Changes in Selected Nutrients and Microstructure of White Starch Quality Maize and Common Maize During Tortilla Preparation and Storage

Abstract

Raw maize, masa, and fresh and stored tortillas of white starch quality maize (Costen˜o) and common maize were analysed for chemical composition, dietary fibre, digestible (DS) and resistant (RS) starches. Changes in starch crystallinity and microstructure were also evaluated. Protein content was lower in masa and tortillas than in the original maize samples. Insoluble (IDF) and soluble (SDF) dietary fibres were higher in Costen˜o than in common maize, but stored tortillas showed the highest value in both samples. DS decreased and RS increased during tortillas storage, made with both starches. The development of RS explained the observed decrease in DS in masa (enthalpy of gelatinisation). Differential scanning calorimetry studies showed peak gelatinisation temperatures (T p ) of 75.1 and 69.4 C for Costen˜o and common maize respectively. Masa of common maize showed a second transition endotherm (T p , 108.9 C) which corresponded to amylose-lipid complexation. Tortillas with 5 and 10 days of storage showed an endothermic event at 53 and 55.7, and 54.5 and 59.9 C for Costen˜o and common maize respectively, due to starch retrogradation. These values were in accordance with the higher total RS contents recorded after prolonged storage. Microscopic structures for masa and fresh tortillas showed that the high temperature imposed on the masa and the influence of mechanical stress during tortillas making were great enough to disrupt starch granules. In general, structural changes were in agreement with changes in starch.

Improvement of home‐made maize tortilla with soybean

“…During tortilla production, the corn has been reported to lose approximately 1.5% of proteins (Figueroa et al. , 2001; Mora‐Escobedo et al. , 2004).…”

Effect of Different Corn Processing Techniques in the Nutritional Composition of Nixtamalized Corn Tortillas

“…It is known that MF industry prefers hard endosperm maize, as opposed to TM that favours white landraces [17]. Previous studies report PC, on dry basis, for MD tortillas of 7.58-15.63 g/100 g [10,[18][19][20][21]. These reports have different maize descriptions, suggesting phenotypes were different; but also is known PC varies according to endosperm hardness [17].…”

“…These may be due to different extent of lime removal on TM because around of 0.5% differences were reported between MD tortillas made on different maize varieties that were soaked for 12-16 h in a solution of lime 0.6-2% g/kg of grain [10,[19][20][21]; although, some authors report that differences are due to pericarp removal [24], suggesting there is no direct relationship between amount of lime used in the process and ash content.…”

Effect of baking method on some characteristics of starch in pound cake crumbs

“…This retrogradation was present in conventionally baked product from the second day of storage with a T p of 52.94 ± 0.25 °C and a Δ H of 0.105 ± 0.04 J g −1 until the eighth day of storage with a T p of 51.15 ± 0.07 °C and a Δ H of 0.314 ± 0.02 J g −1 showing a significant ( P > 0.05) increase in amylopectin retrogradation. Microwaved pound cake showed a lower degree of amylopectin retrogradation since the Δ H was only 0.025 ± 0.04 on the fourth day of storage and 0.107 ± 0.02 J g −1 on the eighth day, and this may be attributed to a lower moisture content of microwaved pound cake 33…”

“…The crystallisation that occurs in bread with staling does not imply a return to the same degree of order found in native starch granules. 33 Thus the crystallinity peaks present in conventionally baked pound cake after 2-8 days of storage might be associated with the RS3 content; the resistant retrograded starch formed during storage is reflected in the XRD pattern. 30…”