A. Kusur, A. Karić, M. Andrejaš, H. Alibašić, “Change in the quantity of ascorbic acid after thermal processing of potato”, Technologica Acta, vol. 13, no. 2, pp. 1-4, 2020. 1 ISSN 1840-0426 (P); ISSN 2232-7588 (E) http://tf.untz.ba/technologica-acta CHANGE IN THE QUANTITY OF ASCORBIC ACID AFTER THERMAL PROCESSING OF POTATO ORIGINAL SCIENTIFIC PAPER Amela Kusur  , Aldin Karić, Martina Andrejaš, Hurija Alibašić DOI: 10.5281/zenodo.4540037 RECEIVED 2020-08-01 ACCEPTED 2020-05-11 Faculty of Technology, University of Tuzla, Urfeta Vejzagića 8, 75000 Tuzla, Bosnia and Herzegovina  amelakusur_@hotmail.com ABSTRACT: Potato isn’t eaten raw, it has to be thermally processed which influences the presence of the vitamin C consider- ing its sensitivity, fast degradability, and a great loss of vitamin C is expected. Many different ways of thermal processing are used such as boiling, frying, baking and similar. The vitamin C loss depends on the different pro- cessing ways and potato preparation. This paper aims to show how much quantity of ascorbic acid that is kept in the potato after boiling it in its skin, without the skin and when cut into pieces, as well as after frying and baking in an oven and baking in a foil. The goal of thermal processing is to keep as many nutritional ingredients as pos- sible, and this paper will show which way of processing and preparation is the most convenient for eating. KEYWORDS: potato, vitamin C, thermal processing INTRODUCTION Potato, a vegetable that represents the main food after the grains, is the main representative of bulbous vegetables. This fact states that the potato is con- sumed largely and its advantages are affordable price, availability during the whole year, as well as the pos- sibility to prepare various meals and to produce a wide range of species of this product. The chemical composition of the potato is rather variable depend- ing on the type, climate, production methods, soil fertility and other factors. Carbohydrates that make around 75% of dry matter are the main source of en- ergy. Potato also contains significant amounts of pro- teins, vitamins and minerals. It is also rich with en- zymes and acids. The potato contains biologically high-value proteins that contain various essential amino acids among which lysin, valin and leucin are especially important [1]. The vitamin C that is essential for human diet, gives to the potato a special value. The vitamin C is unique because it does multiple physiological func- tions in the body and it is the only vitamin that has a role in almost all organism functions. The ascorbic acid is well-known by its antioxidative effect by which decreases the cancer risk, participates in the synthesis of collagen, carnitine and neurotransmit- ters, the synthesis and catabolism of tyrosine, as well as some other metabolism processes on the micro- some level [2]. Since bone matrix contains collagen, the vitamin C is important for maintaining the con- nective tissue and wound healing as well as bone formation [2]. Collagen goes into the structure of the essential substance that surrounds the cell membrane and the lack of the vitamin C brings to the capillary fragility. The vitamin C can contribute to decreasing the risk of cardiovascular diseases, stroke prevention and it can cause mild lowering of systolic blood pres- sure [2]. In human diet, the potato can be used in a pro- cessed and unprocessed form. In its unprocessed form, it is still mostly used for human nutrition, espe- cially in less developed countries. Fresh potatoes are baked, boiled or fried and used in many different ways in many different recipes. It is a very grateful food substance used for the preparation of various dishes in the household. It is considered that less than 50% of potatoes are used as fresh and the rest is used for industrial production in various product [3]. The transition to the use of processed food prod- ucts also arises from the need to facilitate household and catering work. Potatoes are industrially pro- cessed into a range of food products for human con- sumption. According to the quantity of production and consumption in the world, the most important processed products are French fries, chips and mashed potatoes [4]. In the process of industrial pota- to processing, starch is obtained, which is an im- portant raw material in the pharmaceutical, food, tex- tile and other industries. Starch produces dextrin, starch syrup, glucose and alcohol, which are also widely used in various industries [1]. Ascorbic acid is very sensitive to the action of enzymes and to oxidation in all steps of food pro- cessing, storage and preparation. Significant losses of