Allelic effects on starch structure and properties of six starch biosynthetic genes in a rice recombinant inbred line population

BACKGROUND: The genetic diversity of six starch biosynthetic genes (Wx, SSI, SSIIa, SBEI, SBEIIa and SBEIIb) in indica and japonica rices opens an opportunity to produce a new variety with more favourable grain starch quality. However, there is limited information about the effects of these six gene allele combinations on starch structure and properties. A recombinant inbred line population from a cross between indica and japonica varieties offers opportunities to combine specific alleles of the six genes. RESULTS: The allelic (indica vs japonica) effects of six starch biosynthetic genes on starch structure, functional properties, and abundance of granule bound proteins in rice grains were investigated in a common genetic background using a recombinant inbred line population. The indica Wx (Wxi) allele played a major role while indica SSI (SSIi), japonica SSIIa (SSIIaj) and indica SBEI (SBEIi) alleles had minor roles on the increase of amylose content. SSIIaj and japonica SBEIIb (SBEIIbj) alleles had a major and a minor role on high ratio of ∑DP ≤ 10 to ∑DP ≤ 24 fractions (RCL10/24), respectively. Both major alleles (Wxi and SSIIaj) reduced peak viscosity (PV), onset, peak and end gelatinization temperatures (GTs) of amylopectin, and increased amylose-lipid complex dissociation enthalpy compared with their counterpart-alleles, respectively. SBEIIai and SBEIIbj decreased PV, whereas SSIi and SBEIIbj decreased FV. SBEIi reduced setback viscosity and gelatinization enthalpy. RCL10/24 of chain length distribution in amylopectin is negatively correlated with PV and BD of paste property and GTs of thermal properties. We also report RILs with superior starch properties combining Wxi, SSIj, SSIIaj, SBEIi and SBEIIbj alleles. Additionally, a clear relation is drawn to starch biosynthetic gene alleles, starch structure, properties, and abundance of granule bound starch biosynthetic enzymes inside starch granules. CONCLUSIONS: Rice Wxi and SSIIaj alleles play major roles, while SSIi, SBEIi, SBEIIai and SBEIIbj alleles have minor roles in the determination of starch properties between indica and japonica rice through starch structural modification. The combination of these alleles is a key factor for starch quality improvement in rice breeding programs. RCL10/24 value is critical for starch structure and property determination.Jixun Luo was supported by CSC (Chinese Scholarship Council) and Australian National University scholarships. This work was funded by CSIRO Food Future National Research Flagship

Characterization and property analysis of starch from broken parboiled rice

Rice (Oryza sativa L.) is the primary food consumed by half of the world’s population and it provides 40-60 per cent of energy in daily diet. Production and consumption is anticipated to grow steadily every year. Rice is the rich source of starch, a polysaccharide consisting of amylose and amylopectin. Broken rice is the by-product and a key indicator of rice quality. Nearly 14 per cent of rice is broken while milling and during threshing process. The present study was carried out, to compare the properties and utilization of broken rice with whole rice. Alkaline extraction process is the best extraction method to isolate starch from broken rice that yields upto 70% of total starch with fewer residues. The characterisation of extracted starch from broken parboiled rice was investigated by Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermo Gravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM). The quality of starch from broken rice estimated through physical, thermal and physiological properties show a similar property as like starch extracted from rice. It is the colourless and odourless compound which doesn’t affect the colour and flavour of the product to be added that can be easily used in food industries at low cost.  This study paves a way to utilize broken rice, a food industrial by-product and agro residue in an effective manner. Key words: broken rice starch, property analysis, industrial by-product, agro residue, characterization, alkaline extractio

Analysis of Nutrient and Anti-Nutrient Compositions of “Suweg” (Amorphophallus paeoniifolius) Cultivated in Java

Amorphophallus paeoniifolius (Dennts.) Nicolson belongs to the family Araceae. It is also known as  elephant foot yam or suweg, notably for the Javanese. It is a common species in Java and is cultivated for its edible tubers. The suweg tubers used for this research were collected from Kuningan (West Java), Yogyakarta and Kediri (East Java). The study aimed to elucidate the nutrient and anti-nutrient compositions of suweg’s tuber, including carbohydrate, fat, proteins and minerals viz. Ca, Fe and P. The Kjeldhal method was used for protein determination, soxhlet extraction method for lipids, spectrophotometer method for carbohydrate, and Atomic Absorption Spectrophotometer method was used for mineral elements. Anti-nutrient contents determinated were Ca Oxalate and HCN using spectrophotometer method.  Both fresh tuber and flour powder of suweg were analysed to indicate the highest percentage of Ca Oxalate content. The results showed that nutrient contents of suweg were carbohydrate 87.02 %, protein 7.08 % and fat 0.18%. These indicated that suweg has high carbohydrate and low fat contents; therefore it is suitable for dietary therapy. The concentration of anti-nutrient, such as Ca Oxalate was lower on the flour powder (0.01 %) rather than fresh tuber (0,21 %). This means the tuber of suweg was not harmful to consume after being processed

Laboratory scale production of glucose syrup by the enzymatic hydrolysis of starch made from maize, millet and sorghum

Glucose syrup production from maize, millet and sorghum starch was investigated. The starch extracted from yellow maize after steeping for 72hrs and purified by sedimentation method had the greatest yield of 86.71% (4.34 ± 0.37g) followed by the starch made from millet and sorghum with a yield of 65.94% (3.30 ± 0.25g) and 64.71% (3.23 ± 0.09g), respectively. The lowest gelatinization onset temperature of 59.25 ± 0.90oC was observed with sorghum starch. The glucose recovered with pure amyloglucosidase from Rhizopus mold produced 17.15 ± 0.10 mg/ml reducing sugar from yellow maize starch after 10 minutes. Millet and sorghum starch followed with a yield of 15.79 ± 0.20mg/ml and 11.32 ± 0.26mg/ml in 10 minutes, respectively. Liquid glucose produced with the pure amyloglucosidase revealed a dextrose equivalent of 78.28 ± 0.57%, 73.50 ± 0.66% and 65.66 ± 0.61% for sorghum, yellow maize and millet, respectively. Sorghum and yellow maize starch exhibited good potential as substrates for glucose syrup production

Chemical, functional, pasting and sensory properties of fried chips produced from cassava flour enriched with cowpea flour

Composite flours were produced from blends of high quality cassava flour and cowpea flour. The flours were blended in six different ratios: 75:25, 60:40, 50:50, 40:60, 25:75 and 100:0 which served as the control sample. The chemical, functional, pasting and sensory properties of the samples were determined. The results showed that significant differences (p<0.05) exist between the control sample and other blended samples. Sample 25:75 cassava-cowpea flour had the highest protein, ash, fat and crude fiber contents. Cyanide content of the composite flour decreased as the percentage of cowpea flour increased. The highest water absorption capacity, oil absorption capacity and swelling capacity were recorded for sample containing 100% cassava flour. Blending of high quality cassava flour with cowpea flour enhanced the nutritional quality of the cassava flour through increased protein and reduced cyanide contents

A comparative study of some properties of cassava (Manihot esculenta, Crantz) and cocoyam (Colocasia esculenta, Linn) starches

Some properties of cassava and cocoyam starches were studied and compared with a view to determining the functional applications in food systems for which they are suitable. The starches were compared in terms of their microscopic, thermal, physicochemical and rheological properties. Microscopy revealed smaller granule sizes of cocoyam starch compared with cassava. The amylose content was higher in cocoyam starch (33.3%) than in cassava starch (29.3%). Gelatinization in cassava starch occurred at a lower temperature range (60.11 o -72.67oC) compared with cocoyam (72.96o – 80.25oC) with the endothermic gelatinization enthalpy higher in cocoyam. The swelling power and solubility patterns indicated lower relaxation temperature, higher swelling and solubilization rates in cassava starch compared with cocoyam starch. The pasting characteristics of 8% (db, dry basis) starch slurry showed that cassava had higher peak viscosity but lower stability and setback ratios compared with cocoyam. This indicates that cocoyam starch paste is better in withstanding processing conditions and would present a superior thickening characteristic than cassava starch paste. The flow properties of both starch pastes showed non-Newtonian behaviour and could be best described by the Herschel-Bulkley model. The rate index and yield stress of cocoyam starch paste was higher than that of cassava. The storage modulus of cocoyam starch paste was higher than that of cassava indicating that cocoyam starch paste was more rigid than cassava starch paste. Cassava starch paste exhibited higher paste clarity and freeze-thaw stability than cocoyam starch paste. The properties of cassava and cocoyam starches dictate their food applications

New starches: Physicochemical properties of sweetsop (Annona squamosa) and soursop (Annona muricata) starches

Starch from the fruits of sweetsop (Anonna squamosa) and soursop (Anonna muricata) were isolated and purified and the fat, ash, phosphorus and protein contents measured. The amount of amylose present was determined spectrophotometrically and found to be very similar ( 19%) for both starches. Scanning electron microscopy showed very small indented and spherical granules from both with an average granule size of 4.84 μm and 4.72 μm, respectively. The physicochemical properties, namely the swelling power, solubility, pasting characteristics, paste clarity and freeze–thaw stability were studied to assess the functionality of the starch pastes as hydrocolloids. The sweetsop starch showed higher swelling power and solubility compared to soursop starch and had a lower gelatinization temperature indicating a weaker granular structure. Sweetsop starch exhibited a lower pasting temperature, higher viscosity peak, higher viscosity breakdown and lower setback, higher paste clarity and freeze–thaw stability compared to soursop starch. The low gelatinization temperature and high freeze thaw stability of sweetsop starch are comparable to that of waxy corn. The properties of sweetsop indicate that it has potential for application as a thickener in frozen foods

Biological Control of Aflatoxin Contamination in U.S. Crops and the Use of Bioplastic Formulations of Aspergillus flavus Biocontrol Strains To Optimize Application Strategies

Aflatoxin contamination has a major economic impact on crop production in the southern United States. Reduction of aflatoxin contamination in harvested crops has been achieved by applying nonaflatoxigenic biocontrol Aspergillus flavus strains that can out-compete wild aflatoxigenic A. flavus, reducing their numbers at the site of application. Currently, the standard method for applying biocontrol A. flavus strains to soil is using a nutrient-supplying carrier (e.g., pearled barley for Afla-Guard). Granules of Bioplastic (partially acetylated corn starch) have been investigated as an alternative nutritive carrier for biocontrol agents. Bioplastic granules have also been used to prepare a sprayable biocontrol formulation that gives effective reduction of aflatoxin contamination in harvested corn kernels with application of much smaller amounts to leaves later in the growing season. The ultimate goal of biocontrol research is to produce biocontrol systems that can be applied to crops only when long-range weather forecasting indicates they will be needed

Variableselectioninmultivariatecalibrationbasedonclusteringofvariableconcept

Recentlywehaveproposedanewvariableselectionalgorithm,basedonclusteringofvariableconcept(CLoVA)inclassificationproblem.Withthesameidea,thisnewconcepthasbeenappliedtoaregres-sionproblemandthentheobtainedresultshavebeencomparedwithconventionalvariableselectionstrategiesforPLS.Thebasicideabehindtheclusteringofvariableisthat,theinstrumentchannelsareclusteredintodifferentclustersviaclusteringalgorithms.Then,thespectraldataofeachclusteraresubjectedtoPLSregression.Differentrealdatasets(Cargillcorn,Biscuitdough,ACEQSAR,Soy,andTablet)havebeenusedtoevaluatetheinfluenceoftheclusteringofvariablesonthepredictionper-formancesofPLS.Almostintheallcases,thestatisticalparameterespeciallyinpredictionerrorshowsthesuperiorityofCLoVA-PLSrespecttoothervariableselectionstrategies.Finallythesynergyclusteringofvariable(sCLoVA-PLS),whichisusedthecombinationofcluster,hasbeenproposedasanefficientandmodificationofCLoVAalgorithm.Theobtainedstatisticalparameterindicatesthatvariableclusteringcansplitusefulpartfromredundantones,andthenbasedoninformativecluster;stablemodelcanbereache