Muleya Molly, Li Dongfang, Chiutsi-Phiri Gabriella, Botoman Lester, Brameld John M, Salter Andrew M
Future Food Beacon, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
School of Biosciences, Division of Food, Nutrition and Dietetics, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, UK.
Heliyon. 2023 Sep 4;9(9):e19797. doi: 10.1016/j.heliyon.2023.e19797. eCollection 2023 Sep.
There is an urgent need to alleviate protein deficiencies in low-income countries where cereal-based diets dominate. The objective of this study was to use the INFOGEST static digestion method and a recently established analytical workflow to determine the in vitro amino acid digestibility and protein quality of seven maize varieties grown in Malawi. Protein quality was measured using the in vitro digestible indispensable amino acid score (DIAAS). Amino acid digestibility was higher for the dehulled, low fibre, provitamin A maize flour (66%), compared to whole grain maize flours (51-61%), suggesting that the presence of fibre reduced digestibility (p < 0.05). Lysine was the limiting amino acid in all varieties, with the following DIAAS values for each variety; Provitamin A maize - 24, SC 719 - 32, Mtsikinya - 37, SC 167 - 39, Quality protein maize (QPM) - 40, Bantum - 40, SC 403 - 44. In addition to the variety of maize, protein quality was dependent on the level of processing and the agronomic practice applied with higher protein quality for the SC 403 variety in which zinc enriched fertilizer was applied. Comparing protein quality data with published in vivo data showed that DIAAS data were in closer agreement than amino acid digestibility data, which was slightly lower than published values, with mean in vitro amino acid digestibilities of 56-70% compared to a mean in vivo value of 77%. Overall, the in vitro method was able to correctly predict both the direction and magnitude of response. The INFOGEST digestion method coupled with the new analytical workflow will therefore be useful in the screening of high protein cereal crops and subsequent development of cereal-based foods with high protein quality.
在以谷类为主食的低收入国家，迫切需要缓解蛋白质缺乏的状况。本研究的目的是使用INFOGEST静态消化法和最近建立的分析流程，来测定在马拉维种植的7个玉米品种的体外氨基酸消化率和蛋白质质量。使用体外可消化必需氨基酸评分（DIAAS）来衡量蛋白质质量。与全谷物玉米粉（51%-61%）相比，去皮、低纤维、富含维生素A的玉米粉的氨基酸消化率更高（66%），这表明纤维的存在降低了消化率（p<0.05）。赖氨酸是所有品种中的限制性氨基酸，各品种的DIAAS值如下：富含维生素A的玉米-24，SC 719-32，姆齐金亚-37，SC 167-39，优质蛋白玉米（QPM）-40，班图姆-40，SC 403-44。除了玉米品种外，蛋白质质量还取决于加工水平和农艺措施，施用富锌肥料的SC 403品种蛋白质质量更高。将蛋白质质量数据与已发表的体内数据进行比较表明，DIAAS数据的一致性比氨基酸消化率数据更好，氨基酸消化率数据略低于已发表的值，体外氨基酸平均消化率为56%-70%，而体内平均消化率值为77%。总体而言，体外方法能够正确预测反应的方向和幅度。因此，INFOGEST消化法与新的分析流程将有助于筛选高蛋白谷类作物，并随后开发出高质量的谷类食品。
