Nutrition, chemical and physical evaluation of flour of local Madura corn and powder of underutilized Holothuria species

The purpose of this study was to evaluate the nutrition, chemical, and physical properties of flour of the local Madura corn and sea cucumber of underutilized Holothuria species, which may be valuable for future use in formulating new products from the two materials. Tambin corn was collected from farmers in the Bangkalan regency in Madura, Indonesia. Untreated (non-nixtamalized) and nixtamalized corn was dried, ground, sifted in 60 mesh, and then analysed for proximate analysis, mineral content, gelatinization profile, FT-IR spectrum and colorimetry. Three abundant and underutilised sea cucumber species, identified as Holothuria atra, H. leucospilata, and H. impatiens, were collected from Bawean islands, cooked in sea water until rubbery, dried, and then analyzed for proximate analysis and mineral content. Results showed that the protein content of non-nixtamalized and nixtamalized corn was 6.40% and 6.59%, respectively; while those of H. atra, H. leucospilata, and H. impatiens were 66.64%, 79.23%, and 60.12%, respectively. Ash content of non-nixtamalized corn, nixtamalized corn, H. atra, H. leucospilata, and H. impatiens, were 2.30%, 1.82%, 26.29%, 27.78% and 39.18%, respectively. The fat content of non-nixtamalized corn, nixtamalized corn, H. atra, H. leucospilata, and H. impatiens, were 7.69%, 6.02%, 1.44%, 1.48% and 1.35%, respectively; while calcium content was 32.227, 163.546, 337.471, 314.910 and 307.670 mg/100 g, respectively; iron content were 23.367, 20.207, 16.796, 15.136 and 15.611 mg/100 g, respectively; zinc content was 13.095, 12.076, 10.015, 7.142 and 8.073 mg/100 g, respectively. The gelation profile indicated that peak viscosities were 1368 cP and 281 cP, peak temperatures were 75°C and 53°C, set back viscosities were 1443 cP and 94 cP, for non-nixtamalized and nixtamalized corn respectively. The addition of sea cucumber powder at 5% and 10% reduced all gelatinization parameters. Fourier transform infrared (FTIR) spectrum indicated that the main bands of nixtamalized corn were less intense than those shown by raw corn, with an absorption band at 3009 cm-1 corresponding to the C-H group and at 1646 cm-1 corresponding to the N-H bending vibration of primary amines. Colorimetry analysis on corn results showed a reduction of L and an increase of a and b values by nixtamalization.