Milk packaging features

Sterilization Methods

When you pick up a milk carton, you’ll often see different sterilization methods listed on the top. These are generally categorized into three types: pasteurized milk, ultra-high temperature (UHT) sterilized milk, and continuously sterilized milk.

Pasteurized Milk: This type is commonly found in simple plastic bags, bottles, or glass containers. The plastic used is typically made from polyethylene.

Lee: Pasteurization usually occurs at temperatures below 100°C. It's commonly done at 72-75°C for 15-16 seconds or 80-85°C for 10-15 seconds. Because it uses low-temperature pasteurization, it preserves more of the original flavor and nutrients. The loss of B vitamins is only around 10%, making it ideal for those who prefer fresh, natural-tasting milk.

Cons: However, since this method doesn’t completely eliminate all bacteria, some heat-resistant microorganisms may remain. If not stored properly—usually requiring cold chain transportation—it can spoil quickly. Therefore, it’s best consumed within a few days and not ideal for long trips.

Sterilized Milk: This is often packaged in composite plastic bags, paper-plastic composites, aluminum foil, or pillow-shaped and brick-shaped containers. These materials offer better protection against light and air, helping to maintain freshness.

Lee: UHT sterilized milk is processed at high temperatures above 100°C, which kills all active bacteria and enzymes. After aseptic filling, it can be stored at room temperature for extended periods. This makes it convenient for transport and storage, perfect for busy lifestyles. However, the high heat can affect the taste and texture, leading to a slightly cooked flavor. B vitamin loss ranges between 20% and 30%.

Disadvantages: Some people find it less flavorful compared to fresh milk, as it lacks the natural taste of raw milk. Still, it's a great option for those who need long-lasting milk without refrigeration.

Continuously Sterilized Milk: This type is usually sold in composite plastic bottles or aluminum-lined boxes. It undergoes a continuous sterilization process, similar to UHT, but with slight variations.

Lee: The process is largely the same as UHT, but in some cases, it may involve secondary sterilization, which can lead to even greater nutrient loss.

Shelf Life Variations

Different sterilization methods result in varying shelf lives. Generally, they fall into three categories: short-term, medium-term, and long-term.

Short-Term: Shelf life is typically within one week, sometimes just 3-4 days. This is common for low-temperature pasteurized milk. It's ideal for households that consume milk daily or for people living close to supermarkets who can buy fresh milk each morning. Note: It's best to purchase before 5 PM, as milk left overnight may not be available anymore.

Medium-Term: Shelf life is about 30 to 45 days. This is standard for UHT milk, which can be stored at room temperature. It's suitable for office workers or people who don't have time to shop daily.

Long-Term: Shelf life can last up to six months. This is typically for continuously sterilized milk, which is ideal for remote areas where transportation takes longer.

With so many options available, choosing the right milk depends on your lifestyle, taste preferences, and storage conditions. Whether you prioritize freshness, convenience, or long shelf life, there's a milk product that suits your needs.