Rice is one of the most popular items on the worldwide market. With the fast-growing market for ready meals, the demand for rice is expected to grow significantly between 2017 and 2022. Along with the growing market, comes the increasing number of rice varieties available. Wholegrain, wild rice, and black rice are some varieties that have gained popularity due to the growing trend for healthier meals. While the demand for rice and rice varieties is increasing, there is still the challenge of processing rice for freezing which needs to be addressed.
There are more than 100 varieties of rice commercially produced in the United States. Of these varieties, three types are the most prevalent: Indica long grain rice, Indica medium grain rice, and short and medium grain Japonica varieties. Long grain rice represents the majority of total rice sold in the United States. Long grain is preferred for prepared foods because it is easy to prepare and durable.
To prepare rice, some opt for parboiling before rice milling. With parboiling, rice is soaked in water and steamed while it is still brown rice. This gelatinizes the starch in the rice kernel, causing the starch granules to melt together. To allow water to enter the rice, heat is applied to cause the crystalline structure to be diffused. This step increases randomness in the starch structure and decreases the number and size of crystalline regions. It allows nutrients from the outer bran to precipitate into the grain itself, preventing the loss of nutrients during milling and improving the shelf life of the rice. This step also mends cracks in the rice.
After parboiling and drying, the grain structure becomes compact. The content of vitamins and minerals is also enhanced and the moisture content is reduced by 13%. The rice is ready to go through the milling process, which reduces it to about 68% of its harvested weight. Milling creates firmer, more separate rice grains that are more stable, less brittle, and less susceptible to overcooking than regular-milled white rice.
Parboiled-milled rice, regular-milled rice, and brown rice can all be cooked and dried before packaging to provide prepared food that has a very short consumer preparation time (90 seconds to 15 minutes). With instant, quick-cooking and boil-in-bag products, the rice is blanched in hot water, steamed, and rinsed. Then the product is placed in a dehydration oven until the moisture content reaches about 12%. When the moisture level of the rice is increased using steam or water, it forms cracks or holes in the kernels. This allows for fast cooking when the rice is re-cooked because water can easily and quickly penetrate into the grain. For frozen rice, the cooked grains are then individually frozen before packaging for an easy to use and delicious product.
Stickiness and IQF Rice
It’s easy to prepare the perfect rice when cooked in small batches on your home stove. The problem rice processors have is making 10,000 pounds of rice per hour while maintaining consistent quality. The biggest challenge that needs to be overcome is the stickiness of rice after it is processed. The degree of stickiness depends on rice variety, blanching time, length of the washing process, drying process, and hold time after blanching to absorb moisture. Rice stickiness not only creates an undesirable product, but it can also make it difficult to maintain reliable food safety. This is why it is important to have a highly efficient, hygienic, and easy to clean freezer. To prevent stickiness, pretreat your IQF rice by washing it multiple times to decrease the amount of starch. More washing leads to less stickiness and better product separation.
AFE provides a full array of exceptional mechanical chilling and freezing systems to help you achieve good product separation and natural appearance as well as maintain the highest food safety standards. Each piece is crafted from high-quality stainless steel with expert welding for durability. You can trust that all of our unsurpassed hygienic designs and equipment exceeds standards for sanitization and dependability.