1,721,016 research outputs found
Analysis of wine phenolics by high-performance liquid chromatography using a monolithic type column
No full textThe phenolic composition of red grapes and wines as influenced by Oidium tuckeri development
No full textEvaluation of antiradical activity in single tissues of different italian grapes
No full textEvaluation of antiradical activity in single tissues of different italian grape
An improved HPLC method for the analysis of organic acids, carbohydrates, and alcohols in grape musts and wines
No full textAn improved high performance liquid chromatography (HPLC) method for the analysis of the main organic compounds in musts and wines is presented. A column packed with hydrogen sulfonated divinyl benzene-styrene copolymer and two detectors connected in series were used (UV at 210 nm and RI, respectively). The addition of acetonitrile (6%) to the mobile phase (0.045N H2SO4) allowed the simultaneous separation and quantification of several organic acids, glucose, fructose, glycerol, and ethanol. Direct injection and sample clean-up with a SAX cartridge was tested and compared. The SAX fractionation gave satisfactory results, however the direct injection of diluted wine (1:20) provided the best precision (CV ≤ 2.1%) and accuracy of analysis. Statistical analysis (paired t- test) disclosed significant differences only for glucose, fructose, α-ketoglutaric, and pyruvic acid. The role of column temperature for the analysis of vitamin C (ascorbic acid) was also investigated. Vitamin C underwent thermal degradation during analysis with column temperature ≥30°C
Esperienze di applicazione della microossigenazione come tecnica di affinamento dei vini
No full textEsperienze di applicazione della microossigenazione come tecnica di affinamento dei vin
Stevioside as a replacement of sucrose in peach juice: Sensory evaluation
No full textThe suitability of stevioside as a sweetener in peach juice was investigated. Comparison between stevioside and sucrose in terms of sweetness, sweet and bitter aftertastes were determined both in water and peach juice. The results demonstrated that 160 mg/L of stevioside may replace 34 g/L of sucrose in juice, with a 25% decrease in calories, without affecting the sensory characteristics of the product. Synergistic and inhibitory effects between sucrose and stevioside were also monitored at different stevioside concentration. A new juice formulation sweetened with a binary mixture of stevioside (160 mg/L) and sucrose (56 g/L) was not significantly different in terms of desirability from a reference product sweetened with 9% sucrose
Preliminary studies on the effect of Oidium tuckeri on the phenolic composition of grapes and wines
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