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The present investigation evaluated the chemical and thermal properties using lime and alternative calcium salts, and their effect on the characteristics of masa and tortilla obtained in a two‐step nixtamalization process. White dent corn was cooked in calcium hydroxide solution (1.2% [w/v]; 1:3 maize : water ratio) at 80C (30 min), and the calcium hydroxide was replaced either by calcium chloride or lactate at calcium equilibrated concentration (30 min), and steeped in a cooking solution for 2,400 min. Grains were analyzed for water and calcium absorption, and apparent diffusion coefficients were calculated. Thermal properties of flour made from these grains were also determined. Additionally, the masa and tortilla made with nixtamalized corn flours were analyzed for texture and color, and an acceptability test was performed on the tortilla. Water absorption showed a notable increase during cooking, approaching an asymptotic maximum absorption after 8 h of steeping for all treatments. The maximum calcium absorption was obtained in stepwise nixtamalization with solutes of CaCl2 and C6H10O6Ca. The water apparent diffusion coefficients were adequately described by Fick's model and it was found that C6H10O6Ca showed the highest value (5.5901 × 10−10 m2/s), while that for calcium diffusion the model gave low fits. The thermal analysis showed that gelatinization temperatures were affected significantly (P < 0.05) by the cooking and steeping times, while the gelatinization range and enthalpy were affected significantly (P < 0.05) by salt type. The masas and tortillas obtained from all treatments presented good texture and color characteristics in comparison with the commercial flour. Sensory analysis showed that the tortilla nixtamalized with C6H10O6Ca was the most acceptable to consumers. PRACTICAL APPLICATIONS The main contribution of the present study is the utilization of different salts as an alternative to calcium during cooking and steeping in a two‐phase nixtamalization process. The different calcium salts provide an option to avoid undesirable changes in the products' quality characteristics present in the typical nixtamalization process produced by high lime concentration. At the same time, these alternatives could contribute to reduced environmental pollution, specifically in the waste water (decreased pH and the solids). A prediction model for water and calcium absorption during the nixtamalization process is proposed for the different calcium salts. The physical, chemical and thermal changes that occur in the nixtamalization in the different treatments for the different calcium salts were related to color and texture characteristics of masa and tortilla as well as tortilla acceptability.

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Essential oils are widely employed in food industry as natural flavors, however, these compounds are very difficult to handle due to they are very susceptible to oxidation and volatilization during process and storage generating undesirable flavors, therefore, it is necessary to use a protection method as microencapsulation. Chemical and thermo‐mechanically modified rice starch was used as wall material together with native rice starch, maltodextrin, and protein to microencapsulate orange essential oil by a spray‐drying technology. Microcapsules obtained were characterized in encapsulation efficiency (%EE), encapsulation yield (%YE), solubility, humidity (%), water activity (Aw), and color difference (ΔE). Through a surface response analysis, best formulations were selected and evaluated by its microestructure and stability of encapsulated essential oil. Results showed that the best encapsulating agent was the one with modified rice starch as predominant ingredient (>50%) of the wall material, showing higher efficiency than commercial encapsulating ingredients. Practical applications Microencapsulation is widely employed in food industry due to its ability to protect a compound of interest from adverse conditions that can generate decomposition of it or, in terms of flavor compounds, the generation of undesirable aroma and flavor characteristics. A lot of wall materials have been used to develop microencapsulation, however, starch is one of the main natural wall materials employed in microencapsulation by spray‐drying due to its high encapsulation efficiency. Rice starch is proposed in this study because is an abundant raw material, has the property of generate spherical aggregates and, together with another wall materials (maltodextrin and protein), can generate a resistant wall material with high encapsulation efficiency. Furthermore, the modification of rice starch involves a less employment of reactives, due to the thermomechanical process, obtaining a starch with more affinity to nonpolar compounds (essential oil), low viscosity, and solubility at room temperature (25 °C); which made this, an environmental friendly process. The procurement of the best wall material formulation suitable for encapsulation by spray drying, is of primary importance in order to preserve the quality and integrity of the encapsulated essential oil by reducing the presence of oxidation byproducts, increasing the shelf life and improving with this, its application inside a food matrix. Once the best wall material formulation is obtained, it can be used for the encapsulation of any type of essential oils used in the food industry.