Аbоut a theoretical yield of glucose from starch

• Main Authors: V. V. Ananskikh, L. D. Shleina
• Format: Article
• Language: Russian
• Published: Voronezh state university of engineering technologies 2016-11-01
• Series: Vestnik Voronežskogo Gosudarstvennogo Universiteta Inženernyh Tehnologij
• Subjects: hydrolysis; glucose equivalent; supersaturation; crystallization; centrifugation; glucose; hydrol; glucose yield
• Online Access: https://www.vestnik-vsuet.ru/vguit/article/view/1062

Starch is the raw materials for production of crystal food glucose. With at enzyme conversion of the high purity starch, it is possible to receive glucosic syrups of a glucose equivalent (GE) 98%, where there is about 95% glucose and maltose and maltotriose – of about 5%. Starch hydrolysis is carried out with a gain of solids. Thus, 100 kg of amylum is possible to give up to 109.81 kg of glucose syrup on dry basis. Taking in account the losses at manufacture steps a yield can decrease to 105.61 kg. The purified glucose syrup is concentrated up to 73–75% of dry matters and goes to a crystallization step. Crystallization of glucose is carried out in a supersaturated solution within 56–70 hours at reduced temperature from 46–48 °C to 24–26 °C, resulting a mixture of glucose crystals and an intercrystal run-off syrup called a massecuite. The crystallization process is stopped when a 50% of crystals content in massecuite is reached. At the same time glucose yield will be 105.61/2 = 52.8%. Crystallization is carried out according to the single-stage scheme, with partial return of the end product – hydrol into the hydrolised syrup. Then the massecuite is sent to a centrifugation step for dividing glucose crystals and a run-off syrup, which is partially returned to the initial syrup to reduce in GE. The second part of the run-off syrup goes to realization. It must be kept in mind: the higher GE of the glucose syrup sent to a crystallization step, the more quantity of a hydrol is possible to be returned to hydrolysed syrup. Therefore, it is in a resulted a higher yield of glucose crystals. On the basis of the carried-out calculations the computer program was made with which it is possible to define a theoretical glucose and a hydrol yield, while changing values of a hydrolysed syrup. The higher GE values of a hydrolysed syrup are the higher yield of crystal glucose and the lower one of hydrol are. So, at 98% GE of a hydrolysed syrup it is possible to return about 64.66 kg of a hydrol to 105.61 kg of syrup the glucose yield will increase up to 85%, and at the same time a hydrol yield will be (105,61 – 85) i.e. 20.61%.