A high-throughput cheese manufacturing model for effective cheese starter culture screening

Abstract

Cheese making is a process in which enzymatic coagulation of milk is followed by protein separation, carbohydrate removal, and an extended bacterial fermentation. The number of variables in this complex process that influence cheese quality is so large that the developments of new manufacturing protocols are cumbersome. To reduce screening costs, several models have been developed to miniaturize the cheese manufacturing process. However, these models are not able to accommodate the throughputs required for systematic screening programs. Here, we describe a protocol that allows the parallel manufacturing of approximately 600 cheeses in individual cheese vats each with individual process specifications. Protocols for the production of miniaturized Gouda- and Cheddar-type cheeses have been developed. Starting with as little as 1.7 mL of milk, miniature cheeses of about 170 mg can be produced and they closely resemble conventionally produced cheese in terms of acidification profiles, moisture and salt contents, proteolysis, flavor profiles, and microstructure. Flavor profiling of miniature cheeses manufactured with and without mixed-strain adjunct starter cultures allowed the distinguishing of the different cheeses. Moreover, single-strain adjunct starter cultures engineered to overexpress important flavor-related enzymes revealed effects similar to those described in industrial cheese. Benchmarking against industrial cheese produced from the same raw materials established a good correlation between their proteolytic degradation products and their flavor profiles. These miniature cheeses, referred to as microcheeses, open new possibilities to study many aspects of cheese production, which will not only accelerate product development but also allow a more systematic approach to investigate the complex biochemistry and microbiology of cheese making.

Time‐resolved genetic responses of Lactococcus lactis to a dairy environment

“…, 2006). Intriguingly, accumulation of acetate in cheese is observed between 1 and 6 weeks of cheese ripening (Bachmann et al. , 2009) suggesting that this pathway may be operational in cheese.…”

“…The high‐throughput manufacturing of miniature cheeses (∼170 mg per cheese) was performed in 2 ml deep‐well microplate model using a protocol that was described recently (Bachmann et al. , 2009).…”

Genotype-phenotype matching analysis of 38 Lactococcus lactisstrains using random forest methods

“…Activity of several enzymes, i.e. branched chain aminotransferase, alpha-hydroxyisocaproic acid dehydrogenase, aminopeptidase N, cystathionine β lyase, X-prolyl dipeptidyl aminopeptidase and esterase in strains growing on GM17-broth or CDM-media, were previously assessed [32,33]. More information about phenotyping experiments and results of these experiments are available in an Additional file 1.…”

Systems solutions by lactic acid bacteria: from paradigms to practice

“…An efficient cre-lox system for obtaining such multiple mutants in an efficient and successive way have been described for Lactobacillus plantarum that may be considered as self-cloning [102]. On the practical side also high throughput developments have been reported and an ingenious system of small cheeses has been designed and used [103]. Finally, a variety of in vitro systems that may predict practical conditions have been reported, such as the use of non-growing cells of Lactococcus lactis strains for the rapid analysis of flavor production [104].…”