1. The effects of pH and NaCl concentration on the structure of β‐casein from buffalo milk
- Author
-
Kong Yang Wu, Quan Yang Li, and Tong Xiang Yang
- Subjects
buffalo milk ,0303 health sciences ,Circular dichroism ,Nutrition. Foods and food supply ,Sodium ,0402 animal and dairy science ,Tryptophan ,Fluorescence spectrometry ,chemistry.chemical_element ,04 agricultural and veterinary sciences ,fluorescence spectrometry ,040201 dairy & animal science ,β‐casein ,Fluorescence spectroscopy ,Blueshift ,circular dichroism ,03 medical and health sciences ,Dynamic light scattering ,chemistry ,TX341-641 ,Particle size ,030304 developmental biology ,Food Science ,Nuclear chemistry ,Original Research - Abstract
In the present study, we aimed to investigate the effects of pH and sodium chloride (NaCl) concentration on the structure of β‐casein (β‐CN) purified from buffalo milk using circular dichroism (CD), intrinsic tryptophan, and anilino‐8‐naphthalene sulfonate (ANS) fluorescence spectroscopy. We found that NaCl concentration played a critical role in the stability of the secondary structure of β‐CN. The CD negative peak had a redshift as the NaCl concentration was increased and accompanied by a decrease of β‐sheet content and an increase of α‐helix content. ANS fluorescence spectroscopy also indicated that higher NaCl concentration and lower pH significantly affected the tertiary structure of β‐CN. Dynamic light scattering (DLS) results showed that the particle size of buffalo β‐CN had a blueshift, and then a redshift within the pH range of 5.0–7.5, and it showed a redshift when the NaCl concentration was increased., This study aimed to investigate the effects of pH and NaCl concentration on purified β‐casein structure from buffalo milk using circular dichroism (CD), intrinsic tryptophan and ANS fluorescence spectroscopic. It was found that NaCl concentration was a critical factor in affecting stability of the secondary structure of β‐casein.
- Published
- 2021