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Water dynamics of Ser‐His‐Glu‐Cys‐Asn powder and effects of moisture absorption on its chemical properties
Author(s) -
Lin Songyi,
Xue Peiyu,
Yang Shuailing,
Li Xingfang,
Dong Xiuping,
Chen Feng
Publication year - 2017
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.8154
Subject(s) - moisture , chemistry , absorption (acoustics) , spectroscopy , sorption , absorption of water , water activity , water content , relative humidity , nuclear magnetic resonance spectroscopy , infrared spectroscopy , absorption spectroscopy , chemical structure , analytical chemistry (journal) , chromatography , materials science , organic chemistry , adsorption , physics , geotechnical engineering , quantum mechanics , engineering , composite material , thermodynamics
BACKGROUND This study has elucidated moisture dynamics in the soybean peptide, Ser‐His‐Glu‐Cys‐Asn ( SHECN ) powder by using dynamic vapor sorption ( DVS ) and nuclear magnetic resonance ( NMR ). We also tried to investigate the effects of moisture absorption on the biological activity and chemical properties of SHECN with some effective methods such as mid‐infrared ( MIR ) spectroscopy and gas chromatography–mass spectrometry ( GC‐MS ). RESULTS DVS results showed that the moisture absorption of SHECN could reach a maximum of 33%, and the SHECN powder after synthesis actually existed in a trihydrate state of SHECN . 3H 2 O . Low‐field NMR revealed that three water proportions including strong combined water, binding water and bulk water were involved in SHECN moisture absorption and absored water dominantly existed in the form of combined water. Magnetic resonance imaging ( MRI ) and MIR spectroscopy results indicated that moisture absorption could change the morphology and structure of SHECN . After moisture absorption at 50% and 75% relative humidity, 19 volatiles were identified by GC‐MS analysis. Additionally, this study showed that a part of reductive groups in SHECN was oxidized and its antioxidant ability declined significantly ( P < 0.05) after moisture absorption. CONCLUSION Water absorbed into SHECN powder can significantly change its microstructure and cause its activity to decrease. We must prevent SHECN from absorbing moisture during storage because the water can accelerate the oxidation of samples and promote microbial reactions. © 2016 Society of Chemical Industry