The nutritional differences between shelf-stable (UHT) milk and refrigerated (fresh) milk primarily stem from the different pasteurization processes they undergo:

1. Pasteurization Process:
   • Shelf-Stable Milk: It’s typically ultra-high temperature (UHT) pasteurized. This process involves heating the milk to a temperature of about 135°C (275°F) for a few seconds. This higher temperature extends shelf life by killing more bacteria and spores.
   • Refrigerated Milk: This is usually pasteurized using the high-temperature short-time (HTST) method, where milk is heated to about 72°C (161°F) for 15 seconds. This process kills harmful bacteria but has a shorter shelf life.
2. Nutritional Content:
   • Vitamins: Some heat-sensitive vitamins, like vitamin C and some B vitamins, may be slightly reduced in UHT milk due to the higher temperatures. However, the loss is generally minimal and not nutritionally significant.
   • Proteins and Fats: The protein and fat content remains largely unchanged between UHT and HTST pasteurized milk.
   • Taste and Color: UHT milk may have a slightly different taste and a slightly creamier color due to the Maillard reaction, which occurs at high temperatures. This does not significantly affect the nutritional value but can alter sensory qualities.
3. Shelf Life and Storage:
   • Shelf-Stable Milk: Can be stored without refrigeration until opened, due to the more thorough sterilization process. This makes it a convenient option for storage and transport.
   • Refrigerated Milk: Requires refrigeration even when unopened due to a higher potential for bacterial growth.
4. Digestibility:
   • There is no significant difference in digestibility between UHT and HTST pasteurized milk for most people. However, individuals with certain sensitivities or digestive issues might notice a difference in how they tolerate these types of milk.

While there are minor differences in vitamin content and taste due to the pasteurization process, both shelf-stable and refrigerated milk are nutritionally similar and provide similar health benefits. The choice between them often comes down to preference, convenience, and storage considerations.

Milk is a nutritious beverage that offers a range of essential nutrients. The nutritional content can vary slightly depending on factors like fat content (whole, 2%, skim, etc.) and fortification, but generally, one cup (approximately 240 ml) of whole cow’s milk typically contains:

1. Calories: Around 150 calories.
2. Protein: Approximately 8 grams, which is high-quality and contains all essential amino acids.
3. Fat: About 8 grams in whole milk. This includes saturated fats and a small amount of trans fats. Lower-fat or skim milk will have less fat content.
4. Carbohydrates: Around 12 grams, primarily from lactose (milk sugar).
5. Vitamins:
   • Vitamin D: Fortified milk is a significant source of vitamin D, essential for bone health.
   • Vitamin B12: Important for brain health and the production of red blood cells.
   • Riboflavin (B2): Plays a key role in energy production.
   • Vitamin A: Important for the immune system, vision, and skin health. Usually added to reduced-fat and skim milk.
6. Minerals:
   • Calcium: About 300 mg, crucial for bone health, muscle function, and nerve signaling.
   • Phosphorus: Helps with bone formation and energy production.
   • Potassium: Important for blood pressure control and heart health.
   • Magnesium: Necessary for many biochemical reactions in the body.
   • Zinc: Essential for immune function and growth.
7. Cholesterol: Whole milk contains about 24 mg of cholesterol per cup.
8. Water: A significant portion of milk is water, making it a good source of hydration.

Milk can also contain small amounts of other nutrients, including niacin, pantothenic acid, selenium, and iodine. The exact nutritional content can vary based on the type of milk, its fortification, and the diet and treatment of the cows it comes from. For those who are lactose intolerant or allergic to cow’s milk, plant-based alternatives like almond, soy, or oat milk are available, but their nutritional profiles will differ from cow’s milk.