Cheese quality – The importance of grass

29 July 2023

How to Assess Milk and Cheese Quality: Insights from Roberto Rubino, President of the National Association of Cheeses under the Sky *ANFOSC) and a Friend of Cheese since its Inception.

First and foremost, let’s clarify what “quality” means.

What tools do we have to measure it? While wine research has extensively studied aroma and color, there are still many gaps in understanding taste. The factors influencing the molecules responsible for flavor remain largely unknown.

Nutritional Profiles

“When it comes to milk and meat, we know that flavor and nutritional value are influenced by the animals’ diet, even though we don’t know the molecules responsible for taste. From a nutritional perspective, the main elements of interest are the degree of antioxidant protection and the omega-6/omega-3 ratio.”

Antioxidant protection

“In milk, the only antioxidants are beta-carotene and Vitamin E, the tocopherols. These not only help block oxidation but also control beta-carotene, which, if excessive, is also subject to oxidation. Many cheeses today have a metallic aftertaste, resulting from fat oxidation due to an imbalance in the animal diet.”

Antioxidants in milk not only block the oxidation of unsaturated fatty acids but also protect against cholesterol oxidation. “Our analysis results are clear. When animals graze, the antioxidant protection index goes from 0 to 20. In other words, the milk of grazing animals has up to 20 times more protection against oxidation compared to milk from animals fed in barns.”

Omega-3/Omega-6 Ratio

The omega-6/omega-3 ratio, which should be as low as possible, seems to support this theory. “Omega-3 comes from herbs, while omega-6 is present in seeds and concentrates. Grazing animals either eat only grass or receive modest amounts of concentrates. In barns, the grass intake is low, often in the form of hay or silage, comprising less than 40% of their diet, while concentrates can reach up to 70%. The results are as expected: grazing animals have an index close to 1 or even below, while barn-fed animals can reach up to 20. It’s worth noting that milk also contains polyphenols and flavonoids, which affect color and potential antioxidant properties, though this area is less studied at the moment.”

The Conference – Cheese Quality: The Role of Grass

Animal diets, particularly the role of grass and concentrates, play a significant role in determining the variations between different types of cheese. This will be discussed after tasting caciocavalli produced by the same cheesemaker, on the same day, but with milk from differently-fed animals. Carlo Fiori (Guffanti Allevatori di Formaggi) and Luigi di Cecca (DeD formaggi) will join Roberto Rubino in this discussion.

Aromatic profile

Nutritionally speaking, milk from animals grazing on diverse herbs is better than milk from animals fed in barns. Additionally, from an aromatic perspective, milk from animals grazing on a variety of herbs is superior. Rubino believes that both the health and taste benefits of milk can be attributed to the same factor: grass. While the science seems to support this, Rubino is convinced that animal diet is the most fundamental and immediate element in determining milk and cheese quality.

The Seasons of Cheeses

Animal nutrition significantly influences cheese quality. Uniform diets throughout the year result in cheeses with consistent characteristics. On the other hand, when animals graze during a certain period and are fed well-made, green, and diverse hay during the rest of the year, cheeses show great variability, even from day to day.

Rubino explains that cheeses produced in spring are highly aromatic but less flavorful. This is due to the animals’ diet during that time, with lush green, fragrant grass, resulting in cheeses with low levels of heavy molecules and polyphenols. As the season progresses, the grass changes, and more mature plants contribute to the formation of heavier molecules and polyphenols, giving the cheese a more persistent flavor.

Thus, the production period affects the balance between aroma and taste, with the most persistent-tasting cheeses being those with higher levels of heavy molecules and polyphenols, which are associated with an herb-based diet, preferably with more mature plants.

Approaches to Tasting

For non-professional tasters, Rubino suggests comparative tastings, which will be the focus of the Cheese conference, as differences become more evident. He also highlights cheese color as a vital aspect of evaluation. A Rubinos explains, the equation is simple: “Different colors correspond to specific molecules. The yellow color of cheese, often not favored by consumers, indicates a high presence of antioxidants, namely carotenoids.”

The Color of Cheese

The situation varies among different types of cheese. Here’s a brief overview differs across species. Here’s a brief overview:

  • Cow’s Milk: The color heavily depends on the animal’s diet. It is yellow when they graze on grass and white when predominantly fed hay and concentrates.
  • Sheep’s Milk: The color varies significantly due to the presence of xanthophylls and lutein (other carotenoids) in sheep’s milk, resulting in shades ranging from ivory white (like pecorino romano) to intense yellow or almost brown (like fiore sardo). The intensity of the color provides insights into the animals’ diet and the type of pastures they graze on. A whiter color indicates higher consumption of concentrates and less grass.
  • Goat’s Milk and Buffalo Milk: Goat’s milk, like buffalo milk, is usually white due to its direct transformation of beta-carotene into vitamin A, which doesn’t impart color. However, cheeses from grazing goats have various shades of gray, while those from intensive farming are neutral white. Historically, even buffalo cheeses were colored, giving a subtle greenish-blue hue.

Embrace Cheese Diversity! Rubino encourages embracing the variety of cheese colors. In the case of cow’s milk products, yellow color should be seen as a positive attribute rather than a defect.

by Silvia Ceriani, i[email protected]

Cheese 2023 is organized by Slow Food and the City of Bra from September 15-18. See you there! #Cheese2023

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