Developments in effective use of volatile organic compound analysis to assess flavour formation during cheese ripening

In the burgeoning demand for optimization of cheese production, ascertaining cheese flavour formation during the cheese making process has been the focal point of determining cheese quality. In this research reflection, we have highlighted how valuable volatile organic compound (VOC) analysis has been in assessing contingent cheese flavour compounds arising from non-starter lactic acid bacteria (NSLAB) along with starter lactic acid bacteria (SLAB), and whether VOC analysis associated with other high-throughput data might help provide a better understanding the cheese flavour formation during cheese process. It is widely known that there is a keen interest to merge all omics data to find specific biomarkers and/or to assess aroma formation of cheese. Towards that end, results of VOC analysis have provided valuable insights into the cheese flavour profile. In this review, we are pinpointing the effective use of flavour compound analysis to perceive flavour-forming ability of microbial strains that are convenient for dairy production, intertwining microbiome and metabolome to unveil potential biomarkers that occur during cheese ripening. In doing so, we summarised the functionality and integration of aromatic compound analysis in cheese making and gave reflections on reconsidering what the role of flavour-based analysis might have in the future.

High-Resolution Mass Spectrometry and Chemometrics for the Detailed Characterization of Short Endogenous Peptides in Milk By-Products

The process of cheese-making has long been part of human food culture and nowadays dairy represents a large sector of the food industry. Being the main byproduct of cheese-making, the revalorization of milk whey is nowadays one of the primary goals in alignment with the principles of the circular economy. In the present paper, a deep and detailed investigation of short endogenous peptides in milk and its byproducts (whole whey, skimmed whey, and whey permeate) was carried out by high-resolution mass spectrometry, with a dedicated suspect screening data acquisition and data analysis approach. A total of 79 short peptides was tentatively identified, including several sequences already known for their exerted biological activities. An unsupervised chemometric approach was then employed for highlighting the differences in the short peptide content among the four sets of samples. Whole and skimmed whey showed not merely a higher content of short bioactive peptides compared to whole milk, but also a peculiar composition of peptides that are likely generated during the process of cheese-making. The results clearly demonstrate that whey represents a valuable source of bioactive compounds and that the set-up of processes of revalorization of milk byproducts is a promising path in the obtention of high revenue-generating products from dairy industrial waste.

Influence of k-casein genotype on heat stability and cheese making properties of milk powder

In this study the effect of k-casein gene polymorphism on the technological characteristics of milk powder obtained by spray (AA1:BB1) and freeze drying (AA2:BB2) was investigated. Standardized and generally accepted methods were used in the field of physical and chemical control of dairy products, as well as methods for assessing the heat stability and cheese making properties of milk. The most heat-resistant were the samples with a predominance of milk obtained from cows with the AA CSN3 genotype, in the pH range from 6.4 to 7.0 (36-91 minutes for AA1:BB1 and 37-101 minutes for AA2:BB2). In systems with a fraction of 25 % to 100 % of milk from cows with the AA CSN3 genotype obtained by freeze drying, higher (by 3-10 %) stabilization qualities of protein were revealed when heated in the pH range from 6.4 to 7.0 compared to spray drying. The analysis of the results regarding the cheese making properties showed that with an increase in the proportion of milk from cows with the BB CSN3 genotype from 0 % to 100 % in model systems, the rennet coagulation time decreases for all samples, regardless of the drying method. It was also found that when using freeze drying, coagulum of all samples were assigned to the highest class of milk quality in terms of cheese making properties, while during spray drying only the samples consisting of min. 75 % or completely of milk obtained from cows with genotype BB CSN3 corresponded to this category.

A review of artisanal cheese making: An African perspective

Artisanal cheeses and other fermented milk products have long been part of the diet of African rural communities. Cheese is a source of nutrients that are essential to the development and growth of children in rural areas, where intake of amino acids, vitamin A, vitamin B12, calcium, phosphate, and polyunsaturated fatty acids may be limited. Wara, Karish, Ayib, Takammart, Wagashi, Domiati, and Ras are prominent cheeses of African origin. Artisanal cheese making should be expanded to improve people’s nutritional status at low cost, stimulate the local economy, and empower small-scale farmers. This review firstly gives an overview of artisanal cheese production and consumption, and evaluates opportunities and challenges, while focusing on an African perspective. Secondly, it provides an insight into strategies that could improve cheese making at small-scale level. Possible areas of research and knowledge gaps are highlighted, particularly ways of improving cheese quality and safety.

Effects of microbial transglutaminase levels on donkey cheese production

Microbial transglutaminase (MTGase) is an enzyme widely used in the dairy sector to improve the functional properties of protein-based products via the formation of a network between protein molecules. The aim of this study involving cheese from the milk of donkeys was to evaluate the effects of treatment with MTGase at the concentrations of 0 (control), 5, 8 and 10 U/g milk protein on the cheese-making process parameters, as well as the physical and chemical characteristics of the resulting cheese. MTGase influenced the time of gel formation from rennet addition (P < 0.05), with a delay at the two highest concentrations, accompanied by a lower (P < 0.01) pH of cheese and the lowest (P < 0.01) loss in cheese weight at 24 h of storage. The highest gel viscosity (P < 0.01) was observed at the highest concentration of the enzyme, reaching the value of 70 mPa⋅sec after 60 min. The chemical composition and color of the cheeses were not significantly affected by the inclusion of MTGase, regardless of the enzyme concentration. These findings may be of relevance in adapting the cheese-making process and might help in the design of new dairy products from donkey's milk.

Chemometrics for the Identification of Nitrogen and Acid Compounds in Milk-Whey as by-Products from Crescenza and Grana Padano Type Cheese-Making

Proteomics and metabolomics are analytic tools used in combination with bioinformatics to study proteins and metabolites which contribute to describing complex biological systems. The growing interest in research concerning the resolution of these systems has stimulated the development of sophisticated procedures and new applications. This paper introduces the evolution of statistical techniques for the treatment of data, suggesting the possibility to successfully characterize the milk-whey syneresis process by applying two-dimensional correlation analysis (2DCOR) to a series of CE electropherograms referring to milk-whey samples collected during cheese manufacturing. Two cheese-making processes to produce hard cheese (Grana type) and fresh cheese (Crescenza) were taken as models. The applied chemometric tools were shown to be useful for the treatment of data acquired in a systematically perturbed chemical system as a function of time.