Padmanaban G. Krishnan

Variability and relationships among Mixolab, Mixograph, and baking parameters based on multienvironment spring wheat trials.

ABSTRACT Because of the large number of cultivars that require examination in the development of spring wheat (Triticum aestivum L.) cultivars, breeding programs use predictive methods to test end use quality. The Mixograph is a widely used predictive test with which end use quality of many genotypes can be assessed in a short time. By comparison, the Mixolab is a relatively new device with additional capability that might be used for the same purpose. Our objective was to document variability of, and relationships among, 20 parameters obtained from Mixolab, Mixograph, and bake tests. Tests were performed on flour from 18 genotypes grown in 20 environments. Both genotype and environment had significant effects on quality parameter values. Several Mixograph and Mixolab parameters were highly significantly correlated, particularly when genotype mean values over environments were considered. Correlations between loaf volume and Mixolab parameters within environments were inconsistent and suggest that average...

Effect of Wheat Genotype and Environment on Relationships Between Dough Extensibility and Breadmaking Quality

ABSTRACT Dough extensibility affects processing ease, gas retention, and loaf volume of finished products. The Kieffer dough extensibility test was developed to assess extensibility of small dough samples and is therefore adapted for use in breeding programs. Information is lacking on relationships between wheat growing environments and dough properties measured by the Kieffer dough extensibility test. This study documents the variability of dough extensibility (Ext), maximum resistance to extension (Rmax), and area under the extensibility curve (Area) in relation to breadmaking quality, and the effect of wheat growing environments. Mixograph, Kieffer dough extensibility, and bake tests were performed on flour milled from 19 hard red spring wheat (Triticum aestivum L.) genotypes grown during three growing seasons (2007-2009) at six South Dakota locations. Although both genotype and environment had significant effects on Kieffer dough extensibility variables, environment represented the largest source of v...

Microstructural, textural, and sensory properties of whole-wheat noodle modified by enzymes and emulsifiers.

With the utilization of enzymes including endoxylanase, glucose oxidase (GOX) and transglutaminase (TG), and emulsifiers comprising sodium stearoyl lactate (SSL) and soy lecithin, the microstructural, textural, and sensory properties of whole-wheat noodle (WWN) were modified. The development time and stability of whole-wheat dough (WWD) were enhanced by TG due to the formation of a more compact gluten network, and by SSL resulting from the enhanced gluten strength. Microstructure graphs by scanning electron microscopy (SEM) verified that TG and SSL promoted the connectivity of gluten network and the coverage of starch granules in WWN. TG increased the hardness and elasticity of cooked WWN, while two emulsifiers increased the noodle cohesiveness. Additionally, TG and SSL improved the sensory properties of noodle such as bite, springiness, and mouth-feel. The results suggest that TG and SSL are effective ingredients in enhancing the gluten strength of WWD and improving the qualities of WWN.

Dough Strain Hardening Properties as Indicators of Baking Performance

Bread loaf volume is an important economic criterion. Breeders, millers, and bakers need measurements allowing them to evaluate dough performance during processing. Strain hardening is an important dough property. It describes the stability of the gas cell walls and the ability of cells to expand further; therefore, the higher the strain hardening index (n), the better the baking performance. Dough exhibits strain hardening during uniaxial extensibility tests. However, obtaining n from an extensibility test is time consuming. The objectives of this study were to identify the extensibility parameters that contribute to n. Three parameters were retained in the model (R2 = 0.90): dough strength (Rmax), extensional delay (EDiff), and initial slope of the curve (Ei). Rmax was the largest contributor and was proportional to the dough strain hardening properties. EDiff and Ei had a detrimental effect on n. The appropriateness of the model was validated with two sample sets (19 genotypes, 12 environments). Signif...

Potential Bleaching Techniques for use in Distillers Grains

The ethanol industry is booming. And extensive research is currently being pursued to develop alternative uses for distillers dried grains (DDG) and distillers dried grains with solubles (DDGS), coproducts of the ethanol production process. Currently, DDG and DDGS are used exclusively as livestock feed. previous research has shown promising avenues for the use of DDG and DDGS in human foods. The low starch, high protein and high fiber grains seem ideally suited for medical conditions such as diabetes and Celiacs disease. Processing methods need to be investigated to create functional flours that can be used effectively. Refining aspects such as color, odor, and baking functionality will eventually hold the key to the use of distillers grains in food products. The objective of this paper was to examine previous research on bleaching various food products, and to discuss their potential applicability for distillers grains. No research has yet been completed on bleaching distillers grains. This will be the topic of future research, and will be reported at a later date.

FRACTIONATION TECHNIQUES TO CONCENTRATE NUTRIENT STREAMS IN DISTILLERS GRAINS

Corn, the most widely produced feed grain in the United States, accounts for more than 90% of the total value and production of feed grains. It is also used for food, industrial materials, and fuel ethanol production. Distillers grains, the major coproduct from ethanol manufacturing, are used as livestock feed. There are, however, other potential options, including value-added food, industrial, chemical, and energy applications. Fractionating distillers grains into concentrated streams of protein, fiber, and fat may be key to facilitating these types of utilization. Previous studies on other products have shown that fractionation is a promising mechanism for extracting valuable components and nutrients from various food, biological, and organic streams. There are many mechanisms by which materials can be fractionated, including size classification, air classification, and aqueous extraction. The goals of this study are to review these techniques for a variety of industries and products, as well as to discuss what has been accomplished to date for ethanol coproduct materials. The information discussed here will be helpful for those interested in fractionating various residue streams, including distillers grains.

Postcolumn fluorimetric HPLC procedure for determination of niacin content of cereals

ABSTRACT Analytical procedures for determining niacin or vitamin B3 content of foods are tedious, require large quantities of toxic chemicals, and are timeconsuming. In addition, food matrices are difficult as samples because of their complex nature. A selective, sensitive HPLC technique was developed with postcolumn derivatization as well as fluorescence and spectroscopic detection systems. Niacin was separated and retained for 6.5 min on a polymeric column with an aqueous mobile phase containing sodium acetate buffer. A postcolumn system consisting of a stainless-steel pump and reaction coil allowed detection and quantitation of niacin. An acid-enzyme sample-extraction method was most compatible with HPLC and postcolumn derivatization with 5% each of acidified p-aminophenol and cyanogen bromide. Lower detection limit and mean recovery were 3.6 ng and 99.43%, respectively. Fluorescence response for nicotinamide was half that of nicotinic acid. A lower response for nicotinamide was also noted with convent...

Update on Ethanol Processing Residue Properties

The production of corn-based ethanol in the U.S. is dramatically increasing, and consequently so is the amount of byproduct materials generated from this processing sector. These coproduct streams are currently solely utilized as livestock feed, which is a route that provides ethanol processors with a substantial revenue source and significantly increases the profitability of the production process. With the construction and operation of many new plants in recent years, these residuals do, however, have much potential for value-added processing and utilization in other sectors as well. This option holds promise of economic benefit for corn processors, especially if the livestock feed market eventually becomes saturated with byproduct feeds. Physical and nutritional properties, however, are needed for the proper design of processing operations and byproduct applications. Because information concerning ethanol byproduct materials is somewhat disparate outside the livestock arena, the objective of this study is to fully review the existing literature base and compile a physical and nutritional properties knowledge bank for these residual streams. This study will identify several gaps that currently exist in the knowledge base, which could thus provide fertile ground for future studies.

Polyethylene-Starch Extrudates as Erodible Carriers for Bioactive Materials: I. Erodibility and in vitro Dye Release Studies

The objective of the present investigation is to develop and evaluate polyethylene-starch based carriers for sustaining the release of bioactive materials. Polyethylene-starch carriers were prepared by incorporating various amounts of corn starch 0, 40, 80, and 100% in polyethylene beads with and without dye. Acid orange dye was incorporated (1%) to study release patterns and the effect of starch (%) on release. The granulated mixtures were extruded to form uniform dispersions of starch and polyethylene throughout the extrudate. The extrudates obtained were studied for SEM surface characterization before, during, and after release studies to study the erosion process. In the case of 100% starch, 80% of the matrix was eroded in 5 weeks, while with 40% and 80% starch, erosion was less than 20%. The dye release studies showed that release could be sustained well over 12 weeks, depending on the starch (%) incorporated. The erosion process was studied using scanning electron microscopic techniques, which showed gradual erosion of starch particles, leaving a polyethylene skeleton. These materials show promising potential for use as carriers for bioactive materials.

Influence of processing conditions on apparent viscosity and system parameters during extrusion of distiller’s dried grains-based snacks

Abstract A combination of different levels of distillers dried grains processed for food application (FDDG), garbanzo flour and corn grits were chosen as a source of high‐protein and high‐fiber extruded snacks. A four‐factor central composite rotatable design was adopted to study the effect of FDDG level, moisture content of blends, extrusion temperature, and screw speed on the apparent viscosity, mass flow rate or MFR, torque, and specific mechanical energy or SME during the extrusion process. With increase in the extrusion temperature from 100 to 140°C, apparent viscosity, specific mechanical energy, and torque value decreased. Increase in FDDG level resulted in increase in apparent viscosity, SME and torque. FDDG had no significant effect (p > .5) on mass flow rate. SME also increased with increase in the screw speed which could be due to the higher shear rates at higher screw speeds. Screw speed and moisture content had significant negative effect (p < .05) on the torque. The apparent viscosity of dough inside the extruder and the system parameters were affected by the processing conditions. This study will be useful for control of extrusion process of blends containing these ingredients for the development of high‐protein high‐fiber extruded snacks.