Abstract:

The nutritional components of eggs and skin of Oncorhynchus mykiss Walbaum cultured in spring water in
Guizhou province were determined. The results showed that 18 kinds of amino acids were found in eggs and the skin;
the ratios of essential amino acid to total amino acid and to non-essential amino acid in eggs were 43.0% and 75.5%,
respectively, while those in skin were 20.7% and 26.0%, respectively, but the ratio of delicious amino acid (DAA) to total
amino acid was higher (50.1%) with glycine (180.0 mg/g) being the most abundant DAA. The eggs and skin contained
with 22 and 18 kinds of fatty acids, respectively, in which the saturated fatty acids accounted for 83.11% and 66.96%,
respectively, and the polyunsaturated fatty acids accounted for 58.51% and 29.55%, respectively. The proportion of EPA +
DHA was 16.53% in eggs, which was higher than that in skin (2.90%). In eggs, P was the most abundant and Mn the least
abundant mineral element, and their contents were 10 520.00 and 1.79 mg/kg, respectively. In skin, the content of Ca was
the highest, and Mn was the lowest, which were 9 199.03 and 0.50 mg/kg, respectively. The contents of predominant mineral
elements (Ca, P, Cu, Zn, Mn and Se) in eggs were higher than in skin, while K, Ca and Fe contents were lower than in skin.
This research showed that the eggs of farmed Oncorhynchus mykiss Walbaum were a high-quality protein source, while the
skin contained an abundant amount of collagen. Both eggs and skin were rich in minerals and unsaturated fatty acids, with
huge potential for development and utilization.

Key words: spring water, Oncorhynchus mykiss Walbaum, fish eggs, fish skin, nutritional component