Describe the science of heating, cooling and drying in a food processing factory?
Answers
Drying is defined as the application of heat under controlled conditions, to remove the water present in foods by evaporation to yield solid products. It differs from evaporation, which yields concentrated liquid products. The main purpose of drying is to extend the shelf-life of foods by reducing their in-water activity. Micro-organisms which cause food spoilage and decay and many of the enzymes which promote undesired changes in the chemical composition of the food are unable to grow, multiply or function in the absence of sufficient water (BAT in the Food, Drink and Milk Industries, June 2005).
Answer:
During sugar processing, the cooling and drying of crystalized sugar is the most important step after the purification process to guarantee a high quality of finished product. Sugar drying removes excess moisture from the sugar using heat, while cooling the sugar brings it to an ideal temperature for storage and transport. Without processing sugar in this way, clumping and discoloration during storage would occur, degrading the quality and value of the final product.
THE HISTORY OF SUGAR PROCESSING
The origin of sugar processing can be traced back to the early civilizations in New Guinea, Southeast Asia, Southern China, and India. The first organized sugar production began in India as early as 350 AD[1]. The cultivation of sugar has a rich history beginning during the Crusades and continuing through to settlement of the Caribbean Islands, Central America, and South America.
In the late 18th century, German scientist Andreas Marggrafdiscovered that sucrose could be extracted from beet root, leading to the first sugar beet processing factory in Poland. British blockades of sugar cane during the Napoleonic Wars, ultimately stimulated the rapid growth of the European sugar beet industry. Sugar processing, traditionally a labor intensive process, became more mechanized and efficient in the 18th century with the introduction of the steam engine. Today the sugar industry is thriving worldwide, with sugar production reaching 175.1 million metric tonnes in 2015[2].
WHAT SUGAR IS, HOW IT IS PROCESSED
Sugar (sucrose) is a natural carbohydrate found in most plants. All green plants manufacture sugar through the process of photosynthesis, but only sugar cane and sugar beet contain it in sufficient concentrations for efficient extraction.
Sugar is processed into a few different final forms. Granulated (crystalline) sugar, the most commonly-used sugar in households, is essentially pure sucrose and is naturally white. Icing sugar is powdered granulated sugar, typically with a small amount of cornstarch to prevent caking. Brown sugar is granulated sugar that includes molasses (either added back to granulated sugar or left from unrefined sugar), which gives it its distinctive colouring.
SUGAR CANE VS. SUGAR BEET
Sugar is the same composition whether it is extracted from sugar cane or sugar beet.
Sugar cane is a tropical grass that grows between 10 and 30 feet high. The stalks contain 12% to 14% sucrose. The main producers of sugar cane are Brazil, China, Mexico, Australia, Thailand, and the United States.
Sugar beet is found in temperate climates, with the highest producers being the European Union, Russia, Turkey, Japan, China, and the United States. The beet root contains 16% to 20% sucrose.
SUGAR PROCESSING
Fundamentally, sugar processing is very similar between both sugar cane and sugar beet. The main differences between both processes are the way the juice is extracted and purified. In the case of sugar cane, the natural sugar is found in the stalk, while in the sugar beet, it is found in the root. The sugar cane stalk is cut and shredded before the extraction of the juice which takes place by squeezing mills or hot water diffusers. The sugar juice is purified to remove any remaining plant fibers or soil. For the sugar beet, the root is cut into slices called cossettes. The cossettes then enter a diffusion tower for the extraction and purification process. In both instances, the sugar juice is concentrated by evaporating water until it reaches a thicker syrup state. The syrup is fed to the crystallizers where sucrose crystals grows, resulting in a mixture of sugar and molasses. Finally, large rapidly spinning centrifuges separate the crystals from the molasses before being dried, cooled, and stored. Raw sugar can be produced in a very similar way with less purifications stages, and then transported to the sugar refinery where it is melted, filtered, and purified before crystallization occurs again.