TY - JOUR
T1 - Physicochemical properties of banana starch oxidized under different conditions
AU - Sánchez-Rivera, Mirna M.
AU - Méndez-Montealvo, Guadalupe
AU - Núñez-Santiago, Carmen
AU - De La Rosa-Millan, Julian
AU - Wang, Ya Jane
AU - Bello-Péreza, Luis A.
PY - 2009/4
Y1 - 2009/4
N2 - Starch isolated from unripe bananas was oxidized under different conditions and the physicochemical properties of the oxidized banana starches were characterized. It was found that pH was the dominating factor in the formation of carboxyl groups. Higher yields of carboxyl groups were found when oxidized starch was prepared at pH 11.5 as compared with 7.5. Longer reaction time also produced a higher carboxyl value. Maltese crosses were still visible in the polarized light micrographs of oxidized banana starch, indicating that the ordered arrangement of starch molecules was not altered. The diffraction pattern of both native and oxidized banana starches was a mixture of A- and B-types. No difference was noted in the absorbance ratio as measured by infrared spectroscopy between the oxidized banana starches at both pHs. The onset and peak gelatinization temperatures increased and gelatinization range decreased with increasing pH during the oxidation. For pasting properties, viscosity significantly decreased during heating and cooling with the most drastic reduction noted for the sample oxidized at pH 11.5. All starches showed a non-Newtonian shearthinning behavior. The oxidation reaction that incorporated chemical groups produced a softer system in banana starch due to the possible incorporation of more water molecules in its structure.
AB - Starch isolated from unripe bananas was oxidized under different conditions and the physicochemical properties of the oxidized banana starches were characterized. It was found that pH was the dominating factor in the formation of carboxyl groups. Higher yields of carboxyl groups were found when oxidized starch was prepared at pH 11.5 as compared with 7.5. Longer reaction time also produced a higher carboxyl value. Maltese crosses were still visible in the polarized light micrographs of oxidized banana starch, indicating that the ordered arrangement of starch molecules was not altered. The diffraction pattern of both native and oxidized banana starches was a mixture of A- and B-types. No difference was noted in the absorbance ratio as measured by infrared spectroscopy between the oxidized banana starches at both pHs. The onset and peak gelatinization temperatures increased and gelatinization range decreased with increasing pH during the oxidation. For pasting properties, viscosity significantly decreased during heating and cooling with the most drastic reduction noted for the sample oxidized at pH 11.5. All starches showed a non-Newtonian shearthinning behavior. The oxidation reaction that incorporated chemical groups produced a softer system in banana starch due to the possible incorporation of more water molecules in its structure.
KW - Carboxyl groups
KW - FTIR
KW - Musa paradisiaca
KW - Sodium hypochlorite
KW - Viscosity
KW - X-ray
UR - http://www.scopus.com/inward/record.url?scp=65349090086&partnerID=8YFLogxK
U2 - 10.1002/star.200800033
DO - 10.1002/star.200800033
M3 - Artículo
SN - 0038-9056
VL - 61
SP - 206
EP - 213
JO - Starch/Staerke
JF - Starch/Staerke
IS - 3-4
ER -