Adsorption and controlled release performances of flavor compounds by rice bran insoluble dietary fiber improved through steam explosion method.

In this study, steam explosion was employed as a modification process for rice bran insoluble dietary fiber (RBIDF) to improve the flavor adsorption and controlled release capacities of RBIDF. Results showed that the flavor adsorption ability of RBIDF was effectively improved due to the unfolding structure, increased specific surface area and pore volume and exposure of more functional groups after steam explosion treatment. The mechanism of the flavor adsorption behavior of modified RBIDF was preliminarily explored using adsorption kinetics and isotherms combined with SEM and DSC analysis. Results showed that the Langmuir isotherm model and pseudo-second-order kinetic model yielded the best fit to the adsorption data, indicating monolayer adsorption of flavor onto the modified RBIDF, and the adsorption was mainly driven by chemisorption process. The flavor release profile of modified RBIDF was investigated by HS-SPME/GC-MS and E-nose. After long-time storage, the flavor compounds were retained at a higher concentration in the modified RBIDF compared with the untreated RBIDF, indicating that the steam explosion treatment prolonged the retention time and enhanced the retention and controlled release capacities of RBIDF for flavor compounds. This study provides indications for potential applications of steam explosion-modified RBIDF as a novel flavor delivery system and functional ingredient.

catena-Poly[[[diaqua-diformato-cobalt(II)]-µ-1,4-bis-(1H-benzimidazol-1-yl)benzene] dihydrate].

In the title coordination polymer, {[Co(CHO(2))(2)(C(20)H(14)N(4))(H(2)O)(2)]·2H(2)O}(n), the Co(II) atom (site symmetry [Formula: see text]) is coordinated by two formate O atoms, two water O atoms and two N atoms from two 1,4-bis-(1H-benzimidazol-1-yl)benzene ligands (L), resulting in a distorted trans-CoN(2)O(4) octa-hedral coordin-ation environment. The complete L ligand is generated by crystallographic inversion symmetry and serves to bridge the cobalt ions into a chain propagating in [1[Formula: see text][Formula: see text]]. The dihedral angle between the central benzene ring and the imidazole ring system is 38.48 (12)°. O-H⋯O hydrogen bonds involving both the coordinated and uncoordinated water mol-ecules occur and help to link the chains together.

catena-Poly[[bis-(acetato-κO,O')cobalt(II)]-µ-4,4'-bis-(benzimidazol-1-yl)biphenyl-κN:N].

In the title one-dimensional coordination polymer, [Co(C(2)H(3)O(2))(2)(C(26)H(18)N(4))](n), the Co(II) atom (site symmetry 2) is coordinated by two O,O'-bidentate acetate ions and two 4,4'-bis-(benzimidazol-1-yl)biphenyl ligands in a distorted cis-CoN(2)O(4) octa-hedral geometry. The bridging ligand, which is completed by crystallographic twofold symmetry, links the Co(II) atoms into [10] chains. Within the ligand, the dihedral angle between the benzene and benzimidazole rings is 48.31 (8)°.