Does sorghum phenolic extract have antifungal effect?

This study aimed to evaluate the antifungal effect of SC319 sorghum phenolic extract (SPE) on the Aspergillus, Fusarium, Penicillium, Stenocarpella, Colletotrichum, and Macrophomina genera. SPE was extracted by 20% ethanol and used in four assays: (1) against Fusarium verticillioides in solid (PDA) and liquid (PD) potato dextrose media; (2) Minimum Inhibitory Concentration (MIC) assay with 16 fungi isolates; (3) Conidial Germination Rate (CGR) with 14 fungi isolates and (4) Growth Curve (GC) with 11 fungi isolates. There was no reduction in the mycelial growth (colony diameter and dry weight) and in the number of Fusarium verticillioides spores in assay 1 (PDA and PD). The colony's dry weight was almost six times higher in the presence than in the absence of SPE. All SPE samples presented MIC (assay 1) above the maximum concentration tested (5000 µg.mL-1) for the 16 isolates. Also, there was no inhibitory effect of SPE on conidia germination rate (CGR). Oppositely, in GC assay, the control had a higher CFU count than the samples with SPE in 24 h. This result suggests that SPE can delay the fungal growth in the first hours of incubation, which is an important finding that may help reduce the severity of fungal diseases in plants. However, further studies are needed to confirm these results, including sorghum genotypes with different profiles of phenolic compounds. Although the SC319 SPE was not effective as an antifungal agent, it may have potential as a growth promoter of beneficial fungi in the food and pharmaceutical industries.

Physicochemical and sensorial characteristics of beef burgers with added tannin and tannin-free whole sorghum flours as isolated soy protein replacer.

The physicochemical and sensorial characterization of beef burgers with added sorghum flours as replacer for the isolated soy protein (ISP) usually used in the conventional formulations was performed. Three formulations were prepared: one conventional (CN) with 3% ISP and two with 3% tannin (BRS 305) and tannin-free (BR 501) whole sorghum flour (WSF) of BRS 305 and BR 501 genotypes. There was no difference among the formulations for most of the physicochemical characteristics. The moisture retention was higher in BRS 305 (P < .05). The added WSF influenced the color of the raw beef burger; and the proximate composition and the antioxidant characteristics of the raw and cooked formulations (P < .05). The purchase intention and flavor, texture and overall acceptability scores were higher for the sorghum products than CN (P < .05). Therefore, the replacing of ISP by WSF in beef burger, especially by the BRS 305 genotype, might be a technologically, nutritionally and sensorially viable option.

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.

Resistant starch content among several sorghum (Sorghum bicolor) genotypes and the effect of heat treatment on resistant starch retention in two genotypes.

The resistant starch (RS) contents in 49 sorghum genotypes and the effects of heat treatment using dry and wet heat on the grain and flour from two sorghum genotypes were investigated. The results showed a wide variation in the RS contents of the genotypes analyzed. The RS mean values were grouped into six distinct groups and ranged from 0.31±0.33 g/100 g to 65.66±5.46 g/100 g sorghum flour on dry basis. Dry heat causes minor losses in the RS content with retentions of up to 97.19±1.92% of this compound, whereas wet heat retained at most 6.98±0.43% of the RS. The SC 59 and (SSN76)FC6608 RED KAFIR BAZINE (ASA N23) cultivars, which have an average RS content of 65.51 g/100 g, were appropriate for human consumption, and the use of dry heat is presented as a better alternative for the preservation of RS in heat-treated grains.

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.