title: Effect of storage time on the retrogradation of banana starch extrudate.
abstract: Starch was isolated from banana starch and the retrogradation phenomenon was studied using diverse techniques, including an enzymatic measurement. Wide-angle X-ray scattering (WAXS) showed that the sample stored for 7 h presented small peaks and when the storage time increased the peaks increased in intensity. The type of diffraction pattern found in banana extrudates is typical of the A-type crystal polymorph. The crystallinity index from the diffractograms, showed a plateau after approximately 20 h of storage. The short-range order measurement with Fourier transform infrared (FTIR) spectroscopy showed that banana starch retrogradation reached a maximum value at approximately 11 h of storage, a value that agrees with the results obtained with differential scanning calorimetry (DSC), because the maximum enthalpy value (approximately 5 J/g) was calculated in the stored sample for 8 h, without changes in the stored samples for more time. Retrograded resistant starch values did not change after 12 h of storage, obtaining the maximum starch retrogradation level. FTIR, DSC, and the enzymatic technique showed the changes at the molecular level in starch during storage; in the case of WAXS, they determine the long-range order that explains the differences found in the starch retrogradation pattern measurement in banana starch.
authors.affiliation: Centro de Desarrollo de Productos Bióticos del IPN, Km 8.5 carr, Yautepec-Jojutla, colonia San Isidro, apartado postal 24, 62731 Yautepec, Morelos, México. labellop@ipn.mx
authors.forename: L A
authors.initials: LA
authors.lastname: Bello-Pérez
authors.forename: M-A
authors.initials: MA
authors.lastname: Ottenhof
authors.forename: E
authors.initials: E
authors.lastname: Agama-Acevedo
authors.forename: I A
authors.initials: IA
authors.lastname: Farhat
mesh_terms: D002152:Calorimetry, Differential Scanning; D005519:Food Preservation; D005638:Fruit / Q000737:chemistry*; D028521:Musa / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry* / Q000302:isolation & purification; D013816:Thermodynamics; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D013213:Starch