Question: Who may be the largest manufacturer of maize flour?

Context paragraphs:
Kalu Khani Thalee: Kalu-Khani Thalee were traditional glazed earthenware deep dishes or plates used on special occasions to serve guests or members of "Hashar" (collective voluntary working force) in the past till last quarter of 20th century in most of the villages of Swabi District.  Every household used to keep a few of these decorative glazed dishes for serving the guests on special occasions and celebrations.  This special dish or bowl used to be decorated and glazed in different colours.  Conventionally, hot chicken curry used to be dished out in this special dish almost enough for 4 to 6 persons for combined or group eating added with another special paste-curry called "Lawanr."  The tasty and thick "Lawanr" being a viscous mixture was especially cooked for the purpose of thickening the otherwise thin chicken curry from "Shumle" and maize flour.

Ugali: Ugali (also sometimes called kimnyet, sima, sembe, obokima, kaunga, dona, obusuma, ngima, arega or posho) is a dish made of maize flour (cornmeal), millet flour, or sorghum flour (sometimes mixed with cassava flour) cooked in boiling liquid (water or milk) to a stiff or firm dough-like consistency (when it is a porridge then it is called uji) and served with salad.  It is the most common staple starch featured in the local cuisines of the African Great Lakes region and Southern Africa.  When ugali is made from another starch, it is usually given a specific regional name.

Kulesha: Kulesha is a surname of Ukrainian origin.  In the Ukrainian language "kulesha" means a porridge of maize flour.

Kokoro (snack food): Kokoro is a common snack food in Nigeria.  It is made from a paste of maize flour mixed with sugar and gari (cassava) or yam flour and deep-fried.  It is commonly sold in ogun state in Nigeria.

Fufu: Fufu (variants of the name include foofoo, fufuo, foufou) is a staple food, common in many countries in Africa.  It is often made with cassava and green Plantain Flour.  Other flours, such as semolina, maize flour or mashed plantains may take the place of cassava flour.  Fufu is often served with groundnut soup, palm nut soup or light soup.

Eish merahrah: Eish merahrah (Egyptian Arabic: عيش مرحرح‎ ‎ , ] ) is an Egyptian flat bread made with 5 -10% ground fenugreek seeds and maize.  It is part of the traditional diet of the Egyptian countryside, prepared locally in village homes in Upper Egypt.  Eish merahrah is similar to "markouk", a Lebanese bread.  The loaves are flat and wide, and usually about 50 cm in diameter.  The bread is made of maize flour made into a soft dough fermented overnight with a sourdough starter, shaped into round loaves, and then allowed to rise or “proof” for 30 minutes before being flattened into round disks then baked.  They can be kept for days in an airtight container.  The addition of fenugreek seeds increases the protein content, storage length, and digestibility of the bread.

Gruma: Gruma, S.A.B. de C.V., known as Gruma, is a Mexican multinational corn flour and tortillas manufacturing company headquartered in San Pedro, near Monterrey, Mexico.  It may be the largest corn flour and tortillas manufacturer in the world.  Its brand names include Mission (Misión in Mexico), Maseca, and Guerrero.

Banana beer: Banana beer is an alcoholic beverage made from fermentation of mashed bananas. Sorghum, millet or maize flour are added as a source of wild yeast.

Masa: Masa ( ; ] ) is a maize (corn) flour or dough that has been soaked and cooked in an alkaline solution in the nixtamalization process.  It is used for making corn tortillas, tamales, "pupusas", and many other Latin American dishes.  The full name is masa de maíz, the dried and powdered form is called "masa harina", "masa de harina", and sometimes "Maseca", the name of a leading commercial brand.  It is reconstituted with water before use.

Harina P.A.N.: Harina P.A.N. (Producto Alimenticio Nacional) is the first brand of boiled corn flour in Venezuela.  The brand itself became a synecdoche, as even with other large competitors in the market, it is used as a noun to indicate any similar maize flour.  This flour is similar to the main ingredient of the Italian Polenta.

Supporting paragraphs: Gruma Masa
Answer: Gruma