Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 5/1/2003
Publication Date: 9/28/2003
Citation: Singh, H., Lyne, R.K., Chung, O.K., Seib, P.A., Lookhart, G.L. 2003. The staling of wheat flour tortillas studied by a texture analyzer and SE-HPLC. Program Book of the 88th AACC Annual Meeeting. Abstract No. 369b. p. 147-148. Meeting Abstract. Interpretive Summary: Abstract for the AACC Annual Meeting to be held September 28 - October 2, 2003, in Portland, OR
Technical Abstract: Staling has been a major cause of quality loss in tortillas but has been poorly understood at the molecular level. This research was a study of the changes involved in staling using a texture analyzer (TAXT2 Plus) and size-exclusion high-performance liquid chromatography (SE-HPLC). Tortillas were made in duplicate from wheat flour. The changes in stretchability and stress relaxation (SR) with storage time; 0, 1, 2, 4, 6 and 8 days were studied using tortilla extensibility tests. The average of values plotted against time for these parameters showed a linear relationship up to 4 days of storage then reached a plateau. When the stretchability was followed from day 0 to day 8, the max force increased from 6.5 to 12 N and the modulus of deformation from 1.5 to 9.99 N/mm. Stress relaxation, a determinant of viscoelastic behavior, decreased by ~10% during 8days of storage. Another batch of tortillas from the same processing day were freeze dried after similar storage times, ground and sieved (150 m) and used to follow changes in extractable protein (in 1-propanol, 50%) using SE-HPLC. The decrease in polymeric void volume peak in SE-HPLC chromatogram with increase in storage time suggested the involvement of protein during staling of tortillas.