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This study evaluated the effect of storage temperature (4, 25 and 40°C) and time on the color and contents of 3-deoxyanthocyanins, total anthocyanins, total phenols and tannins of sorghum stored for 180days. Two genotypes SC319 (grain and flour) and TX430 (bran and flour) were analyzed. The SC319 flour showed luteolinidin and apigeninidin contents higher than the grain and the TX430 bran had the levels of all compounds higher than the flour. The storage temperature did not affect most of the analyzed variables. The content of most of the compounds reduced during the first 60days when they became stable. At day 180, the retention of the compounds in the genotypes SC319 and TX430 ranged from 56.1-77.9% and 67.3-80.1% (3-deoxyanthocyanins), 88.4-93.8% and 84.6-96.8% (total anthocyanins) and 86.7-86.8 and 89.4-100% (phenols) respectively. The retention of tannins ranged from 56.6 to 85.3%. The color of samples remained stable for 120days., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

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., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The profile and levels of bioactive amines in different sorghum lines were reported for the first time. The amines were quantified by ion-pair HPLC, post-column derivatisation with o-phthalaldehyde and fluorimetric detection. The extraction procedure was optimised: 420 μm particle size, extraction with 5% trichloroacetic acid and three extractions. The screening of 22 sorghum lines showed that four of the ten amines investigated were detected. Spermine and spermidine were the prevalent amines (100%), followed by putrescine (77%) and cadaverine (14%). Total amines ranged from 5.8 to 41.4 mg/100 g, and the polyamines represented 60-100% of the total. Sorghum without tannin had higher amines levels compared to sorghum with tannin and cadaverine was specific to samples without tannin. Hydric stress caused accumulation of spermidine in the grains and affected the levels of other amines at rates depending on the presence or not of tannin. Sorghum is a significant source of polyamines., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

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., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The effects of domestic processing with dry heat (F2-oven/milling; F3-milling/oven; F4-microwave oven/milling; F5-milling/microwave oven; F6-popped grains/milling) and wet heat (F7-cooking in water/drying/milling) on the antioxidant profile of sorghum flours (F1-raw flour) were evaluated. 3-Deoxyanthocyanidins and total phenolic compounds were stable to dry heat (retention between 96.1% and 106.3%) and reduced with wet heat. All processing with dry heat increased the vitamin E content (2,201.9-3,112.1 μg/100 g) and its retention, and reduced the carotenoids (4.78-17.27 μg/100 g). The antioxidant activity in processed flours with dry heat remained constant (F3 and F6) or increased (F2, F4 and F5) and decreased after processing with wet heat. Overall, the grains milled before processing in oven and in microwave oven retained more vitamin E and less carotenoids than those milled after these processing. In conclusion, dry heat did not affect the phenolic compounds and 3-deoxyanthocyanidins of sorghum, but increased the vitamin E and antioxidant activity, and reduced the carotenoids. The wet heat processing reduced all antioxidant compounds except carotenoids, which increased., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The in vivo protein qualities were evaluated in flours from raw sorghum grains (RF) and flours from sorghum grains subjected to heat treatment in an oven (HTF) from the hybrids BRS 305, BRS 309 and BRS 310, developed by the Brazilian Agricultural Research Corporation (Embrapa). There were no differences in feed efficiency ratios among experimental groups. Heat-treated flour from BRS 309 and BRS 310 genotypes had higher protein efficiency ratios and net protein ratio values; however, they did not differ from those of flour from raw grain of BRS 310 genotype. Effects of heat treatment were observed in the BRS 309 genotype. Heat treatment did not affect true digestibility observed for the RF and HTF of the three genotypes. Lysine was the first limiting amino acid of the three sorghum genotypes. The HTF BRS 305 showed the lowest protein digestibility-corrected amino acid score value. Heat treatment improved the protein quality of genotype BRS 309; however, no differences were observed among the other genotypes., (Copyright © 2012 Elsevier Ltd. All rights reserved.)