Purple maize arabinoxylan could protect antioxidant compounds during digestion.

Purple maize is a pigmented variety rich in antioxidants. Arabinoxylans (AX) are prebiotic compounds also found in the grain wall that can form gels. Recently, antioxidants have extensively been studied for their beneficial effects. However, these bioactive compounds do not easily reach the intestine in a stable form. These gels can protect certain compounds during in vitro digestion. This work aimed to extract the AX and simultaneously obtain the antioxidant compounds present in the external walls of the purple maize grain to produce gels with 2% and 4% AX to apply an in vitro digestion method. Popcorn maize (unpigmented) was used as a control. The amount of ferulic acid, polyphenols, and anthocyanins, and their antioxidative activity, were measured at in vitro digestion of the gels. This work highlights the ability of AX gels to enhance the potential bioavailability of antioxidant compounds including anthocyanins from purple maize after digestion.

Effect of Different Wheat Sprouting Conditions on the Characteristics of Whole-Wheat Flour.

Research background: Controlled sprouting promotes physiological and biochemical changes in whole grains, improves their nutritional value and offers technological advantages for breadmaking as an alternative to traditional whole grains. The aim of this study is to find sprouting conditions for the grains of Klein Valor wheat variety (Triticum aestivum L.) that would increase the nutritional value without significantly affecting the gluten proteins, which are essential in wholegrain baked goods. Experimental approach: The chemical and nutritional composition, enzymatic activity and pasting properties of the suspensions of unsprouted and sprouted whole-wheat flour were evaluated. Results and conclusions: This bioprocess allowed us to obtain sprouted whole-wheat flour with different degrees of modification in its chemical composition. Sprouting at 25 °C resulted in an observable increase in enzymatic activity and metabolic processes, particularly α-amylases, which significantly affect the starch matrix and the associated pasting properties. Additionally, there was a smaller but still notable effect on the structure of the cell walls and the protein matrix due to the activation of endoxylanases and proteases. In contrast, sprouting at 15 and 20 °C for 24 h allowed for better process control as it resulted in nutritional improvements such as a higher content of free amino acid groups, free phenolic compounds and antioxidant capacity, as well as a lower content of phytates. In addition, it provided techno-functional advantages due to the moderate activation of α-amylase and xylanase. A moderate decrease in peak viscosity of sprouted whole-wheat flour suspensions was observed compared to the control flour, while protein degradation was not significantly prolonged. Novelty and scientific contribution: Sprouted whole-wheat flour obtained under milder sprouting conditions with moderate enzymatic activity could be a promising and interesting ingredient for wholegrain baked goods with improved nutritional values and techno-functional properties. This approach could avoid the use of conventional flour improvers and thus have a positive impact on consumer acceptance and enable the labelling of the product with a clean label.

Co-ingestion of Cereals and Legumes during Infant Complementary Feeding: Starch and Protein in vitro Digestion.

This study explores the impact of co-ingesting cereals and legumes on starch and protein during simulated infant in vitro digestion. Various legumes (chickpeas, lentils, peas) were added to cereals (durum wheat, brown rice, white maize), and their effects on starch and protein hydrolysis were analyzed. Substituting 50% of cereal with legumes increased proteins, minerals, and dietary fiber. Infant food with legumes exhibited smoother pasting properties. Legumes in cereal purées led to varying starch hydrolysis trends, with the lowest values in durum wheat with chickpea and all cereal blends with peas. Resistant starch levels exceeding 50% were found in infant food samples. Digested protein hydrolysis increased with legumes in durum wheat, except for peas. Brown rice mixtures decreased significantly compared to the control with chickpeas (61%) and peas (42%), while lentil blends increased by 46%. Legumes generally did not significantly affect starch bioavailability, even with α-amylase inhibitors. Lentil-cereal purées could enhance infant food nutritional value.

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.

Sorghum Pasta and Noodles: Technological and Nutritional Aspects.

Sorghum is a major cereal crop with various agronomic advantages, contains health-promoting compounds and is gluten-free. There is a growing tendency to use sorghum in pasta and noodle formulations, which are among the most widely consumed products in the world, but its potential benefits in human diet are not being fully exploited. Here we review research carried out during the past few years on the use of sorghum as the main ingredient or as an additive in pasta and noodles, highlighting its properties and production technology. Pasta and noodles can be produced with 5 to 100% of sorghum at laboratory, pilot or industrial scale with suitable cooking and textural quality coupled with distinctive sensory attributes. Cooking loss shows minimum values of 0.85 and 1.9 g/100 g for pasta and noodles, respectively, and high water absorption (up to 345 g/100 g). The interesting nutritional profile of the products generally includes up to 45% resistant starch (RS) and phenolic compound content with high antioxidant activity. In addition, tannins decrease starch digestibility 15-20%, producing low glycemic index (GI) products (below 65). This is especially important for celiac people, offering them the alternative of gluten-free sorghum pasta and noodles.

Gluten-free sorghum pasta: starch digestibility and antioxidant capacity compared with commercial products.

BACKGROUND: The development of new products with a focus on nutrition, rather than other technical aspects, is essential to improve the quality of celiac diets. Nutritional attributes of white and brown sorghum gluten-free pasta developed in a previous work were analyzed. The extent and kinetics of starch in vitro digestion, estimated glycemic index (eGI), potentially bioaccessible and dialyzable polyphenols, and antioxidant activity were evaluated and compared with commercial products. RESULTS: Sorghum flour samples were used to obtain pasta with high protein (≈170 g kg-1 ), dietary fiber (≈80 g kg-1 ), polyphenols (2.6 g GA kg-1 pasta), and antioxidant activity. This sorghum pasta showed slower starch in vitro digestion than the other gluten-free pasta, with a high level of protein hydrolysis (76%). The highest eGI was observed in a rice sample (69.8) followed by a corn-based pasta (66.4). White and brown sorghum gluten-free pasta showed 2.9 and 2.4 times, respectively, higher potentially bioaccessible polyphenol content compared to that in cooked pasta. No significant variation in antioxidant activity was found in sorghum pasta after digestion and around 48% and 36% of activity was detected in dialysate. CONCLUSION: Both types of sorghum gluten-free pasta have demonstrated their nutritional value and represent a good potential alternative to current commercial pasta. © 2018 Society of Chemical Industry.

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.

In vitro dialyzability of essential minerals from white and whole grain pasta.

The aim of the present investigation was to study the in vitro mineral dialyzability of pasta made with white and whole-grain flours obtained from two genotypes (Klein Guerrero and Baguette Premium 11) with different mineral contents. Pasta samples were made from white flour (FP), and whole grain flour from cyclonic mill (WFAP) and blade mill (WFBP). Mineral content and in vitro digestion were determined on all samples to study starch variation and mineral dialyzability. Whole-grain pasta contained significantly higher amounts of minerals than FP, since bran and embryo are richer in minerals than endosperm. In addition to the low content of mineral composition observed in FP, the dialyzability of some minerals (Cu, Fe, Mg and Zn) was higher than whole-grain pasta even when the percentage of starch hydrolyzed after intestinal digestion was higher than FP. These results can also be useful for developing wheat-based products rich in the desired minerals.

The Influence of Different Air-Drying Conditions on Bioactive Compounds and Antioxidant Activity of Berries.

The aim of the present research was to study the effect of convective drying on color, bioactive compounds, and antioxidant activity of berry fruits and to chemically characterize the polyphenolic composition of raspberry, boysenberry, redcurrants, and blackcurrants fruit. Drying berries at 65 °C provoked the best conservations of color, particularly for boysenberry and blackcurrant. Drying at 65 °C was also the condition that showed higher level of polyphenols, while drying at 50 or 130 °C showed above % degradation of them due to the long time or high temperature drying. Radical scavenging activity was the predominant antioxidant mechanism in all samples, with 65 °C dried berries being the most active ones possibly because of polyphenol depolymerization. The anthocyanin profile showed that delphinidin and cyanidin derivatives were the most abundant anthocyanidins with different predominance between berry genera. Degradation of anthocyanins was increased with drying temperature been Cy 3-glucoside and Cy 3-rutinoside the most abundant.

Effect of Ingredients on the Quality of Gluten-Free Sorghum Pasta.

Sorghum is an underutilized cereal in human food production, despite its flour being a potential gluten-free (GF) source in the development of several foods. Thus, the aim of the present investigation was to evaluate the effects and interactions of different ingredients on cooking quality and texture of GF pasta. Egg albumen (A), egg powder (E), xanthan gum (X), and pregelatinized corn starch (P) were used as ingredients, and Box-Behnken experimental design was applied to study the effects of these ingredients on pasta cooking behavior, color, and texture attributes. Responses were fitted to a second order polynomial equation, and multivariable optimization was performed using maximization of general desirability. Next, optimal formulations were validated, compared with two commercial gluten-free pastas by sensory evaluation, and finally, an industrial assay was carried out. Regression coefficients indicated that A and P improved cooking properties while A and E contributed the most to improving the pasta textural properties. As, X and P effects varied depending on the kind of sorghum flour used, the optimal formulations levels were different, but in both cases these models were satisfactory and capable of predicting responses. The industrial assay was carried out with white sorghum flour because it showed a higher acceptability in the sensory evaluation than brown sorghum flour pasta. This industrially made pasta resulted in slightly better cooking properties than the laboratory produced one, with the formulation adapting well to the conventional wheat pasta industrial process. Gluten-free sorghum pasta was produced, showing good cooking and textural properties and being a suitable option for gluten-sensitive individuals.