Academic Journal of Plant Sciences 4 (4): 114-117, 2011 ISSN 1995-8986 © IDOSI Publications, 2011 Corresponding Author: Dr. Majid Rashidi, Ph.D., Department of Agriculture, Shahr-e-Rey Branch, Islamic Azad University, Shahr-e-Rey, Iran. 114 Prediction of Carrot Water Content Based on Total Soluble Solids and Firmness of Carrot Majid Rashidi and Fereydoun Keshavarzpour Department of Agriculture, Shahr-e-Rey Branch, Islamic Azad University, Shahr-e-Rey, Iran Abstract: Fruit water content (WC) is commonly determined using time consuming laboratory tests, but it may be more suitable to develop a model which uses other determined quality characteristics. In this study, a two-variable linear regression model for predicting carrot WC based on total soluble solids (TSS) and firmness (FIR) of carrot was suggested. Paired samples t-test results showed that the difference between the WC values predicted by two-variable linear regression model and measured by laboratory tests were not statistically significant and to predict carrot WC based on TSS and FIR of carrot the two-variable linear regression model WC = 75.76 - 1.640 TSS + 0.008 FIR with R = 0.94 can be recommended. 2 Key words: Carrot Prediction Water content Total soluble solids Firmness INTRODUCTION MATERIALS AND METHODS Carrot (Daucus carota L.) is an important vegetable Plant Materials: Carrots (cv. Nantes) were purchased because of its large yield per unit area throughout the from a local market in Karaj, Iran. They were visually world and its increasing importance as human food [1]. It inspected for freedom of defects and blemishes. Carrots belongs to the family Umbelliferae. The carrot is believed were then washed with tap water and treated for the to have originated in Asia and now under cultivation in prevention of development of decay by dipping for 20 min many countries [2]. It is orange-yellow in color, which at 20°C in 0.5 g L aqueous solution of iprodione and adds attractiveness to foods on a plate and makes it rich then air dried for approximately 1 h. After that, they were in carotene, a precursor of vitamin A. It contains transferred to the laboratory and held at 5±1°C and 90±5% abundant amounts of nutrients such as protein, relative humidity until laboratory tests. carbohydrate, fiber, vitamin A, potassium, sodium, thiamine and riboflavin [1-4] and is also high in sugar [5]. Experimental Procedure: In order to obtain required data It is consumed fresh or cooked, either alone or with other for determining two-variable linear regression model, three vegetables, in the preparation of soups, stews, curries quality characteristics of carrot, i.e. total soluble solids, and pies. Fresh grated roots are used in salads and tender firmness and water content of seventy-five randomly roots are pickled [6]. Its use increases resistance against selected carrots were measured using laboratory tests the blood and eye diseases [2]. (Table 1). Also, in order to verify the two-variable linear Fruits and vegetables contain large quantities of regression model by comparing its results with those of water in proportion to their weight. Vegetables contain the laboratory tests, ten carrots were taken at random. generally 90-96% water while for fruits normal water Once more, total soluble solids, firmness and water content is between 80 and 90% [7]. Water content has content of them were determined using laboratory tests important effects on the storage period length of fruits (Table 2). and vegetables [8-10]. It also exerts a profound influence on the quality characteristics of fruits and vegetables Total Soluble Solids (TSS): The TSS of carrots was [6, 7, 11]. measured using an ATC-1E hand-held refractometer The present study was conducted to develop a two- (ATAGO, Japan) at temperature of 20°C. variable linear regression model for predicting carrot water content based on total soluble solids and firmness of Firmness (FIR): The FIR of carrots was analyzed using carrot. a Hounsfield texture analyzer (Hounsfield Corp., UK). 1