## 3 Results and Discussion  
There are some studies concerning the production of instant beverages (fruit-based, coffee, etc.) where technology covers the production of beverages and further drying, e.g., spray-drying or lyophilization [4]. Contrary to them, in the case of powdered beverages, parts of the components are insoluble and form a suspension that must be stabilized to maintain the desired organoleptic properties. It strongly affects bioaccessibility and bioactivity. According to our knowledge, this is the first attempt at studying the breakthrough properties of the potentially bioaccessible fractions. The contents of total phenolics, carotenoids and chlorophylls in the raw beverages and their digests are presented in Table 1. The content of low-molecular-antioxidants was tailored by the incorporation of lyophilized fruits and vegetables, the addition of flaxseed gum (FSG), as well as the replacement of a sprouted lentil flour with lentil proteins fraction (AGF). In the raw beverages the higher content of phenolics was determined in the beverages enriched with the FSG and lyophilized fruit (P15F; 18.62 mg/100 mL)--1.3, 1.6 and 0.93-fold increase compared to the control containing, respectively, the sprouted lentil flour (C), the beverages based on AGF (P0) and the beverages based on AGF enriched with lyophilized fruit. The results indicated that both the FSG and lyophilized additives are responsible for an elevation of total phenolics. An addition of FSG to the beverages containing AGF caused a linear increase in the phenolic content. Generally, such behavior was recorded in all the studied beverages. In the case of chlorophylls, and carotenoids only slight changes were observed. The contents of chlorophyll \(a\) and carotenoids were the most significantly increased by the incorporation of green lyophilized vegetables (the samples P0V-P15V). These results correspond well with our previous studies describing the changes to low-molecular antioxidants in a chemically-extractable fraction of powdered beverages [23]. Estimation of the nutritional value of new foods is usually based on the concentration of nutrients and phytochemicals and/or the level of pro-health properties; however, the real bioactivity offood is created by many additional factors. It is widely accepted that not all constituents present in the food matrix may be completely bioaccessible; thus, in vitro methodologies have been developed for better evaluation of food quality [42]. Digestion in vitro effectively released phenolics from all matrices which corresponds with other studies describing the bioaccessibility of these compounds from plant-origin food [28; 43]. Relative bioaccessibility factors ranged from 2.62 to 6.72 in the beverages based on the sprouted lentil flour and enriched with lyophilized vegetables and those with AGF without any additives. The highest contents of polyphenols in the potentially bioavailable fraction were recorded for the P5V (57.6 mg/100 mL) and the P0F (53.8 mg/100 mL). The results indicated that the lentil protein isolates used in the beverages are a rich source of phenolics which confirms our previous results obtained for chemically extracted phenolics [23]. This phenomenon was also reported by [PERSON] and co-workers in pea and bean protein isolates which contained 3.8 and 5.5 mg of phenolics per g, respectively [44]. Additionally, as expected, the addition of lyophilized fruit and vegetables increased the content of low-molecular-weight antioxidants. A final concentration of phenolics is the result of several factors--the introduction of functional components, such as FSG and lyophilized vegetables and fruit at the same time caused a reduction in the phenolics-rich AGF level. The influence of inulin with different degrees of polymerization as a stabilizer of soursp whey beverage on the bioaccessibility of bioactive compounds was studied by [PERSON] and co-workers [12].