Lysine and tryptophan fortification of nixtamalized corn flour

Abstract

Summary Sensory evaluation was used to determine the effect of lysine and tryptophan fortification on certain properties of corn tortillas. Lysine and tryptophan were added to nixtamalized corn flour to give concentrations which were either 83, 100 or 150% of suggested FAO concentrations. The analysis of sensory panelists results as well as colour parameter changes of enriched tortilla have shown that nixtamalized corn flour would be capable of supplying up to 83% of lysine and tryptophan needed in the diet of an average consumer. It would be logical to offer enriched tortillas mainly to the low income groups of Latin Americans, who normally consume tortillas as a main source of protein in their diet.

Sensory Properties Changes of Fortified Nixtamalized Corn Flour With Lysine and Tryptophan During Storage

“…Also nixtamalized flour was stored in sealed jars which permitted us to avoid flour humidification and possible formation of nonenzymatic browning products and rancid reaction as occurred in the mentioned before study [10]. In our previous study of enrichment of fresh nixtamalized corn flour with lysine and tryptophan at three fortification levels the following attributes: aroma (descriptor corny), flavor (descriptors: corny, rancid, bitter, and burnt lime), aftertaste (descriptors: dry, sticky, bitter, and rancid) and appearance (descriptors: yellowness and uniformity of cooking), manual texture attribute: including softness, dryness, and fragility have shown no statistical difference between treatments and control [8]. But in the case of analysis of manual texture attributes (rollability) and oral texture attributes (graininess and softness), statistical differences were found between control and treatment 1 compared to treatments 2 and 3.…”

“…In these studies, no results were published on the effect of amino acid supplementation on sensory properties of enriched tortilla, For the past 6 years, Fermex in Mexico (Kyowa subsidiary, Kyowa, Japan) has been offering a low priced and highly purified lysine and tryptophan for human consumption. In our previous study, sensory panelists' results as well as color parameter changes of enriched tortilla, have shown that nixtamalized corn flour would be supplied up to 83% of lysine and tryptophan level [8]. In this study, lysine and tryptophan were added directly to the masa in water solution used to prepare tortilla and some doubts appeared if these free amino acids added in powder form to nixtamalized corn flour could affect sensory properties of the flour during storage and finally tortilla sensory quality.…”

Sensorial and biological evaluation of an extruded product made from corn supplemented with soybean and safflower pastes

“…It is commonly known that the main nutritional drawback to cereals, particularly corn, is their low protein content and the limited biological quality of their proteins (highly deficient in lysine and tryptophan) (Mertz, 1970; Ortega et al. , 1986; Waliszewski et al. , 2000), when compared with proteins found in animals.…”

“…Although carbohydrates are their main dietary contribution, they also provide proteins and smaller amounts of lipids, fibre and vitamins. It is commonly known that the main nutritional drawback to cereals, particularly corn, is their low protein content and the limited biological quality of their proteins (highly deficient in lysine and tryptophan) (Mertz, 1970;Ortega et al, 1986;Waliszewski et al, 2000), when compared with proteins found in animals. Nevertheless, the protein quality found in a given cereal can be improved by combining it with other sources of protein.…”

Recovery of lysine and tryptophan from fortified nixtamalized cornflour and tortillas

“…In our recent study (Waliszewski et al ., 2000), sensory and colour analysis of enriched tortillas showed that nixtamalized cornflour could supply up to 83% of the Food and Agricultural Organization (FAO) lysine and tryptophan requirements with acceptable colour and flavour.…”