Joye Iris J, Lamberts Lieve, Brijs Kristof, Delcour Jan A
Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
Food Chem. 2011 Nov 15;129(2):395-401. doi: 10.1016/j.foodchem.2011.04.090. Epub 2011 May 4.
Breakfast cereals are an important part of an equilibrated diet in the Western world, making them extremely suited for carrying health benefits. Intake of γ-aminobutyric acid (GABA), a major inhibitory neurotransmitter of the nervous system, has been related to blood pressure lowering in hypertensive individuals. In vivo, GABA is formed from glutamic acid (GA) by glutamic acid decarboxylase (GAD), a widely distributed enzyme in prokaryotic and eukaryotic species. We here enriched breakfast cereals with GABA by recipe and process optimisation. The dynamics of GA and GABA were monitored throughout the production process. Addition of exogenous recombinantly produced GAD of Yersinia intermedia increased GABA levels by 2- to 5-fold. As only trace levels of GABA (<15ppm) and relatively low levels of its precursor (GA, <100ppm) are present in the wheat and rice flour used, a well-thought ingredient choice (inclusion of quinoa flour (ca. 90ppm GABA and 700ppm GA) or bran enrichment (ca. 66ppm GABA and 500ppm GA)) also significantly increases the GABA content in the final flakes. Finally, a strict control of the heating steps during the production process reduces GA and GABA losses. Consumption of one portion (30g) of the here produced enriched breakfast cereals can even meet up to 55% of the daily intake earlier reported to lower blood pressure (ca. 10mg).
早餐谷物是西方均衡饮食的重要组成部分，使其非常适合带来健康益处。摄入γ-氨基丁酸（GABA），一种神经系统的主要抑制性神经递质，与高血压个体的血压降低有关。在体内，GABA由谷氨酸（GA）通过谷氨酸脱羧酶（GAD）形成，GAD是一种在原核生物和真核生物中广泛分布的酶。我们通过配方和工艺优化，在早餐谷物中富集了GABA。在整个生产过程中监测了GA和GABA的动态变化。添加外源重组产生的中间耶尔森菌GAD可使GABA水平提高2至5倍。由于所用小麦粉和米粉中仅含有痕量水平的GABA（<15ppm）及其前体（GA，<100ppm）的相对较低水平，精心选择原料（加入藜麦粉（约90ppm GABA和700ppm GA）或麸皮富集（约66ppm GABA和500ppm GA））也能显著提高最终片状谷物中的GABA含量。最后，在生产过程中严格控制加热步骤可减少GA和GABA的损失。食用一份（30克）此处生产的富含GABA的早餐谷物甚至可以满足先前报道的降低血压的每日摄入量（约10毫克）的55%。
