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John R N Taylor - One of the best experts on this subject based on the ideXlab platform.
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effect of Sorghum type and malting on production of free amino nitrogen in conjunction with exogenous protease enzymes
Journal of the Science of Food and Agriculture, 2015Co-Authors: Bhekisisa Chushuta Dlamini, E M Buys, John R N TaylorAbstract:BACKGROUND Sorghum types suitable for brewing and bioethanol production are required. The effect of Sorghum type (white non-tannin versus white type II tannin) on free amino nitrogen (FAN) production from Sorghum grain and malt using exogenous protease enzymes was investigated over extended incubation at moderate temperature (45 °C). RESULTS With grain in the absence of exogenous proteases, white non-tannin Sorghum produced substantially higher levels of FAN than white type II tannin Sorghum, due to the tannins in the latter. Incubating Sorghum grain with neutral proteinase and amino-peptidase in combination improved FAN production. The two Sorghum types produced similar FAN levels when malted and incubated in the absence of the exogenous proteases. When both Sorghums were malted and incubated with neutral proteinase alone substantially more FAN yield (124–126 mg 100 g−1) occurred than with grains (61–84 mg 100 g−1). The combination of amino-peptidase and proteinase did not improve FAN further. Neither, did malting influence wort free amino acid profile. Group B amino acids constituted the highest percentage (42–47%). CONCLUSION With grain, white non-tannin Sorghum plus proteinase and amino-peptidase yields the highest FAN, with malt both white non-tannin and white type II tannin Sorghums plus proteinase yield the highest FAN. © 2014 Society of Chemical Industry
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effect of phytate reduction of Sorghum through genetic modification on iron and zinc availability as assessed by an in vitro dialysability bioaccessibility assay caco 2 cell uptake assay and suckling rat pup absorption model
Food Chemistry, 2013Co-Authors: Johanita Kruger, John R N Taylor, Fabiana F De Moura, Bo Lonnerdal, Andre OelofseAbstract:Improved iron and zinc availability from Sorghum, a commonly consumed staple, will benefit many malnourished communities in rural Africa burdened with high prevalence of iron and zinc deficiency. This research compared the effect of genetic phytate reduction in Sorghum on iron and zinc bioaccessibility and uptake measured by in vitro dialysability and Caco-2 cell uptake assays to that of iron and zinc absorption measured by a suckling rat pup model. The phytate reduction (80-86%) in these Sorghums significantly increased zinc availability. The Caco-2 cell method, but not the dialysability assay, proved useful in estimating zinc absorption. The measured increase in iron availability differed between the methods, possibly due to the effect of varying mineral (Ca, Fe, Zn, P) contents of the Sorghums. This effect was most prominent in the iron uptake results. More research is needed to determine the effect of naturally occurring variations in mineral contents of Sorghum on the iron uptake by Caco-2 cells.
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influence of Sorghum grain type on wort physico chemical and sensory quality in a whole grain and commercial enzyme mashing process
Journal of The Institute of Brewing, 2013Co-Authors: Adeoluwa Iyiade Adetunji, Sandile Khoza, Henrietta Letitia De Kock, John R N TaylorAbstract:To determine the most suitable types of Sorghum for whole-grain adjunct in lager beer brewing, 14 cultivars of five different types: white tan-plant, white non-tan-plant, red non-tannin, white tannin (type II) and red tannin (type III) were evaluated. The effects of grain type on wort physico-chemical and sensory quality with raw grain and malt plus commercial enzyme mashing were assessed. Tannin content correlated significantly and negatively with wort extract and fermentable sugars (p < 0.001) and free amino nitrogen (FAN; p < 0.1). This is attributable to inactivation of the exogenous enzymes by the tannins during the mashing process. However, the type II tannin Sorghums had wort quality attributes closer to the non-tannin Sorghum types, probably owing to their relatively low tannin content (≤1%). Malting gave a great improvement in wort extract, fermentable sugars and FAN, but substantially influenced wort sensory properties in terms of higher sourness, bitterness and astringency, as well as the expected more malty flavour. Worts from raw red non-tannin Sorghums were similar to those of white tan-plant Sorghums in both physico-chemical and sensory quality. Thus, red non-tannin Sorghums, in view of their better agronomic quality, have considerable potential as a whole-grain adjunct in lager beer brewing. Copyright © 2013 The Institute of Brewing & Distilling
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Original article Polyphenol oxidase activity in white tan-plant-type Sorghums: An important determinant of the relatively dark colour of their porridges
2013Co-Authors: Doreen M. Hikeezi, Medson Chisi, Kwaku G. Duodu, Lloyd W. Rooney, John R N TaylorAbstract:Summary The relatively dark colour of food products from white tan-plant (food-grade) Sorghums can compromise their acceptability. The relationship between white tan-plant Sorghum polyphenol oxidase activity (PPO) and porridge colour was investigated, primarily using lines grown in the same locality over two seasons. Sorghum was intermediate in PPO between wheat and maize. White tan-plant Sorghum and white maize whole grain flours were similar in colour. However, with white tan-plant Sorghum, the transition from flour to porridge caused a much larger reduction in L* value. Further, the correlation between white tan-plant Sorghum PPO activity and porridge L* values was highly significantly negative (P < 0.001), the relationship accounting for 40–50% of variation. PPO in white tan-plant-type Sorghums is therefore an important determinant of the relatively dark colour of porridges. Breeding to reduce PPO activity could improve consumer appeal. Cultivar Sima (IS 23520) that had low PPO activity and produced lightcoloured porridge could be useful for breeding.
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Polyphenol oxidase activity in white tan‐plant‐type Sorghums: An important determinant of the relatively dark colour of their porridges
International Journal of Food Science & Technology, 2012Co-Authors: Doreen M. Hikeezi, Medson Chisi, Kwaku G. Duodu, Lloyd W. Rooney, John R N TaylorAbstract:Summary The relatively dark colour of food products from white tan-plant (food-grade) Sorghums can compromise their acceptability. The relationship between white tan-plant Sorghum polyphenol oxidase activity (PPO) and porridge colour was investigated, primarily using lines grown in the same locality over two seasons. Sorghum was intermediate in PPO between wheat and maize. White tan-plant Sorghum and white maize whole grain flours were similar in colour. However, with white tan-plant Sorghum, the transition from flour to porridge caused a much larger reduction in L* value. Further, the correlation between white tan-plant Sorghum PPO activity and porridge L* values was highly significantly negative (P
William L. Rooney - One of the best experts on this subject based on the ideXlab platform.
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Qualitative assessment of ‘highly digestible’ protein mutation in hard endosperm Sorghum and its functional properties
Food Chemistry, 2018Co-Authors: Tadesse F. Teferra, Derrick B. Amoako, William L. Rooney, Joseph M. AwikaAbstract:Abstract Sorghum mutants with altered protein body structure have improved protein nutritional quality; however, practical methods to accurately track heritability of the trait are lacking. We evaluated suitability of the in vitro pepsin assay, and a new high-resolution field emission electron microscopy (FE-SEM) method to detect the mutation (HD) in hard-endosperm Sorghum; and compared the physicochemical properties of experimental HD Sorghums to wild type (LD) lines. FE-SEM reliably resolved Sorghum protein body structure, allowing for qualitative classification of Sorghum as HD or LD. The pepsin assay was less reliable, with significant variations across environments. Nevertheless, HD lines averaged higher protein digestibility (69.4% raw, 57.6% cooked) than LD lines (61.7% raw, 45.6% cooked). The HD lines also had better water solubility and starch pasting profiles than LD lines. FE-SEM, but not pepsin assay, reliably detects HD nutation in Sorghum. The HD trait may improve food-use functionality of Sorghum.
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High-parent heterosis for biomass yield in photoperiod-sensitive Sorghum hybrids
Field Crops Research, 2014Co-Authors: Daniel J. Packer, William L. RooneyAbstract:Biomass Sorghums are being developed as a dedicated energy crop. These Sorghums are managed to maximize biomass yields and are tall (3.5-5 m) with dry, pithy stems. To facilitate seed production, they are produced as hybrids using grain Sorghum seed parents. Besides facilitating seed production, these hybrids may provide high-parent heterosis for improved biomass yields. To measure potential heterosis, biomass hybrids derived from 13 different biomass pollinators and 4 grain Sorghum seed parents were evaluated for biomass yield in 4 environments. High-parent heterosis in these hybrids averaged 24.8% across all the environments and was available in many hybrid combinations. Hybrids out-yielded the pollinators in each environment. Across environments, the hybrids yielded 32.4 Mg/ha compared to the 27.0 Mg/ha of the pollinators. While heterosis was available in many hybrids, specific combining abilities and environmental interactions combine to maximize heterosis and biomass yields. Heterosis can serve as an effective tool for improving biomass Sorghum yields. © 2014 Elsevier B.V. All rights reserved.
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variation in biomass composition components among forage biomass Sorghum sudangrass and sweet Sorghum types
Crop Science, 2012Co-Authors: Thomas R Stefaniak, Jeffery A Dahlberg, Brent Bean, Nilesh Dighe, Edward J Wolfrum, William L. RooneyAbstract:Alternative biomass sources must be developed if the United States is to meet the goal in the U.S. Energy Security Act of 2007 to derive 30% of its petroleum from renewable sources, and several different biomass crops are currently in development. Sorghum [Sorghum bicolor (L.) Moench] is one such crop that will be an important feedstock source for biofuel production. As composition influences productivity, there exists a need to understand the range in composition observed within the crop. The goal of this research was to assess the range in dietary fiber composition observed within different types of biomass Sorghums. A total of 152 Sorghum samples were divided into the four end-use types of Sorghum: biomass, forage, Sorghum-sudangrass, and sweet. These samples were analyzed chemically using dietary fiber analysis performed at the National Renewable Energy Laboratory using published protocols. Significant variation among the groups was detected for glucan and ash. Positive and highly significant correlations were detected between structural carbohydrates in the biomass and sweet Sorghums while many of these correlations were negative or not significant in the forage and Sorghum-sudangrass types. In addition, a wide range of variation was present within each group indicating that there is potential to manipulatemore » the composition of the crop.« less
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sweet Sorghum genetic diversity and association mapping for brix and height
The Plant Genome, 2009Co-Authors: Seth C Murray, William L. Rooney, Martha T Hamblin, Sharon E Mitchell, Stephen KresovichAbstract:Sweet Sorghum [Sorghum bicolor (L.) Moench], like its close relative, sugarcane (Saccharum spp.), has been selected to accumulate high levels of edible sugars in the stem. Sweet Sorghums are tall and produce high biomass in addition to sugar. Little has been documented about the genetic relationships and diversity within sweet Sorghums and how sweet Sorghums relate to grain Sorghum racial types. In this study, a diverse panel of 125 Sorghums (mostly sweet) was successfully genotyped with 47 simple sequence repeats (SSRs) and 322 single nucleotide polymorphisms (SNPs). Using both distance-based and model based methods, we identified three main genetic groupings of sweet Sorghums. Based on observed phenotypes and known origins we classified the three groups as historical and modern syrup, modern sugar/energy types, and amber types. Using SSR markers also scored in an available large grain Sorghum germplasm panel, we found that these three sweet groupings clustered with kafi r/bicolor, caudatum, and bicolor types, respectively. Using the information on population structure and relatedness, association mapping was performed for height and stem sugar (brix) traits. Three significant associations for height were detected. Two of these, on chromosomes 9 and 6, support published QTL studies. One significant association for brix, on chromosome 1, 12kb from a glucose-6-phosphate isomerase homolog, was detected.
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quantitative trait loci analysis of endosperm color and carotenoid content in Sorghum grain
Crop Science, 2008Co-Authors: Maria Salas G Fernandez, William L. Rooney, Mitchell R. Tuinstra, Martha T Hamblin, Stephen KresovichAbstract:Vitamin A defi ciency affects approximately 250 million people in semiarid regions of Africa and Asia, where Sorghum (Sorghum bicolor Moench) is a major staple crop. Yellow endosperm Sorghums contain carotenoids, some of which can be transformed by humans into vitamin A. Our objective was to study the genetic basis of variation in carotenoid levels in Sorghum endosperm by mapping quantitative trait loci (QTL) associated with carotenoid content and endosperm color, as a putative predictor of carotenoid concentration. A recombinant inbred line population developed from a yellow (‘KS115’) by a white endosperm (‘Macia’) parental cross was evaluated in two locations in 2005. A genetic map was generated using 112 molecular markers including nine carotenoid candidate genes. Lutein, zeaxanthin, and β-carotene were the major carotenoids identifi ed. Several QTL were detected for each compound as well as for color and total carotenoids. Color was signifi cantly correlated with the levels of all compounds, and color QTL co-localized with carotenoid QTL. For β-carotene (provitamin A), fi ve QTL were localized on chromosomes 1, 2, and 10. One of them, on chromosome 2, was stable across both environments, had positive additive effects (1.179 and 1.379), explained large proportions of the phenotypic variance (11.6% and 15.15%), and was associated with a new phytoene synthase gene (Psy3). This fi rst report of QTL for carotenoid content in Sorghum grain provides a starting point for breeding high-provitamin A Sorghums.
Joseph M. Awika - One of the best experts on this subject based on the ideXlab platform.
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Qualitative assessment of ‘highly digestible’ protein mutation in hard endosperm Sorghum and its functional properties
Food Chemistry, 2018Co-Authors: Tadesse F. Teferra, Derrick B. Amoako, William L. Rooney, Joseph M. AwikaAbstract:Abstract Sorghum mutants with altered protein body structure have improved protein nutritional quality; however, practical methods to accurately track heritability of the trait are lacking. We evaluated suitability of the in vitro pepsin assay, and a new high-resolution field emission electron microscopy (FE-SEM) method to detect the mutation (HD) in hard-endosperm Sorghum; and compared the physicochemical properties of experimental HD Sorghums to wild type (LD) lines. FE-SEM reliably resolved Sorghum protein body structure, allowing for qualitative classification of Sorghum as HD or LD. The pepsin assay was less reliable, with significant variations across environments. Nevertheless, HD lines averaged higher protein digestibility (69.4% raw, 57.6% cooked) than LD lines (61.7% raw, 45.6% cooked). The HD lines also had better water solubility and starch pasting profiles than LD lines. FE-SEM, but not pepsin assay, reliably detects HD nutation in Sorghum. The HD trait may improve food-use functionality of Sorghum.
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comparative antioxidant antiproliferative and phase ii enzyme inducing potential of Sorghum Sorghum bicolor varieties
Lwt - Food Science and Technology, 2009Co-Authors: Joseph M. Awika, Liyi Yang, Jimmy D Browning, Abdul K FarajAbstract:Abstract Epidemiological evidence has linked consumption of Sorghum with reduced incidences of gastrointestinal cancer, especially cancer of esophagus. No information is available on how Sorghum may effect the chemoprotective properties. We investigated in vitro potential of eight Sorghum varieties to induce phase II detoxifying enzymes using the NAD(P)H:quinone oxidoreductase (NQO) enzyme assay, and also inhibit proliferation of esophageal, OE33, and colon, HT-29, carcinoma cells using the PicoGreen and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays; these properties were compared to phenolic profile and antioxidant activity of the Sorghum. Black Sorghum extract high in 3-deoxyanthocyanins was the most potent NQO inducer, doubling NQO activity at 5.0 μg/mL and maximally inducing the enzyme activity by 3.0 times. White Sorghum was a moderately strong inducer, maximally increasing NQO activity by 80%; tannin-containing Sorghums were non-inducers. On the other hand, the tannin-containing Sorghum extracts had strongest antiproliferative activity against both OE33 and HT-29 cells (IC 50 , 38–105 μg/mL); the white Sorghum extract was the least potent (IC 50 , 389–>800 μg/mL). Antiproliferative activity correlated with antioxidant activity whereas NQO-inducer capacity did not. Sorghum extracts have strong chemoprotective potential which is partially independent of their antioxidant properties. They may thus be valuable health-promoting ingredients in whole-grain based products.
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Sorghum phytochemicals and their potential impact on human health
Phytochemistry, 2004Co-Authors: Joseph M. Awika, L.w. RooneyAbstract:Sorghum is a rich source of various phytochemicals including tannins, phenolic acids, anthocyanins, phytosterols and policosanols. These phytochemicals have potential to significantly impact human health. Sorghum fractions possess high antioxidant activity in vitro relative to other cereals or fruits. These fractions may offer similar health benefits commonly associated with fruits. Available epidemiological evidence suggests that Sorghum consumption reduces the risk of certain types of cancer in humans compared to other cereals. The high concentration of phytochemicals in Sorghum may be partly responsible. Sorghums containing tannins are widely reported to reduce caloric availability and hence weight gain in animals. This property is potentially useful in helping reduce obesity in humans. Sorghum phytochemicals also promote cardiovascular health in animals. Such properties have not been reported in humans and require investigation, since cardiovascular disease is currently the leading killer in the developed world. This paper reviews available information on Sorghum phytochemicals, how the information relates to current phytonutrient research and how it has potential to combat common nutrition-related diseases including cancer, cardiovascular disease and obesity.
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screening methods to measure antioxidant activity of Sorghum Sorghum bicolor and Sorghum products
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Joseph M. Awika, Ronald L Prior, L.w. Rooney, Xianli Wu, Luis CisneroszevallosAbstract:Specialty Sorghums, their brans, and baked and extruded products were analyzed for antioxidant activity using three methods: oxygen radical absorbance capacity (ORAC), 2,2‘-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH). All Sorghum samples were also analyzed for phenolic contents. Both ABTS and DPPH correlated highly with ORAC (R2 = 0.99 and 0.97, respectively, n = 18). Phenol contents of the Sorghums correlated highly with their antioxidant activity measured by the three methods (R2 ≥ 0.96). The ABTS and DPPH methods, which are more cost effective and simpler, were demonstrated to have similar predictive power as ORAC on Sorghum antioxidant activity. There is a need to standardize these methods to allow for data comparisons across laboratories. Keywords: Sorghum; antioxidant; phenols; ORAC; ABTS; DPPH
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Processing of Sorghum (Sorghum bicolor) and Sorghum Products Alters Procyanidin Oligomer and Polymer Distribution and Content
Journal of agricultural and food chemistry, 2003Co-Authors: Joseph M. Awika, Linda Dykes, And Lloyd W Rooney, Ronald L PriorAbstract:Sorghum procyanidins were characterized and quantified from two brown Sorghum varieties and their processed products by normal phase HPLC with fluorescence detection. The DP of the procyanidins was determined by thiolysis. Quantification was done by using purified oligomeric and polymeric cocoa procyanidins as external standards. Sorghum procyanidins were composed mostly of high MW (DP > 10) polymers. Significant differences were observed in levels as well as distribution of the different MW procyanidins between the Sorghums. Processing of the Sorghum brans into cookies and bread significantly reduced the levels of procyanidins; this effect was more pronounced in the higher MW polymers. Cookies had a higher retention of procyanidins (42−84%) than bread (13−69%). Extrusion of Sorghum grain resulted in an increase in the levels of procyanidin oligomers with DP ≤ 4 and decrease in polymers with DP ≥ 6. This suggests a possible breakdown of the high MW polymers to the lower MW constituents during extrusion. P...
Wilfred Vermerris - One of the best experts on this subject based on the ideXlab platform.
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the relationship between plant height and sugar accumulation in the stems of sweet Sorghum Sorghum bicolor l moench
Field Crops Research, 2017Co-Authors: Sanyukta Shukla, Terry J Felderhoff, Ana Saballos, Wilfred VermerrisAbstract:Abstract Sweet Sorghum ( Sorghum bicolor (L.) Moench) is a tall, seed-propagated C 4 grass with stems that contain saccharine juice. The sugars in the juice can be easily extracted with a press, which generates large amounts of bagasse. Sweet Sorghum has potential as a multi-purpose crop whereby depending on the available infrastructure and market demands, all fermentable sugars from juice and biomass can be converted to renewable fuels and chemicals, or the juice can be processed to syrup, fuels, or chemicals, while the bagasse is either burned or used as fodder. Large-scale industrial production of sweet Sorghum requires large amounts of seed, but due to their height, sweet Sorghums are not compatible with existing combine harvesters. In addition, grain yield is often limited. The availability of hybrid seed that can be produced on short seed parents would enable combine harvesting and offer greater seed yield. This requires the availability of short, sweet inbred lines. All known sweet Sorghums, however, are tall, and prior research identified a positive correlation between height and sugar accumulation. Since the physiological mechanisms underlying sugar accumulation in sweet Sorghum are not well understood, it is unknown whether the apparent association between sugar accumulation in the stem and plant height is the result of selection, or dictated by physiological or genetic constraints. Three experiments were conducted to examine this relationship. First, the role of shading on sugar accumulation was examined in breeding populations with contrasting heights. Second, the sugar concentration was compared between short plants harboring the unstable dwarf3 ( dw3 ) allele and their tall Dw3 revertants. Third, tall photoperiod-sensitive lines were compared with their matching short, photoperiod-insensitive lines. The results from these three experiments indicated that high sugar concentration in sweet Sorghum is not conditional on the plants being tall, making the development of short, sweet inbred lines feasible. This information will also significantly benefit studies aimed at identifying QTL for sugar yield in sweet Sorghum.
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forage Sorghum Sorghum bicolor overview and management 1
2013Co-Authors: Yoana C Newman, John E Erickson, Wilfred Vermerris, David WrightAbstract:Sorghum (Sorghum bicolor [L.] Moench) is a warm-season (C 4 photosynthetic pathway), short-day annual grass. It grows best under relatively high temperatures and under sunny conditions. Sorghum as a crop originated as far back as 3,000 years ago. The selection in those early times was for grain more than for forage. However, selection for forage varieties has been occurring for the last hundred years. Forage Sorghums are similar to grain types but are taller and have higher forage quality. Sorghums in general can be classified into two types: forage types (mainly for forage or animal feed) and grain types (mainly for human consumption and not discussed in this publication). The forage Sorghums are further grouped into four types: (a) hybrid forage Sorghum, (b) sudangrass, (c) Sorghum x sudan hybrids (also known as sudan hybrids), and (d) sweet Sorghum. The latter is used mainly for molas ses but more recently for biofuel production as well.
Kwaku G. Duodu - One of the best experts on this subject based on the ideXlab platform.
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Original article Polyphenol oxidase activity in white tan-plant-type Sorghums: An important determinant of the relatively dark colour of their porridges
2013Co-Authors: Doreen M. Hikeezi, Medson Chisi, Kwaku G. Duodu, Lloyd W. Rooney, John R N TaylorAbstract:Summary The relatively dark colour of food products from white tan-plant (food-grade) Sorghums can compromise their acceptability. The relationship between white tan-plant Sorghum polyphenol oxidase activity (PPO) and porridge colour was investigated, primarily using lines grown in the same locality over two seasons. Sorghum was intermediate in PPO between wheat and maize. White tan-plant Sorghum and white maize whole grain flours were similar in colour. However, with white tan-plant Sorghum, the transition from flour to porridge caused a much larger reduction in L* value. Further, the correlation between white tan-plant Sorghum PPO activity and porridge L* values was highly significantly negative (P < 0.001), the relationship accounting for 40–50% of variation. PPO in white tan-plant-type Sorghums is therefore an important determinant of the relatively dark colour of porridges. Breeding to reduce PPO activity could improve consumer appeal. Cultivar Sima (IS 23520) that had low PPO activity and produced lightcoloured porridge could be useful for breeding.
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Polyphenol oxidase activity in white tan‐plant‐type Sorghums: An important determinant of the relatively dark colour of their porridges
International Journal of Food Science & Technology, 2012Co-Authors: Doreen M. Hikeezi, Medson Chisi, Kwaku G. Duodu, Lloyd W. Rooney, John R N TaylorAbstract:Summary The relatively dark colour of food products from white tan-plant (food-grade) Sorghums can compromise their acceptability. The relationship between white tan-plant Sorghum polyphenol oxidase activity (PPO) and porridge colour was investigated, primarily using lines grown in the same locality over two seasons. Sorghum was intermediate in PPO between wheat and maize. White tan-plant Sorghum and white maize whole grain flours were similar in colour. However, with white tan-plant Sorghum, the transition from flour to porridge caused a much larger reduction in L* value. Further, the correlation between white tan-plant Sorghum PPO activity and porridge L* values was highly significantly negative (P
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FTIR and Solid State13C NMR Spectroscopy of Proteins of Wet Cooked and Popped Sorghum and Maize
Journal of Cereal Science, 2001Co-Authors: Kwaku G. Duodu, Huiru Tang, A. Grant, Nikolaus Wellner, Peter S. Belton, John R N TaylorAbstract:Fourier transform infrared (FTIR) and solid state13C NMR spectroscopic methods were used to investigate changes in maize and Sorghum proteins on wet cooking and popping. FTIR spectra indicated that wet cooking led to proteins in two normal Sorghums, namely NK 283 (a red hybrid) and KAT 369 (a white variety), two Sorghum mutants (P850029 and P851171) and a maize hybrid (PAN 6043) assuming more antiparallel intermolecular s-sheet character, possibly at the expense of some a-helical conformation. Solid state13C NMR, using the technique of Cross Polarisation Magic Angle Spinning showed shifts of the protein carbonyl carbon and a-carbon resonances upfield on wet cooking in all samples, also indicating a change in protein secondary structure from a-helical to s-sheet conformation. The extent of secondary structural change on wet cooking seemed to be greater in Sorghum than in maize and may have a bearing on the inferior protein digestibility of wet cooked Sorghum compared to maize. Popping produced the same secondary structural change as observed for wet cooking in both Sorghum and maize. However, the extent of change on popping was less than on wet cooking in Sorghum and maize.
