Assessment of Technological and Sensory Properties, Digestibility, and Bioactive Compounds in Polentas from Different Maize Genotypes.

The sensory profile of polenta and the connections between technological attributes and varieties of maize have not been extensively studied. Thus, it is necessary to understand the possible effect of its consumption on consumers' health in terms of postprandial glucose levels and molecules associated with healthy activities. This work aims to study polenta's technological and sensory properties from different maize genotypes and evaluate their digestibility and the potential contribution of bioactive compounds on health. A commercial hybrid, two open-pollinated varieties, and three inbred lines were used. Grain physical determinations and physical-chemical semolina traits were determined. Polenta's technological quality was evaluated after simulated cooking. In vitro digestion was performed for polentas, and a sensory evaluation test was conducted. A significant correlation was found between semolina polyphenols and rapidly digestible starch (r = -0.6). Panellists characterised the genotype C6006 as having a good flavour, sandier mouthfeel, and low consistency. Also, the polenta from the hybrid exhibited sensory attributes more closely resembling commercial polenta in terms of maize odour, flavour, and consistency. The higher content of polyphenols presents in semolina affected the digestion of polenta, showing a lower proportion of rapidly digestible starch and a lower amount of bioaccessible protein fraction.

Technological and Sensory Quality of Gluten-Free Pasta Made from Flint Maize Cultivars.

The development of quality gluten-free products presents a major technological challenge in terms of structure, texture, and shelf life. However, there is insufficient information available to identify genotypes for obtaining gluten-free maize pasta of good acceptability and technological quality. The objective of this work was to evaluate the technological and sensory quality of gluten-free pasta made from different maize cultivars. The flint open-pollinated variety, flint inbred line, and three dent commercial hybrids were used. Grain and flour's physical characteristics and chemical composition were determined. Gluten-free pasta was made via extrusion, and its quality traits were studied. A sensory evaluation test was carried out. Flint cultivars showed the lowest values on swelling index (both 1.77) and water absorption (124.30 and 134.58%). Pasta swelling index showed a negative association r = -0.77 to sodium carbonate retention capacity (p = 8.5 × 10-5) and water retention capacity (p = 6.6 × 10-5). Evaluators' preference results showed a higher frequency of choices at the top level of preference (4) for the flint open-pollinated variety C6006. Thus, evaluators' choices showed a positive association between sample preference and firmness. Pasta preference and technological quality have a direct relationship with fast tests over grain, such as test weight and float index.

High-Power Ultrasound in Gas Phase: Effects on the Bioactive Compounds Release from Red Bell Pepper during In Vitro Gastrointestinal Digestion.

High-power ultrasound in gas-phase (28.8 kW/m3 for 120 min at 17.5 ± 0.3 °C) has been evaluated as a pre-treatment to enhance the release of antioxidants and phenolic compounds from red bell pepper during digestion. The moisture content decreased (34 ± 4%) while both the antioxidant activity (between 4 ± 1% and 21 ± 1%) and the phenolic compounds content (37 ± 4%) increased after the treatment. Moreover, microstructural changes were observed in the treated sample, with the appearance of breaks in the plant tissue, cell shrinkage, and an increased number of cells per area unit (28 ± 2%). Bioaccessibility was determined by in vitro gastrointestinal digestion. The total release of antioxidants and phenolic compounds after gastrointestinal digestion was 22-55% higher and 45 ± 7% higher, respectively, in the sonicated sample, with cell swelling and a 9.2 ± 0.1% higher number of cells per area unit. Therefore, the ultrasound treatment caused microstructural changes in the red bell pepper tissue, which could help to explain the higher release of bioactive compounds.

Sodium chloride replacement by potassium chloride in bread: Determination of sensorial potassium threshold and effect on dough properties and breadmaking quality.

High sodium intakes represent an important risk factor for hypertension, cardiovascular diseases and kidney diseases. Even during the current COVID-19 pandemic, hypertension was related to higher mortality rate in patients with coronavirus. Thus, it is necessary to apply strategies to reduce or replace sodium content in food most widely consumed, like bread. This work aimed at determining the sensorial potassium threshold when potassium chloride is used as a sodium chloride replacer in bread formulation, and at analyzing the effects of such replacement on the properties of dough and on the technological and sensorial quality of bread. A decrease was observed in dough rheological properties with NaCl reduction in the formulation. Sensorial potassium threshold was determined and KCl was used in bread formulation as a NaCl replacement up to 0.92% of the regular salt content (2%) undetected by its characteristic taste. NaCl reduction resulted in bread with lower specific volume, higher firmness, faster staling and clearer crust. KCl bread showed similar technological to 2% NaCl bread. Finally, it was possible to replace 50% of NaCl with KCl without reducing quality and consumer acceptability.

Starch Digestion in Infants: An Update of Available In Vitro Methods-A Mini Review.

Complementary feeding starts at around six months of age because neither breast milk nor formula assure the proper nutrition of infants. Therefore, along with breast milk, solid foods are gradually introduced, particularly cereal-based foods, which will provide starch as a new source of energy and nutrients. As a result, the need of an adequate in vitro digestion method to study the influence of different aspects of weaning period is unquestionable. This critical review summarizes the in vitro digestion methods available for the analysis of starch hydrolysis under infant conditions considering different features, namely, starch digestion, infant digestive conditions and in vitro models suitable for the study of starch digestion (static, semi-dynamic and dynamic). Key factors such as enzyme concentrations, transit time, oral, gastric and intestinal conditions and differences with current adult models, have been addressed. The need for standardized infant digestion models adapted to the complementary feeding period was discussed. Existing literature data demonstrate that more effort has to be done to improve the research on this issue, in order to obtain comparable results that would address a better understanding of the digestibility of different food nutrients under infant conditions facilitating the development of appropriate formulations that may assure proper infant nutrition.

Effect of Wholewheat Flour Particle Shape Obtained by Different Milling Processes on Physicochemical Characteristics and Quality of Bread.

RESEARCH BACKGROUND: Wholewheat flour is a very good source of nutritional compounds and functional ingredients for human diet. However, it causes negative effect on bread quality. Different milling techniques can be used to obtain wholewheat flour, minimizing the negative effect of both bran and germ on bread quality. The aim of this work is to study the effect of particle size and shape of wholegrain flour on the interaction among the different components, water distribution, dough rheology and bread volume. EXPERIMENTAL APPROACH: Wholewheat flour of three varieties (Klein Rayo, Fuste and INTA 815) was obtained in cyclonic, hammer and roller mills. The characteristics of wholewheat flour were explored, and the water distribution and rheological properties of dough were determined by thermogravimetric analysis and Mixolab test, respectively. Finally, microscale bread was prepared. RESULTS AND CONCLUSIONS: The amount of water-soluble pentosans, damaged starch and wet gluten was affected by the milling procedure. Regarding dough rheological properties, wholewheat flour obtained in hammer mill had the lowest water absorption capacity and the highest developing time. This result could be mainly attributed to particle shape in these samples with large amount of endosperm attached to the bran, hindering protein unfolding. Thermogravimetric analysis showed that both fine and large bran particle size seem to have the same effect on water properties in wholewheat dough during heating. Bread made with Klein Rayo variety had the highest specific volume, indicating that wheat with high protein content and breadmaking quality is needed to make wholewheat bread. The results of this work showed that particle shape, rather than particle size, affected the quality of wholewheat flour for breadmaking. NOVELTY AND SCIENTIFIC CONTRIBUTION: The effect of milling type and particle shape of the wholewheat flour had a greater effect than the wheat variety. Thus, the wholegrain milling process should be carefully selected taking to account the shape of the produced particle. This may open new opportunities for developing wholewheat bread with better acceptance by consumers.

Physico-chemical characterization of protein fraction from stabilized wheat germ.

Wheat germ shows the highest nutritional value of the kernel. It is highly susceptible to rancidity due to high content of unsaturated fat and presence of oxidative and hydrolytic enzymes. In order to improve its shelf life, it is necessary to inactivate these enzymes by a thermal process. In this work the functional properties and some characteristics of the protein fraction of treated wheat germ were evaluated. Sequential extraction of proteins showed loss of protein solubility and formation of aggregates after heating. DSC thermograms showed that wheat germ treated for 20 min at 175 °C reached a protein denaturation degree of ~ 77%. The stabilization process of wheat germ affected significantly some functional properties, such as foaming stability and protein solubility at pH 2 and pH 8. Nevertheless, heating did not affect the water holding, oil holding and foaming capacity of protein isolates.

Whole grain cereals: functional components and health benefits.

Cereal-based food products have been the basis of the human diet since ancient times. Dietary guidelines all over the world are recommending the inclusion of whole grains because of the increasing evidence that whole grains and whole-grain-based products have the ability to enhance health beyond the simple provision of energy and nutrients. In this review we will examine the main chemical components present in whole grains that may have health enhancing properties (dietary fiber, inulin, beta-glucan, resistant starch, carotenoids, phenolics, tocotrienols, and tocopherols) and the role that whole grains may play in disease prevention (cardiovascular diseases and strokes, hypertension, metabolic syndrome, type 2 diabetes mellitus, obesity, as well as different forms of cancer). The knowledge derived from the functional properties of the different chemical components present in whole grains will aid in the formulation and development of new food products with health enhancing characteristics.

Differential scanning calorimetry (DSC) studies on the thermal properties of peanut proteins.

Studies related to the functional and thermal properties of peanut proteins are limited if compared with other vegetable protein sources. The aim of this work was to study the thermal denaturation of peanut protein isolates (PPI) by DSC. The thermal profile of PPI showed two endothermic peaks (assigned to denaturation of arachin and conarachin fractions). The thermal stability of arachin and conarachin increased when water content decreased, and a critical water level was found for both fractions. The effect of protein denaturants was studied. Low contents of urea stabilized protein fractions, but lower T(d) values were found with increasing concentrations. DeltaH values of arachin were affected by urea. SDS affected DeltaH values and thermal stability of conarachin; the arachin fraction showed higher resistance to SDS-induced denaturation. DTT addition did not affect conarachin stability, although enthalpy values decreased significantly. On the other hand, arachin was greatly affected by DTT. In summary, thermal denaturation parameters of PPI were sensitive to water content, indicating that polar groups of arachin and conarachin contribute to structure stabilization. Urea addition mainly affected the structure of the arachin fraction, which was attributed to its higher surface hydrophobicity. Results obtained from SDS and DTT suggest that hydrophobic interactions and disulfide bonds play an important role in structure maintenance of arachin and conarachin.