Based on this, apple pomace was hydrolysed with the phosphoric acid
(H3PO4) and neutralized with NaOH. In fact the salt formed after
this process was sodium phosphate, which remained in the hydrolysate
to be used as nutrient by microorganisms. Therefore, a
filtration operation was not needed with the consequent advantages:
the improvement of process profitability (avoiding salts
removal and decreasing the amount of nutrients needed for
fermentation) and positive impact to the environment (the salt
formed was not a waste) [18]. F and HMF are fermentation inhibitory
byproducts of pentose and hexose sugars. According to HPLC
results, F or HMF could not be detected in the apple pomace hydrolysates.
The lack of furfural formationwas most probably due to
the stability of arabinose. Since HMF and F are inhibitory to
fermentation, absence of these inhibitory products exhibited great
advantage for efficiency of forthcoming fermentations.