Potato Starch Technology

Abstract

A total of 7.0 × 10 6 and 7.3 × 10 6 t starch was produced in 1996 and 1997, respectively, in the European Union, consisting of 15 member states [1,2]. The trend of a steadily increasing starch production is obvious. During a long period, potato starch played an important role in covering approximately 25 % of the available shares; the situation changed in 1995 by the decision of the European Commission to limit subsidies connected with the production of potatoes and their utilisation in starch factories. The instrument used to limit costs became a quota system issued to each potato starch producing member country; in fact, 8 of the 15 member states. A maximum potato starch production has been fixed at approximately 1,864 × 10 3 t/a. The main share is covered by four member states: Germany (696.3 × 10 3 t), Netherlands (538.3 × 10 3 t), France (281.5 × 10 3 t) and Denmark (178.5 × 10 3 t). Smaller quotas (49 to 64 × 10 3 ) are held by Sweden, Finland and Austria, while Spain owns a quota of 2,000 t ( Fig. 1) [3]. Recent resolutions, in connection with the development of EU's Agenda 2000 system, resulted in further reduction of starch production limits by 100 × 10 3 t. The relevant decreases in production will be approx. 40 × 10 3 t for Germany and 31 × 10 3 t for The Netherlands as the main potato starch producing countries. As result of these regulations, potatoes will not be used increasingly as substrates of starch production. Maize and wheat will cover future growth, with more important prospects for wheat.Potato starch production encountered drastic changes during the last years, in particular in economics and substrate supply. Because of economically required reductions in subsidisation, production of potato starch will decrease. Changes in technology are characterised by savings in wash water and process water streams that are effected by increased efficiency introduced with new machinery and changed technological concepts. From an ecological point of view, an early and maximum fruit water separation (up to 95 %) based on dilution of gratings with process water and decanter separation allowed to reduce the fresh water supply to 0.4 to 0.5 m 3 /t of processed potatoes. For economical isolation of potato protein a correspondingly high protein recovery rate (up to 90 %) is essential. Concerning starch extraction, a minimum of 95 % is reached in modern potato starch plants, but optimum engineering (rasping, decanting, sieving) gives recovery rates of 97 to 98 %. In starch refinement, three-phase nozzle separators equipped with wash water supply and constructed for efficient displacement washing allow to achieve a fine fibre removal of 98 % within three separation stages and a final concentration of purified starch milk of 22 to 23°Bé. Potato protein isolates (protein content 83 to 85 %) are produced by isoelectric precipitation combined with heat coagulation while stringent solutions for treatment of de-proteinised fruit water are still lacking. * Publication No. 7075 of the Federal Centre for Cereal, Potato a...

Processing, Valorization and Application of Bio-Waste Derived Compounds from Potato, Tomato, Olive and Cereals: A Review

“…Commonly, proteins are extracted through precipitation by steam injection and pH adjustment leading to protein concentrates with yields about 50%. Such a process was developed by Westfalia Separator Industry GmbH and is shown on Figure 2 [130]. However, the recovered proteins possess a low solubility which is disadvantageous for food application [122,[131][132][133].…”

“…Distinctly higher amounts of dry matter (85-86%) can be obtained by using centrifugal sieves. An alternative is the application of pressure cloth filters, although this process is restricted by film formation and the limited processing due to batch-wise application [130]. The completely dehydrated pulp can be used in the paper industry to substitute wood fibers [152].…”

Utilization of Potato Protein Recovered from Wastewater of Potato Starch Factory as Cattle Feed

“…Protein recovery from industrial PFJ is presently achieved through heat coagulation by steam injection after pH adjustment (i.e. isoelectric precipitation) [7,8]. However, due to the high cost of thermal energy in Japan, heat coagulation is not well suited to this purpose.…”

“…Therefore, the recovery of protein from PFJ is required to prevent the powerful stench. Recovery of protein from PFJ with different methods has been reported [6,7]. The most common way to coagulate potato protein from food processing waste effluents consists of pH adjustment, followed by heat treatment at a temperature between 75°C and 120°C [6].…”

“…Heat coagulation is another possible process for potato protein recovery. High energy costs induced by the recovery procedures charge the economy of potato starch production [7]. On the other hand, isoelectric precipitation is a method that can simply and efficiently recover protein from a large quantity of wastewater [8].…”