苦荞籽粒蛋白质营养评价及其对硒的响应  

Nutritional Evaluation of Protein in Tartary Buckwheat Grain and Its Response to Selenium

作　　者：田秀英[1] 李会合[1] 

机构地区：[1]重庆文理学院生命科学与技术学院,重庆402168

出　　处：《食品科学》2010年第7期105-108,共4页Food Science

基　　金：重庆市自然科学基金项目(2007BB1457);重庆市教委科学技术研究项目(KJ091205)

摘　　要：采用盆栽实验研究苦荞籽粒蛋白质营养评价对硒的响应。结果表明,不施硒时,苦荞籽粒必需氨基酸与氨基酸总量比值(E/T)和必需氨基酸与非必需氨基酸比值(E/N)分别为34.4%和52.2%,与WHO/FAO提出的E/T约40%,E/N约60%相接近,苦荞蛋白质为优质蛋白。在所测定的必需氨基酸中,含硫氨基酸(蛋氨酸+胱氨酸)含量和各评分值均最低,是第一限制性氨基酸。除施硒量0.5mg/kg土壤处理外,施硒使苏氨酸和赖氨酸含量有不同程度升高,蛋氨酸+胱氨酸随外源硒质量分数的增加而降低;施硒量≥1.0mg/kg时,苦荞籽粒的粗蛋白(CP)、必需氨基酸、非必需氨基酸和氨基酸总量随施硒量的增加而增加;施硒量1.5～2.0mg/kg土壤时,除含硫氨基酸(蛋氨酸+胱氨酸)外其余各必需氨基酸的含量和各评价指标均优于不施硒的处理。Pot-culture experiment was conducted to nutritional evaluation of protein in tartary buckwheat grain and its response to selenium.Results indicated that the ratios of E/T（essential amino acid/total amino acid） and E/N（essential amino acid/nonessential amino acid） in buckwheat grain cultured in soil without selenite were 34.4% and 52.2%,respectively,which was similar with WHO/FAO standard（40% for E/T and 60% for E/N）.Meanwhile,proteins in buckwheat grain exhibited excellent quality.The content,amino acid score（AAS） and chemical score（CS） of sulfur amino acids（methionine ＋ cystine） exhibited the lowest level in all determined essential amino acids.This demonstrates that they were the first limited amino acid.However,an increase of threonine and lysine contents and a reduction of sulfur amino acids（Met ＋ Cys） were observed in tartary buckwheat cultured in soil containing 0.5 mg/kg selenite.In addition,when soil supplemented with selenite larger than 1.0 mg/kg,crude protein,essential amino acids,non-essential amino acids and total amino acids in tartary buckwheat grain exhibited an increase.Compared to the control without selenite treatment,the soil supplemented with selenite in the range of 1.5-2.0 mg/kg could result in an obvious enhancement in ASS and CS of all other essential amino acids except methionine and cystine in tartary buckwheat grain.

关 键 词：苦荞 硒 蛋白质 营养评价 

分 类 号：S143[农业科学—肥料学] S517[农业科学—农业基础科学]