Wheat Flour Tortillas Research Articles

Improving the nutritional and textural properties of wheat flour tortillas

Wheat flour tortillas are the fastest growing segment of the North American baking industry. As this market grows, the search for healthier alternatives to traditional foods also increases. Nutritionally, flour tortillas are rich in carbohydrates that generate a high glycemic index subsequent to ingestion, demonstrating a behaviour similar to white bread. Hence, the formulation of more nutritious tortillas, with higher levels of protein, dietary fiber and antioxidants, appears to be promising. Although the number of publications concerning the nutritional improvement of flour tortillas is limited, attempts utilizing soybean, whole wheat, and triticale flours have been reported. Additionally, as different ingredients are added to traditional formulations, the texture is very likely to be affected, as are the shelf-life and other sensory properties. Among other additives, hydrocolloids have been reported to improve the textural qualities of bakery goods and flour tortillas. They comprise a number of water-soluble polysaccharides with varied chemical structures providing a range of functional properties that make them suitable to this application. This paper discusses the tortilla market, reviews research attempting to develop novel and nutritious products, and discusses the application of hydrocoloids as texture improvers.

Influence of added bean flour (Phaseolus vulgaris L.) on some physical and nutritional properties of wheat flour tortillas

Composite flours containing 15%, 25%, or 35% of small red, black, pinto, or navy bean flours (BF) and wheat were made into tortillas. Dough rheology, firmness, cohesiveness, rollability, and some physical properties of tortillas were negatively affected as BF concentration increased regardless of bean cultivar. Nutritionally, all bean tortillas had significantly higher levels of crude protein, total phenols, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS+) in vitro antioxidant activity (AA) and antinutritional compounds such as phytic acid (PA) and trypsin inhibitors (TI) than the wheat control. Tortillas to which 35% of small red, pinto and black BF was added had the highest levels of phenols, which were significantly correlated with both DPPH (r=0.99) and ABTS+ (r=0.99) AA. Compared to raw flours, PA and TI were reduced from 37.37% to 43.78% and from 50% to 66%, respectively, in the tortillas. Overall analysis indicated that tortillas with acceptable texture and improved nutritional profile were produced at 25% substitution.

Fortification of All-Purpose Wheat-Flour Tortillas with Calcium Lactate, Calcium Carbonate, or Calcium Citrate Is Acceptable

Fortification helps provide adequate nutrients for individuals not meeting daily needs. Foods may be fortified with calcium to assist individuals with lactose intolerance and others preferring not to consume traditional forms of dairy. This study examined the quality of all-purpose wheat-flour tortillas fortified with calcium lactate, calcium carbonate, or calcium citrate. These tortillas were compared to similarly prepared nonfortified flour tortillas (control) and commercial nonfortified flour tortillas. Calcium-fortified tortillas contained 114 mg elemental calcium per standard serving (48 g tortilla), an 8.6-fold increase compared to nonfortified tortillas. Moisture contents and rollabilities of all tortillas were similar. Consumers (N=87) evaluated each tortilla in duplicate using a hedonic scale and reported liking the appearance, texture, flavor, aftertaste, and overall acceptability of all tortillas. However, the appearance of control tortillas was preferred over commercial tortillas ( P<0.01), whereas the aftertaste of commercial tortillas or those fortified with calcium carbonate was preferred over the control ( P<0.05). Despite these differences, consumers were equally willing to purchase both fortified and nonfortified tortillas, suggesting that appearance and aftertaste may not influence willingness to purchase. Overall, this study shows that fortification of flour tortillas with various forms of calcium is a feasible alternative calcium source.

Rheological and Sensory Evaluation of Wheat Flour Tortillas During Storage

ABSTRACTTexture of wheat flour tortillas over 15 days at room temperature was evaluated using an expert sensory panel, consumer panels, subjective rollability test, large deformation rheological methods (i.e., bending, extensibility [1‐D and 2‐D], and puncture tests), and stress relaxation method. Most of the changes in texture occurred during the initial 8 days of storage, while texture of tortillas changed slowly thereafter. Differences in texture between fresh and 1‐day‐old tortillas were detected by many objective rheological methods but not by either sensory panel. The expert sensory panel observed a rapid decrease in tortilla extensibility and an increase in staleness between 1 and 8 days of storage and smaller changes in sensory scores after 8 days of storage. Most objective rheological parameters changed rapidly between 0 and 5 days, and slowly after 5 days of storage. Significant correlations and factor analysis reveal that changes occurring in flour tortillas during staling are estimated better by subjective rollability, sensory evaluation (expert and consumer panels), and 2‐dimensional extensibility test than by other methods. Hence, some rheological methods are useful to estimate sensory properties of flour tortillas.

Elimination of Listeria monocytogenes from Ready-to-Eat Turkey and Cheese Tortilla Wraps Using Ionizing Radiation

Listeria monocytogenes is a common postprocess contaminant on ready-to-eat foods including premade ready-to-eat sandwiches. One popular type of sandwich product is the tortilla wrap, which contains sliced luncheon meats and cheeses rolled within a flour tortilla. This study determined the radiation resistance of L. monocytogenes surface inoculated onto two types of commercially available wheat flour tortillas, processed cheese slices, and deli turkey meat. The D10-values for L. monocytogenes (the radiation dose required to inactivate 1 log of the pathogen) were 0.27 kGy when inoculated onto two flour tortilla types, 0.28 and 0.30 kGy when inoculated onto two types of sliced processed cheeses, and 0.58 and 0.65 kGy when inoculated onto two types of sliced deli turkey meat. When two types of tortilla wraps were assembled from the individual components and L. monocytogenes was inoculated into the interfaces between the individual components, the D10-values were 0.27 to 0.37 kGy in the tortilla and cheese interfaces, 0.33 to 0.41 kGy in the cheese and turkey interfaces, and 0.25 to 0.33 kGy in the turkey and tortilla interfaces. The ability of ionizing radiation to reduce pathogen levels on the complex tortilla, cheese, and luncheon meat product was limited by the higher radiation resistance of L. monocytogenes when inoculated onto the ready-to-eat turkey-meat component.

Potential of Triticale as a Substitute for Wheat in Flour Tortilla Production

ABSTRACTThe potential of triticale as a partial or total substitute for wheat in flour tortilla production was evaluated. Different mixtures of triticale and wheat flours were tested in a typical hot‐press formulation. Both grains yielded similar amounts of flour. Wheat flour contained 1.5% more crude protein, 1.6× more gluten, and produced stronger dough than triticale. Triticale flour significantly reduced optimum water absorption and mix time of blends. Flour tortillas with 100% triticale absorbed 8% less water and required 25% of the mix time of the control wheat flour tortilla. The yield of triticale tortillas was lower than the rest of the tortillas due to lower moisture content and water absorption. Triticale dough balls required less proofing and ruptured during hot pressing, thus producing defective tortillas. The 50:50 flour mixture produced doughs with acceptable rheological properties and good quality tortillas. Addition of 1% vital gluten to the 75:25 triticale‐wheat flour mix or 2% to the 100% triticale flour significantly increased water absorption and mix time and improved dough properties and tortilla yields. Textural studies indicated that increasing levels of triticale flour reduced the force required to rupture tortillas. For all tortilla systems, rupture force gradually increased, and extensibility decreased during seven days of storage at room temperature; the highest rate of change occurred during the first day. Sensory evaluation tests indicated that triticale could substitute for 50% of wheat flour without affecting texture, color, flavor, and overall acceptability of tortillas. For production of 100% triticale flour tortillas, at least 2% vital gluten had to be added to the formulation.

The Effects of Storage Temperature on the Staling of Wheat Flour Tortillas

Abstract Wheat flour tortillas (31·9% moisture) were stored at −60, −12, 0, 4, 22, and 35 °C to evaluate textural changes during staling. Subjective rollability and two-dimensional extensibility tests revealed that tortillas stored at ≥0 °C had increasing force, work and modulus of deformation values during storage. Tortillas stored at ≤−12 °C retained their fresh attributes over 25 days. Tortillas staled more as defined by rheological changes when stored at 22 °C than at 0, 4, or 35 °C. Optimum storage temperatures of wheat flour tortillas are ≤−12 °C while optimum staling temperatures are between 4 and 35 °C.

Objective Texture Measurements of Commercial Wheat Flour Tortillas

ABSTRACTTexture is a property of major importance in the evaluation of baked products. To determine a sample of commercial ranges for stretchability, rollability, firmness, and Kramer shear cell measurements for wheat flour tortillas using the TA‐XT2 texture analyzer, three separate sets of five tortilla brands purchased from stores in Manhattan, KS, were evaluated. Two brands had two formulations, regular and fat‐free. Significant differences (P &lt; 0.05) in stretchability, firmness, and Kramer shear cell occurred between regular and fat‐free tortillas of one tortilla brand. Significant differences (P &lt; 0.05) also were found among the sets of some tortilla brands. Kramer shear cell and stretchability measurements are recommended because Kramer shear cell measures the force combined with compression, shearing, and extrusion. Stretchability measurements were repeatable and are an important textural property of wheat flour tortillas. Ranges for textural properties for commercial wheat flour tortillas were determined, as well as the variability of the textural methods used.

Effect of Partial Waxy Wheat on Processing and Quality of Wheat Flour Tortillas

ABSTRACTThe processing and quality of wheat flour tortillas prepared with partial waxy and normal flour were evaluated. Control procedures and formula were utilized with water absorption varied to obtain machineable doughs. Amylose content was lower in most partial waxy compared with normal wheats. The type of wheat starch did not affect most dough properties or tortilla diameter. Tortilla height and opacity were adversely affected by the decreased amount of amylose in partial waxy wheats. Sufficient leavening reactions occurred early in baking (after 10 sec) to yield an opaque disk, but some baked tortillas lost opacity and become partially transparent after baking. Starch gelatinizes, disperses, and retrogrades concurrently with the leavening reaction during the short (&lt;30 sec) baking time. Amylose functionality during baking and cooling appears to be involved in the retention of air bubbles in tortillas.

Effects of Leavening Acids and Dough Temperature in Wheat Flour Tortillas

ABSTRACTFunctionality of four leavening acids (sodium aluminum phosphate [SALP], sodium aluminum sulfate [SAS], monocalcium phosphate [MCP] and sodium acid pyrophosphate [SAPP‐28]) was evaluated during processing of wheat flour tortillas. Formulas were optimized to yield opaque, large‐diameter tortillas with pH 5.9–6.1. Each leavening acid and sodium bicarbonate was first evaluated at 38°C and then evaluated in combination with fumaric acid at 34 and 38°C. Ionic and pH interactions of leavening salts adversely affected dough properties and resting time. Opacity and pH of tortillas prepared with MCP was lower than for other treatments. Higher dough temperature required more leavening acid and base to compensate for some of the loss of CO2 incurred during dough mixing and resting at 38°C. The addition of fumaric acid decreased the amount of leavening acid, the dough‐resting time and tortilla pH, and improved storage stability. Combinations of MCP, SALP (or SAS), and fumaric acid produced dough and tortillas with good qualities. Tortillas prepared using SALP (or SAS) and fumaric acid tended to be of better quality.

Effect of Infrared Baking on Wheat Flour Tortilla Characteristics

ABSTRACTA new and improved method for baking wheat flour tortillas was evaluated. The method was faster and reduced tortilla dehydration. The aim of the study was to evaluate the efficiency of the infrared baking method on rollability, puffing, layering, color (lightness), and texture (cutting force and tensile strength) characteristics of wheat tortillas formulated and formed by the traditional (hand‐rolled) and commercial (hot‐press) methods. These tortillas were also compared with traditional tortillas cooked on a hot griddle and commercial tortillas cooked in a three‐tier, gas‐fired oven. In the infrared radiation (IR) method, tortillas were baked for 17 or 19 sec by IR using black‐body radiation at a selected wavelength band and emission temperatures of 549 or 584°C. IR‐baked tortillas showed good characteristics of rollability, puffing, layering, color, and texture. The loss of moisture during baking of the tortillas formed by hot‐pressing and baked by IR was significantly lower than that of tortillas baked by traditional and commercial methods. X‐ray diffraction of tortillas prepared by the traditional process and baked by the IR method showed a pattern similar to that of homemade tortillas baked on a hot griddle. The average energy used by the IR oven was less than that used in the commercial method which, in turn, is more efficient than the traditional hot griddle method.

Vitamin A deficiency and low prevalence of anemia in Yaqui Indian children in northwest Mexico.

A study of 296 school-age Yaqui Indian children (6-10 y) was conducted in 26 rural communities. Vitamin A status was determined by retinol and carotenoid serum levels according to a method described previously (IVACG, 1982). Serum retinol and carotenoids in children were analyzed according to community size. Vitamin A intake was assessed in a sub-sample by means of a 24 h recall questionnaire. Serum retinol distribution showed that 6.3% of the children were below 10 microg/100 mL (0.35 micromol/L) and 40% were in the range of 10-20 microg/100 mL (0.35-0.70 micromol/L). Differences (p < 0.02) were found between small and large communities (Median, 95% CI): 19.2 (17.1, 20.9) microg/100 mL and 22.9 (20.3, 24.1) microg/100 mL. Serum carotenoid levels were significantly higher in large than in small and medium communities: 72 (68.2, 77.8) microg/100 mL versus 62.4 (53.3, 68.2) and 62.4 (55.7, 69.6) microg/100 mL, respectively. Food staples were wheat flour tortillas, pinto beans, corn tortillas, few animal products and scarce fresh vegetables. Mean vitamin A consumption was 244+/-29 microg RE (34.9% of the US RDA). Iron status showed that only 4 children were classified as anemic, with two of them having iron deficiency anemia. Iron deficient erythropoiesis was observed in 7.8% of the children and iron depletion only in 4.4%. The Yaqui diet seems to provide adequate amounts of iron but not of vitamin A or its precursors, which renders a vitamin A status of sub-clinical deficiency that could be considered a public health problem.

Microstructure of wheat flour tortillas: effects of soluble and insoluble fibres / Microestructura de tortillas de harina de trigo: éfectos de la adición de fibra soluble e insoluble

Soluble and insoluble fibres influenced both the quality and microstructure of dough and wheat flour tortillas. Doughs containing 8% soluble fibre had poor gluten development and extensive starch gelatinization during baking. This resulted in a tortilla with a dense, pasty crumb. Doughs containing 8% insoluble fibre had better gluten structures than those prepared using soluble fibres. Strands of insoluble fibre particles, however, physically disrupted the gluten network, causing the air bubbles to collapse, and decreased the shelf-stability of tortillas. It appears that soluble and insoluble fibres weaken the gluten matrix by different mechanisms.

Surveillance of fumonisins in UK maize‐based foods and other cereals

A survey has been carried out to determine the levels of fumonisins in a variety of maize‐based foods and cereals available in the UK. The fate of fumonisins during commercial processing of maize was also assessed at each stage of the process. Fumonisins were not detected in samples of barley, wheat, soya, oats, rice, corn syrup or oil, corn‐on‐the‐cob, corn‐fed chicken or wheat flour tortilla. Despite detectable fumonisin contamination in samples of the original maize, fumonisins were not detected in samples of the food products obtained from commercial maize processing. Low levels were detected in samples of tacos and in some foods containing corn‐based thickeners, such as instant semolina pudding and instant custard powder. Approximately 78% of corn snack samples contained fumonisins (11–220 μg/kg), while 24% of breakfast cereals contained total fumonisins at between 11 and 194 μg/kg. Although none of the ready‐made popcorn samples contained detectable levels of fumonisins, 46% of popping corn samples and microwaveable popcorn contained fumonisins at 14–784 μg/kg. The highest levels of fumonisins were detected in samples of polenta with concentrations ranging from 16 to 2124 μg/kg. Overall, fumonisins were detected in 26% (76) of the 291 retail samples analysed.

Microstructure Changes in Wheat Flour Tortillas During Baking

ABSTRACTThe texture of tortillas depends upon the retention of gases by the gluten matrix. Raw and hot‐pressed tortilla dough was dense, with few air cells. Intact starch granules were embedded in a gluten matrix. Hot‐pressing sealed the surface and edges. The tortilla passed through three tiers of a gas oven and expanded due to steam and carbon dioxide formation during baking. The edges and surface remained sealed, allowing the tortilla to expand; the center of the tortilla was split apart. Surface starch granules were dehydrated and ungelatinized throughout baking. The combined use of SEM and ESEM facilitated efforts to discern the internal structure.

LITERATURE ABSTRACTS

LITERATURE ABSTRACTS

Effect of Defatted Soybean and Soybean Isolate Fortification on the Nutritional, Physical, Chemical and Sensory Properties of Wheat Flour Tortillas

ABSTRACTWheat flour fortified with 11.1% defatted soybean meal (SBM) or 5.6% soybean isolate (SBI) was processed into flour tortillas. Fortified tortillas contained 35% more protein and twice as much lysine as the 100% wheat flour tortilla. Addition of SBM or SBI decreased dough elasticity but increased dough water absorption and the force required to stretch the dough. The SBM fortified tortilla had better texture (P &lt; 0.05) than the 100% wheat flour tortilla and similar flavor and color (P &gt; 0.05). Rats fed fortified tortillas gained three times as much weight and doubled the protein efficiency ratio (PER) when compared to rats fed wheat flour tortillas. The apparent biological and net protein utilization values of the fortified tortillas were similar (P &gt; 0.05) and higher (P &lt; 0.05) than the wheat flour tortilla. The SBI fortified tortilla had a higher apparent protein digestibility (P &lt; 0.05) than the 100% wheat flour and SBM fortified tortillas.