Biofortification of Edible Crops

Abstract

Humans require sufficient amounts of at least 18 mineral elements for normal development and well‐being. Unfortunately, many people's diets lack sufficient iron, zinc, calcium, magnesium, iodine and selenium. Mineral malnutrition can be addressed by dietary diversification, mineral supplementation, food fortification or the biofortification of edible crops. Biofortification can be achieved by two complementary strategies. The ‘genetic’ strategy, which includes breeding and genetic manipulation of crops, aims not only to increase the acquisition of mineral elements and their accumulation in edible portions but also to improve their bioavailability by altering concentrations affecting uptake by the gut. The ‘agronomic’ strategy, which includes effective soil management and fertiliser applications, aims to increase the phytoavailability of mineral elements. Using these strategies, staple crops can be adequately biofortified with minerals currently lacking in people's diets. Furthermore, biofortification appears to be a cost‐effective approach to alleviating mineral malnutrition, reaching urban and rural populations in developed and developing nations. Key Concepts Human diets must supply sufficient quantities of 18 essential mineral elements. Many people's diets lack sufficient iron, zinc, calcium, magnesium, iodine or selenium. One strategy to combat mineral malnutrition in humans is biofortification of edible crops. Biofortification increases the bioavailable concentrations of essential minerals in produce. Agronomic biofortification strategies include effective soil management and fertiliser applications. Genetic biofortification strategies employ the selection, breeding or genetic manipulation of crops. Crop genotypes can be developed with greater acquisition and accumulation of minerals in edible portions. Crop genotypes can be developed with reduced concentrations of antinutrients, such as phytate or oxalate, or greater concentrations of promoter substances, such as ascorbate, β‐carotene, protein cysteine and various organic acids and amino acids, to improve the bioavailability of minerals. Biofortification is a cost‐effective strategy to alleviate mineral malnutrition and can reach both urban and rural populations in developed and developing nations.

Limits to the Biofortification of Leafy Brassicas with Zinc

“…This observation could have implications for increasing dietary Zn intake and the alleviation of Zn deficiencies in human populations. If it is assumed that brassicas constitute 5% of the Zn in current diets [3,4], increasing their shoot Zn concentrations from 0.057 mg Zn g −1 DW-the average value obtained without the addition of Zn fertilisers in the six experiments reported here (Table S1)-to 0.10-0.30 mg Zn g −1 DW through the application of Zn fertilisers to appropriate genotypes could increase dietary Zn intake by 3.8-21.3% without loss of crop yield. This has the potential to raise the Zn status and general health of human populations without any necessity for people to change their diets.…”

“…It is estimated that over one-fifth of the world's population suffers from zinc (Zn) deficiency, which results in impaired development, ill health, and a reduction in gross domestic product [1][2][3][4][5]. One strategy to increase human dietary Zn intake is to increase Zn concentrations in edible produce.…”

“…One strategy to increase human dietary Zn intake is to increase Zn concentrations in edible produce. This strategy is termed biofortification and can be achieved through the use of Zn fertilisers on plant genotypes that have greater ability to acquire and accumulate Zn in their edible tissues [1,[4][5][6][7][8][9]. Zinc might be applied to the soil as inorganic or organic fertilisers or to foliage as soluble salts [1,7,[9][10][11].…”

“…Leafy vegetables are a significant source of micronutrients for human populations, especially those with low incomes or with a vegetarian diet [3,4]. Brassicaceous vegetables, such as cabbage (Brassica oleracea var.…”

“…The health benefits of brassicaceous vegetables are not only associated with their mineral composition but also their vitamin content and the presence of other organic compounds, particularly glucosinolates [22,24,25]. Although leafy vegetables currently contribute proportionally less Zn to human diets than animal products or cereals [3,4], their greater potential for Zn biofortification could be exploited to increase Zn intake and improve human health.…”