Current research on the effects of cyclodextrins (CDs) on the sweetness of aspartame (ASP) focuses on the stability of aspartame as protected by CDs. We propose a relationship between the sweetness intensity of aspartame and its thermodynamic binding affinity with CDs. In this paper, we describe the sensory evaluation of aspartame with the five CDs α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), and methyl-β-cyclodextrin (Met-β-CD). β-CD was found to significantly enhance the sweetness intensity of aspartame. The binding affinity of CDs with aspartame was then investigated using isothermal titration calorimetry (ITC) and fluorescence spectroscopy. The binding of aspartame with β-CD resulted in a free energy change with the largest binding constant. Differential scanning calorimetry (DSC), nuclear magnetic resonance (1H NMR), and Fourier transform infrared (FT-IR) spectroscopy further revealed the mechanism behind the complexation. This research gives insight to the contribution of the thermodynamic binding affinity to the sweetness intensity of aspartame. It also provides an approach for screening flavorretention agents by measuring binding constants.
Received: 25 July 2016
Published: 28 September 2016
Fund: the Zhejiang Provincial Top Key Discipline of Food Science and Biotechnology, China(JYTSP20141012);NationalNatural Science Foundation of China(21673207);Graduate Innovation Project of Zhejiang Gongshang University, China(CX201610053，20151216)
Tian-Tian ZHU,Shu-Zhen XU,Bing-Qiang GE,Zhong-Xiu CHEN. Sweetness Enhancement of Aspartame in the Presence of Cyclodextrins and the Thermodynamics in Bindinge. Acta Physico-Chimica Sinca, 2016, 32(12): 2871-2878.