Physicochemical and functional properties of protein extracts from Torreya grandis seeds

- Physicochemical and functional properties of T. grandis proteins were investigated.
- Two cultivars of seed proteins were compared while they had similar composition.
- T. grandis protein fractions were mostly about 31-37 kDa and 20-21 kDa.
- Proteins showed high denatured temperature and good solubility.
- Both proteins had favourable emulsifying and foaming and fat absorption capacities.

Proteins extracted from Torreya grandis seeds were investigated for their physicochemical and functional properties. The results showed protein extracts from two cultivars of T. grandis, Shengzhou I (SZPI) and Dazinaiyou (DNPI), had similar protein contents and appropriate amino acid balances with about 41% of the essential amino acid. The molecular weights of seed protein fractions were mostly about 31-37 kDa and 20-21 kDa. SZPI and DNPI had similar denaturation temperature of around 93.7 °C while free sulfhydryl group and disulfide bond contents were found to differ slightly. The surface hydrophobicity of DNPI was 982, significantly (p < 0.05) greater than that of SZPI (649). Both proteins exhibited high solubilities and favourable emulsifying abilities, foaming and fat absorption capacities, although their in-vitro digestibilities were rather low. Therefore, T. grandis seed proteins have potential as valuable nutrition sources and functional ingredients in food industry.