不同萌芽程度苦荞全谷物粉营养品质分析与评价

徐芊; 叶文俊; 沈汪洋; 汪丽萍; 高琨; 李晓宁; 谭斌

doi:10.13386/j.issn1002-0306.2023090139

不同萌芽程度苦荞全谷物粉营养品质分析与评价

Analysis and Evaluation of the Nutrient Quality of Tartary Buckwheat Whole Grain Powder at Different Germination Degrees

摘要

摘要: 研究了萌芽程度（芽长）对苦荞全谷物粉（Tartary Buckwheat Whole Grain Powder，TBWGP）营养组分、生物活性组分和抗氧化活性的影响。结果表明，随着萌芽程度增加，萌芽后TBWGP中淀粉、蛋白质和脂肪等组分的绝对含量以及直链淀粉与总淀粉的比值降低，膳食纤维含量升高（P<0.05）。不同萌芽程度TBWGP中均含有17种氨基酸，包括8种必需氨基酸，第一限制性氨基酸为苏氨酸，各类氨基酸含量总体呈上升趋势；风味氨基酸和功能性氨基酸总量增加；氨基酸比值系数法评价显示，芽长达1/2籽粒长度（One-half of the Seed Length，1/2 SL）时苦荞蛋白质品质最优。检测到13种脂肪酸，萌芽过程中，亚油酸（C18:2）和亚麻酸（C18:3n3）相对含量逐渐升高；必需脂肪酸总量（EFA）增加，单不饱和脂肪酸和多不饱和脂肪酸总量的比值（MUFA/PUFA）以及（n-6）系和（n-3）系多不饱和脂肪酸总量的比值（n-6PUFA/n-3PUFA）逐渐减小，脂肪酸致动脉粥样硬化指数（AI）和血栓形成指数（TI）逐渐降低。多酚和黄酮含量逐渐升高；芦丁在露白阶段（Dewy Stage，DS）含量最高，槲皮素在浸泡阶段（Soaking Phase，SP）含量最高，此后逐渐降低；D-手性肌醇含量显著升高（P<0.05）；抗氧化活性逐渐增强。综上，相较于苦荞原料（Tartary Buckwheat Material，TBM），萌芽TBWGP的营养价值和生物活性均得到提高，芽长达籽粒长度（Bud Length equal to the Seed Length，SL）时品质最佳，1/2 SL时次之。

Abstract: The effect of germination degree (shoot length) on the content of nutritional and bioactive components, antioxidant activity was investigated in tartary buckwheat whole grain powder (TBWGP). The findings demonstrated that as germination degree increased, the absolute contents of total starch, protein and fat fractions as well as the ratio of straight-chain starch to total starch in TBWGP decreased, and the content of dietary fiber (IDF, SDF, TDF) elevated (P<0.05). There were 17 amino acids in TBWGP with varying germination degrees, including 8 essential amino acids, threonine was the first limiting amino acid. A general trend of increasing content was observed for all types of amino acids. The total amount of flavour amino acids and functional amino acids in TBWGP increased. According to the amino acid ratio coefficient method, the protein quality of tartary buckwheat was optimal when the bud length was one-half of the seed length (1/2 SL). Thirteen different types of fatty acids were identified, with a progressive increase in the relative concentrations of linoleic acid (C18:2) and linolenic acid (C18:3n3). The total essential fatty acids (EFA) gradually increased, however, the ratio of the total monounsaturated fatty acids to total polyunsaturated fatty acids (MUFA/PUFA) and ratio of total polyunsaturated fatty acids in the (n-6) to (n-3) series (n-6PUFA/n-3PUFA) decreased. Additionally, the atherogenic index (AI) and thrombogenic index (TI) of fatty acids decreased progressively. The content of polyphenols and flavonoids progressively rose. The concentration of rutin peaked during the dewy stage (DS) while quercetin peaked during the soaking phase stage (SP), and then decreased gradually. The content of D-chiral inositol as well as the antioxidant activity increased significantly (P<0.05). In conclusion, the nutritional value and biological activity of germination of TBWGP were improved in comparison to tartary buckwheat material (TBM). And the quality of the bud length equal to the seed length (SL) was found to be excellent, with 1/2 SL following suit.