Films of biopolymers, pectin and gellan, enriched with natamycin and clove essential oils for the packaging of Corn tortilla: Protection against Staphylococcus aureus and Candida parapsilosis.

It was investigated the microbial protection of corn tortilla, traditional Mexican food with high acceptance, for food safety. We elaborated a functional film (FF) prepared with 0.4% (w/v) gellan gum, 2% (w/v) citrus pectin, 0.5% (w/v) glycerol, 0.0003% (w/v) natamycin, 0.03% (v/v) essential clove oils, and 0.1% (v/v) tween 80. The FF impeded the growth of indicator microorganisms in corn tortilla medium: Staphylococcus aureus (i.e., 35 °C, 50% RH, 7 days) and Candida parapsilosis (i.e., 27 °C, 42% RH, 7 days; and 9 °C, 95% RH, 30 days). In packaged artisanal corn tortilla storage at 22 °C and 50% RH for 30 days, the FF-treatments showed 5.5 log CFU/g total aerobes and 4.8 log CFU/g yeasts and moulds, being two and three logs lower than the concentrations recorded in the controls with no film, respectively. Some physical-mechanical properties of FF were Young's modulus, 500 MPa; elongation at break, 10%; stress at break, 18.5 MPa; oxygen permeability, 4 × 10-13 g m Pa-1 s-1 m-2; and water vapour permeability, 4.8 × 10-11 g m Pa-1 s-1 m-2. Also, the sensory evaluation of wrapped tortilla suggested no negative effects. The obtained results envisage potential food-packaging applications with the elaborated films.

Changes in phytochemical content, bioaccesibility and antioxidant capacity of corn tortillas during simulated in vitro gastrointestinal digestion.

There is a little information about the effect of corn process conditions on the bioactive compounds of tortillas during gastrointestinal digestion. Tortillas elaborated with traditional and extrusion nixtamalization process were subjected to in vitro digestion. Extracts recovered from digestion were employed to determine the changes in phytochemicals, bioaccesibility and antioxidant capacity (DPPH, ABTS and FRAP). Digestion contributed to a greater solubilization of phenolic compounds in raw corn and tortillas, especially in the intestinal phase (311.4-583.2 mg GAE/100 g). With bioaccessibility indexes of 162.83 to 960.7 %. Intestinal phase affected the content of anthocyanins, reaching a lower bioaccessibility value than the found in undigested samples (17.90-29.91 %). Even though the traditional white tortilla showed the highest bioaccessibility values, blue tortilla showed a higher antioxidant activity in different phases of digestion. Both tortillas could function as prebiotic agents in the large intestine. Corn-based products are valuable as part of a healthy diet.

Alternativas para el aprovechamiento del cuajilote (Parmentiera edulis): una especie agroindustrial subutilizada / Alternatives for the use of cuajilote (Parmentiera edulis): an underutilized agro-industrial species

Resumen El fruto de la especie Parmentiera edulis, conocida como cuajilote, se produce de forma abundante por temporada, es rico en nutrientes y puede ser aprovechado para elaborar alimentos. El objetivo de este trabajo fue establecer la viabilidad técnica de utilizar el cuajilote en la formulación de alimentos y bebidas fermentadas para promover su aprovechamiento comercial. Se determinó la composición nutricional, el contenido fenólico y su capacidad antioxidante. Los frutos se deshidrataron y se obtuvo una harina que se mezcló al 0 % (control), 5 %, 10 % y 15 % con harina de maíz, para preparar tortillas, y se evaluó su composición nutricional y aceptación organoléptica. También, se elaboró una bebida fermentada y una bebida destilada, usando Sacharomyces cereviseae, a partir de pulpa de fruta con y sin cáscara. Los mostos para la bebida fermentada se pasteurizaron a 72 ºC/15 s. El fruto presentó alto contenido de proteína (6.5 ± 2.5 %) y fibra (3.9 ± 1.6 %), de compuestos fenólicos y capacidad antioxidante. En las tortillas, al aumentar la cantidad de cuajilote se elevó la cantidad de fibra y proteína. Sensorialmente, las tortillas adicionadas con 5 % y 10 % de cuajilote fueron mejor aceptadas. En la bebida fermentada no se encontró diferencia significativa en sus parámetros fisicoquímicos al elaborarla con y sin cáscara, excepto para la acidez total. Tampoco modificó el rendimiento de producción de bebida fermentada o de alcohol destilado. El cuajilote es un fruto poco incorporado a la dieta que presenta propiedades funcionales nutricionales adecuadas y puede ser aprovechado como materia prima en la elaboración de tortillas, aumentando su valor nutricional o para producir bebidas fermentadas o alcohol etílico.

Abstract The fruit of the species Parmentiera edulis, known as cuajilote, is abundantly produced per season, is rich in nutrients and can be used to make food. The objective of this work was to establish the technical feasibility of using cuajilote in the formulation of fermented foods and beverages to promote its commercial use. The nutritional composition, the phenolic content and its antioxidant capacity were determined. The fruits were dehydrated and a flour was obtained that was mixed at 0 % (control), 5 %, 10 % and 15 % with corn flour, to prepare tortillas, and its nutritional composition and organoleptic acceptance were evaluated. Also, a fermented beverage and a distilled beverage were elaborated, using Saccharomyces cereviseae, from fruit pulp with and without shell. The musts for the fermented beverage were pasteurized at 72 ºC/15 s. The fruit presented a high content of protein (6.5 ± 2.5 %) and fiber (3.9 ± 1.6 %) of phenolic compounds and antioxidant capacity. In tortillas, increasing the amount of cuajilote increased the amount of fiber and protein. Sensorially, the tortillas added with 5 % and 10 % cuajilote were better accepted. In the fermented beverage, no significant difference was found in its physicochemical parameters when it was made with and without shell, except for total acidity. Nor did it modify the production yield of fermented beverage or distilled alcohol. Cuajilote is a fruit rarely incorporated into the diet that has adequate functional and nutritional properties and can be used as a raw material in the manufacture of tortillas, increasing its nutritional value or to produce fermented beverages or ethyl alcohol.

Physicochemical Properties and Resistant Starch Content of Corn Tortilla Flours Refrigerated at Different Storage Times.

The tortilla is a foodstuff that has a short shelf-life, causing great losses to the industry. The objective of this work was to evaluate, for the first time, the physicochemical properties and resistant starch (RS) content of flours. These were obtained from nixtamalized corn tortillas made with traditional and industrial (commercial) methods, stored at 4 °C for 7, 15, and 30 days. The flours were characterized by measuring particle size distribution, color, water absorption index (WAI), water solubility index (WSI), viscosity, calcium, and RS content. Additionally, chemical proximate analysis, scanning electron microscopy (SEM), and thermal analysis were conducted. Storage at 4 °C increased the friability of tortillas and shifted the particle size distribution toward a greater content of coarse particles in corn tortilla flours. The commercial corn tortilla flours showed higher WAI and WSI values than the traditional corn tortilla flours. On the other hand, the traditional corn tortilla flours exhibited higher RS content values than commercial corn tortilla flours as well as peak viscosity. X-ray diffractograms revealed the presence of amylose-lipid complexes (RS5) in experimental samples. The thermograms evidenced three endotherms corresponding to corn starch gelatinization and melting of type I and type II amylose-lipid complexes.

Modeling of Effective Moisture Diffusivity in Corn Tortilla Baking.

The objective of this work was to model the mass transfer in corn tortilla baking using different approaches for effective diffusivity based on the Fick's law of diffusion and to evaluate the impact of the process on quality parameters. The 1st one assumes constant effective diffusivity (method of slopes by subperiods and method of successive approximations) and the 2nd one considers variable effective diffusivity (quadratic function of time and Weibull distribution). In addition, the Weibull distribution was applied to fracturability. The effective moisture diffusivity inside the tortilla during baking is not constant and the estimations generated when considering variable diffusivity with quadratic time and Weibull distribution showed better fits (both, R2 = 0.999) to the average moisture content. Quality parameter fracturability was affected by the baking process and the Weibull model adequately described (R2 = 0.996) the fracturability behavior. This work will allow an adequate estimation of the concentration profiles and histories for mass transfer operations in products that can be represented as an infinite plate. The obtained analytical solutions with variable diffusivity will help to estimate the optimal conditions of the baking process to achieve the required final moisture content for baked corn tortilla shells. PRACTICAL APPLICATION: The analytical solutions of the Fick's law of diffusion for the moisture content in products that can be represented as an infinite plate, considering variable diffusivity, can be useful in studies when accurate estimations of effective diffusivity and concentration are needed.

Sensory and Quality Evaluation of Traditional Compared with Power Ultrasound Processed Corn (Zea Mays) Tortilla Chips.

Power ultrasound reduces the traditional corn steeping time from 18 to 1.5 h during tortilla chips dough (masa) processing. This study sought to examine consumer (n = 99) acceptability and quality of tortilla chips made from the masa by traditional compared with ultrasonic methods. Overall appearance, flavor, and texture acceptability scores were evaluated using a 9-point hedonic scale. The baked chips (process intermediate) before and after frying (finished product) were analyzed using a texture analyzer and machine vision. The texture values were determined using the 3-point bend test using breaking force gradient (BFG), peak breaking force (PBF), and breaking distance (BD). The fracturing properties determined by the crisp fracture support rig using fracture force gradient (FFG), peak fracture force (PFF), and fracture distance (FD). The machine vision evaluated the total surface area, lightness (L), color difference (ΔE), Hue (°h), and Chroma (C*). The results were evaluated by analysis of variance and means were separated using Tukey's test. Machine vision values of L, °h, were higher (P < 0.05) and ΔE was lower (P < 0.05) for fried and L, °h were significantly (P < 0.05) higher for baked chips produced from ultra-sonication as compare to traditional. Baked chips texture for ultra-sonication was significantly higher (P < 0.05) on BFG, BPD, PFF, and FD. Fried tortilla chips texture were higher significantly (P < 0.05) in BFG and PFF for ultra-sonication than traditional processing. However, the instrumental differences were not detected in sensory analysis, concluding possibility of power ultrasound as potential tortilla chips processing aid.