Understanding the structure, digestibility, texture and flavor attributes of rice noodles complexation with xanthan and dodecyl gallate

Abstract

Food desirable characteristics are significantly affected by the structures formed during processing. To rational design of rice noodles with desirable digestibility and sensory qualities, the effects of xanthan and/or dodecyl gallate (DG) on structures that determine digestibility, texture and aromas were investigated. Results showed that addition of xanthan and DG respectively increased slowly digestible starch (SDS) and resistant starch (RS), and both decreased the predicted glycemic index (pGI) and the estimated glycemic load (eGL) values. Xanthan mainly improved the gumminess, chewiness, cohesiveness and resilience; and DG enhanced hardness and springiness. The total flavor release decreased after addition of xanthan or DG with low concentration and showed reversed trends at higher content. Structure-function relationships analysis revealed that the hydrogel network aggregated structures with compact mesh size formed within xanthan-starch matrices contributed to improving SDS and textural quality but reducing aroma release. The formation of starch-DG inclusion complexes and starch rearrangement along with more molecular ordered structures after DG complexation increased RS and rigidity, which more effectively reduced pGI and eGL values than after xanthan complexation. A combination of xanthan and DG could synergistically increase SDS (16.29–18.94%) and RS (19.98–20.46%), decrease pGI values with medium eGL values (15.81–18.34) and exhibit desirable texture and abundant aroma compounds. Through molecular interactions between suitable amounts of xanthan and DG of rice noodles, different key structures formed and thus digestibility, texture and aromas can be controlled.