Nsabimana Samuel, Ismail Tariq, Lazarte Claudia E
Division of Food and Pharma, Department of Process and Life Science Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
Food Science and Technology, University of Rwanda-College of Agriculture, Animal Sciences and Veterinary Medicine (UR-CAVM), Nyagatare, Rwanda.
Front Nutr. 2024 Dec 2;11:1478155. doi: 10.3389/fnut.2024.1478155. eCollection 2024.
Phytates are nutrient-binding compounds found mainly in cereals and legumes, which may significantly contribute to micronutrient malnutrition in regions where phytate-rich cereals, such as maize, are staple food.
This study investigated how maize fermentation, both alone and in combination with soaking and germination, can reduce phytate levels and enhance the estimated bioavailability of iron and zinc.
We evaluated various fermentation methods, including spontaneous fermentation; fermentation with starter cultures, either 299v (Lp299) or yogurt containing viable ; and fermentation with Lp299 of soaked and germinated maize. The outcome variables included changes in pH and lactic acid content during fermentation, and measurements of phytate levels (spectrophotometry), minerals (Atomic absorption) and protein (protein analyzer) in maize samples before and after treatments.
Fermentation with Lp299 of soaked and germinated maize grains yielded a phytate reduction of up to 85.6% decreasing from 9.58 ± 0.05 g·kg in raw maize to 1.39 ± 0.09 g·kg after processing. Fermentation of raw maize flour using Lp299 or yogurt resulted in a similar phytate reduction of 65.3% (3.35 ± 0.26 g·kg) and 68.7% (3.02 ± 0.01 g·kg) respectively. Spontaneous fermentation yielded a phytate reduction of 51.8% (4.65 ± 0.40 g·kg). This reduction in phytate content enhanced the estimated bioavailability of iron and zinc, particularly in the soaking-germination-fermentation combination, where the Phytate:Zinc molar ratio (Phy:Zn) dropped from 40.76 to 7.77, representing 81% reduction from the raw maize. The Phytate:Iron molar ratio (Phy:Fe) dropped from 41.42 to 6.24 indicating an 85% reduction. Additionally, fermentation led to a significant increase ( = 0.001) in protein content in maize flour after fermentation, ranging from 7.3 to 10.3% after the various fermentation treatments. There was not significant difference in the protein increase when compared the fermentation types.
Lactic acid fermentation of soaked and germinated maize grains, emerged as the most promising process to enhance the bioavailability of essential minerals. This approach could help alleviate mineral deficiencies in populations dependent on maize-based diets. The findings underscore the potential of fermentation to be applied at the household level, which may bring up an alternative for programs and policies focused on reducing micronutrient deficiencies and improving food security in developing regions.
植酸盐是主要存在于谷物和豆类中的营养结合化合物，在以富含植酸盐的谷物（如玉米）为主食的地区，可能是导致微量营养素营养不良的重要因素。
本研究调查了单独的玉米发酵以及与浸泡和发芽相结合的发酵方式如何降低植酸盐水平，并提高铁和锌的估计生物利用率。
我们评估了各种发酵方法，包括自然发酵；使用发酵剂培养物（299v（Lp299）或含有活性菌的酸奶）进行发酵；以及用Lp299对浸泡和发芽后的玉米进行发酵。结果变量包括发酵过程中pH值和乳酸含量的变化，以及处理前后玉米样品中植酸盐水平（分光光度法）、矿物质（原子吸收法）和蛋白质（蛋白质分析仪）的测量值。
用Lp299对浸泡和发芽后的玉米粒进行发酵，植酸盐减少量高达85.6%，从生玉米中的9.58±0.05 g·kg降至加工后的1.39±0.09 g·kg。使用Lp299或酸奶对生玉米粉进行发酵，植酸盐减少量相似，分别为65.3%（3.35±0.26 g·kg）和68.7%（3.02±0.01 g·kg）。自然发酵使植酸盐减少了51.8%（4.65±0.40 g·kg）。植酸盐含量的降低提高了铁和锌的估计生物利用率，特别是在浸泡-发芽-发酵组合中，植酸盐:锌摩尔比（Phy:Zn）从40.76降至7.77，比生玉米降低了81%。植酸盐:铁摩尔比（Phy:Fe）从41.42降至6.24，表明降低了85%。此外，发酵导致发酵后玉米粉中的蛋白质含量显著增加（P = 0.001），各种发酵处理后蛋白质含量在7.3%至10.3%之间。比较不同发酵类型时，蛋白质增加量没有显著差异。
对浸泡和发芽后的玉米粒进行乳酸发酵，是提高必需矿物质生物利用率最有前景的方法。这种方法有助于缓解依赖玉米为主食人群的矿物质缺乏问题。研究结果强调了发酵在家庭层面应用的潜力，这可能为发展中地区旨在减少微量营养素缺乏和改善粮食安全的项目和政策提供一种替代方案。
