**6. Production of Bioflavors**

The production of high-added value compounds from pomaces has also been shown to produce bioflavors. The production of aromas from apple pomace fermentation was explored in a recent experiment with yeasts (*Hanseniaspora uvarum*, *Hanseniaspora valbyensis*, and *Saccharomyces cerevisiae*) [100]. This study indicated a strain-dependent effect in the formation of volatile compounds wherein the use of *Saccharomyces cerevisiae* led to a bigger accumulation of volatile fatty acids and their respective ethyl esters, whereas the fermentation with *Hanseniaspora* strains favored the generation of volatile acetic acid esters. A related study evaluated the effect of fermented pomace in a volatile composition of beer [101]. In this case, apple pomace was fermented with lactic acid bacteria (*Lactobacillus rhamnosus* 1473 and 1019, and *Lactobacillus casei* 2246) and significant differences were reported among volatile compositions of apple pomace. However, the fermented pomace (*Lactobacillus rhamnosus* 1473) led to slight modifications in the volatile composition (particularly for ketones and alcohols) of beer. The production of bioflavors was also explored using *Lacticaseibacillus rhamnosus* to ferment orange pomace [102]. This study revealed that fermented pomace had floral (citronellyl formate, 1-nonanol, and β-linalool), citrus (citral and limonene), fruity (β-cyclocitral and benzaldehyde), herbaceous (1-hexanol), bready and caramelly (furfural), and spice (eugenol and carveol) notes.

Finally, another aspect to be considered in the context of the utilization of high-added value compounds obtained from the fermentation/biotransformation of pomaces is their safety. Mycotoxins and pesticides are relevant contaminants in the peels of fruits that may persist in pomaces [103–105]. The effect of fermentation to decontaminate fruits and pomaces is still poorly studied.
