Effect of Drying Temperatures on Starch-Related Functional and Thermal Properties of Acorn Flours

• Published in: Journal of food science Vol. 76; no. 2; pp. E196 - E202
• Main Authors: Correia, P.R., Beirão-da-Costa, M.L.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.03.2011; Wiley; Wiley Subscription Services, Inc
• Subjects: acorn flours; Biological and medical sciences; Carbohydrates; Desiccation; Drying; Flour; Food engineering; Food Handling - methods; Food industries; Food preservation; Food science; Foods; functional properties; Fundamental and applied biological sciences. Psychology; General aspects; Hot Temperature; Microscopy, Electron, Scanning; Nuts; Nuts - chemistry; Portugal; Quercus; starch; Starch - chemistry; Starch and starchy product industries; Temperature effects; thermal analysis; Thermal properties; Thermodynamics; Portugal; Thermal properties; functional properties; Temperature; Starch; Carbohydrate; Thermal analysis; Flour; Acorn; acorn flours; Polysaccharide; Drying
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2010.01978.x

:  The application of starchy flours from different origins in food systems depends greatly on information about the chemical and functional properties of such food materials. Acorns are important forestry resources in the central and southern regions of Portugal. To preserve these fruits and to optimize their use, techniques like drying are needed. The effects of different drying temperatures on starch‐related functional properties of acorn flours obtained from dried fruits of Quercus rotundifolia (QR) and Quercus suber (QS) were evaluated. Flours were characterized for amylose and resistant starch (RS) contents, swelling ability, and gelatinization properties. Drying temperature mainly affected amylose content and viscoamylographic properties. Amylograms of flours from fruits dried at 60 °C displayed higher consistency (2102 B.U. and 1560 B.U., respectively, for QR and QS). The transition temperatures and enthalpy were less affected by drying temperature, suggesting few modifications in starch structure during drying. QR flours presented different functional properties to those obtained from QS acorn flours. The effect of drying temperatures were more evident in QR.