Pasting behaviour of high impact ball milled rice flours and its correlation with the starch structure

GONZÁLEZ, LUCIANA CARLA; TOLABA, MARCELA PATRICIA; LOUBES, MARIA ANA

JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE

ASSOC FOOD SCIENT TECHN INDIA

Año: 2018

0022-1155

The effects of rotational speed and milling timeon pasting profile, particle size and morphology, damagedstarch and gelatinization enthalpy of modified rice flourswere analysed by response surface methodology to investigatethe relationships among functional attributes andstarch structure. Morphological changes were corroboratedby scanning electron microscopy. Peak time (Pt), pastingtemperature (PT), peak and final viscosities from rapidvisco-analysis showed a significant decrease with increasingof milling severity. The reduction in final viscosity (FVup to 4770 mPa s), particularly for the refined flour fraction(volume median diameter, D50` lm), evidencedthe poor capacity of damaged starch to bind water duringheating step. In comparison with native flour, the modifiedflours presented higher values of damaged starch (DS5.94?16.46%), and viscosities as well as lower values ofgelatinization enthalpy (DH 4.67?0.71 J/g), Pt and PTdenoting a lower resistance to shear stress and cooking.Such behavior is desirable in mixture design to enhanceflour particles dispersion and to facilitate the interactionamong food ingredients. Structural changes of starch werestrongly associated to pasting behavior as it can beappreciated from the significant correlations founded: FV?DS, setback viscosity (SB)?DS, SB?D50, SB?DH. Planetaryball milling is a novel green method to obtain physically modified rice flours with distinctive characteristicsregarding native flours, which could be well controlledby selecting suitable milling conditions. Morestudies should be required to expand the applications of themodified rice flours, in food and non-food products, withspecific functional requirements.