Lime treatment of com

Much work has been carried out on the nutritional benefits derived from the lime treatment of com (7,8). Although this aspect is very important, an understanding of the overall physical-chemical changes occurring in the com, which determine the mechanical and sensory properties of the resultant food products, is also essential. Such information can lead to modification of the traditional lime treatment process to... 

Lime Treatment of Corn for Tortilla Preparation. The lime treatment of com for tortilla preparation consists of the following (see Figure 2) a 3 1 mixture of lime water (1.3%, w/v) and dry com grains is... 

Zein, which is the major protein in corn, was chosen because it contains no lysine. This precluded the formation of LAL during alkali treatment. Therefore, any changes in digestibility or uptake could be attributed to racemization effects alone. Additionally, we were interested in comparing the effects of sodium hydroxide treatment with the effects of calcium hydroxide treatment because lime is used in the preparation of corn meal for use in tortillas. If the traditional lime treatment of com meal is unnecessarily harsh, it could have important nutritional consequences because a large segment of the Mexican population obtains much of their dietary protein in the form of tortillas (22). 

Preparation for the lime treatment 500 g com + 1000 mL water + 21 g lime. Normal, modified, and opaque corns of the variety Veracruz 181 X Old Group 2. 

Sources. Niacin and substances that are convertible to niacin are found naturally in meat (especially red meat), poultry, fish, legumes, and yeast. In addition to preformed niacin, some L-tryptophan found in the proteins of these foods is metabolized to niacin. Niacin is also present in cereal grains, such as corn and wheat. However, consumption of corn-rich diets has resulted in niacin deficiency in certain populations. The reason for this is that niacin exists in cereal grains in bound forms, such as the glycoside niacytin, which exhibit little or no nutritional availability. Interestingly, niacin deficiency is not common in Mexico and Central America even though the diets of those in these countries are based on com. Alkaline treatment, such as soaking corn in a lime solution—the process used by the populations of Mexico and Central America in the production of com tortillas—yields release of bound niacin and increased availability of the vitamin. 

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