Zinc in Wheat Grain, Processing, and Food

Abstract

Improving zinc (Zn) content in wheat and its processed foods is an effective way to solve human Zn deficiency, which can cause a variety of diseases. This article summarizes the works on Zn in wheat grain, wheat processing, and wheat-derived foods. Grain Zn content in wheat was 31.84 mg·kg^-1 globally but varied across continents, for example, 25.10 mg·kg^-1 in Europe, 29.00 mg·kg^-1 in Africa, 33.63 mg·kg^-1 in Asia, and 33.91 mg·kg^-1 in North America. Grain Zn content in wheat improved from 28.96 to 36.61 mg·kg^-1 and that in flour increased from 10.51 to 14.82 mg·kg^-1 after Zn fortification. Furthermore, Zn content varied in the different processed components of wheat; that is, Zn content was 12.58 mg·kg^-1 in flour, 70.49 mg·kg^-1 in shorts, and 86.45 mg·kg^-1 in bran. Zinc content was also different in wheat-derived foods, such as 13.65 mg·kg^-1 in baked food, 10.65 mg·kg^-1 in fried food, and 8.03 mg·kg^-1 in cooking food. Therefore, the suitable Zn fortification, appropriate processing, and food type of wheat are important to meet people's Zn requirement through wheat.

Keywords: bioavailability; flour; fortification; wheat; zinc.

Figure 1

Zinc content of wheat among different countries and continents. These data come from references (, –47). Letters a and b indicate a significant difference at the level of P < 0.05.

Figure 2

Zinc content in fortified and unfortified wheat. Letters a and b indicate a significant difference at the level of P < 0.05; n is the total number of samples.

Figure 3

Zinc content in wheat grain and flour with year.

Figure 4

Comparison of wheat flour with different treatments. Data are from references (, , , , , , , –69). Letters a, b, and c indicate a significant difference at the level of P < 0.05; n is the total number of samples.

Figure 5

Schematic diagram of zinc content in the powder path. These data are from references (38, 59, 70).

Figure 6

Zinc content in different wheat processed foods. Letters a, b, and c indicate a significant difference at the level of P < 0.05; n is the total number of samples.