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1.
《Cereal Chemistry》2017,94(6):917-921
Neural tube defects occur at higher rates in Hispanic populations in the United States. Such populations would benefit from folic acid fortification of corn masa flour (CMF). This study evaluated folate stability in fortified CMFs and tortillas and tortilla chips made therefrom. There was no significant loss of folate during the six‐month shelf life of fortified tortilla CMF and tortilla chip CMF. There was a 13% loss (P < 0.05) of folate during tortilla baking and no loss during tortilla chip frying. Both tortillas and tortilla chips showed significant folate losses over the two‐month shelf life for these products, with a 17% loss in fortified tortillas and a 9% loss in tortilla chips. Folate in fortified CMFs, tortillas, and tortilla chips is relatively stable and comparable to the stability of folate in wheat flour and breads.  相似文献   

2.
Starch digestibility was evaluated in freshly prepared tortillas elaborated from masa obtained from different procedures (laboratory‐made masa, commercial masa, and nixtamalized corn flour) and from laboratory‐made masa with added commercial hydrocolloid, and stored for 24, 48, and 74 hr. Tortillas prepared with commercial masa had the highest available starch (AS) content and the commercial tortillas had the lowest, showing a decrease in AS content when storage time increased. Tortilla of commercial masa showed the lowest resistant starch (RS) content that agrees with the AS measured. However, tortilla of laboratory‐made masa presented the highest AS and RS contents. RS increased with storage time, a pattern that is related to the starch retrogradation phenomenon observed when retrograded resistant starch (RRS) was quantified. Commercial tortillas showed predicted glycemic index (pGI) values of 62–75% using a chewing/dialysis procedure (semi in vitro method). Index values were lower than those determined in vitro. The pGI of tortillas decreased, and the values were different depending on the method used to prepare the masa and tortilla. Commercial tortilla and tortilla of NCF had the lowest pGI. Therefore, the procedure to obtain masa and thereafter obtain tortillas influenced the starch digestibility of the product.  相似文献   

3.
Nixtamalization is the process of steeping dried corn in hot water with calcium hydroxide (lime) with subsequent removal of all or most of the pericarp through washing. The resulting product is called nixtamal. Approximately 60% of corn tortillas in Mexico are produced from nixtamal, with the remainder prepared from nixtamalized corn flour. Nixtamal was fortified with micronutrient premix containing iron, zinc, folic acid, niacin, riboflavin, and thiamin. Premix composition followed a proposed Mexican regulation for corn flour fortification, adjusted for moisture. Effects of premix on masa adhesiveness, hardness, and pH, as well as tortilla sensory properties, stretchability, rollability, and color were measured. Micronutrient levels were tested in the dry corn, nixtamal, masa, and tortillas. There were no significant differences in masa texture or pH, tortilla rollability, or consumer acceptance of tortillas when comparing unfortified control and fortified treatments. Added thiamin was almost entirely degraded during processing. Folic acid and riboflavin decreased 26 and 45%, respectively, through the masa‐tortilla manufacturing process. Niacin showed no significant loss. Despite processing losses, fortification resulted in significant nutrient increases compared with control tortillas. Folic acid increased 974%, riboflavin increased 300%, niacin increased 141%, iron increased 156%, and zinc increased 153% in fortified tortillas.  相似文献   

4.
Degradation of added folic acid and native folates in micronutrient‐fortified corn masa and tortillas was evaluated using masa prepared from either nixtamalized corn flour or fresh nixtamal. Variations in masa pH, masa holding time at an elevated temperature, and iron source failed to show significant differences in folate loss in corn flour masa prepared in the laboratory. Masa was subsequently prepared from fresh nixtamal in a commercial mill in Mexico, and fortified with one of two different micronutrient premixes containing iron, zinc, B‐vitamins, and either unencapsulated or lipid‐encapsulated folic acid. Folate loss in commercial masa increased significantly with prebake masa holding time for both premixes. Unencapsulated folic acid showed a 73% loss after 4 hr of holding, compared to 60% loss for encapsulated. The difference was statistically significant, indicating a protective effect from the lipid coating. No significant differences in folate levels were found between prebake masa and baked tortillas. Holding baked tortillas for up to 12 hr also had no effect on folate levels. Native folate showed no significant losses throughout the process. Results from the commercial tortilla mill indicate that most of the loss in added folic acid occurs during prebake holding of masa, possibly from microbial degradation.  相似文献   

5.
A high‐amylose, non‐floury corn, a floury corn, and a 1:1 blend were made into masa and then tortillas. The masa flour made with the high‐amylose corn had a greater amount of resistant starch (RS 28.8%) and a greater amount of total dietary fiber (TDF 42.1%) than that with the floury corn (RS 2.9%, TDF 9.6%), producing a high‐fiber tortilla. The masa was evaluated for pasting properties using a Rapid ViscoAnalyser (RVA). The high‐amylose masa slurry gelatinized little at 95°C. The floury masa had the greatest peak viscosity, whereas the 1:1 blend was intermediate in value. Sensory evaluations of the tortillas for the textural attributes showed the floury tortillas to be chewier, more rollable, and grittier than the high‐amylose tortillas, whereas the blend tortillas were intermediate for most attributes. The cutting force of the high‐amylose tortillas, measured on a texture analyzer, was very low; the blend and floury tortillas required more force. Chewiness was correlated to rollability (r = 0.99, P = 0.05). The %RS and %TDF were correlated to rollability (r = –0.99), and cutting force (r = 0.99). The floury and blend tortillas had firm textures expected of desirable tortillas, whereas the high‐amylose tortillas broke under little force, and would not roll. The high‐amylose tortillas had high amounts of RS and TDF but poor texture. The blend tortillas retained most floury tortilla textural properties, making them suitable products for consumer use.  相似文献   

6.
Texture 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 < 0.05) in stretchability, firmness, and Kramer shear cell occurred between regular and fat‐free tortillas of one tortilla brand. Significant differences (P < 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.  相似文献   

7.
Antistaling properties of a bacterial maltogenic amylase, sodium carboxymethylcellulose (CMC), and vital wheat gluten on quality of corn tortillas were evaluated during 14 days of storage. Amylopectin recrystallization was the driving force behind the staling of corn tortillas. Increasing levels of recrystallized amylopectin measured by differential scanning calorimetry (DSC) correlated significantly with increased tortilla stiffness (r = 0.43) and reduction in tortilla pliability (r = ‐0.42) during storage. Maltogenic amylase (275–1,650 activity units) made tortillas less stiff but did not preserve pliability and extensibility as effectively as CMC (0.25–0.5%). The combination of 825 MANU of maltogenic amylase (to interfere with intragranular amylopectin recrystallization) and 0.25% CMC (to create a more flexible intergranular matrix than retrograded amylose and amylopectin) produced less stiff, equally flexible, and less chewy tortillas than did 0.5% CMC. Vital wheat gluten was not as effective as CMC in preserving tortilla flexibility or as good as the maltogenic amylase in reducing stiffness. Further research is required to optimize the addition of maltogenic amylases in continuous processing lines that use fresh masa instead of nixtamalized corn flour (NCF) and to determine how these amylases interfere with amylopectin recrystallization.  相似文献   

8.
Instant masa flour finds extensive use in the food industry for making tortillas, taco shells, tamales, corn chips, and tortilla chips, and as an ingredient in extruded snacks. Due to lack of standard techniques for measuring masa functionality, processors and end‐users use masa flour particle‐size distribution and rheological characteristics in an attempt to predict its end use. In this study, a commercial masa flour sample was characterized by fractionating on the basis of particle size. Physicochemical and functional properties of masa flour fractions were investigated to establish structure‐composition and functionality relationships. It was observed that Rapid Visco Analyser (RVA) pasting profiles of flour fractions and textural properties of dough prepared on rehydration were related to particle size, yet, upon regrinding, RVA profiles did not change as markedly as expected. Differences in RVA measurements of the sized fractions could not be explained on the basis of hydration rate or total starch content. It was concluded that masa dough textural and RVA characteristics may be influenced by the status of starch polymer structures formed during nixtamalization.  相似文献   

9.
Refined wheat flours commercially produced by five different U.S. and Mexican wheat blends intended for tortilla production were tested for quality and then processed into tortillas through the hot‐press forming procedure. Tortilla‐making qualities of the flour samples were evaluated during dough handling, hot pressing, baking, and the first five days on the shelf at room temperature. The predominant variables that affected the flour tortilla performance were wet gluten content, alveograph W (220–303) and P/L (0.70–0.94) parameters, farinograph water absorption (57%) and stability (10.8–18.7 min), starch damage (5.43–6.71%), and size distribution curves (uniform particle distribution). Flours produced from a blend of Dark Northern Spring (80%) and Mexican Rayon (20%) wheat had the highest water absorption, and tortillas obtained from this blend showed the highest diameter and lowest thickness. The whitest and best textured tortillas were obtained from the flour milled from three hard types of Mexican wheat blend. A Mixolab profile was generated from the best tortilla flours, those produced by mills 3 and 4. The Mixolab profile showed that a good flour for hot‐press tortillas had a relatively lower absorption and short dough mix time compared with a bread flour and should have a significantly higher gluten compared with an all‐purpose flour. Compared with bread flour, the tortilla flour had higher retrogradation and viscosity values. The Mixolab profile proved to be a good preliminary test to evaluate flours for hot‐press tortillas.  相似文献   

10.
The 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.  相似文献   

11.
Wheat starches were isolated from three wheat flours. Two vital wheat glutens, one from a commercial source and another one isolated from straight-grade flour, were combined with wheat starches to form reconstituted flours with a protein level of 10%. Several characteristics of tortillas made with the hot-press method were measured. No significant difference (P < 0.05) occurred in texture of tortillas made with hard wheat gluten and soft wheat gluten. Wheat starches did not have any significant (P < 0.05) effect on tortilla stretchability or foldability. Analysis of variance confirmed that wheat starch and gluten had limited effects on tortilla texture. The possible reasons were that the solubles of wheat flour were not included, and the shortening in the tortilla formula interfered with the interaction of gluten and starch.  相似文献   

12.
The effects of raw and gelatinized sorghum and rice flours on the structure and texture of baked corn and tortilla chips were evaluated. Dry masa flour was hydrated into masa, sheeted, and cut. Corn chips were baked in an air-impingement oven, and tortilla chips were baked first in a three-tier oven and then in an air-impingement oven. Baked tortilla chips required significantly greater force to break and were less susceptible to breakage during handling than baked corn chips. Raw and gelatinized, normal and waxy rice and sorghum flours significantly changed the texture and structure of baked chips. Waxy rice and sorghum flours reduced peak force and work, increased chip thickness, and improved overall acceptability (as assessed by a taste panel), but waxy rice and sorghum chips were more fragile and had a greater number of large central air cells. Waxy rice was more beneficial than waxy sorghum flour. Gelatinization of waxy flours increased thickness of baked chips, whereas gelatinization of nonwaxy flours had no improvement over waxy flours alone. Gelatinization of sorghum flour significantly decreased the peak force and work values for baked tortilla chips when compared with the control chips. Gelatinized rice flour tortilla chips were not significantly different than the control chips but were significantly harder than the other baked tortilla chips. The complex interactions that occur in baked corn and baked tortilla chips suggest that each ingredient acts differently in the two products. Thus, each ingredient must be evaluated for specific products and processes.  相似文献   

13.
Wheat flour tortillas were made from flour streams of three wheat cultivars: Jagger hard red winter wheat, 4AT-9900 hard white winter wheat, and Ernie soft red winter wheat. Wheat samples were milled on a Miag experimental mill. Twelve flour streams and one straight-grade flour were obtained. Tortillas were made from each flour stream and the straightgrade flour by the hot-press method. Tortilla stretchability and foldability were evaluated by a texture analyzer and six panelists, respectively. Flour protein and water absorption affected tortilla texture. The foldability evaluated by panelists was positively correlated with flour protein content, farinograph water absorption, and damaged starch (P < 0.05). The 2BK and 3BK streams of hard wheat produced tortillas with strong stretchability and good foldability. Middling streams of hard wheat yielded tortillas with lighter color and less stretchability. Under the conditions tested in this study, soft wheat flours were not good for producing flour tortillas.  相似文献   

14.
Amylose content is closely related to wheat flour pasting or thermal properties, and thus affects final food qualities. Fourteen flour blends with amylose content ranges of <1 to 29% were used to study tortilla production and quality parameters. Reduced amylose contents decreased dough stickiness and pliability; low amylose doughs were also very smooth in appearance. Very low flour amylose content was associated with earlier tortilla puffing and poor machinability during baking, darker color, low opacity, larger diameters, and reduced flexibility after storage. Tortilla texture analysis indicated that lowering amylose content gave fresh tortillas higher extensibility; after three or more days storage, however, low amylose flours required more force to break the tortillas and the rupture distances became shorter. These results, as reflected in covariate analysis, were not significantly affected by the flour blend's protein content, swelling volume/power, SDS‐sedimentation volume, mixograph dough development time, or mixograph tolerance score. Based on our observation of an initial increase in extensibility with reduced‐amylose tortillas, adding 10–20% waxy flour into wild‐type flours should be ideal for restaurant (on‐site) tortilla production or circumstances where tortillas are consumed shortly (within a day) after production. The optimal flour amylose content for hot‐press wheat tortilla products is 24–26%.  相似文献   

15.
Wheat cultivars possessing quality attributes needed to produce optimum quality tortillas have not been identified. This study investigated the effect of variations in high‐molecular‐weight glutenin subunits encoded at the Glu‐1 loci (Glu‐A1, Glu‐B1, and Glu‐D1) on dough properties and tortilla quality. Flour protein profiles, dough texture, and tortilla physical quality attributes were evaluated. Deletion at Glu‐D1 resulted in reduced insoluble polymeric protein content of flour, reduced dough compression force, and large dough extensibility. These properties produced very large tortillas (181 mm diameter) compared with a control made with commercial tortilla wheat flour (161 mm). Presence of a 7 + 9 allelic pair at Glu‐B1 increased dough strength (largest compression force, reduced extensibility, and small‐diameter tortillas). Deletion at Glu‐A1 produced large tortillas (173 mm) but with unacceptable flexibility during storage (score <3.0 at day 16). In general, presence of 2* at Glu‐A1, in combination with 5 + 10 at Glu‐D1, produced small‐diameter tortillas that required large force to rupture (tough texture). Presence of 2 + 12 alleles instead of 5 + 10 at Glu‐D1 produced tortillas with a good compromise between diameter (>165 mm) and flexibility during storage (>3.0 at day 16). These allele combinations, along with deletion at Glu‐D1, show promise for tortilla wheat development.  相似文献   

16.
The corn tortilla plays an integral role in the Mexican diet and is an ideal vehicle for micronutrient fortification. Approximately 60% of corn tortillas in Mexico are produced from nixtamal, with the remainder prepared from masa flour. A process for continuous fortification of nixtamal tortillas was evaluated in two commercial mills in Mexico. A commercial powder dosifier was used to add micronutrient premix containing iron, zinc, folic acid, niacin, riboflavin, and thiamin to nixtamal (1 g/kg) as it was milled. After training and preliminary sampling, mills produced fortified tortillas unassisted for four weeks. Masa flow rates over a four‐day period were 10–12 kg/min in both plants. Premix flow from the dosifier showed good stability, with an average coefficient of variation of 1.6%. Initial results indicated consistency in the fortification process, with significantly increased variation during the four‐week production period. Fortified tortillas had significantly higher levels of all nutrients tested. Micronutrient losses were <11% in all cases except folic acid, which showed an 80% loss. Despite processing losses, fortification resulted in a nearly fivefold increase in folic acid compared with control tortillas. The new fortification process is technically viable and was well received by millers.  相似文献   

17.
To investigate the effects of mechanically damaged starch and flour particle size on the texture of fresh and stored flour tortillas, two commercial hard red winter wheat flour samples were reground four times using decreasing roll gaps. Tortillas were made with a modified hot‐press procedure. Texture characteristics were measured after tortillas were stored 2 hr (fresh tortilla), 2 days, and 4 days. Damaged starch and particle size significantly affected (P < 0.05) flour water absorption, dough extensibility and resistance, and dough viscosity. As damaged starch increased and particle size decreased, the flour tortillas became less stretchable, the maximum force of Kramer shear decreased, and firmness and rollability increased. The effects of damaged starch and particle size on stretchability and Kramer shear were greater in fresh tortillas than in stored tortillas and became smaller as the storage time increased. However, the effects of damaged starch and particle size on rollability and firmness were smaller in fresh tortillas than in stored tortillas but became greater as the storage time increased.  相似文献   

18.
The objective of this work was to study the formation of resistant starch (RS) in tortillas from an ecological nixtamalization process compared with the traditional nixtamalization process. The RS increased through all the steps of tortilla production. It was found that the increase of the RS corresponds mainly to the formation of RS5 (V‐amylose‐lipid complex), but in tortillas two major types of RS coexist: RS5 and RS3 (retrograded starch). In general, tortillas from the ecological nixtamalization process gave higher values of protein, lipids, total dietary fiber, insoluble fiber, soluble fiber, and RS compared with tortillas from the traditional nixtamalization process and commercial flour. The highest glycemic index (GI) occurred in the tortillas from commercial flour, whereas tortillas from 0.4% CaCO3 and 0.6% CaSO4 were classified as medium‐GI (GI 50–70). Tortillas from 0.6% CaCl2 had the lowest value of GI. The ecological nixtamalization processes caused significant differences in quality and nutritional properties of tortillas.  相似文献   

19.
Five white corn hybrids were processed (nixtamalized) using 10 different processing conditions; tortillas were prepared to establish relationships between corn composition, physical characteristics, and nixtamalization process or product properties. Corn hybrids were characterized by proximate analysis and by measuring Stenvert hardness, Wisconsin breakage, percent floaters, TADD overs, thousand‐kernel weight, and test weight. Corn characteristics were correlated with process and product variables (effluent dry matter loss and pH; nixtamal moisture and color; masa moisture, color, and texture; and tortilla moisture, color, and rollability). Process and product variables such as corn solid loss, nixtamal moisture, masa texture, and tortilla color were influenced not only by processing parameters (cook temperature, cook time, and steep time) but also depended on corn characteristics. Significant regression equations were developed for nixtamalization dry matter loss (P < 0.05, r2 = 0.79), nixtamal moisture (P < 0.05, r2 = 0.78), masa gumminess (P < 0.05, r2 = 0.78), tortilla texture (P < 0.05, r2 = 0.77), tortilla moisture (P < 0.05, r2 = 0.80), tortilla calcium (P < 0.05, r2 = 0.93), and tortilla color a value (P < 0.05, r2 = 0.87).  相似文献   

20.
《Cereal Chemistry》2017,94(2):277-283
Sorghum bran (SB) is a good source of phenolic compounds with high antioxidant capacity that increases the antioxidant activity (AOX) of tortillas prepared with extruded nixtamalized corn flour. The objective of this research was to study the effects of bran addition (0, 5, or 10%) before (ENBESB) or after (ENAFSB) extrusion, in the features and composition of baked tortillas in terms of total phenolic compounds (TPC), AOX, color (L , a , b, hue, chroma, and E value), and tortilla firmness. It was possible to retain more than 81.8 and 89.9% of TPC and AOX, respectively, in ENBESB‐10% flour. Tortillas prepared with ENAFSB‐10% flour retained more than 92 and 76% of TPC and AOX, respectively, compared with ENBESB. However, tortillas elaborated with ENAFSB flour showed a higher firmness and lower flexibility than counterparts produced from ENBESB. The use of extrusion to produce nixtamalized corn flours and the strategy of adding the SB to the corn meal before extrusion were essential to retain TPC and AOX and, additionally, to enhance texture of tortillas.  相似文献   

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