The nutritional and bioactive content of banana and red beetroot peels was investigated. The basic macrocomponent composition was determined using standard AOAC (Association of Official Analytical Chemists) methods, while the recovery efficiency of bioactive compounds was investigated using conventional and innovative extraction techniques (subcritical water extraction, ultrasound- and microwave-assisted extraction). Extracts were analyzed for biological effects in vitro on human hepatic, tongue and colon cancer cell lines. A macrocomponent analysis revealed a notable amount of dietary fiber in banana and beetroot peels (39.0 and 33.6% dmb) and a relatively high content of protein in beetroot peel (18.3% dmb). Regarding the micronutrients-minerals, banana and beetroot peels were shown to be a very good source of potassium (75.06 and 41.86 mg g⁻¹ dmb). Both extracts of banana and beetroot peels obtained by conventional extraction - decoction (100 °C, 20 min) exhibited the highest total phenolic content and antioxidant capacity. Additionally, in banana peel, these extracts were the richest in dopamine content (12.63 mg g⁻¹ dmb). Extraction by infusion (80 °C, 30 min) yielded a beetroot peel extract with the highest total betacyanin content (9.80 mg g⁻¹ dmb). Biological effects in vitro were dose- and time-dependent, as well as influenced by the presence of polysaccharides.

Health-conscious consumers seek convenient ways of incorporating different functional ingredients into their diets. Gummy candies are among the most popular confectionery products but generally regarded as nutritionally empty. A gelatin–sugar matrix, providing a highly appreciated sensory experience of sweetness and chewiness, could be used to deliver various bioactive compounds, especially those carrying an unpleasant taste. This work aimed to formulate gelatin gummies based on the mountain germander extract (MGe) as a source of phenylethanoid glycosides (PhEG). Sucrose and glucose syrup contents were partially or completely substituted with combinations of xylitol, maltitol and prebiotic poly- and oligosaccharides. Chemical, textural and sensory parameters were evaluated after production and 2 months of storage. Formulations containing fructooligosaccharides and xylooligosaccharides maintained a characteristic appearance during storage at all three levels of sugar (high, low and none), whereas inulin-added and plain (i.e., without prebiotic) candies suffered from mold contamination or appearance/textural changes. The color of the candies noticeably changed and appeared darker. The PhEG were shown to be stable during the candies’ production (approximately 90%) and generally maintained their contents during storage. Texture parameters, except hardness, exhibited high positive correlations and resembled the commercial product. Sensory-wise, a moderate bitterness intensity with a decreasing tendency, along with the high transparency and preservation of the characteristic shape facilitated high general acceptance. Gummy candies with prebiotics were shown to be a highly suitable matrix for the bitter MGe, delivering up to 40 mg of PhEG and 4.5 g of prebiotics in one serving size. This study provides a reference for implementing herbal extracts and emerging prebiotics (XOS) in functional confectionery.

The instrumental analysis of complex mixtures of sugars often requires derivatization to enhance the method’s selectivity and sensitivity. 1-Phenyl-3-methyl-5-pyrazolone (PMP) is a common sugar derivatization agent used in high-performance liquid chromatography (HPLC). Although many C18 column applications for PMP–sugar derivative analysis have been developed, their transferability is not straightforward due to variations in column chemistry and preparation technology. The aim of this study was to develop and validate an application for Zorbax Extend C18 columns for the analysis of 8 neutral and 2 acidic sugars commonly found in plant polysaccharides. The method was further compared to well-established alditol acetates and m-hydroxydiphenyl methods and employed for sugar profiling of selected agro-industrial wastes. The most influential separation factors were the mobile-phase pH and acetonitrile content, optimized at 8.0 and a 12–17% gradient, respectively. The method showed excellent linearity, repeatability and intermediate precision. High sensitivity was achieved, especially for neutral sugars, with an accuracy error range of 5–10% relative standard deviation. The sugar profiling results were highly correlated to the reference method for neutral sugars. The HPLC method was highly applicable for the evaluation of polysaccharides in selected wastes and showed advantages in terms of simplicity, accuracy in acidic sugar determination and suitability for their simultaneous analysis with neutral sugars.