A new equipment to predict the milling yield of wheat grain

A new equipment to predict the milling yield of wheat grain. XI journées de l'innovation CHOPI

Wheat Milling Quality: Influencing Factors and New Method of Assessment

Wheat Milling Quality: Influencing Factors and New Method of Assessment. IAOM MidEast and Africa Conferenc

Thermomechanically Induced Protein Aggregation and Starch Structural Changes in Wheat Flour Dough

12 pages, 7 figures, 2 tables. In compliance with the publisher's copyright policy, the pre-print full-text version of the paper is attached.Various studies have been carried out on wheat flour to understand protein and starch changes when subjected to mixing and temperature constraints, but structural changes of proteins and starch at the typical moisture levels of a dough system are not fully understood. The aim of this research was to improve our understanding of (micro) structural changes at the mesoscopic level, through empirical rheology, microscopy (light and scanning electron microscopy), sequential protein extractions, and glutenin macropolymer wet weight along the mixing, heating, and cooling stages of the Mixolab assay. Studies were performed on three wheat flours with different protein contents. The rheological analysis allowed identifying the role of the proteins and the relationship between the protein content and different primary and secondary parameters obtained from the recorded curves. The progressive heating and mixing stages during the Mixolab assay resulted in a dynamic de-and restructuring of proteins involving interactions between the flour proteins from water soluble to SDS soluble to SDS insoluble and vice versa. The microstructure analysis with light, polarized, and scanning electron microscopy revealed the changes that proteins and starch molecules underwent during mixing, heating, and cooling. Qualitatively, the starch structural changes, swelling, and gelatinization observed by microscopic techniques showed some parallels with protein (and glutenin) content of the respective flour. Nevertheless, this tentative finding needs further confirmation by studying flour samples with large differences in glutenin content.Spanish Scientific Research Council (CSIC) and the Spanish Ministry of Economy and Sustainability (Project AGL2011-23802/ALI). R. C. Altamirano-Fortoul expresses gratitude for a predoctoral grant by the CSIC (Spain).Peer reviewe

Bread wheat milling behavior: effects of genetic and environmental factors, and modeling using grain mechanical resistance traits

International audienceGenetic (Pinb-D1 alleles) and environment (through vitreousness) have important effects on bread wheat milling behavior. SKCS optimal values corresponding to soft vitreous or hard mealy grains were defined to obtain the highest total flour yield.Near-isogenic lines of bread wheat that differ in hardness, due to distinct puroindoline-b alleles (the wild type, Pinb-D1a, or the mutated forms, Pinb-D1b or Pinb-D1d), were grown in different environments and under two nitrogen fertilization levels, to study genetic and environmental effects on milling behavior. Milling tests used a prototype mill, equipped with two break steps, one sizing step, and two reduction steps, and this enabled 21 individual or aggregated milling fractions to be collected. Four current grain characters, thousand grain weight, test weight, grain diameter, and protein content, were measured, and three characters known to influence grain mechanical resistance, NIRS hardness, SKCS hardness index, and grain vitreousness (a character affecting the grain mechanical behavior but generally not studied). As expected, the wild type or mutated forms of Pinb-D1 alleles led to contrasted milling behavior: soft genotypes produced high quantities of break flour and low quantities of reduction flour, whereas reverse quantities were observed for hard genotypes. This different milling behavior had only a moderate influence on total flour production. NIRS hardness and vitreousness were, respectively, the most important and the second most important grain characters to explain milling behavior. However, contrary to NIRS hardness, vitreousness was only involved in endosperm reduction and not in the separation between the starchy endosperm and the outer layers. The highest flour yields were obtained for SKCS values comprised between 30 and 50, which corresponded either to soft vitreous or hard mealy grains. Prediction equations were defined and showed a good accuracy estimating break and reduction flours portions, but should be used more cautiously for total flour

Evaluation of the quality of nixtamalized maize flours for tortilla production with a new Mixolab protocol

Background and objectives: Nixtamalized maize flours (NMF) are convenient products to obtain an array of nixtamalized products such as table tortillas and chips. In the present study, a Mixolab protocol was set up for the analysis of NMF and to predict mixing conditions in tortilla making. The validity of the procedure was tested with 10 commercial NMF. Water absorption (WA) and mixing times obtained from Mixolab analysis were used to produce doughs and tortillas. The correlations among the Mixolab parameters and quality features of NMF, doughs and tortillas were determined. Findings: Mixolab curves permitted to characterize the NMF dough development time, mixing stability, starch gelatinization, starch gel stability and retrogradation. This analysis was efficient to discern among the quality of different samples. Tortillas produced with the WA and mixing time predicted with the Mixolab analysis using the optimized protocol had adequate moisture and textural characteristics. Good correlations among the Mixolab parameters and the tortilla moisture and texture confirmed the validity of the method. Conclusion: The optimized Mixolab test proved to be a useful tool to evaluate the quality of NMF. Significance and novelty: The new Mixolab protocol could be used to predict relevant process parameters for tortilla production.This research was supported by the research group of Emerging Technologies and Nutriomics (Tecnológico de Monterrey), the joint project between research group from IATA-CSIC and Nutriomics from Tecnologico de Monterrey, and the Generalitat Valenciana grant (Prometeo 2017/189).Peer reviewe