Effect of the Storage Conditions on the Microbiological Quality and Selected Bioactive Compound Content in Fruit Mousses for Infants and Young Children

Fruit mousses, as low-processed products, are highly susceptible to external conditions, and storage leads to the degradation of bioactive compounds, particularly phenolic compounds and vitamins, as well as promoting the growth of yeasts and molds. This study investigated the impact of storage conditions on the microbiological quality and degradation of selected bioactive compounds in fruit mousses from various producers (from apples, pears, and multi-components). Total phenolic (TPC) and total flavonoid (TFC) contents, vitamin C level, antioxidant capacity (AC, measured by the DPPH assay), and concentrations of macro- and microminerals were evaluated in fresh mousses and those stored for 48 h at 23 °C and 4 °C. Changes in total aerobic mesophilic bacteria (TAMB), yeast and mold counts, and selected microbial groups were also checked. It was found that the analyzed compounds varied depending on the components of the mousses. Multi-component mousses contained the highest levels of TPC, TFC, and vitamin C, and had 2–5 times higher AC values compared to apple and pear mousses. Storage at room temperature resulted in TFC lowering of up to 25% in apple mousses and vitamin C reductions of up to 22% in multi-component mousses. During refrigerated storage, the highest losses were observed in pear mousses, with TPC decreasing by up to 13% and vitamin C by up to 11%. Among the minerals, magnesium and zinc levels decreased most significantly in apple mousses stored at 23 °C (up to 33% and up to 29%, respectively). Microbiological analysis revealed variability in TAMB, yeast, and mold counts, with refrigeration (4 °C) generally limiting microbial growth compared to room temperature (23 °C). Notably, no pathogenic bacteria were detected under any storage conditions, and the mousses retained a high microbiological quality even after room-temperature storage.