Molecular Changes in Soy and Wheat Breads during Storage as Probed by Nuclear Magnetic Resonance (NMR)
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- 作者：Alessia Lodi ; Stefano Tiziani ; Yael Vodovotz
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：July 11, 2007
- 年：2007
- 卷：55
- 期：14
- 页码：5850 - 5857
- 全文大小：130K
- 年卷期：v.55,no.14(July 11, 2007)
- ISSN：1520-5118
文摘
Addition of raw ground almond has been shown to improve loaf quality (e.g., loaf specific volume) ofsoy bread. To better understand the effects of almond addition to soy bread and to follow thesethrough storage, nuclear magnetic resonance spectroscopy relaxation times and cross-relaxationexperiments were performed. Spin-spin relaxation times of water protons were similar for the twosoy breads, and therefore changes of water interactions with the other components of the soy breads(with and without almond) were not considered to be major contributors to the differences in loafquality observed between these breads. Additionally, T2 values of water protons were found to havea similar decreasing trend during storage, especially up to day 3, for all of the products studied. Onthe other hand, during storage, lipid proton relaxation times exhibited only small changes in wheatand regular soy bread, whereas the soy-almond bread showed a major decrease of lipid protonmobility in particular after day 3 and up to day 10. These findings may indicate that, after a few daysof storage, the lipid fraction contributes to better plasticization of the soy bread with almond, whichcan affect acceptability and storage stability of the final product. Thus, the higher amount of lipidsintroduced in the almond-enriched soy bread is likely to be responsible for the improved loaf qualityand may significantly affect shelf stability of the soy-containing product.