USDA, Agricultural Research Service, Robert Holley Center for Agriculture and Health, Ithaca, NY, USA.
International Center for Tropical Agriculture (CIAT), Regional Office for Africa, Nairobi, Kenya.
J Nutr. 2020 Nov 19;150(11):3013-3023. doi: 10.1093/jn/nxaa193.
The predominant bean iron (Fe) biofortification approach is to breed for high Fe concentration and assumes the average Fe concentration is 50 μg/g. This approach also assumes that a 40 μg/g increase is sustainable and Fe bioavailability will not decrease to negate the increase in Fe.
The overall objective was to determine if bean Fe biofortification via breeding for high Fe is producing beans with higher Fe concentration relative to nonbiofortified lines found in the East Africa marketplace.
Seventy-six marketplace samples (East Africa Marketplace Collection; EAMC), and 154 genotypes known to be representative of the marketplace were collected from breeders in the Pan-Africa Bean Research Alliance (designated the East Africa Breeder Collection; EABC). Within the EAMC and EABC were 18 and 35 samples, respectively, that were released as biofortified lines. All samples were measured for Fe concentration. The Caco-2 cell bioassay assessed Fe bioavailability of the EAMC. Biofortified versus nonbiofortified samples were compared by the appropriate t-test or ANOVA.
The Fe concentration of the 58 nonbiofortified EAMC lines was (mean ± SD [range]) 71 ± 9 μg/g (52-93 μg/g) which did not differ significantly from the 18 biofortified EAMC varieties (71 ± 11 μg/g [55-94 μg/g]). The Fe concentration of the 119 nonbiofortified EABC varieties was 66 ± 7 μg/g (51-90 μg/g) which was significantly different (P < 0.0001) from the 35 EABC biofortified lines (73 ± 9 μg/g [60-91 μg/g]). However, the EABC biofortified lines were not different from the nonbiofortified EAMC samples. In the Caco-2 cell bioassay, biofortified EAMC varieties did not deliver more Fe compared with nonbiofortified EAMC varieties.
The assumptions of the high Fe bean biofortification approach are not met in the East African marketplace. Iron concentration and bioavailability measurement indicate the biofortified bean varieties are providing no additional dietary Fe.
主要的豆类铁（Fe）生物强化方法是培育高 Fe 浓度，并假设平均 Fe 浓度为 50μg/g。这种方法还假设增加 40μg/g 是可持续的，并且 Fe 的生物利用度不会降低，从而否定 Fe 的增加。
总体目标是确定通过培育高 Fe 来进行豆类 Fe 生物强化是否会产生相对于在东非市场上发现的非生物强化品种具有更高 Fe 浓度的豆类。
从泛非豆类研究联盟（Pan-African Bean Research Alliance）的种植者那里收集了 76 个市场样本（东非市场收集；EAMC）和 154 个已知代表市场的基因型，这些样本被指定为东非种植者收集（East Africa Breeder Collection；EABC）。在 EAMC 和 EABC 中，分别有 18 和 35 个样本作为生物强化线释放。所有样本均测量 Fe 浓度。Caco-2 细胞生物测定法评估了 EAMC 的 Fe 生物利用度。通过适当的 t 检验或 ANOVA 比较生物强化与非生物强化样本。
58 个非生物强化 EAMC 品系的 Fe 浓度（平均值±SD[范围]）为 71±9μg/g（52-93μg/g），与 18 个生物强化 EAMC 品种无显著差异（71±11μg/g [55-94μg/g]）。119 个非生物强化 EABC 品种的 Fe 浓度为 66±7μg/g（51-90μg/g），与 35 个 EABC 生物强化线（73±9μg/g[60-91μg/g]）有显著差异（P<0.0001）。然而，EABC 生物强化线与非生物强化 EAMC 样本无差异。在 Caco-2 细胞生物测定中，与非生物强化 EAMC 品种相比，生物强化 EAMC 品种并没有提供更多的 Fe。
在东非市场上，高 Fe 豆类生物强化方法的假设没有得到满足。Fe 浓度和生物利用度测量表明，生物强化豆品种没有提供额外的膳食 Fe。
