The compositional results of four samples are listed in Table 1.
The TS varied from 8.39% to 25.64%, while the VS contents were
similar (88.5–97.4%). To be noted, the potato peeling technologies
significantly affect the peel composition. Hand peeling (WPP) tends
to have more starch/cellulose (55.2%) and less hemicellulose (2.9%)
in the peel as comparing to the commercial steam peeling (SPP),
which has 38.4% starch/cellulose and 14.9% hemicellulose. The
samples BP and OP had a total 59.7% and 38.1% carbohydrate,
respectively, which were values similar to those previously
reported (Anhwange et al., 2009; Chua and Huang, 2003). The protein
content of BP and OP samples was 8.0–8.6% as compared to
16.1–22.8% in WPP and SPP samples. These chemical profiles make
the peel samples good candidates for organic acid production.