# Disaccharides: Influence on Volatiles and Phenolics of Sour Cherry Juice
## 1 Introduction  
Food products are a complex matrix consisting of volatile and non-volatile compounds. Chemical composition, the macro- and micro-structure of foods and particle size are known to influence the volatile and non-volatile amount [1]. The characteristic flavor and color of fruits and their products greatly contributes to their overall acceptance by the consumer. The fragility and high post-harvest respiration rate of fruits results in nutritional and microbiological deterioration and limited shelf-life, as well as a loss of quality and health benefits. To minimize these negative effects, fruits are converted into frozen, dried, and cannot products, or processed into jams, jellies, and juices for longer storage to satisfy various markets and consumer demands [2, 3]. It is important that fruit properties are transferred from the raw material to the product. Nevertheless, during processing, chemical and biochemical changes of characteristic compounds cannot be avoided, causing a change of the color and aroma of fruit products. The flavor of fruits and fruit products is the result of a mixture of different volatile compounds. The equilibrium between the different volatile compounds and their concentrations are responsible for the overall flavor profile of fruits and their products [4]. The flavor of sour cherries is composed of a great number of organic components, including carbonyls, alcohols, esters, acids and terpen. Next to benzaldehyde, which is described as a character-impact compound, the important aroma compounds of sour cherry are benzyl alcohol, 2-phenyl ethyl alcohol, eugenol, 2-hexanal, \(\alpha\)-ionon and \(\beta\)-ionion [5, 6]. Besides the aroma profile, color is one of the main distinguishing characteristics between products. Anthocyanins are responsible for the red color of sour cherry. Sour cherry is rich in phenolic compounds with substantial quantities of anthocyanins, in addition to hydroxycinnamates, flavonols, and flavan-3-ols[procyanidims] [7, 8, 9, 10, 11]. These compounds, as other polyphenols, are natural antioxidants. Antioxidants have potential health benefits and antioxidant activity is one of the most considered features in the definition of food nutritional quality. There are more and more studies associating antioxidant-rich diets with a lower incidence of cardiovascular disease, cancers, and age-related degenerative processes [12]. Sucrose is a commonly-used sugar in fruitproduct formulation. Next to sucrose, maltose and trehalose, two sugars that have a lower sweetness than sucrose, were chosen for this study. Also, all selected sugars are chemical isomers. The influence of sugars on fruit product quality has been the subject of many studies [13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24]. The positive influence of trehalose, as a replacement or partial replacement of sucrose, on the retention of volatile compounds has been proven in different products and semi-products such as strawberry cream fillings, strawberry puree, pear products, and freeze-dried sour cherry pure [13; 14; 15; 16; 17; 18; 19]. Also, a positive influence has been proven on phenolics, anthocyanins and antioxidant activity in mandarin juice, blackberry juice, freeze-dried sour cherry puree, freeze-dried apple puree, and strawberry cream fillings [19; 20; 21; 22; 23; 24].  
The aim of this study was to evaluate the influence of the addition of disaccharides (sucrose, maltose and trehalose) to sour cherry juice. Phenolic compounds, anthocyanins and antioxidant activity were investigated in order to evaluate the influence of the mentioned sugars on the color of sour cherry juice, but also on the possible health benefits of prepared products. For consumer acceptance, the flavor of products is very important, thus the volatile profile of prepared products was investigated so that disaccharide impact on both color and flavor can be estimated.