Impact of Composition and Quality of Milk in Artisanal Production

Project entitled:

Better Understanding the Role of the Milk Typicity in the Quality of Fine Cheeses

Highlights

In Quebec, locally produced products are becoming increasingly important to consumers. This project is one of the rare undertakings exploring the characteristics of locally produced milk and the characterization of indigenous fungal species in fine cheeses.

Objectives

The general objective of the project is to increase microbiological and technological knowledge about local milks in order to improve and regulate the quality of fine artisanal cheeses from Quebec and identify their unique characteristics.

Specific objectives:

• 1) Verify the influence of the indigenous fungal microflora of milk on the cheese ageing process.
• 2) Determine the impact of secondary fungal microflora on the flavour profiles of cheeses.
• 3) Determine the components of milk that influence the growth of fungal microflora involved in the ageing process and secondary microflora.

Results and potential benefits

• The interactions between 12 indigenous yeast strains of raw milk and two Fungi used in the cheese ageing process were characterized. A molecular quantification method (gPCR) was optimized for some of the strains to evaluate the distribution of species in local cheeses. These species were also analyzed to examine their contribution to cheese flavour profiles. Floral, malted and rancid flavours were also associated with some of the indigenous yeast species.
• We also compared the composition of milk from different breeds (Canadian, Jersey, Brown Swiss, Holstein and industrial) and different regions of Quebec, as well as their impact on the growth of lactococcal strains and yeasts. For a single breed, the origin of the milk (region/locality) had a non-negligible influence on composition. In general, the lactococcal strains grew better in milk from Brown Swiss cattle. Pasteurization of the milk improves growth rates (1 additional log) and lactic acid production is 4 times higher than in raw milk. It was demonstrated that some lactococcal strains only required the presence of caseins to grow while others also required the presence of serum proteins.
• This study allows for a better understanding of the impact of milk composition and indigenous microflora on the properties of local cheeses. This information helps us to identify the particularities of milk produced locally and the key indigenous species that have an impact on cheese quality.

Professionals trained

• Joanie Côté, M.Sc. candidate. (microbiology, physical chemistry)
• Andréanne Lamarche, M.Sc. candidate. (microbiology, molecular biology)
• Ariane Pelletier, M.Sc. candidate. (microbiology, analytics)

Financial contributions

Partnership for innovation in dairy production and dairy processing (EPI2011-2017):

• Fonds de recherche du Québec – Nature et technologies
• Ministère de l’Agriculture, des Pêcheries et de l’Alimentation du Québec
• Novalait

Andréanne Lamarche and Ariane Pelletier have received scholarships from the Canadian Dairy Commission in collaboration with Novalait.
Andréanne Lamarche has received a scholarship Agro:Inno from INITIA, CTAQ and INAF.