In vitro starch digestibility changes during storage of maize flour tortillas

Abstract

Nixtamalized maize flours elaborated by four factories in Mexico were used for tortilla preparation. Samples were stored at 4 degrees C for up to 72 h and their in vitro starch digestibility features were evaluated. Moisture content was different between flour and tortilla but no evident relation could be established. Protein and lipid levels were lower in tortillas than in flour but ash content was not different in both samples. A decrease in available starch content was observed upon 48 h cold storage (4 degrees C), changes that were concomitant with increased total resistant starch (RS) levels. These changes were due mainly to retrogradation, as suggested by the increased retrograded resistant starch (RRS) levels recorded in stored tortillas; in some samples, RRS represented up to 100% of total RS. The digestion (alpha-amylolysis) rate (DR) of freshly prepared tortillas differed for the various samples. Although the amylolysis patterns for fresh and 72 h-stored tortillas were similar, lower DR values were shown for the stored materials. The differences found among the various tortilla samples may be due to variations in processing conditions during commercial maize flour preparation, and to the use of different maize varieties.

Formulation, physicochemical, nutritional and sensorial evaluation of corn tortillas supplemented with chía seed (Salvia hispanica L.)

“…There were no significant (P > 0.05) differences in the total ash content in either type of tortillas supplemented with different levels of chia powders (Table 1). The ash content found in the chia seed-added tortilla was higher than that reported for conventional tortillas (Agama-Acevedo et al 2004). Islas-Hernández et al (2007) reported similar values for tortilla fortified with amaranth, 1.4% in tortilla from 100% maize and 1.5% for corn/amaranth tortilla.…”

“…These results show that the starch present in the tortillas is available for hydrolysis by the digestive enzymes used in this method, because it includes a boiling/Termamyl treatment that converts native resistant granules in digestible starch. The AS contents determined in chia seed-added tortilla were lower than those determined in tortilla prepared with nixtamalised corn flour (66-76%) (Agama-Acevedo et al 2004) and in masa-made tortilla (67-76%) (AgamaAcevedo et al 2005). The AS value is important due to its ability to supply glucose to the blood after the meal consumption.…”

“…Significant increases were observed at all levels of substitution; however, 15% and 20% substitutions resulted in more evident changes. Chia seed flour has 20% higher protein level (Ayerza & Coates 1999) than that in the NCF (9.33%) (Agama- Acevedo et al 2004), which influenced this parameter. Figueroa et al (2001) observed a 3% protein content increase when the tortilla was fortified with 4% of defatted soy.…”

“…Rendón-Villalobos et al (2009) showed that the reduction in the moisture content in tortilla resulted from increased levels of substitution of flax seed flour with corn. According to Agama-Acevedo et al (2004) the moisture content in tortillas ranges between 35% and 50%, depending on the conditions during the nixtamalisation. The maize variety used may also influence the final product moisture, since blue corn tortillas exhibit a lower moisture content (34.7%) than white tortillas (38.3%) prepared under identical nixtamalisation conditions (Hernández-Uribe et al 2007).…”

Composition and characteristics of oil extracted from flaxseed-added corn tortilla

“…An increase in the protein content was observed with respect to the level of flaxseed added to the tortilla. Flaxseed flour has 21% higher protein level (Ramcharitar, Badrie, Mattfeldt-Bemam, Matsuo, & Ridley, 2005) than that in the NCF (9.33%) (Agama-Acevedo et al, 2004), which influenced this parameter. Figueroa et al (2001) observed 3% higher protein content when the tortilla was fortified with 4% of defatted soy.…”