2.2. Acidic hydrolysis
In the present study HCl was used to achieve acidic hydrolysis.
Hydrochloric acid is usually used for complete hydrolysis of plant
origin carbohydrates to simple reducing sugars, with no adverse effects
on the material. To an 250 ml Erlenmeyer flask with fermentation
trap, 40 g of PPW containing 85% moisture, 6 g dry matter
(15%) and 52.09% starch per dry weight, was added together with
0.5% NH4NO3, 0.1% peptone and 120 ml HCl 0.5 M. The mixture
was sterilized at 121 C for 15 min. During sterilisation the carbohydrates
from potato peel were transformed into fermentable sugars
due to acid hydrolysis. After sterilisation the pH was corrected
to 4.15 with NaOH (1 M).