Beet Storage Impact on Factory Processing
Tom Astrup, Vice President – Operations
When we talk about whether beet storage is good or bad, people most often talk about pile shrink and about how many tons of beets we’ve had to discard. Those are important metrics, but beyond that, beet storage can have a large impact on factory processing. The most common factory processing impacts are on tons of beets sliced per day, and on the amount of sugar recovered from every ton of sugarbeets sliced.
Besides sucrose in the beet, there are other types of sugars present such as invert (fructose and glucose) and raffinose, among others. Invert and raffinose normally accumulate in stored beets until the sugarbeets are frozen. Over the last several weeks, we have seen much higher accumulations of invert sugar in our processed sugarbeets. Invert sugar is created when enzymes break down sucrose in the sugarbeet. Invert brings with it a whole host of problems in the production of sugar. When invert is broken down in the juice purification process, color is formed along with various acids. The elevated color carries into the sugar end of the plant, forcing the centrifugals to work harder, reducing the throughput of the factory. Also, the slimy material from degraded beets interferes with various stages of filtration, which also reduce throughput.
In addition to reducing throughput, the extra washing results in more sugar ending up in the molasses and less as granulated white sugar. So, not only is sucrose lost when it breaks down into invert in the storage pile, but it is estimated for every pound of invert, approximately 1.5 pounds of good sugar are lost to the molasses.
Most of these destructive processes in the storage piles are greatest at warmer temperatures, and as stated earlier, stop altogether when the sugarbeets are frozen. This is why the warm weather we have been having is challenging our ability to recover sugar from the beets. We are hopeful that freezing temperatures will be here soon.