Deep dive into Individual Quick Freezing technology
Individual Quick Freezing (IQF) is a revolutionary method that allows food, particularly delicate and perishable items like fruits, to be preserved at peak freshness. This rapid freezing technique ensures that fruits maintain their flavour, texture, and nutritional value, making it a preferred preserving solution in the food industry. For our business, IQF technology is instrumental in capturing the premium quality of our fruit, allowing us to deliver fresh-tasting, nutrient-rich products year-round, regardless of seasonality.
In this article, we will explore the technical process, science, innovations, advantages and challenges of IQF in greater depth.
The IQF process
The core principle behind IQF freezing lies in speed. Unlike conventional freezing methods, where food freezes slowly, allowing large ice crystals to form and damage cell structures, IQF rapidly freezes food products at ultra-low temperatures. This quick freeze prevents cellular rupture and maintains the food's natural integrity. The technical process involves several steps:
- Pre-treatment: Before entering the freezing tunnel, the fresh fruit undergoes several pre-treatments, depending on the fruit type, and the desired application. This can include washing, peeling, pitting, cutting, and calibrating.
- Cryogenic freezing in tunnels: Once pre-treated, the fruit is sent into the IQF freezer, a conveyor belt moving through a tunnel with controlled airflow. The temperature in these tunnels range from -20°C to as low as -40°C, depending on the product being frozen. The tunnels are equipped with cold air jets, spraying liquid nitrogen directly onto the food. Liquid nitrogen has a boiling point of -196°C (-320°F), which allows for almost instantaneous freezing. This technique is especially useful for delicate or high-value items, such as berries, which benefit from ultra-fast freezing to maintain texture and appearance. The stream of air is directed upwards through the conveyor, causing lightweight food items to ‘float’ slightly, allowing even freezing around all sides. This ensures that each piece is frozen individually, and prevents clumping.
- Final packaging: Once frozen, the fruit moves out of the tunnel, where it’s packaged in laminated PE bags or octabins for bulk storage. To preserve the fruit even longer, it is stored in strictly controlled freezer units, and transported to you, with the greatest care.
The science behind IQF
IQF excels at preserving food quality because it creates small ice crystals, also known as microcrystals, rather than large ones. In traditional freezing methods, food freezes slowly, allowing large ice crystals to from within the cells of the food. These large crystals can puncture the cellular structure of the food, leading to moisture loss and texture degradation once thawed. In addition, traditional freezing methods can cause nutrient degradation, especially the loss of water-soluble vitamins (such as vitamin C) or oxidation of fasts.
In the IQF process, the formation of microcrystals prevents these issues. Because food is frozen so quickly, the water inside the cells forms tiny, harmless ice crystals that don’t break the food’s structural integrity. As a result, when thawed, the food retains its original texture, taste, and nutritional content.
IQF vs. other freezing methods
Compared to other freezing methods, such as plate freezing or blast freezing, IQF offers distinct advantages:
- In Slow Freezing (Conventional Freezing), food is placed in a large freezer and frozen slowly over several hours or even days at a temperature between -18°C and -20°C (0°F and -4°f), causing large ice crystals to from. The prolonged exposure to air may even cause oxidation. With IQF, rapidly freezing at lower temperatures eliminates the risk on large ice crystals and oxidation.
- Air Blast Freezing involves using high-velocity cold air, with temperatures between -30°C and -40°C (-22°F and -40°F) to freeze large quantities of food at once. However, this method may result in clumping, uneven freezing, particularly for smaller pieces, and dehydration. IQF, on the other hand, is still way faster, and ensures uniform freezing of individual pieces.
- Plate Freezing is often used for bulk items and works by pressing food between cold metal plates. While effective for block freezing, plate freezing is not ideal for delicate items like berries, since the direct contact may squeeze some moisture out of the food. IQF is a more versatile option for fragile food.
Innovations and future trends in IQF technology
- Sustainability and energy efficiency: as environmental concerns grow, the industry is seeking ways to reduce the energy consumption of IQF systems. Some manufacturers are developing hybrid systems that combine traditional freezing with IQF for optimized energy use.
- Smart freezing technologies: Automation and smart freezing systems are being integrated into IQF processes. Sensors that monitor product temperature, humidity, and airflow are becoming more common, enabling better control of freezing conditions and improving product consistency.
- Expanding product applications: IQF is increasingly being applied to new categories beyond fruits and vegetables. Dairy products, precooked meals, and seafood, are seeing growth in IQF adoption, helping to cater to the rising demand for convenient, high-quality frozen foods.
Benefits of IQF freezing
The decision to use IQF for our fruits has allowed us to grow and expand our product offerings while maintaining a high standard of quality. Here are some specific ways IQF benefits our operations:
- Extending shelf life: IQF technology significantly extends the shelf life of our fruit. By freezing the fruit at peak freshness, we ensure that it can be stored and enjoyed long after its natural harvest period. This reduces waste and allows us to meet customer demand even when fresh supplies are low.
- Reducing food waste: Because IQF ensures that fruits do not clump together, our customers can use only the portion they need without defrosting an entire package. This means less food waste and greater customer satisfaction, as the unused portions remain frozen and fresh for future use.
- Improved food safety: By freezing our fruits immediately after harvest and processing, we minimize the risk of bacterial contamination or spoilage. Freezing at ultra-low temperatures effectively halts microbial growth, ensuring that our products meet the highest standards of food safety.
- Sustainability: IQF freezing supports our commitment to sustainability by reducing food spoilage and waste. It also allows us to utilize the entire harvest effectively, freezing surplus produce that would otherwise go unused during peak seasons. This approach ensures more efficient use of resources and aligns with our goals for environmentally responsible food production.
Challenges and future of IQF
While IQF freezing provides significant advantages for our fruit products, there are a few challenges and considerations we face:
- Cost of equipment and energy: IQF requires specialized freezing tunnels and significant energy input to maintain the low temperatures necessary for rapid freezing. These factors can increase operational costs. However, as technology advances, we are exploring more energy-efficient systems and renewable energy sources to power our operations sustainably.
- Fruit variety considerations: Different fruits have different water content, texture, and freezing behaviour. Some fruits, such as berries, are ideal for IQF freezing, while others, like softer fruits with high moisture content, may require additional considerations. We continue to refine our processes for each fruit variety to ensure the best possible outcome in terms of quality and texture.
Conclusion
For our business, IQF technology is more than just a freezing method—it's a vital part of our commitment to delivering the highest quality fruit products to our customers. By using IQF freezing, we can preserve the natural taste, texture, and nutritional value of our fruits, providing consumers with fresh, high-quality fruit year-round. Whether it's frozen berries, diced pineapple, or any other application, IQF allows us to meet the diverse needs of our customers while maintaining the superior standards of our products.
As we continue to innovate, we aim to explore new ways to expand the use of IQF technology across a wider variety of fruits, while improving sustainability in our operations. Our goal is to maintain our commitment to delivering premium frozen fruits while adapting to new market demands and emerging technologies.
