Changes of Amino Acid Composition and Contents in Fresh Walnut of Different Varieties during Cold Storage

The purpose of this research was to discuss the changes and differences of compositions and contents of amino acid in 'Liaohe4'(L4), 'Xifu1'(X1) and 'Xifu2'(X2) fresh walnuts which were packed in 0.03 mm polyethylene bags and stored at the temperature of(0±1)℃, the relative humidity of 70 %-80 %, and the amino acid contents were determined regularly. The results indicated that fresh walnut was rich in 17 kinds of amino acids, in which content of 7 kinds of essential amino acids accounted for 28.88 % of total amino acids;the contents of total amino acids, essential amino acids, essential amino acids for children, amino acid score(AAS), gustatory and medicine-effect amino acids were the highest when storing for 30 d, then followed by the overall downward trend; all kinds of amino acids contents were greatly affected by varieties of fresh walnut. In general, the content of amino acids was the highest in L4 walnuts in which the essential amino acids is the closest to the body needs and L4 is of the highest utilization in amino acids.