Consumption of a drink containing extruded sorghum reduces glycaemic response of the subsequent meal.

PURPOSE: Glycaemic control is essential to prevent the manifestation of diabetes in predisposed individuals and the development of associated comorbidities. It is believed that sorghum may modulate the glucose response. In this study, we investigated the effect of extruded sorghum consumption, and the profile of bioactive compounds, on postprandial glycaemia of a subsequent meal in normal weight and normoglycaemic subjects. METHODS: This was a randomized, single-blind, crossover designed study. After a 12 h overnight fasting, ten subjects reported to the laboratory to participate in four experimental sessions, and consumed one of three sorghum test drinks: sorghum P 3-DXAs (with proanthocyanidins-P and rich in 3-deoxyanthocyanidins-3-DXAs); 3-DXAs (without proanthocyanidins and rich in 3-DXAs); and control (low in 3-DXAs and without proanthocyanidins); or a non-sorghum drink. 30 min later, the subjects consumed a glucose solution (25 g glucose). Glycaemic response was monitored at times 0 (before glucose solution), 15, 30, 45, 60, 90, 120 min (after glucose solution consumption). The incremental areas under the glycaemic curve (iAUC) were calculated by the trapezoidal method. RESULTS: Intake of P 3-DXAs drink before the glucose solution resulted in a postprandial iAUC lower than the other sorghum test drinks. Sorghum drinks minimized the postprandial glycaemia peak. CONCLUSION: Sorghum drinks consumption, especially the P 3-DXAs drink, 30 min before the glucose solution resulted in lower iAUC compared to the non-sorghum drink, leading to a lower glycaemic response.

Effect of Processing on Bioactive Compounds, Physicochemical and Rheological Characteristics of Juçara, Banana and Strawberry Smoothie.

This study aimed to evaluate the effect of processing steps on bioactive compounds and physicochemical and rheological characteristics of a juçara, banana and strawberry smoothie. The product was obtained by mixing the pulps of these fruits in previously defined proportions. The mixture was standardized in a pilot disintegrator, homogenized at 60 MPa in continuous mode and pasteurized at 90 °C for 35 s. The homogenization step increased the concentration of cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside, major anthocyanins in the smoothie. However, these anthocyanins, as well as perlagonidin-3-O-glucoside, have been reduced (p<0.05) after the pasteurization step. The pasteurization also affected the instrumental color of the smoothie, expressed by Hue angle (p<0.05). Regarding to the rheological behavior, the smoothie, in all processing steps, presented a non-Newtonian fluid behavior with pseudoplastic characteristics (n<1). After homogenization, the smoothie became more fluid and homogeneous. Thus, despite the negative impact of pasteurization on the smoothie's color, the pasteurized product preserves the bioactive compounds such as flavonoids and phenolic acids that are of great importance to human health. Furthermore, the development of this product contributes to add value to the juçara agro-chain and Atlantic Forest preservation.

Changes in nutritional and physico-chemical properties of pearl millet (Pennisetum glaucum) Ex-Borno variety flour as a result of malting.

The effect of malting periods on the nutritional composition and physico-chemical properties of flour from pearl millet (Ex-Borno) variety was evaluated. Grains were steeped at 25 °C for 24 h and germinated for different durations (12, 24, 36, 48, 60, 72, 84 and 96 h) before kilning at 55 °C for 18 h. The kilned seeds were devegetated, milled, sieved and analysed for their proximate composition, amino acid composition, total phenolic content, functional and pasting properties. The carbohydrate, fat and total phenolic contents of the pearl millet flour samples decreased while protein content increased with increased malting periods. Leucine was the dominant amino acid in the flour and 48 h-malted flour had the highest total amino acid (6.72). Peak viscosity significantly decreased as the malting period increased. Solubility index, pasting temperature and phenolic content of the flours ranged from 5.13 to 17.24%, 69.05 to 89.5 °C and 130.20 to 169.90 mg/100 g, respectively. Malting offers a means of improving the nutritional profile of Ex-Borno pearl millet flour with an increased protein and fibre and reduced fat content. Malting also enhanced the functional and pasting properties of the flour.

Evaluation of the Physical, Chemical, Technological, and Sensorial Properties of Extrudates and Cookies from Composite Sorghum and Cowpea Flours.

In recent years, there has been a growing demand for gluten-free and functional products, driven by consumer preferences for healthier and more diverse food choices. Therefore, there is a need to explore new ingredients that can be used as alternatives to traditional gluten-containing grains. Thus, this work evaluated the physical, chemical, technological, and sensorial properties of extrudates and cookies from composite tannin sorghum (rich in resistant starch) and white cowpea flours. Extrudates and cookies were produced from a composite flour made of sorghum and cowpea, at a sorghum:cowpea flour ratio of 70:30, 50:50, and 30:70. Then, raw flours, cookies, and extrudates were characterized (dietary fiber, resistant starch, proteins, antioxidant capacity, pasting properties, etc.). Results obtained for particle size distribution and bulk density indicated that the particles increased and the color changed with the addition of cowpea flour. The raw tannin sorghum flour had a higher resistant starch concentration (36.3%) and antioxidant capacity (211.2 µmolTE/g), whereas cowpea flour had higher levels of proteins (18.7%) and dietary fiber (20.1%). This difference in the raw flour composition contributed to the nutritional value of the extrudates and cookies, especially the cookies which undergo dry heat and had higher retention of resistant starch and antioxidants. Moreover, sorghum flour presented a higher tendency to retrograde (high setback), which was decreased by the addition of cowpea flour. Overall acceptance and intention to purchase were higher for extrudates with 100% sorghum flour (6.52 and 68.3%, respectively) and cookies with 70% cowpea flour (7.03 and 76.7%, respectively). Therefore, nutritious and functional gluten-free extrudates and cookies, of good acceptability, can be produced from composite tannin sorghum and white cowpea flours.

Germinated and non-germinated cooked whole millet (Pennisetum glaucum (L.) R. Br.) flours show a promising effect on protein quality, biochemical profile and intestinal health in vivo.

Millet is a promising cereal with high amounts of dietary fibre and protein, and in addition, bioactive compounds with health-promoting functional properties. This study aimed to evaluate the effect of germinated and cooked whole millet flour (Pennisetum glaucum (L.) R. Br.) on protein quality, biochemical profile and intestinal health in vivo. Thirty-two male Wistar rats (21 days old) were separated into four groups, which received a casein control diet (CC; n = 8), a free protein diet (aproteic; n = 8) and two treatment diets: non-germinated millet (NM; n = 8) and germinated millet (GM; n = 8) for 29 days. The whole millet flours presented an adequate essential amino acid profile, except for lysine. The GM group presented a higher protein efficiency ratio and net protein ratio compared to the NM group. Weight gain, Lee index, and food efficiency ratio were lower in the treatment groups, compared to the control group. The GM group had lower plasma glucose, uric acid, cholesterol, and faecal pH compared to the other groups. The treatment groups presented lower triglyceride levels, higher levels of acetic and propionic acids, a larger thickness and depth of the colonic crypts, and a higher expression of PepT1 genes than the CC group. In conclusion, the millet flours demonstrated potential for controlling the lipid profile and biometric measurements. Additionally, the whole germinated millet flour provided better protein quality and improved intestinal morphology and functionality. These results indicate that the consumption of millet could be increased in human food, and considering its potential health benefits, it could be an alternative for dietary diversification, and germination is a good processing option.

Microencapsulation of vitamin D3 by complex coacervation using carboxymethyl tara gum (Caesalpinia spinosa) and gelatin A.

Vitamin D3 plays a fundamental role in human health; however, it is highly susceptible to environmental conditions and the gastrointestinal tract. In this study, complex coacervates obtained from gelatin A and carboxymethyl tara gum (CMTG) were used as wall materials for the encapsulation of vitamin D3 (VD3). Zeta potential and turbidity measurements were employed to optimize the pH and ratio (gelatin A:CMTG), and the results showed that the ideal conditions for the complex coacervation were pH 4.0 and a 6:1 ratio. The encapsulation efficiency (EE) was determined as a function of the total concentration of biopolymers (TC%) and the core-to-wall ratio, and the greatest EE (80%) was achieved at a TC of 1% and a ratio of 1:2; spherical particles with an average size of 0.25 µm were obtained. The microencapsulation increased the thermal stability of VD3, and FTIR confirmed the presence of the biopolymers and VD3 in the capsules. An in vitro simulation showed a more pronounced release in the small intestine with a vitamin bioaccessibility of 56%. The encapsulation of bioactive lipophilic compounds by complex coacervates of gelatin A and CMTG resulted in improved stability and prolonged release during digestion.

Effect of extrusion and turmeric addition on phenolic compounds and kafirin properties in tannin and tannin-free sorghum.

Sorghum is a potential substitute for corn/wheat in cereal-based extruded products. Despite agronomic advantages and its rich diversity of phenolic compounds, sorghum kafirins group together and form complex with tannins, leading to a low digestibility. Phenolic content/profile by UPLC-ESI-QTOF-MSE and kafirins polymerization by SE-HPLC were evaluated in wholemeal sorghum extrudates; tannin-rich (#SC319) and tannin-free (#BRS330) genotypes with/without turmeric powder. Total phenolic, proantocyanidin and flavonoid contents were strongly correlated with antioxidant capacity (r > 0.9, p < 0.05). Extrusion increased free (+60%) and decreased bound phenolics (-40%) in #SC319, but reduced both (-40%; -90%, respectively) in #BRS330, which presented lower abundance after extrusion. Turmeric addition did not significantly impact antioxidant activity, phenolic content and profile and kafirins profile. Tannins presence/absence impacted phenolic profiles and polymerization of kafirins which appears related to the thermoplastic process. The extrusion improved proteins solubility and can positively enhance their digestibility (phenolic compounds-proteins interactions), making more accessible to proteolysis in sorghum extrudates.

Stability of B vitamins, vitamin E, xanthophylls and flavonoids during germination and maceration of sorghum (Sorghum bicolor L.).

The impact of maceration and germination on the concentration of bioactive compounds still needs to be evaluated. The stability of B complex vitamins (thiamine, riboflavin, pyridoxine), vitamin E (α, ß, γ, δ tocopherols and tocotrienols), xanthophylls (lutein and zeaxanthin) and flavonoids (3-deoxyanthocyanidins-3-DXAs, flavones and flavanones) was evaluated in sorghum grains subjected to maceration and germination, using High Performance Liquid Chromatography. Maceration and germination reduced thiamine and pyridoxine concentrations (retentions ranging from 3.8 to 50.2%). Riboflavin and Vitamin E concentrations were not affected by maceration. Germination increased riboflavin and reduced vitamin E. 3-DXAs were sensitive to maceration and germination (retentions of 69.6% and 69.9%, respectively). Flavones contents decreased with germination. Our results indicate that, after germination and/or maceration, sorghum had important nutritional and functional value. Thus, its intake, mainly in macerated forms, should be encouraged, since concentrations of riboflavin, vitamin E and flavones were not altered during this processing.

Physicochemical, thermal and rheological properties of synthesized carboxymethyl tara gum (Caesalpinia spinosa).

Carboxymethyl tara gum (CMTG) was synthesized from the reaction between tara gum (TG) and monochloroacetic acid (MCA) in the presence of sodium hydroxide. The modification reaction was optimized in terms of the MCA/NaOH ratio, reaction time and temperature evaluated for degree of substitution (DS). The etherification was confirmed by FTIR and 13C NMR spectroscopy, and it was characterized by different analyses. After carboxymethylation, CMTG showed new bonds at 1592, 1413 and 1320 cm-1 by FTIR and a new peak at δ = 178 ppm by 13C NMR in response to the insertion of the carbonyl group. The microscopy showed higher degradation on the surface of the CMTG particles, and XRD indicated low crystallinity of the CMTG. Static light scattering demonstrated a reduction in the molar mass of tara gum after carboxymethylation. Thermal analysis (TGA and DSC) revealed a lower thermal stability of carboxymethylated gum compared to that of unmodified gum. Despite the insertion of negative charges demonstrated by the potential-zeta, CMTG and TG presented pseudoplastic behavior according to the rheological analyses, and CMTG presented lower viscosity at the concentrations that were studied.

Formation and characterization of the complex coacervates obtained between lactoferrin and sodium alginate.

The aim of this study was to evaluate the influence of some parameters (pH, NaCl, and ratio of biopolymers) on the formation of the complex coacervates of lactoferrin and sodium alginate. Different ratios of lactoferrin:sodium alginate were tested (1:1, 1:2, 1:4,1:8, 2:1, 4:1, and 8:1) at pH levels ranging from 2.0 to 7.0 with different concentrations of NaCl (0, 50, 100, 150, and 200 mM). Sodium alginate has a molecular weight of 138 kDa ±â€¯0.07. The ratio of 8:1(lactoferrin: sodium alginate) at a pH of 4.0 with a low salt concentration was the optimal condition for the formation of the complex. The thermodynamic parameters demonstrated that the interaction between lactoferrin and sodium alginate was exothermic and spontaneous with a favorable enthalpic and unfavorable entropic contribution during the interaction. The chemical, thermal and morphological characteristics of the biopolymers and the complex coacervates demonstrated their nature and changes due to electrostatic interactions. The formation of complex coacervates between lactoferrrin and sodium alginate can serve as an alternative to the incorporation of lipophilic functional ingredients sensitive to high temperatures in various food systems.

Tocochromanols and carotenoids in sorghum (Sorghum bicolor L.): diversity and stability to the heat treatment.

The content and stability (retention) to dry heat in a conventional oven (DHCO) and extrusion of tocochromanols and carotenoids in sorghum genotypes were evaluated. One hundred sorghum genotypes showed high variability in tocochromanol content (280.7-2962.4 µg/100g in wet basis) and 23% of the genotypes were classified as source of vitamin E. The total carotenoid varied from 2.12 to 85.46 µg/100g in one hundred sorghum genotypes. According to the genetic variability for carotenoids and tocochromanols, the 100 genotypes were grouped into 7 groups. The retention of the total tocochromanols and α-tocopherol equivalent decreased after extrusion (69.1-84.8% and 52.4-85.0%, respectively) but increased after DHCO (106.8-114.7% and 109.9-115.8%, respectively). Sorghum carotenoids were sensitive to extrusion (30.7-37.1%) and DHCO (58.6-79.2%). In conclusion, the tocochromanols profile in sorghum varied widely and the genotypes presented high genetic variability for carotenoids and tocochromanols. Sorghum was a source of tocochromanols, which increased after DHCO and decreased after extrusion. The carotenoid content in sorghum decreased after DHCO and extrusion.