The effect of dual modification of corn starch, including hydrolysis and succinylation, were evaluated through peak viscosity (PV) analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. This dual modification was shown to increase the reaction efficiency (RE) and degree substitution (DS) compared with starches that were not subjected to acid hydrolysis pretreatment with a 44% and 45% increase respectively. After acid hydrolysis pretreatment, the surface of the corn starch granules exhibited exo-erosion and whitish points due to the accumulation of succinyl groups. The peak viscosity was reduced significantly with the acid hydrolysis pretreatment (between 3 and 3.5-fold decrease), which decreased the pasting temperature and peak time to 20 °C and 100 s respectively. In addition, the dual modification of corn starch altered certain thermal properties, including a reduction in the enthalpy of gelatinization (ΔH) and a higher range of gelatinization (around 6 °C), which may effectively improve industrial applications. Modifications on the FTIR spectra indicated that the dual modification affected the starch crystallinity, while the Raman spectra revealed that the dual modification disrupted the short-range molecular order in the starch. Rearrangement and molecular destabilization of the starch components promoted their granular amphiphilic properties.

Mucilage extracted from the parenchymatous and chlorenchymatous tissues of Opuntia robusta were obtained using water or ethanol as the extraction solvent. The changes in the different tissues by using different extraction solvents were evaluated via scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) and Raman spectroscopy; in addition, the effect of mucilage coating on the various quality characteristics of tomato (Lycopersicum sculentum) was evaluated. The SEM results showed that the mucilage extracted from the parenchyma had a higher aggregation level that the mucilage extracted from the chlorenchyma. The presence of three characteristic bands of pectic substances in the FT-IR spectra between 1050 and 1120 cm⁻¹ indicated that the mucilage extracted from the parenchymatous tissue had a higher content of pectic compounds than the mucilage extracted from the chlorenchymatous tissue. It was also observed in the Raman spectra that the level of pectic substances in the mucilage extracted from the parenchymatous was higher than that in the mucilage extracted from the chlorenchymatous tissue. The mucilage extracted from the parenchymatous tissue was more effective as an edible coating than the mucilage extracted from the chlorenchymatous tissue. Tomatoes covered with mucilage showed significantly enhanced firmness and reduced weight loss. The uncoated tomatoes showed higher lycopene content than the coated tomatoes on the 21st day. This study showed that the Opuntia robusta tissue and extraction solvent influence mucilage characteristics and that Opuntia robusta mucilage is a promising edible coating.

The inflorescences of Chamaedorea tepejilote Liebm. are consumed as food in Central America and southern Mexico but is an underutilized food because of its sensory characteristics, principally due to its bitter taste. However, the inflorescences of Chamaedorea tepejilote Liebm. are nutritionally promising due to their high protein content (approximately 25%). Protein isolates from pacaya were modified via three different thermal treatments to determine the effect of the treatments on the protein structures. Scanning electron microscopy indicated that the pacaya protein isolate particles had less rough and irregular surfaces with larger particle sizes due to an aggregation process when a thermal treatment was used compared to those when no thermal treatment was used. An increase in the intensity of the low molecular weight protein fractions (≤20 kDa) in the electrophoretic pattern of the proteins was observed, which was generated by the hydrolysis of the proteins by heat treatment. The modifications in the FT-IR spectra showed that thermal treatment of pacaya affected the secondary structure of its proteins, mainly when microwave treatment was used. Raman spectroscopy revealed that the α–helical structure was dominant in the proteins of pacaya and that thermal treatment increased the fraction of the β–sheet structure at the expense of the α–helical structure.

Three biological activities were assessed for peptides obtained from two ayocote bean varieties, antioxidant and antihypertensive properties and antiproliferative activity against MDA breast cancer cells. For the peptides obtained from the ayocote bean black variety the highest antihypertensive activity was obtained with low-molecular weight peptides, principally with those between 5 and 10 kDa. However, for the peptides obtained from ayocote bean purple variety, the highest antihypertensive activity was achieved with peptides with a molecular weight ≥10 kDa, while that the higher antioxidant activity was noted for peptides obtained from ayocote bean purple variety. All peptides from both purple and black ayocote beans varieties inhibited MDA cells proliferation; however, the IC₅₀ was only reached with high concentrations of peptides (2000 or 5000 µg*mL −1) and exposure times of 12 or 72 h. The obtained results reveal a potential relationship among the antihypertensive, antioxidant activities and anticancer properties of the peptides.

Chamaedorea tepejilote Liebm is a palm native to the south of Mexico and Central America. In Mexico, the male inflorescences are roasted, fried, boiled, or accompanied by other ingredients to decrease their bitter aftertaste, and they can be consumed by the inhabitants. However, it has been observed that raw inflorescences have hypoglycemic, antitussive, and antimicrobial potentials, but the thermal treatment effect in these activities has not been studied; for this reason, this study evaluated the impact of three thermal treatments (hydrothermal (HP), steaming at elevated pressure (SEP), and microwave (MW)) on the nutritional and nutraceutical characteristics of Pacaya inflorescences; inflorescences without thermal treatment (WTT) were considered as the control. In the nutritional characterization, only the protein content was the fraction that increased significantly (p < 0.05) when thermal treatment was applied. On the other hand, all thermal treatments significantly modified (p < 0.05) the chlorophyll “a” content (HP reduced 0.59-fold; SEP and MW increased 0.07-0.25-fold), and chlorophyll “b” decreased. A significant (p < 0.05) carotenoids content increase in all thermally treated samples (between 0.80-fold and 8.73-fold) and total phenolic compounds (between 7.75-fold and 8.16-fold) compared to the WTT samples was observed. Microwave cooking was the only thermal treatment that significantly (p < 0.05) increased (0.97-fold) the antioxidant activity in the DPPH radical. HP (14.11%) and SEP (18.20%) significantly (p < 0.05) reduced the dipeptidyl peptidase-IV enzyme inhibition when compared to WTT (24.42%). These changes have been associated with the partial loss, destruction, or denaturalization of cell walls’ proteins, lipids, or cellulose, causing the liberating or creation of compounds with nutritional and nutraceutical activity.