Bayberry (Myrica rubra Sieb. et Zucc.) kernel: A new protein source

Bayberry (Myrica rubra Sieb. et Zucc.) kernel protein isolate (BKPI) was isolated from bayberry kernel defatted flour (BKDF) by isoelectric precipitation. BKPI was evaluated for chemical composition and selected functional properties with defatted kernel flour as reference. BKPI contained over 90% dry weight (DW) of protein versus 60.5% DW of protein in BKDF. It possessed a well-balanced amino acid composition according to the FAO/WHO reference except for a low content of lysine. BKPI had a solubility profile similar to that of BKDF, with minimum solubility observed at pH 4.0 and maximum solubility at pH 12.0. BKPI exhibited minimum foaming capacity (FC) (31.1%) and maximum foaming stability (FS) (72.7%) at pH 4.0. Minimum emulsifying capacity (EC) and emulsifying stability (ES) of BKPI and BKDF were observed at pH 4.0. BKPI had a least gelation concentration of (LGC)of 6% (w/v) at pH 4.0. Results indicated that bayberry kernel has potential to be exploited as a new protein source in China. (C) 2008 Elsevier Ltd. All rights reserved.