玉米子粒蛋白質及離氨酸含量測定方法之研究

Abstract

(一) Dye-binding與Kjeldahl兩法測定54個O2玉米的粗蛋白質量，根據駢對比較差異不顯著，兩者的相關係數r=0.857，故兩法結果相當一致。 (二) Dye-binding法經重複測定同一樣品（臺南5號）的結果（表1），與Kjeldahl法非常接近，故以此法測定玉米蛋白質含量頗為穩定與準確，但其測定樣品的速度較Kjeldahl法快13倍。 (三) 測定離氨酸方法以TNBS法與自動氨基酸分析儀比較，兩者雖有差異，但就O2玉米而言，最低相差0.1，最高相差0.6gm/l00gm蛋白質，而各樣品間，兩法所得結果互有高低，故如能在分析時加以注意，TNBS法可以應用。但fl2玉米則兩法差別甚大，TNBS法不能應用，其原因尚需再加探討。 The purpose of this study was to compare the rapid method for measuring protein and lysine content of corn kernels, Dye-binding and TNBS vs. Kjeldahl and automatic amino acid analyzer we are using respectively in order to facilitate the analysis of protein and lysine in our high protein and high lysine corn breeding program. The results indicated that the Dye-binding method for rapid estimation of protein was almost equal to the protein content obtained by Kjeldahl method. (10.17% and 10.20%, See Table 1). The correlation coefficient was 0.857 for protein content obtained by two methods from 54 different opaque-2 inbred lines. One technician could analyze 132 samples per day by using dye-binding method, hut it was only 10 samples by Kjeldahl method. The lysine content for opaque-2 corn estimated by TNBS method was relatively close to that of the A. A. A. method. However lysine content estimated by this method for floury-2 corn was much lower. This would be due to the different nature of protein for O2 & fl2 corn. The TNBS could analyze 20 samples per day which was much repid than A. A. A. method. It is suggested that Dye-binding method for protein estimation and TNBS method for lysine determination of O2 corn can be used in corn breeding program.