Observations of fresh tubers included the Hunter colours using colour reader Minolta
CR-200b and chemical composition, including dry matter and moisture contents (gravimetry)
and ash (muffle furnace) according to SNI 01-2891-1992 [26], reducing sugar (NelsonSomogy
method) and crude fiber (fibertec) [27] as described in Sudarmadji et al. [27] and
beta-carotene content [28]