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Os tubérculos de batata destinados ao processamento devem apresentar coloração clara após a fritura, o que é condicionado pelos baixos teores de açúcares redutores, glicose e frutose. Para auxiliar os programas de melhoramento na seleção de clones com baixos teores destes açúcares, o objetivo deste trabalho foi adaptar e validar uma metodologia simples, econômica e eficiente para quantificar o teor de glicose em tubérculos de batata utilizando um kit laboratorial enzimático desenvolvido para uso em amostras de sangue e urina. Os procedimentos de validação seguiram as recomendações do INMETRO dispostas no documento DOQ-CGCRE-008 de 2003. O método mostrou-se linear entre 1,25 e 40µg de glicose presente na amostra, sendo que o limite de quantificação foi 0,319mg g-1 de massa fresca de batata. A faixa linear de trabalho do método foi desde o limite de quantificação até 1,32mg g-1 de massa fresca de batata. A recuperação média da extração foi de 99,0%. O método proposto foi aplicado para determinar o teor de glicose em amostras de batata "Macaca", que variou de 1,4 a 2,9mg g-1 massa fresca de batata.The processing industry requires potato tubers with low levels of reduced sugars, glucose and fructose, which is responsible for the whiteness of the chip color. The objective of this research was to optimize and validate a simple, inexpensive, and precise enzymatic method to quantify glucose in potato tubers. This method will be useful in breeding programs to select clones for processing purposes with low levels of glucose. The validation procedure followed the recommendations described in INMETRO document DOQ-CGCRE-008 in 2003. The method was linear between 1.25 to 40µg of glucose in the sample. The quantification limit was 0.319mg g-1 of potato fresh weight. The linear working interval of the method started at the quantification limit and ended at 1.32mg g-1 of potato fresh weight. The average recovery in the extraction was 99.0%. The proposed method was used to determine glucose level in samples of ‘Macaca’ tubers, which ranged from 1.4 to 2.9mg g-1 potato fresh weight.

This article discusses a study which aimed to observe the evolution of the malolactic fermentation in four samples using four different types of starter culture of Oenococcus oeni and compare them with a blank. The study used the wine obtained from grapes harvest at full maturity from Feteasca Neagra variety. It identified the characteristics of the wine before the inoculation. The quantity of L-lactic acid obtained by the study was higher in the sample than in the blank.

The article summarizes the result of a study which examined the evolution of the malolactic fermentation in 4 wine samples using 4 different types of starter culture of Oenococcus oeni, a gram-positive bacteria. The Feteasca Neagra variety of grapes were used to produce the wine utilized in this experiment. Analyses were made on the ethanol level, pH, rH, SO2, quantity of malic acid, lactic acid and on the starter culture. The vitality of the starter culture was determined using the colony-forming unit (CFU) method. The researchers concluded that the quantity of L-lactic acid was higher in the samples that were inoculated with Oenococcus.