AiF 20776 - Vollmundigkeit Käse

Manufacturers of mature milk products, such as semi-hard cheese, face fierce international competition, as more than 50% of production volume is exported.An important economic goal, therefore, is for medium-sized manufacturers in particular to differentiate themselves from their competitors through innovative products that have an intense flavor and/or are comparable in terms of salt perception with reduced sodium chloride content (“flavor tuning”).
It is well known that the breakdown and structural change of lactose, milk fat, and milk protein during ripening can be controlled to produce a wide variety of flavor-active compounds, among other things through the selection of the starter culture, the chymosin preparation, and the ripening conditions. Less attention has been paid to the amino acid composition of the protein content in cheese milk. Preliminary investigations have shown that the addition of non-milk protein, which is characterized by a high content of the amino acids glutamine and/or arginine, can modulate the gustatory perception of the flavor quality or the flavor notes “kokumi” and/or “salty” in matured dairy products.
The aim of the research project was to develop a suitable technology for semi-hard cheese production that would allow products with a new taste experience to be developed and manufactured, taking into account or specifying the techno-functional properties.

As part of the research project, a technology platform for flavor tuning in matured dairy products was developed by adding non-dairy protein. To ensure that the economically important whey was not contaminated with foreign protein (non-dairy protein), the substrate was incorporated directly into the curd.
The initial aim of the experiment was to confirm the hypothesis that the formation of flavor-active γ-glutamyl dipeptides can be accelerated by adding glutamine and increasing enzyme activity through partial microfiltration. To this end, curd was produced from pasteurized and partially microfiltered milk, glutamine was then incorporated into the curd, and a homogeneous cheese matrix was created by extrusion. The cheese samples with and without added glutamine were matured for up to 3 months. The addition of glutamine powder did not significantly affect the texture properties or melting behavior. An increased formation of flavor-active γ-glutamyl dipeptides (flavor quality: kokumi) was detected during ripening, which proceeded more rapidly in cheese made from partially microfiltered milk than in cheese made from pasteurized milk. This can be attributed, among other things, to the increased activity of the original thermolabile γ-glutamyl transferase (partially microfiltered milk > 60% of raw milk, pasteurized milk < 10%).
Based on these findings, glutamine-rich protein preparations should be added instead of pure glutamine to “flavor tune” the cheese matrix. One selection criterion was that the non-milk protein preparations had a higher glutamine content than casein. After glutamine was determined together with glutamic acid (as Glx) using the usual acid hydrolysis methods for determining the amino acid composition of proteins, an enzymatic method for sample preparation was developed and applied to quantify the glutamine content of the preparations. Various gluten preparations were identified as glutamine-rich protein preparations and therefore promising for flavor tuning. The sample preparation and analysis method developed in the project for determining the flavor-active γ-glutamyl dipeptides can be used to track the formation of flavor-active peptides as part of process control. This method also enables high sample throughput.
To compare the cheese (hybrids) produced in this project with commercial samples, a selection of different cheese types was made and characterized in terms of flavor-active γ-glutamyl dipeptides. The total of 29 commercial cheese samples were examined using the methods described above and analyzed by principal component analysis. The matured samples produced in the project could then be classified in this coordinate system. This showed that, due to the increased enzyme activity of a partially microfiltered milk, a (hybrid) cheese produced from it after 12 weeks of maturation corresponds to a Gouda cheese that has been matured for just under 7 months. This confirmed that by preserving the thermolabile γ-glutamyl transferase during maturation, flavor-active substances can be formed more quickly and in higher concentrations.

BMWK - IGF - AiF - FEI

Industrielle Gemeinschaftsforschung (IGF)