Identifying Volatile Markers for Goat Cheese Maturation

A study conducted by the Department of Agriculture, Environmental, and Food Sciences of Italy’s University of Molise, in conjunction with that country’s National Research Council’s Institute of Food Services (Avellino, Italy) aimed to characterize the volatile organic compounds (VOCs) produced during the ripening of goat cheese to find suitable molecular markers for monitoring the maturation process. Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was applied to samples collected at different ripening times. A paper based on this study was published in Sensors.¹

Cheese is produced through the curdling of milk, cream, or skimmed buttermilk obtained from various animal species, such as cows and goats. The end-product can be classified as either fresh or fermented, depending on its processing process, which involves the complex interaction of microbiological and biochemical transformations which, beginning at the first stages of cheesemaking, continue across the aging process.² Cheesemaking typically starts when starter lactic acid bacteria (SLAB), which activates the fermentation by breaking down milk carbohydrates (in particular, lactose), proteins, and fats into simpler compounds, is added to the dairy source.³ These bacteria are sometimes intentionally added to acidify the milk and facilitate curd formation. Once the curd has been produced, the whey is drained, and the curd is then prepared for maturation, which is considered the crucial step in the definition of the final cheese characteristics.^2,4,5 During ripening, cheese develops its unique biochemical and nutritional attributes during ripening, in addition to its peculiar texture, aroma, and flavor profile. The maturation process begins at once after curd formation, and can last from several days to many months, depending on the cheese type,^4,5 During maturation, conditions, such as temperature and humidity, are carefully controlled carefully to fashion the wanted qualities of the final product.⁶.

For this study, the researchers applied HS-SPME/GC-MS to samples of goat cheese collected at ripening times of 0, 30, 60, 90, 120, and 150 days). Sixty-eight different VOCs were identified, including alcohols, esters, ketones, carboxylic acids, aldehydes, terpenes, sulfur compounds, and others. The total volatile content progressively increased up to 120 days and slightly decreased thereafter. The evolution of the VOC pattern revealed distinct biochemical phases, driven by microbial and enzymatic transformations. Carboxylic acids and alcohols dominate the volatile profile of cheese regardless of the ripening process, while esters and ketones, contributing to specific aromatic nuances, followed specific trends. Among the detected compounds, 2-butanone and 2-butanol have been identified as potential volatile markers of the final stage of cheese ripening and are suitable for the design of a sensing method for a rapid and preliminary first screening of the cheese maturation process.¹

The authors of the paper¹ point out that, while their proposed method “is qualitative and not selective for 2-butanone, which limits its practical applications due to interfering compounds, it provides a simple, low-cost, and easily implementable approach for the early indication of cheese maturation.”

Read More on Similar Subjects

Chromatography in Milk Composition and Feeding Regimens
Using GC-MS to Investigate the Aroma Composition of Cheese

References

1. Ferrara, G.; Matarazzo, C.; Staiano, M. et al. The Volatile Signature: Tracking Ripening Dynamics to Ensure Goat Cheese Quality. Sensors (Basel) 2026, 26 (5), 1583. DOI: 10.3390/s26051583
2. Mehla, R.; Dhankhar, J.; Ranvir, S. G.; et al. Biochemical Characterization of Cheese During Ripening. In The Chemistry of Milk and Milk Products; Apple Academic Press, 2023; pp. 185–199.
3. Coelho, M. C.; Malcata, F. X.; Silva, C. C. G. Lactic Acid Bacteria in Raw-Milk Cheeses: From Starter Cultures to Probiotic Functions. Foods 2022, 11 (15), 2276. DOI: 10.3390/foods11152276
4. McSweeney, P. L. Biochemistry of Cheese Ripening. Int. J. Dairy Technol. 2004, 57, 127–144. DOI: 10.1111/j.1471-0307.2004.00147
5. Upadhyay, V. K.; McSweeney, P. L. H.; Magboul, A. A. A. et al. Proteolysis in Cheese During Ripening. In Cheese: Chemistry, Physics and Microbiology, 3rd ed.; Academic Press, 2004; Volume 1, pp. 391–433.
6. McSweeney, P. L.; McNamara, J. P. Cheese Ripening. In Encyclopedia of Dairy Sciences, 3rd ed.; Academic Press, 2022.