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The sensory properties of fruit and vegetables are a result of taste and aroma caused by many volatile and nonvolatile compounds. The sum of organic acids (malic and citric acids) and soluble sugars (fructose and glucose), as well as their balanced combination and interaction, contributes to the characterization of the tomato flavour. The ratio of sugars and organic acids is the key to the sweetness and sourness of tomatoes. This study aimed to determine the sugar and organic acid content, as well as several physicochemical parameters, of eight tomato landraces from Croatia. All the parameters investigated differed between the tomato landraces. The PLS-DA analysis showed that the most important parameters in tomato landrace discriminatory character are malic acid, fructooligosaccharide content, citric acid, dry matter. The results obtained show a significant positive correlation between tomato dry matter and sugar content. At the same time, fructose and sucrose content is negatively correlated with the green to red hue of tomato peel, as well as positively with the blue to yellow hue, indicating that the sugar content increases with yellow color intensity. The blue to yellow hue of the peel color also positively correlates with citric acid content. [ABSTRACT FROM AUTHOR]

Lemon juice is a very common base in sports drinks because of its fresh and pleasant taste. Sugar isomaltulose is relatively new sugar suitable for sports drinks due to low glycemic index, but is still not widely used. Sports drink, the subject of this research, is only one produced in Croatia and present on Croatian market with added isomaltulose. Given this innovation in drink formulation the aim of this study was to monitor the quality and sensorial properties of the drink during six months storage at ambient temperature 20±2oC. Researched drink was produced in industrial plant in Croatia in ordinary production for commercial purpose, and was formulated and declared as isotonic. To achieve the required properties drink besides mentioned ingredients (lemon juice and isomaltulose) contains, fructose, minerals (sodium, potassium, magnesium, calcium, zinc) and vitamins (C, E, niacin). Produced drink was filled in polyethylene terephthalate bottles and analysed after 0, 2, 3, 5 and 6 months of storage. Due to monitoring stability of quality properties of drink soluble dry matter, pH value, acidity, colour parameters (by CIELAB method), osmolality (by osmometer), content of isomaltulose and vitamins (by high-performance liquid chromatography), and minerals (by atomic absorption spectrometer) were determined. Sensory properties were determined by quantitative descriptive method. Considering quality parameters significant changes were observed only in amount of vitamin C as well as colour parameters L*, a*, b* while all others remained unchanged during six months storage at 20±2oC. Further, among sensory attributes researched drink undergone the significant changes in colour (darkening) and taste (lower acidity and fresh fruit taste and higher sweetness). High correlation between sensory and instrumental determined colour was established. Despite mostly all quality parameters remained stable during all storage time without any trend of soon changes, six months of shelf life is maximal due to colour and taste are limiting factors. [ABSTRACT FROM AUTHOR]