Characterization of the content of reducing sugars, total sugars and starch in potato varieties and clones grown in Osorno-Chile

摘要

The purpose of this study was to determine and quantify the content of reducing sugars, total sugars andstarch in six varieties of potatoes (Yagana-INIA, Patagonia-INIA, Karu-INIA, Pukará-INIA, Ona-INIA,Puyehue-INIA) and three advanced clones (R91193-1, R89054-34 and RX90020-9), using Desirée likecontrol. The material came from the Genetic Improvement Program at the Remehue INIA-CHILE from the2009-2010 season.Samples were lyophilized in fresh and cooked states. The extraction of reducing sugars, total sugars andstarch was carried out using a method standardized by the International Potato Center (CIP) in Peru, withslight modifications. The determination of reducing sugars was made directly after extraction with alcohol.For the determination of total sugars was necessary to do a hydrolysis with concentrated HCl for a period of5 minutes in water bath at 65-70 °C. For the determination of starch samples were subjected to acidhydrolysis with 5% HCl for a period of 4 hours in water bath at 100°C. The quantification was performedusing a 3.5 dinitrosalicylic acid spectrophotometric method.Applying Duncan test for multiple comparisons in the lyophilized cooked varieties 7 homogeneous groups inthe starch content were observed, in the reducing sugars 5 were identified and in the total sugars 6homogeneous groups were stablished. In the fresh lyophilized varieties 6 homogeneous groups wereobserved in starch content, 7 were recognized in the reducing sugars and 6 were seen in the total sugars.The fresh variety that contains higher starch content is the clone R89054-34 (16,07±0,18%). Puyehue-INIAhad the highest content of reducing sugars and total sugars (1,11±0,08% and 1,57±0,03% respectively). Thelower values of starch in fresh potato was for Pukará-INIA (13,2±0,07%); instead, the lower values ofreducing sugars was found in Desirée (0,86±0,03%) and total sugars was found in Ona-INIA with1,17±0,03%.This characterization will select varieties according to their technological skills, especially to prevent the useof specimens with high values of reducing sugars in fried and other heat treatments, as they tend to theMaillard reaction, which damage the potatoes characteristic colour and flavour.