No abstract

This report shows the effect of temperature (72, 82, and 92°C) during the cooking stage and steeping time (0, 1, 3, 5, 7, 9, 11, 13, and 15 hr) on calcium and phosphorus contents in nixtamalized corn flours obtained by the traditional nixtamalization process (NCF). In addition, calcium and phosphorus contents in industrial nixtamalized corn flours were analyzed for comparative purposes. Atomic absorption spectroscopy and UV‐vis spectroscopy methods were used to study the calcium and phosphorus contents as well as the Ca2+/P ratio in NCF and industrial nixtamalized corn flours. Additionally, deposition and identification of calcium compounds in the nixtamalized corn pericarp were analyzed by low‐vacuum scanning electron microscopy, energy dispersive spectrometry, and X‐ray diffraction techniques. Dry matter loss in NCF is also reported. As the temperature increased, Ca2+ content was enhanced, while the phosphorus content decreased with statistical differences (P ≤ 0.05) between thermal treatments. Ca2+ content in industrial nixtamalized corn flours was significantly lower (P ≤ 0.05) than that of NCF. On the other hand, no statistical differences (P ≤ 0.05) were found between phosphorus content in commercial nixtamalized corn flours and NCF. Calcium compounds, identified as calcite, were detected in corn pericarp. Statistical differences (P ≤ 0.05) were observed in phosphorous content in NCF obtained at different cooking temperatures. In addition, a decrease in phosphorus levels significantly correlated with the steeping time at 92°C (r = –0.91). At 72, 82, and 92°C, the average Ca2+/P ratio in NCF was 0.45 ± 0.03, 0.61 ± 0.05, and 0.82 ± 0.05, respectively, indicating a correlation between this parameter and the cooking temperature. However, no correlation was found between the Ca2+/P ratio and the steeping time. This behavior is attributed to calcium attached to corn kernel. In commercial nixtamalized corn flours, the Ca2+/P ratio was significantly lower (P ≤ 0.05) than that of NCF. There was a significant correlation (P ≤ 0.01) between dry matter loss and steeping time (r = 0.99) in NCF, this fact influenced the Ca2+/P ratio due to the calcium attached to pericarp. At 82 and 92°C, maximum values of Ca2+/P ratio were detected in NCF at 7 hr of steeping time and at 9 hr at 72°C. These results can be used with industrial purposes to assess a maximum calcium‐to‐phosphorus ratio, and at the same time, to avoid the loss of pericarp to increase the functional properties of NCF.

It is widely accepted that role-based modelling is quite adequate in the context of multi-agent systems (MAS) modelling techniques. Unfortunately, very little work has been reported on how to describe the relationships between several role models. Furthermore, many authors agree on that protocols need to be encapsulated into high-level abstractions. The synthesis of role models is an operation presented in the OORAM methodology that allows us to build new role models from others in order to represent the interrelations they have. To the best of our knowledge this operation has to be performed manually at protocol level and works with protocols expressed by means of messages. In this paper, we present two algorithms to extract the protocol of a role from the protocol of a role model and vice versa that automate the synthesis or role models at the protocol level. Furthermore, in order to deal with protocol descriptions in a top down approach both operations work with protocols expressed by means of an abstraction call multi-role interaction (mRI).