No abstract

Protein functional properties are related to physical and chemical parameters that influence protein behavior in food systems during processing, storage and consumption. The structural and rheological properties of three quinoa hyperprotein flours (without defatting, WD, chemically defatted, CD, and mechanically defatted, MD) were evaluated. The values of the fluidity index (n) were significantly different (p < 0.05), which was associated with changes in protein or starch structures due to solvent treatments or heating of the flour during pressing. In addition, a strong dependence of the consistency index (k) on the shear rate was observed. For dispersions with a concentration of 12% (w/v), CD and WD had a significantly lower setback value than MD. The viscosity peak was affected by the presence of lipid molecules. Greater changes were evident in the β-sheet (1,610 and 1,625 cm−1) and β-spin (1,685 and 1,695 cm−1) structures. The changes identified in these structures were associated with the defatting treatment. Consequently, the intensity ratio 2,920/1,633 cm−1 was more sensitive to changes in the fat content of the flours. It was shown that defatting conditions increase the protein adsorption kinetics and that the viscoelastic properties of the protein increase when the flour has a lower fat content. Hyperprotein quinoa flour could be used to improve the protein content of products such as snacks, pastas, ice cream, bakery products, meat extenders, among others, due to its foaming, gelling or emulsifying capacity. The objective of this work was to study the effect of two types of defatting of hyperprotein quinoa flour on its structural and rheological properties.

The protein, carbohydrate, and fat characteristics of quinoa grains reflect in their techno-functional potential. This aspect has been little studied in quinoa, while some physicochemical and rheological characteristics have been generalized for all cultivars under all primary production conditions. The aim of this research is to determine the agro-industrial potential of different quinoa cultivars evaluated under different environments through physicochemical and rheological responses. This study has a factorial design with a first level corresponding to cultivars and a second level to production zones. The results showed that the cultivars present high compositional variability. It was also found that the altitudinal gradient changes protein and starch composition, protein secondary structure, and starch structural conformation. In addition, significant variations were found in viscosity, breakdown, and dispersion setback for all treatments. However, there were no differences between treatments before heating/cooling and after heat treatment.

The conditions of the agroecological environment play a fundamental role in the physiological performance of quinoa; however, due to the accelerated expansion of quinoa cultivation and the great diversity of cultivars present in the world, it has not been possible to study the effect that their interaction can have, which brings with it problems in productivity and even in the adaptability of cultivars. The aim of this research was to evaluate the physiological performance of seven quinoa cultivars under three altitude gradients in the central region of Colombia (cold, temperate and warm climates). The research was developed using a completely randomized design with a 3 × 7 factorial arrangement where the first factor corresponded to the study areas and the second factor to the selected cultivars. The results showed a highly differential performance between the phenological, physiological and compositional variables, mainly between the quinoa cultivars planted in cold climates and those established in temperate and warm climates. In this sense, the time elapsed between the phenophases, the physiological activity associated with the chlorophyll content and the quantum efficiency of photosystem II, as well as the grain yield and its protein content, are highly influenced by the cultivar and the altitudinal gradient. The results obtained support the notion that the physiological performance of quinoa depends largely on the edaphoclimatic environment by influencing different agronomic and compositional parameters of the seeds. Additionally, it was possible to identify that the evaluated quinoa cultivars were grouped into two large groups. The first group is made up mainly of the Nueva and Soracá cultivars, while the second group includes the Nariño and Puno cultivars. These four cultivars show a lower effect of the factors and their interaction on the parameters evaluated.

In recent years, great interest has been shown in pseudocereals for their high nutritional value. Wet milling has been used to obtain macromolecules such as proteins and starches. However, the co-products obtained from this food industry have been studied little. A factorial design Box-benhken was used to study the effect of surfactant concentration (SDS), sodium hydroxide (NaOH) concentration and maceration temperature on structural and colorimetric properties. Structural properties were evaluated by infrared spectroscopy (FTIR-ATR) and color changes by the CIElab tristimulus method (L*, a*, b*). A decrease in temperature and NaOH causes a decrease in lightness (L*), resulting in lower starch content and higher protein content in the co-product. This behavior was correlated with the infrared spectroscopy (FTIR-ATR) spectra. The spectra show a possible structural change in the amylose/amylopectin ratio of the starch granule at 1,012 cm−1, 1,077 cm−1, and 1,150 cm−1 bands, which are associated with glycosidic bonds, these bonds were sensitive to NaOH concentration. While those bands assigned to Amide II (1,563 cm−1) and Amide I (1,633 cm−1), were sensitive to the effect of NaOH and maceration temperature, evidencing that protein content in the co-products is variable and depends significantly on the extraction conditions. The co-products obtained by wet milling could be used in the development of functional foods, such as bread, snacks, pasta and other products.