Effect of Blanching Method and Soaking Solution on the Properties of Potato Flour Produced from Variety Granola

Potato is one of important agricultural commodities in Indonesia. The widely variety cultivated in Indonesia is Granola, almost 90 % of total area. The tuber is appropriate for table potato and not for processing one. On the other hand, the supply for processing tubers in Indonesia is less than its demand. Therefore, an alternative treatment is required for using variety Granola as raw material for processed product. Appropriate pretreatments are necessary to be applied to produce the flour from this variety. This research aims to examine the properties of potato flour as affected by several pretreatments during flour production from potato variety Granola. Potato tuber variety Granola was obtained from the farmers in Wonosobo, Central Java as one of potato producer in Indonesia. The pretreatments were type of soaking solution (water, solution of citric acid 2% and Lactic Acid Bacteria 0.1%) and type of blanching (without blanching, hot water blanching and steam blanching). Observed parameters were content of moisture, ash, starch, reducing sugar, and color parameter. The result indicates that combination of pretreatment using citric acid solution and steam blanching results better flours properties among others, particularly on the color parameter/ brightness of the flour. The color of potato flour from variety Granola is yellow, which the bright color means more interesting for consumers. In addition, reducing sugars content of flour from this treatment is lower than control, but a disadvantage result also obtained from this treatment that is decreasing starch content of flour. Further research is required to improve flour properties to conform to the standard in Indonesia.