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Maize (Zea mays) was a fundamental part of the diet for the Classic period Maya (ca. 250–900 CE) and other Mesoamerican societies. Nixtamalization, the process whereby maize is cooked in an alkaline solution, is important as it enhances the nutritional value of maize, among other reasons. However, documenting this process in the archaeological record is not straightforward. A microbotanical study of residues collected from ceramic vessels and grinding stones from Late Classic (ca. 600–900 CE) contexts at the Lowland Maya site of La Corona (Peten, Guatemala), revealed the presence of starch spherulites. Their authenticity was confirmed by polarized microscopy and Scanning Electron Microscope (SEM) imaging combined with iodine staining. We argue that nixtamalization as a cooking technique was occurring at La Corona during the 7th and 8th centuries CE. We present evidence from ceremonial contexts, specifically burial and feasting/commensal events. This is the earliest evidence of lime-treated maize in the Maya area recovered directly from ceramic vessels linked to preparation and/or consumption of food. [ABSTRACT FROM AUTHOR]

Nixtamalization is a process used in the production of tortillas. This process offers many advantages, such as improving the rheological, nutritional, and textural properties of the masa. This process is carried out under different steps which affect the quality of the final product such as the cooking and soaking conditions and the quantity of ash. In addition, the fragility of the masa makes the tortillas brittle. The present work was initiated with the aim of determining the nixtamalization conditions that would improve the textural, rheological, and nutritional properties of masa. The response surface methodology, using the central composite design was applied to three factors including the ash content and cooking and soaking times, and the responses evaluated were the adhesiveness, cohesion, final viscosity, and gelatinization temperature of masa obtained from two varieties of maize (Atp-Y and Kassaï). The optimums masa flours obtained were characterized using standard methods. Results showed that, the masa made from Kassaï variety needed a cooking time of 51.21 min and soaking time of 16.10 h in the presence of 0.80 g of ash. For the Atp-Y variety, the conditions included a cooking time of 49.17 min and a soaking time of 23.4 h in the presence of 0.24 g of ash. The responses obtained showed an adhesiveness of 0.10 kg/f and 0.05 kg/f, cohesion of 1.08 kg/f and 1.23 kg/f, final viscosity of 1504.80 cP and 1328.30 cP, gelatinization temperature 73.50 °C and 71.50 °C, and finally retrogradation 435.50 cP and 316 cP, respectively, for Kassaï and Atp-Y. Chemical characterization of the optimum masa showed that the white masa had a high protein content (10.50%), carbohydrates (71.70%), and fiber (2%) while the yellow masa presented the highest lipid content (5.47%). These finding demonstrated that Kassaï (white) maize‐masa flour obtained in optimal conditions can be recommended for the production of good quality tortillas because tortillas made with this masa are less crumbly and more elastic. [ABSTRACT FROM AUTHOR]

Corn plays a fundamental role in the diet of diverse cultures and has nutritional benefits, being a rich source of carbohydrates, fiber, vitamins and minerals, in addition to containing antioxidants with health properties. In places like Peru and Latin America, where corn production and commercialization are significant for various culinary uses (patasca, tamales, humitas, among others), there is a need to industrialize the peeling process to speed up production and advance technologically, overcoming the manual method disadvantages. Therefore, this research aimed to design and manufacture a precooked corn peeling machine based on the friction of corn with a rough surface, through the incorporation of adjustable paddles and constant flow of clean water to remove impurities, in order to obtain larger quantities of peeled corn production, being able to supply the local market. To design the machine, the VDI 2221 methodology was applied, which included the creation of a list of requirements and a function structure. The state of the art corn shelling technology was evaluated using techniques such as the black box, white box and morphological matrix approach to analyze solution options. Design aspects such as shaft diameter, vane strength, cylinder volume, drive belt selection, number of belts and bearing choice were considered. Finally, manufacturing materials were selected. The design of the corn peeling machine was obtained. In addition, data on peeling speed and amount of corn peeling were found through washing tests using different corn grains. It was found that the optimum time is 7 minutes, which considerably improves the artisanal method, which requires more time and physical effort by the producer and for the manufacture of the machine, non-polluting materials will be used for corn, such as stainless steel AISI 304, which does not corrode in contact with water. It was concluded that, with the design of a corn pericarp peeling machine gave a 96.3% efficiency in the peeling process, which shows that it is possible to peel corn for health care, also for use in different gastronomic dishes. In addition, the manufacture of the machine is possible since the materials used can be easily found in the local market and have low costs. [ABSTRACT FROM AUTHOR]

Nejayote, the wastewater from the nixtamalization of maize, is difficult to biodegrade due to its abundant calcium content; low levels of nitrogen, phosphorus, and easily assimilable sugars; elevated pH; and high chemical oxygen demand (COD). The aim of the present study was to isolate microorganisms capable of utilizing filtered nejayote (NEM) as the only source of carbon for growth and to test the best microorganism for the bioremediation of this wastewater by lowering the level of pH and COD. Of the 15 strains of microorganisms tested, Rhodotorula mucilaginosa LCRE was chosen and identified using molecular techniques. Subsequently, its growth kinetics were characterized during cultivation in unenriched NEM (control) and NEM enriched with nitrogen and phosphorus salts. R. mucilaginosa LCRE showed a greater growth (6.9 ≤ X ≤ 8.9 g L−1), biomass yield (0.33 ≤ YX/S ≤ 0.39 g g−1), and specific growth rate (0.748 ≤ µ ≤ 0.80 day−1) in the enriched versus control NEM (X = 6.55 g L−1, YX/S = 0.28 g g−1, and µ = 0.59 day−1). However, a higher total sugar consumption (94.98%), better COD removal efficiency (75.5%), and greater overall COD removal rate (1.73 g L−1 h−1) were found in the control NEM. Hence, R. mucilaginosa LCRE holds promise for the efficient bioremediation of nejayote without costly pretreatments or nutrient supplementation. [ABSTRACT FROM AUTHOR]

Background and Objectives: While alkaline nixtamalization has historically been used for corn, this process may have application in other cereals. Drawbacks to wider use include the lengthy steep time, as well as the volume of alkaline wastewater produced. This study evaluated a novel, waste‐effluent‐free nixtamalization process for oat (Avena sativa) masa, and compared properties of oat masa and tortillas prepared with 1%, 1.5%, and 2% lime, with and without steeping. Findings: A minimal‐water‐addition, 45‐min simmering process, without steeping, was effluent‐free, and produced oat tortillas comparable to those produced using a traditional overnight steep. The pH increased significantly with increasing lime content (r =.982). Consumer overall‐liking scores did not significantly differ across treatments, though appearance scores were significantly higher for 2% lime samples (p <.05), which were significantly darker and more yellow, based on L* and b* values. Masa adhesiveness means ranged from 1.49 to 1.52 N, with no significant differences between the no‐steep treatments. Higher lime addition (1.5%–2%) in the no‐steep process significantly improved tortilla flexibility, based on extensibility and rollability scores, though tortilla rupture force did not vary significantly across treatments. Tortilla rollability scores at 3‐days were lowest (x̅ $\mathop{{\rm{x}}}\limits^{̅}$ = 1.1 + 0.31, indicating less cracking) for the 1.5%–2% lime no‐steep treatments, which were significantly better than the steeped treatment (x̅ $\mathop{{\rm{x}}}\limits^{̅}$ = 3.7 + 0.48). Consumers rated the steeped sample as significantly less flexible. B‐vitamins were negatively impacted by increasing lime, while calcium increased significantly with lime addition. Conclusions: The no‐steep, effluent‐free nixtamalization process produced oat tortillas with good masa and tortilla texture, which were not significantly different in consumer liking than tortillas produced via a traditional process. Significance and Novelty: This research suggests nixtamalization can be applied to other grains in a shorter, environmentally friendly process, with broader commercial applicability. [ABSTRACT FROM AUTHOR]

Corn is one of the major cereal crops produced worldwide. It has recently been used for the production of healthy, gluten-free, and high-fiber bread. However, corn is highly susceptible to aflatoxin (AF) contamination, representing a serious health concern, as aflatoxins (AFs) are carcinogenic to humans. In this study, the cornbread-making process using the unit operations nixtamalization with different calcium sources, fermentation, and baking was evaluated as a method for AF detoxification at 2 different contamination levels. The nixtamalized cornbread-making process with tequesquite (an alkaline mineral complex) showed an average reduction of 77.12% in AF content from 550.33 µg/kg to 114.50 µg/kg. For the second contamination level (2208.33 µg/kg), the cornbread-making process with the nixtamalization using calcium hydroxide was the most effective, resulting in an average reduction in AF content of 83.58% (362.50 µg/kg). At both levels, the control cornbread samples were significantly different (p < 0.05) from others, reaching an average reduction of 55.43% for level 1 and 58.23% for level 2 (125.73 and 522.33 µg/kg respectively). Additionally, when the AF extracts of cornbread samples were subjected to acidic pH values (pH = 3), an additional reduction in AF content was achieved. The chemical structure of AFs did transform to irreversible forms, with only non-fluorescent derivatives remaining. Our results demonstrate that despite the high contamination of corn used as a raw material, the cornbread-making process including nixtamalization as a unit operation was effective in reducing AF content by more than 80%. [ABSTRACT FROM AUTHOR]

Maize is a staple food for most South Africans, yet maize meal (corn flour) does not provide enough sustenance, contributing to food insecurity and malnutrition. Improving the nutrient content of maize and maize-based products could benefit communities where maize is the staple food. This study aimed to determine the relationship and frequency of consuming maize products, side dishes and snacks preferred by consumers of different provinces of origin and language speakers. One hundred respondents participated in a survey after tasting nixtamalized maize products in a sensory laboratory. The results showed that Pap in the forms of soft (58%), stiff (73%), phutu [crumbly] (68%), or porridge (55%) was regularly or frequently included in meals. Pap was eaten daily by 11.2% for breakfast, 17.2% for lunch and 23.2% of respondents for supper. Soft (36.1%), stiff (56.6%) and phutu (43.0%) were preferred for supper, while porridge (73.7%) was preferred for breakfast. Braaied meat (40.2%) and meat stew or soup (40.0%) were enjoyed as side dishes. The language that participants spoke influenced the food items or side dishes more than the province of origin. The study showed the maize consumption habits of South African consumers to inform future product development or nutrition intervention programs. [ABSTRACT FROM AUTHOR]

Coffee is a widely consumed beverage known for its stimulating and cognitive effects. However, the undesirable effects attributed to its consumption have led to an increased interest in coffee substitutes. Coffee substitutes made from roasted plant materials are gaining popularity due to their distinct flavor profiles and potential health benefits. This study compared the nutritional properties of roasted nixtamalized and nonnixtamalized IPB var 6 corn, a corn variety known for its higher protein quality, tryptophan, and lysine content, as a coffee substitute. Twelve treatments were analyzed to evaluate the effects of nixtamalization on the proximate and mineral content of corn. Based on the results obtained from this study, significantly higher moisture, ash and iron content was obtained from nixtamalized treatments. Although significantly higher crude fiber, crude fat, zinc, and potassium content were observed from non-nixtamalized treatments. The differences in the roasting time and temperature in terms of the nutritional properties of the roasted IPB var 6 corn treatments were also determined. At increased roasting temperature and time, the ash, and mineral content were observed to be higher. While varying effects of different roasting time and temperature to the moisture, crude fat, crude protein, and crude fiber were also observed. The non-nixtamalized roasted at 240°C for 45 min obtained the highest crude fiber, zinc, and potassium content. While Treatment 12 (nixtamalized; 240°C for 45 min) obtained the highest ash, moisture, nitrogen free extract, and iron content. [ABSTRACT FROM AUTHOR]

Quality protein maize (QPM) blended with soybean flour in developing countries calls for investigations of new adoptable maize-based food varieties to tackle malnutrition. This study aimed to optimize the formulation of nixtamalized QPM (NQPM) tortillas enriched with soybean flour in terms of physicochemical, nutritional, and sensory properties. Mixture, d-optimal design was used to obtain and analyze the different formulations of the NQPM with soybean flour. The results showed that the incorporation of soybean flour in NQPM significantly (P

Nejayote, the wastewater from the nixtamalization of maize, is difficult to biodegrade due to its abundant calcium content; low levels of nitrogen, phosphorus, and easily assimilable sugars; elevated pH; and high chemical oxygen demand (COD). The aim of the present study was to isolate microorganisms capable of utilizing filtered nejayote (NEM) as the only source of carbon for growth and to test the best microorganism for the bioremediation of this wastewater by lowering the level of pH and COD. Of the 15 strains of microorganisms tested, Rhodotorula mucilaginosa LCRE was chosen and identified using molecular techniques. Subsequently, its growth kinetics were characterized during cultivation in unenriched NEM (control) and NEM enriched with nitrogen and phosphorus salts. R. mucilaginosa LCRE showed a greater growth (6.9 ≤ X ≤ 8.9 g L−1), biomass yield (0.33 ≤ YX/S ≤ 0.39 g g−1), and specific growth rate (0.748 ≤ µ ≤ 0.80 day−1) in the enriched versus control NEM (X = 6.55 g L−1, YX/S = 0.28 g g−1, and µ = 0.59 day−1). However, a higher total sugar consumption (94.98%), better COD removal efficiency (75.5%), and greater overall COD removal rate (1.73 g L−1 h−1) were found in the control NEM. Hence, R. mucilaginosa LCRE holds promise for the efficient bioremediation of nejayote without costly pretreatments or nutrient supplementation.

Poor energy and nutrient-dense complementary food for infants have resulted in malnutrition and poor growth. Some processes are known to improve the nutritional value while reducing the antinutrient factors in food formulations. Maize-soybean-based composite flours from nixtamalized maize and heat-treated soybean were used to formulate six composite flours (CFs). The proximate composition, mineral content, antinutritional effect, mineral molar ratios, and mycotoxin level were investigated. The nixtamalization of maize and the heat treatment of soybean substantially improved the nutritional properties of the CFs. The pH value varied with the nixtamalization process, from 6.82 ± 0.7 to 9.32 ± 0.4. The energy content of the complementary foods was in the range of 354.77 ± 3.2 to 429.56 ± 4 kcal, meeting the minimum standard set for a cereal-based CF, which is 400 kcal. The protein values of the CFs (9.48 ± 0.3 to 13.92 ± 1.92%) on a dry weight basis were slightly below 15% of the recommended levels set by Codex. The antinutrient levels were reduced with nixtamalization and heat treatment. The molar ratio of phytate to minerals (calcium, zinc, and magnesium) was lower than the reported critical value, except for phytate to iron, where only whole maize, nixtamalized maize, and composite flour 3 (CF3) had a molar ratio that exceeded the reported critical value of 1. Although all composite flours were contaminated with mycotoxin, aflatoxin content in CFs ranged from 1.35 ± 0.67 to 13.8 ± 0.29 g/kg and from 0.3 ± 0.07 to 0.63 ± 0.015 mg/kg for fumonisin. Only the control and CFs made from the untreated maize did not meet the EU regulatory threshold (4.0 g/kg) for total aflatoxins and total fumonisin (4 mg/kg). The soybeans were not contaminated with the mycotoxins. The composite flour 5 (Composite flour 25% HS + 75% NixM) can be considered the best composite flour with regard to its nutritional properties, mineral, antinutrient, and mycotoxin content. These findings have shown that nixtamalization and heat treatment can improve the nutritional properties and food safety of composite flours.

Nixtamalized corn flour (NCF) has gained favor worldwide due to the growing popularity of Mexican cuisine. This research evaluates the effect of the amount of calcium hydroxide (Ca(OH)2) employed during the nixtamalization on the water‐adsorption, thermodynamic, and flow properties of NCF. In addition, NCF pasting and thermal properties were evaluated to relate bulk‐powder properties to wet‐dispersion conditions. Ca(OH)2 amounts of 1.5 and 2.0% induced higher ash and calcium content as well as lower fat and protein content. Also, pasting properties and gelatinization enthalpy (ΔHgel) values, in addition to yellowish NCF, were related to Ca(OH)2 concentration. With the independence of the Ca(OH)2 amounts employed, no important differences in the equilibrium's moisture content, as well as a negligible effect of temperature on adsorption behavior, were observed. For prepared NCF, the moisture content corresponding to minimum integral entropy was not observed within the range of the aw analyzed; thus, GAB parameters are more reliable for suggesting the storage conditions. NCF with a low amount of Ca(OH)2 exhibited higher values of mean caking strength (≈1.81 N) and cohesiveness index (≈13.99 × 10−5 N m g−1), in addition to higher resistance to flow. Therefore, the amount of Ca(OH)2 positively influenced flow properties, whereas wet‐dispersion properties such as lower maximal peak viscosity and ΔHgel values were obtained. Practical applications: This study contributes useful information to the manufacturers of NCF concerning the amount of Ca(OH)2 needed to obtain NCF with desirable physical properties while attempting to affect thermal and pasting properties to a lesser extent. In addition, this study characterizes and provides the adequate amount of Ca(OH)2 employed the during the nixtamalization process to improve the flowability of NCF in industry during handling. Finally, the absence of a moisture content corresponding to minimum integral‐adsorption entropy provides clarification for NCF producers regarding the long‐term storage stability of NCF. [ABSTRACT FROM AUTHOR]

Nejayote and pericarp derived from nixtamalization are an environmental problem. Therefore, there is research interest in using these residues as new compostable and environmentally friendly materials. This work aimed to create, characterize (color, thickness, water solubility, water adsorption capacity, microstructure, and degradability), and apply biodegradable films using residues of nejayote and pericarp of nixtamalized popcorn. Three types of films were compared, pericarp (P), nejayote–pericarp (NP), and nejayote (N), and were applied to avocado stored at room temperature. Results showed that the P film was the best because it was significantly (p < 0.05) more transparent (L = 94.75 ± 2.21) and thicker (0.27 ± 0.02 mm). It had higher water adsorption capacity (162.60 ± 14.05%) and higher elastic modulus and toughness (0.004 ± 0.001 MPa, 2.25 ± 0.25 J/m3) values than the N and NP films; in addition, its microstructure showed a roughness value (Ra) of 6.59 ± 0.57 nm that was intermediate compared to other films. Moreover, the P coating slowed down the maturing process of avocado and showed a visual effect against fungal infection. All films were generally soft and had a degradation time between 11 and 12 days. The novelty of this study is to provide the alternative of using nejayote and pericarp in a film that is compostable and maintains the lifespan of avocados. [ABSTRACT FROM AUTHOR]

People are focusing more on gluten free food products with minimal production costs. Maize is one of the major cereal crops and provides up to 30 per cent of food calories to 4.5 billion people in the world. Maize was the first plant cultivated by farmers 7000–10,000 years ago in Mexico and later spread to various parts of the world. Maize is generally classified according to its colour, which ranges from white to yellow to red to black. Another major categorization is based on the size and composition of the endosperm containing an appreciable amount of carbohydrates (66.2%), lipids (3.6%), proteins (11.1%) and vitamins and minerals (3.6%) along with fibres (2.7%). Unfortunately, maize is deficient in two major amino acids, namely tryptophan and lysine and also minerals like iron and zinc and vitamin B12. Due to a good nutritional profile, a high proportion of maize grains is processed industrially for transforming into value-added products by three basic methods:- wet milling, dry milling and nixtamalization that enhance shelf stability of the product by preventing the hydrolysis of lipids. This review hopes to facilitate the feasibility of maize incorporation in various food products prepared from other cereal crops and its impact on quality and shelf life with a prime objective to spread awareness regarding nutritional qualities as an alternative to wheat or rice. [ABSTRACT FROM AUTHOR]

The processes to obtain value-added products from brewers' spent grain, a contaminant industrial waste, require alkaline non-ecofriendly pre-treatments. The arabinoxylans from brewers' spent grain were extracted by nixtamalization evaluating the extraction procedure, antioxidant capacity and molecular characteristics. The best arabinoxylans yields were those extracted with CaO at 100 °C and 25 °C (6.43% and 3.37%, respectively). The antioxidant capacity by 2,2-diphenyl-1-picrylhydrazyl assay of the arabinoxylans after thermal treatment and additional arabinoxylans after thermal treatment proteolysis were 434 and 118 mg TE/g, while by 2,20′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt assay the value was similar (380 μmol TE/g). The intrinsic viscosities and viscosimetric molecular weights were 69 mL/g and 13 kDa for arabinoxylans after thermal treatment, and 15 mL/g and 1.6 kDa for arabinoxylans after thermal treatment proteolysis, respectively. The protein and lignin contents were 3.1% and 6.4% for arabinoxylans after thermal treatment and, 0.9% and 4.6% for arabinoxylans after thermal treatment proteolysis, while their arabinose: xylose ratios were 0.39 and 0.36, with ferulic acid contents of 0.63 and 0.14 mg/g, respectively. Both products of arabinoxylans were molecularly identical by Fourier transform infra-red. Although the purity of the extracted arabinoxylans was improved with proteolysis, their intrinsic viscosity and viscosimetric molecular weight were affected. The extraction of arabinoxylans from brewers' spent grain by CaO nixtamalization alone or after additional proteolysis was successful to obtain purity and good antioxidant capacity. [ABSTRACT FROM AUTHOR]

Nejayote is recognized as the main by-product resulting from the nixtamalization process of maize kernels, which is categorized as an alkaline residue with a chemical composition based on carbohydrates (37.8–55.7%), fiber (22.8–25.5%), protein (4.9–7.4%), and lipids (0.4–1.5%). In addition, Nejayote has an extensive content of simple (e.g., phenolic acids) and complex phenolic compounds (e.g., anthocyanins), which are responsible for the pigmentation and antioxidant activity of maize; therefore, there is a need of their identification depending on the type of maize. The current research has focused on the efficient extraction and identification of the phenolic acids contained in Nejayote after the processing of different types of maize. The target of this work was to fractionate Nejayote from white (NWM), red (NRM), and purple maize (NPM), using three different membranes, such as microfiltration (MF with a pore size of 1 μm) and ultrafiltration (UF100 and UF1 with a molecular weight cut-off of 100 kDa and 1 kDa, respectively), which were strategically applied to extract phenolic acids while retaining other molecules. Such a membrane system exhibited a retention in the first stage of almost all carbohydrates (MF-Retentate: ca. 12–19 g GE/L), while second stage (UF100-Permeate) a concentration of phenolic components was recovered ranging from 768 to 800 mg GAE/L. Finally, in the third stage (UF1-Permeate), 14 phenolic acids were identified, including ferulic and p-coumaric acids, derived from caffeic and ferulic acids, along with other molecules (e.g., glucose and fructose).

Abstract Nixtamalization, which means cooking maize in alkaline water, is the central technique for the culinary use of maize in Mexico and Central America. Without this procedure, relying on maize as the basic starch staple is inadequate because of nutriment deficiencies. Mexico has more than 50 principal racial types of maize, and these differ in grain qualities that can require the adjustment of the nixtamalization process. Properties such as hardness and grain composition influence nixtamalization because they are related to the absorption of water that occurs during cooking and steeping. Some maize preparations, like tortillas and tostadas, can also require the adjustment of nixtamalization to obtain a high-quality foodstuff. We studied how women in three regions of the state of Chiapas, which differ in the prevalent maize race available, prepare their nixtamal and whether they make changes according to the type of food they prepare. Interviews of 30 women follow the measure of relevant variables when the women prepared nixtamal. We found that nixtamalization is adjusted for different grain hardnesses and for environmental conditions. Variations were found in the cooking time of the nixtamal, in the amount of time the nixtamal was steeped, and in a special process of double boiling of the nixtamal performed by some women for tostadas. Women that specialize in production for the market have developed variations preferred by consumers. As practiced by women in Chiapas, nixtamalization is a flexible technique that is adjusted for maize type and for food preparations.

Nixtamalization is usually performed on grains by cooking in an alkaline solution to improve the final product characteristics. White bitter lupin (Lupinus albus) seeds were nixtamalized at various concentrations of calcium hydroxide in the range of 0.16–3.33% at 50, 70, and 90°C for 35 min and steeped for 0, 8, 16, and 24 h, and the moisture uptake was determined to model seed hydration kinetics. Moisture uptake increased with increasing nixtamalization temperature regardless of calcium hydroxide concentration. The Page and Weibull models adequately described white bitter lupin hydration kinetics during nixtamalization. Model parameters Kp (Page model) and α (Weibull model) ranged from 80.2 to 410.03 and from 88.21 and 93.96, respectively, for nixtamalization at different calcium hydroxide concentrations, and from 58.55 to 662.88 and from 68.74 and 132.99, respectively, for nixtamalization at different temperatures. The alkaloid content of raw lupin flour was 1.08 g/100 g and it gradually decreased as a result of nixtamalization in increasingly concentrated calcium hydroxide solutions and higher temperatures. The cracks were visible in the microstructure of nixtamalized seed coats. Their number and size increased with the increase of processing temperature, calcium hydroxide concentration, and steeping duration. Overall, the presented results may be useful in optimizing the industrial nixtamalization of lupin seeds and increasing the possibility of their use as a valuable food ingredient. [ABSTRACT FROM AUTHOR]

Nixtamalized products are very appreciated in México and the world; however, the traditional nixtamalization process (TNP) is highly polluting. Extrusion nixtamalization process (ENP) is an alternative method; however, much research reported high starch damage by ENP that affects the rheology, crystallinity, and general quality of nixtamalized products. This work studies the structural changes of cornstarch exposed to ENP under controlled conditions to produce corn flour, masa, and tortilla. The results of ENP and TNP showed significant differences (p

The objective of this study was to fabricate a solar oven for nixtamalization of maize endemic to Michoacán, Mexico, and then evaluate its performance. Based on the geometry of compound parabolic concentrators. this model oven is innovative in both its design and construction materials. It was designed with dimensions to nixtamalize an amount of maize sufficient to satisfy the needs of a family of four. Results include experimental data for three types of maize: white, yellow, and black. Thermal performance was better than that of other solar devices with similar characteristics. During the cooking process, the oven achieved a standard cooking power of 77.5 W, with no need for reorientation. Cooking times varied for the different kinds of maize studied, but cooking black maize took approximately 3 h under clear skies, indicating that the oven has good efficiency. Future studies will determine nixtamalization times for other endemic varieties of maize in Michoacan.

Nejayote and pericarp derived from nixtamalization are an environmental problem. Therefore, there is research interest in using these residues as new compostable and environmentally friendly materials. This work aimed to create, characterize (color, thickness, water solubility, water adsorption capacity, microstructure, and degradability), and apply biodegradable films using residues of nejayote and pericarp of nixtamalized popcorn. Three types of films were compared, pericarp (P), nejayote–pericarp (NP), and nejayote (N), and were applied to avocado stored at room temperature. Results showed that the P film was the best because it was significantly (p < 0.05) more transparent (L = 94.75 ± 2.21) and thicker (0.27 ± 0.02 mm). It had higher water adsorption capacity (162.60 ± 14.05%) and higher elastic modulus and toughness (0.004 ± 0.001 MPa, 2.25 ± 0.25 J/m3) values than the N and NP films; in addition, its microstructure showed a roughness value (Ra) of 6.59 ± 0.57 nm that was intermediate compared to other films. Moreover, the P coating slowed down the maturing process of avocado and showed a visual effect against fungal infection. All films were generally soft and had a degradation time between 11 and 12 days. The novelty of this study is to provide the alternative of using nejayote and pericarp in a film that is compostable and maintains the lifespan of avocados.

Pearl millet (Pennisetum glaucum), a drought tolerant crop belonging to the family Poaceae is an important type of millet. It is a sturdy plant that can sustain adverse growing conditions. It is rich in vitamins, minerals, oil and phytochemicals. The phytates or phytic acid present acts as antinutritional factor which bind to the proteins and minerals thereby reducing the digestibility and bioavailability of the proteins, carbohydrates and minerals. In the following study, nixtamalization, a process widely used for the treatment of maize, is being used on the millet to lower the antinutritional properties of the millet. The grain was cooked at 95°C with varying lime concent ration (0.5%, 1.0%, 1.5%, 2.0%) while keeping the cooking time (30 min) and steeping time (2 hours) constant. Product (crisp fried dough wafers) was made from the milled nixtamalized flour and different physio-chemical parameters and acrylamide content of the crisp fried dough wafer was analysed. The product made from flour treated with 1.5% lime showed the best results and overall acceptability. This research could be beneficial for increasing the utilization of pearl millet in different parts of the world especially in under developed countries as a health food. Also, the phytochemicals of pearl millet have various health benefits and this study can be used to increase their concentration and thereby promote the use of pearl millet for enrichment of various food products. [ABSTRACT FROM AUTHOR]

Corn kernels were soaked with different selenium (Se) solutions (0, 12 or 24 mg Na2SeO3/L), sprouted for different times and then lime-cooked for the pilot plant production of tortillas. The dough and tortillas were quantified in terms of total Se, starch and protein content. Also, in vitro digestibility, texture, color, and sensory properties were evaluated. Results indicated that lime-cooking times were significantly reduced from 39.15 to 14.34, 8.42 and 2.80 min when whole corn was compared with kernels germinated for 1, 2 or 3 days. The Se content of regular tortillas (0.08 µg/g dw) increased about eight-fold in tortillas (0.651–0.625 µg/g dw) produced of corn germinated for two day and treated with 24 mg of Na2SeO3/L. The highest α-amylase activity and lower starch viscosity values were observed in 3-day germinated supplemented with the highest Se. Se-enriched tortillas produced from 2-day sprouted kernels treated with 12 mg Na2SeO3 showed the highest levels of general acceptability, texture and flavor. [ABSTRACT FROM AUTHOR]

High kernel-zinc maize varieties are available to consumers in several countries in Latin America to contribute to increase the zinc intake of their populations. Minerals, phytic acid and amino acids retention were measured after processing six maize varieties including three high kernel-zinc, one quality protein maize and two conventional maize. Grain for each variety was processed into tortillas, arepas and mazamorra, common maize dishes in the region. To evaluate the effect of processing kernel-zinc maize varieties on zinc retention, varieties were grouped in zinc biofortified maize (ZBM) and non-ZBM. Iron, zinc, phytic acid, tryptophan and lysine concentrations in non-processed maize were 17.1–19.1 ​μg/g DW, 23.9–33.0 ​μg/g DW, 9.9–10.0 ​mg/g DW, 0.06–0.08% and 0.27–0.37%, respectively. In tortillas, the iron, zinc, phytic acid and lysine content did not change (p ​

One of the most traditional foods in Mexico is pozole (a soup of maize grains with pork). Maize starch interacts with fatty acids during its preparation, generating amylose-lipid complexes. This study aimed to determine the effect of lard concentration on the formation of amylose-lipid complexes and their effect on the physicochemical properties of the starch after pozole preparation. Three maize varieties were nixtamalized and cooked, using 0, 6, 8, and 10 % lard. Grain physical parameters, viscosity, resistant starch, and detailed characterization of starch granules were analyzed. X-ray diffraction patterns showed structural damage in the crystalline starch structure. Two of the maize varieties showed an amylose-lipid endotherm with the addition of lard. The viscosity profile was affected by grain hardness and heat treatment, whereas lard addition decreased the viscosity of samples. The addition of higher percentages of lard (8 and 10%) favors the formation of amylose-lipid complexes, as shown in thermal properties and resistant starch.

Grain sorghum is a viable feedstock for lactic acid fermentation; however, tannins contained in some varieties affect the efficiency of hydrolysis and fermentation. This work objective was to assess the effect of pre-treatment of grain sorghum on the production of lactic acid and biomass after fermentation. Sorghum varieties with low, medium, and high tannins were pretreated, enzymatically hydrolyzed, and fermented with Lactobacillus casei. The pre-treatments consisted of cooking the grains in lime, cooking in plain water, and no treatment (control). Pretreated sorghum flours were hydrolyzed using thermostable α-amylase from Bacillus licheniformis and amyloglucosidase from Aspergillus niger. Lime pre-treatment showed a significant improvement in protein content, digestibility, and lactic acid production after fermentation, in relation to the non-treated samples. Although differences were not significant for low and medium tannins, lime treatment increase lactic acid production for the cooked-in-lime high-tannin sorghum in relation to the control. For this sorghum/treatment combination, the lactic acid production was 138 g/L, with a volumetric productivity of 1.57 g/L·h and 85/100 g yield based on initial starch, which is equivalent to 69 g of lactic acid per 100 g of sorghum d.b. [ABSTRACT FROM AUTHOR]

Nixtamalization, which means cooking maize in alkaline water, is the central technique for the culinary use of maize in Mexico and Central America. Without this procedure, relying on maize as the basic starch staple is inadequate because of nutriment deficiencies. Mexico has more than 50 principal racial types of maize, and these differ in grain qualities that can require the adjustment of the nixtamalization process. Properties such as hardness and grain composition influence nixtamalization because they are related to the absorption of water that occurs during cooking and steeping. Some maize preparations, like tortillas and tostadas, can also require the adjustment of nixtamalization to obtain a high-quality foodstuff. We studied how women in three regions of the state of Chiapas, which differ in the prevalent maize race available, prepare their nixtamal and whether they make changes according to the type of food they prepare. Interviews of 30 women follow the measure of relevant variables when the women prepared nixtamal. We found that nixtamalization is adjusted for different grain hardnesses and for environmental conditions. Variations were found in the cooking time of the nixtamal, in the amount of time the nixtamal was steeped, and in a special process of double boiling of the nixtamal performed by some women for tostadas. Women that specialize in production for the market have developed variations preferred by consumers. As practiced by women in Chiapas, nixtamalization is a flexible technique that is adjusted for maize type and for food preparations. [ABSTRACT FROM AUTHOR]

Introduction. Producing new maize cultivars in areas with limited water resources is the main task of plant breeders. However, there is little information regarding their technological characteristics and industrial potential. Besides, snacks have gained worldwide acceptability and become part of modern food culture, especially among young people and children. Thus, our study aimed to produce corn snacks from new yellow corn hybrids planted under water stress in Delta region, Egypt. Study objects and methods. We investigated healthy processing techniques and used nixtamalization and baking instead of frying. We also evaluated the chemical composition and starch crystallinity of flour, the rheological properties of dough, as well as color attributes and sensory characteristics of baked snacks. Results and discussion. Significant differences (P ˂ 0.05) were found between all corn genotypes in their fat, protein, ash, crude fiber, and carbohydrate contents. The experimental drought conditions caused higher protein and fat contents compared to normal conditions. X-ray diffraction indicated that nixtamalization decreased starch crystallinity. Also, X-ray and rapid visco analysis showed that Y2 genotype exhibited the highest crystallinity and the lowest pasting properties, while Y3 and Y5 had the lowest crystallinity and the highest pasting properties. Baked snacks made from nixtamalized corn flour of genotypes planted under drought conditions had comparable quality characteristics in terms of color and sensory properties to the control snacks made from SC178 genotype planted under normal conditions. Conclusion. The new corn hybrids grown in limited water conditions and the developed snacks represent a healthy alternative to cornbased fried snacks.

Abstract Background Drought tolerance and grain quality are the main challenges in maize cultivation due to climatic changes and population growth. So, this study aims to evaluate the suitability of nixtamalized corn flour (NCF) obtained from new drought-tolerant white corn hybrids planted under drought conditions for gluten-free biscuits production. Chemical compositions of corn hybrids, pasting properties of dough, and physical and sensory characteristics of biscuits were evaluated. Results Protein, fat, crude fiber, and ash contents of corn hybrids differed significantly, while there were no significant differences between carbohydrate contents. NCF showed lower peak viscosity, trough value, breakdown, and final and setback viscosities as compared to raw Single Cross Giza (SC 10) flour. This indicates that nixtamalization process reduced retrogradation capability of the produced corn flours. Corn flour with the lowest retrogradation tendency was the one produced from genotype No. 5. Baking quality, sensory properties, and color attributes indicated that biscuits made from NCF of hybrids No. 2 and 5 were significantly more acceptable compared to other samples. Conclusion Gluten-free biscuits could be produced using NCF of all white hybrids with acceptable quality. Moreover, superior sensory characteristics of samples manufactured from genotypes No. 2 and 5 and thereby suitable for gluten-hypersensitive patients.

The production of worldwide nixtamalized products has increased in Latin American countries over the last years. For a better maize handling and exploitation of its nutritional elements, maize is subjected to a nixtamalization pretreatment protocol, which produces meaningful chemical, nutritional and quality changes in maize and its derived products, but large amounts of its primary by-product, well-known as 'nejayote', are also produced. Importantly, nejayote is usually discarded into the urbanized sewage with minimal treatment. Today, according to the recent research reports, new emerging techniques and protocols have been implemented to improve the nixtamalization products and by-products processing. New valorization approaches and biotechnological developments (including biotransformations) toward the reuse of nejayote have been developed according to its considerable content of biomolecules. Therefore, the goal of this paper is to provide a comprehensive review of the main development works at assisting nixtamalization products and by-products processing. Herein, particular attention is paid to experimental insights dealing with the valorization of nejayote. [ABSTRACT FROM AUTHOR]

Background and objectives: The search for safe and effective natural sources of antioxidants and antimicrobials is a current trend. The corn nixtamalization industry involves the production of nejayote, a waste that offers a substrate for making value‐added products. This study evaluated the phytochemical content and certain bioactive properties of a hydroalcoholic extract from nejayote flour and its potential use as an antimicrobial agent of edible coating. Findings: Proximal composition of nejayote flour was 10.34% protein, 6.47% fat, and 76.72% carbohydrates. The total phenolic content of the hydroalcoholic extract was 68.62 mgGAE/100 g; ferulic acid, coumarins, tannins, triterpenes, and flavonoids were identified as major compounds. Antioxidant activity of the extract varied between the methods (p <.05): ORAC (1865.13 µmol TE/100 g) > ABTS•+ (1,670.02 µmol TE/100 g). Nejayote phenolic extract showed a moderate–high antimicrobial power depending on the bacteria (p <.05). The adding of nejayote phenolic extract (2.6%) in alginate coating improves physiochemical properties and exhibits a selective antimicrobial effect. Conclusions: This research provides bases for the nutrimental and phytochemical content of nejayote flour and its bioactive properties. Significance and novelty: The confinement and extraction of phytochemical compounds with biological activity from nejayote promote the technological innovation use and reduction of the environmental impact generated by this by‐product. [ABSTRACT FROM AUTHOR]

In Honduras, corn is the most important staple food for the majority of the population. This high-demand crop is susceptible to biological contamination with mycotoxins, which could represent a latent hazard for consumers. To assess the incidence of aflatoxins and fumonisins in grain, masa and tortilla, and the dietary exposure to these substances among consumers, a study was conducted in four municipalities in the department of Lempira. Total aflatoxin and fumonisin content were quantified by fluorometry in 144 samples from 48 farmers. Sixty five percent of the samples were contaminated with aflatoxins with levels of 1.28–32.05, 1.15 to 12.61, and 1.01–5.98 μg/kg in grain, masa and tortilla, respectively. Fumonisins were detected in 100% of the samples at levels between 0.82 and 28.04, 0.66 and 14.36, and 0.63 and 12.04 mg/kg in grain, masa and tortilla, respectively. The reduction in aflatoxin and fumonisin contamination after processing grains into tortillas was of 83% and 52%, respectively. The difference in aflatoxin and fumonisin concentration in the three products was significant (p < 0.05). With a per capita tortilla consumption of 490 g/day, dietary exposure was estimated between 0.003 and 0.073 μg/kg bw/day for aflatoxins and 6.16 and 151.98 μg/kg bw/day for fumonisins. Therefore, the risk of exposure to mycotoxins in the evaluated communities was considered high. Mixed effect models showed that postharvest grain management and the nixtamalization process affect the incidence of mycotoxins in corn-based products.

The study examined the impact of lime treatment (nixtamalization process) on the functional, proximate, and crystallinity properties of pearl millet flour by cooking them in a 2% calcium hydroxide (Ca (OH)₂) at 75 ± 5 °C for 30 min and then steeping for 4 h. The millets were then milled to produce two types of flour, dry milled nixtamalized flour (DMNF) and wet milled nixtamalized flour (WMNF) and compared with the untreated pearl millet flour (PMF). Nixtamalized samples yielded a flour that contained significantly (p < 0.05) higher content of ash, soluble and insoluble fiber, minerals such as calcium, iron, magnesium, and sodium. Solubility increased with temperature from 30 °C to 90 °C for DMNF (71.86%), WMNF (50%), and for PMF (66.25%) respectively. Shelf-life studies revealed that, the Free Fatty Acid (FFA) content increased from 2.49% to 6.48% for DMNF and from 5.22% to 14.89% for WMNF, with an overall increase of 61.57% for DMNF and 64.94% for WMNF. X-ray diffractogram, of the flour revealed peaks moved towards higher theta values, leading to a reduction in the distance between the planes, consequently reducing the size of crystals. Breakdown of these molecules leads to a disruption/reorientation of the crystalline double-helix pairs, thus reducing crystallinity in nixtamalized samples. [Display omitted] • Pearl millet flour cooked in 2% (Ca (OH)₂), 75 ± 5 °C for 30 min, steeped for 4 h. • Nixtamalized flour (p < 0.05) higher content of ash and soluble and insoluble fiber. • Pearl millet Nixtamalized flour XRD pattern altered peak smaller crystal size. [ABSTRACT FROM AUTHOR]

• RS 2 type from corn starch has nanocrystals with orthorhombic crystal structure. • Part of RS 2 from corn, nixtamal, masa, and tortilla is formed by nanocrystals with orthorhombic crystal structure. • During nixtamalization a fraction of starch grains remain intact. This work aimed to study the changes in starch and isolated starch resulting from the conversion of corn to tortilla, focusing on the orthorhombic crystal structure and its association with resistant starch. Scanning electron microscopy images show whole, partially, and completely damaged starch granules in nixtamalized corn, masa, and tortillas. More importantly, whole isolated starch granules were found in nixtamal, masa, and tortillas. Transmission electron microscopy shows the presence of nanocrystals with orthorhombic structures in isolated starch. Some of them remained almost undamaged during the nixtamalization process. The X-ray patterns showed orthorhombic crystals in nixtamal, masa, and tortilla and their isolated starches. The RS increased from 2.61 to 5.31 % from corn to tortilla and from 2.52 to 5.61 % for isolated starches from corn and tortilla during the traditional nixtamalization process. The results suggest that the nanocrystals in corn to tortilla are part of RS 2. [ABSTRACT FROM AUTHOR]

Maize cooking water is a common by-product of the agro-food processing industries. Such by-product is a current case of study for the research community. The present study analyzed the physicochemical properties of the extract during the ultrafiltration process at different weight reduction factor (WRF) values using a tight pore size membrane. The permeate samples coming from the filtration process were analyzed in terms of total soluble solids (TSS), total solids content (TSC), turbidity, pH, electrical conductivity, total polyphenols, total carbohydrates, and total organic carbon (TOC). At the end of the ultrafiltration process (WRF = 5), the retention efficiencies were of 100.0%, 78.4%, 30.5%, 32.6%, 43.8%, 75.9%, 79.9%, and 1.9% for TSS, TSC, turbidity, pH, conductivity, carbohydrates, TOC, and polyphenols, respectively. In this regard, it can be noticed that a significant quantity of the polyphenols contained in the initial extract was recovered in the permeate stream. According to the results, the selective filtration of this by-product by membrane technology represents a potential alternative for the recovery of its high-added value compounds. Finally, the highlighted results on polyphenol recovery are analyzed and discussed based on the separation process, molecule and membrane characteristics, and some other phenomena occurred in the recovery. [ABSTRACT FROM AUTHOR]

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The identification and quantification of phenolic components separated by ultrafiltration from the alkaline cooking water of three varieties of Mexican maize (white, red and purple) were performed. The total content of polyphenols and the antioxidant activity of the permeate was evaluated. The cooking water (Nejayote) obtained from the nixtamalization process was subjected to a consecutive fractionation process with three membranes of different molecular cutting (MF-UF100-UF1) for the recovery of bioactive components. The highest content of total polyphenols recovered in the fractions was with the integrated MF-UF100 process (UF100-Permeate of white maize, red maize and purple maize) with values of 768.22, 800.72 and 776.88 mg GAE L−1, respectively; and the antioxidant activity in the same fractions was 0.43, 0.33 and 0.33 TE mL−1, respectively. The UHPLC-ESI-MS showed that the hydroxycinnamic acids present at the end of the initial process proposed (MF-UF100-UF1) were ferulic acid and p-coumaric acid; those that were present in the fractions of UF1-Permeate (of white corn, red corn and purple corn) in quantities of 99.89, 138.85 and 211.03 mg L−1, of ferulic acid respectively and p-coumaric acid in amounts of 24.56, 31.88 and 76.21 mg L−1, respectively. The results allow us to visualize possible applications in food industry (bakery products and pastry, mainly) for extracts from Nejayote. [ABSTRACT FROM AUTHOR]

Cereal and legume diets make up the bulk of caloric sources for a majority of households in the developing world. They contain macro‐ and micronutrients as well as phytochemicals embedded as one matrix. Some phytochemicals are antinutritional factors which can bind nutrients thereby hindering their bioavailability. While there are other methods that can be used to enhance nutrient utilization from such foods, we summarize how food processing methods such as extrusion and nixtamalization are employed to break the food matrix and release these nutrients. Both extrusion and nixtamalization can break down complex carbohydrates into simpler, more soluble forms while at the same time inactivating or denaturing protein inhibitors and other antinutritional factors. Such disruptions of complexes within the food matrix are essential for harnessing optimum nutritional and health benefit from these foods. We present mechanistic approaches explaining how these processes enhance nutrient and mineral bioavailability and phytochemical bioactivity while minimizing the undesirable effects of antinutritional factors that coexist in the complex food matrix. [ABSTRACT FROM AUTHOR]

This article is a result of an interdisciplinary, mixed-methods effort to understand the context of "milhos aferventados" dish (nixtamalized maize meal stew), found in the "barrocal" and mountains area, from the Algarve, the most southern continental region of Portugal. "Milhos aferventados", a two-stepped preparation dish, makes use of a nixtamalization technique, singular in the overall context of the Continental Portuguese gastronomic scene: maize is firstly nixtamalized and then it would be stewed with salt-cured/smoked pork meats and vegetable products. Nixtamalization, a classic Mesoamerican technique used to increase the bioavailability of maize nutrients and to soften maize's kernel pericarp, is popularly used in the region to remove kernel's tip cap ("olho preto" [black eye]) avoiding culinary unpleasant texture on the final dish. This work is a result of an historical, culinary, and biochemical structured, triangulated approach to the dish, exploring the introduction of Zea mays L., the culinary aspects, and the cultural/biochemical reasons behind the use of this technique. Regarding the reasons that justify the culinary use of nixtamalization, hypothesis for further research are raised. However, evidence of non-dissemination of pellagra disease was found in the region in the early 20th century, unlike what was happening in other regions of Portugal where maize was eaten without nixtamalization, and pellagra was disseminating. Besides, the popular preference for fig tree ashes in this specific nixtamalization process was also studied. We found that pH of fig tree ash (12.63 ± 0.02) and the ion calcium content (75.19 ± 0.06ppm) were higher than, e.g., the carob tree ash (12.35 ± 0.03 and 55.31 ± 0.04ppm respectively), an alike available wood in the region, but only calcium ion present a significant difference, allowing the destruction of the maize pericarp, being the reason behind the usage of this technique. • A mixed-methods approach to a popular cuisine' dish using nixtamalization in the Algarve region (Portugal). • Reason of empirical selection of fig wood tree is based on its mechanical and chemical properties. • Nixtamalization as a generational transmitted culinary technique. [ABSTRACT FROM AUTHOR]

In this research, the mathematical model associated with the hydrothermal dehydration process of Nixtamalized Corn Grains (NCG) with different Steeping Time (ST) values, allows the fitting of experimental data with initial moisture M0 and the equilibrium moisture ME as a function of Isothermal Dehydration Time (IDT). The moisture percentage for any time t and dehydration rate (isolines M(t) and isolines vI respectively) of the NCG is shown by means of matrix graphics as a simultaneous function of IDT and ST. The relationship between initial dehydration rate v0 and initial moisture M0 establishes as a function of ST. Also, the mathematical model associated with the solution of the second Fick’s law allows calculating the diffusivity rate vk (H2O molecules out of NCG) and verify that the rate of change in moisture and the dynamical proportionality constant k has a non-linear dependence on the IDT and that k is directly proportional to Deff. The k values strongly relate to ST and the calcium ions percentage into NCG according to solubility lime values into cooking water (or nejayote) as a function of decreasing temperature when ST increases.

Acrylamide can be generated from food components during tortilla chips frying. Thus, the aim of this research was to study different nixtamalization processes as traditional (TNP) with lime [Ca(OH)2], ecological (ENP) with CaCO3, classic nixtamalization (CNP) that uses wood ash and extrusion (EXT) with no Ca+2 source on mitigating the acrylamide formation in deep-fat frying tortilla chips. Acrylamide quantification was done through HPLC–UV. Lower acrylamide content in tortilla chips was for CNP with 46.3 µg/kg, followed by TNP with 55.0 µg/kg, ENP with 694.6 µg/kg and EXP with 1443.4 µg/kg. Differences in acrylamide values among samples can be related to effect of cations (Ca2+, Mg2+, Fe2+, Zn2+, Na+ and K+) present in wood ashes, lime and salts used as raw materials. Correlation of (r = 0.85; p <0.0005) was observed in color of tortilla chips, moisture, texture, blisters, and oil with acrylamide. Nixtamalization process is an effective and inexpensive strategy for acrylamide mitigation. [ABSTRACT FROM AUTHOR]

Highlights • High-energy milling nixtamalization (HEM) affected the physicochemical, thermal and rheological characteristics of corn flours. • HEM could be a faster, no pollutant and energy saver alternative traditional nixtamalization process for creole grains. • HEM reduced gelatinization enthalpy, changes in the crystalline structures and FT-IR in control and treated grains. Abstract High-energy milling (HEM) was used to produce nixtamalized corn flours, the traditional nixtamalization process was used as a control. Four creole grains were stone-milled, adjusted to an appropriate moisture content and calcium hydroxide concentration and milled using HEM. The physicochemical, thermal, and rheological characteristics of the flours and corn masas were affected by the HEM process. Negritas and Ahualulco creole grains nixtamalized by HEM showed similar viscosity profiles as a control. HEM reduced the gelatinization enthalpy compared to control and raw flours. Diffractograms showed changes in the crystalline structures and FT-IR demonstrated different regions for lipids, proteins, and carbohydrates in all control and treated grains. The texture of corn masas revealed significant differences according to the grain type. ESEM analysis showed smaller particles of HEM flours compared to those of the control. HEM could be a faster, non-pollutant, energy-saving, alternative nixtamalization process. [ABSTRACT FROM AUTHOR]

This study aimed at evaluating the effect of high-energy milling (HEM) and traditional nixtamalization (TN) on bioactive compounds and antioxidant capacity in nixtamalized creole corn flours obtained from a maize genotype cultivated under rainy temporal conditions in the Mexican semidesert. Four creole grains, including San José de Gracia white and blue (WG and BG), Negritas (NG), and Ahualulco white corn grains (SG), were used. For HEM nixtamalization, corn grains were hammer-milled; then, two different conditions were evaluated: treatment H1, with raw flours with 14% moisture content and 1.1% Ca(OH)2, and treatment H2, with raw corn flours with a 23% moisture content and 1.4% Ca(OH)2. The TN process was utilized as a control. TN recorded significant losses in luminosity value L* (p < 0.05), while HEM nixtamalized blue corn flours remained close to -b* values, that is, near to those of raw flour. Anthocyanin content showed higher content values in HEM treatments compared with TN (759.55 and 252.53 mg cyanidin 3-O-β-D-glucoside (C3G)/kg, respectively) (p < 0.05). Total soluble phenolic content was higher in HEM nixtamalization compared with the traditional process, except for WH2 and SH2 (H2 treatment for WG and SG). Two redundant radical scavenging assays were used: antioxidant capacity (DPPH assay) exhibited less value in nixtamalized flours than in raw flour (p < 0.05). Antioxidant activity by (ABTS) assay was higher in HEM than in TN. Nixtamalized flours produced by HEM demonstrated more improvement in nutraceutical properties than those produced employing TN. [ABSTRACT FROM AUTHOR]

Highlights • The addition of huitlacoche paste to nixtamalized blue-corn flours (NBCF) affected the properties of masas. • The physicochemical, thermal, and rheological properties of blue corn masas added with huitlacoche paste were measured in masas and nixtamalized flours. • The inclusion of huitlacoche paste can be achieved with a maximal addition of 9% in NBCF for an industrial process and could comprise a new industrialization alternative. Abstract The aim of this work was to evaluate the effect of the addition of huitlacoche paste to nixtamalized blue-corn flours (NBCF) on the physicochemical, thermal, and rheological properties of masas. Raw blue maize was nixtamalized (hydrothermal alkalinized process), then was wet-milled in a stone mill, masa was dehydrated, pulverized and sieved to obtain NBCF; commercial nixtamalized blue-corn flour (CNBCF) was used as a control. Huitlacoche paste in concentrations of 3, 6, 9, 12, 15, and 18% was added to nixtamalized flours. Characteristics of the blue grain showed its great effects on water absorption, viscosity, and masa cohesiveness; the addition of huitlacoche significantly influenced adhesiveness, water-absorption, color, and the rheological properties (p < 0.05). Values between 0.03 and 0.083 kg-force resulted in masas with optimal adhesiveness. The inclusion of huitlacoche paste can be achieved with a maximal addition of 9% in NBCF for an industrial process and could comprise a new industrialization alternative. [ABSTRACT FROM AUTHOR]

Highlights • Ohmic heating process (OH) is an alternative for instant corn flours processed. • OH process preserves the phytochemical content of the instant corn flours. • OH process produced no losses of bound phenolic compounds. Abstract We studied the changes in the phytochemicals profile of two instant corn flours produced by different process: traditional nixtamalization process (TN) and by ohmic heating process (OH). The highest total phenolics content was found in the OH flours (OHF), which showed predominance of bound phenolics and free flavonoids compared with the TN flours (TNF). Ferulic acid measured by HPLC-DAD was the most abundant compound in its bound form in the OHF, but decreased by 57% in TNF. The insoluble fiber content was preserved by the OHF (17.49%) and the soluble fiber increased ∼65% compared with TNF. These data suggest that instant corn flours processed by OH preserves the phenolic profile and antioxidant profile similarly than flours processed by TN; furthermore, water waste was reduced significantly, and no effluents were produced in the ohmic heating process. [ABSTRACT FROM AUTHOR]

Abstract Nixtamalization is a pre-Columbian process in which corn kernels are cooked in a calcium hydroxide solution. In the traditional nixtamalization process (TNP), corn kernels undergo physical and chemical changes that result in the quality properties of final food products. However, such method has some disadvantages, especially the generation of a considerable volume of polluting effluents, the long time it requires, and a loss of nutrients. This paper reviews alternative processes aiming to solve those problems, weighing in their pros and cons, and their potential for industrial use. Some ecological methods have been developed replacing calcium hydroxide for other calcium salts (calcium carbonate, calcium sulfate, and calcium chloride), thus reducing the polluting effect of effluents, while obtaining products with acceptable quality properties. Technology-based methods have also been adopted, involving the use of microwaves, ultrasound, extrusion, heating with low-shear transport, and ohmic heating. Just some of the methods mentioned have resulted in intermediate and final products with quality properties similar to those obtained through the TNP. Highlights • Most studies have focused on reducing the pollution of nixtamalization process (NP). • The technologies proposed to replace the NP have not been implemented industrially. • Low-cost and viable technologies must be developed to modernize the NP. [ABSTRACT FROM AUTHOR]

The production of nixtamalized products worldwide has been increased over past decades. The first pre-treatment applied to maize is the well-known Nixtamalization procedure, which produces large quantities of its primary by-product called 'Nejayote'; this by-product is commonly discarded into the urbanized sewage without any additional treatment. Recently, Nejayote has attracted attention due to its high organic load based on high content of organic (arabinoxylans, phenolic compounds, sugars, fibers) and inorganic compounds (calcium). Thus, this by-product may have potential for value-added processing and utilization, which can be alternatives, that simultaneous hold the promise of increased economic benefit for masa producers as well as decreased potential pollution for the environment. The goal of this paper is to provide a critical review of reusing this primary by-product. State-of-the-art of developments in the field are chronologically reported and described. Particular attention is paid to experimental results reported for the reclamation of its high-added value compounds that have been identified as the potential approach concerning on the utilization of the by-product. The recovered components have demonstrated biological activities that increase their potential exploitation. [ABSTRACT FROM AUTHOR]