken. The proteolytic profile of the starters was established by an accelerated ripening study using a model cheese slurry and compared with those of a commercial aromatic starter and commercial Cheddar cheeses. To evaluate the aromatic potential of the starter cultures, quantification of free amino acids liberated and volatile compounds after 15 d of ripening at 30 degrees C as well as sensory analysis were carried out. Results showed that proteolysis patterns of all 13 starter cultures in the curd model were comparable to those of commercial Cheddar cheeses. All tested cultures demonstrated the ability to produce high amounts of amino acids recognized as precursors of aroma compounds. Several differences were observed between the starters and commercial Cheddar cheeses regarding some amino acids such as glutamate, leucine, phenylalanine, proline, and ornithine, reflecting the various enzymatic systems present in the starters. Starters Bt (control) and ULAAC-E exhibited various significant differences regarding their free amino acid profiles, as confirmed by sensory analysis. In addition, identification of volatile compounds confirmed the presence of several key molecules related to aroma, such as 3-methylbutanal and diacetyl. Besides the aroma-producing aspect, 2 starters (ULAAC-A and ULAAC-H) seem to possess an important ability to generate large amounts of gamma-aminobutyric acid, which contributed up to 15% of the total amino acids present in the model curd after 15 d ripening. gamma-Aminobutyric acid is an amine well-known for its antihypertensive and calming effects.

Pendant que le thème de la participation sociale est au centre des récents discours sur le vieillissement, on peut se demander si la définition donnée à ce concept correspond aux réalités et aux aspirations de l’ensemble des aînés. Cet article présente une analyse critique de discours ayant examiné des politiques sur le vieillissement développées par la province de Québec (Canada), entre 2005 et 2012. Les résultats montrent que les interprétations émergentes de la participation peuvent être problématiques lorsqu’elles sont associées à des recommandations, des standards et des attentes. Premièrement, les analyses révèlent que la participation est de plus en plus conçue sous un angle de productivité, amenant à remplacer les discours construits autour du bien-être des aînés par des préoccupations à l’égard de leur utilité sociale. Deuxièmement, le contexte de la participation est passé d’une responsabilité collective à une question de choix personnel dans le cadre d’une communauté locale. Troisièmement, les documents reflètent une polarisation de l’activité et de la perte d’autonomie qui a pour conséquence d’associer participation et bonne santé. Ces résultats suggèrent que la manière dont la participation sociale est articulée et encouragée dans les politiques québécoises du vieillissement peut nuire à l’inclusion des personnes ayant des incapacités dans les milieux communautaires et associatifs.