Ronald L. Madl

Factors impacting ethanol production from grain sorghum in the dry-grind process.

ABSTRACT The goal of this research is to understand the key factors affecting ethanol production from grain sorghum. Seventy genotypes and elite hybrids with a range of chemical compositions and physical properties selected from ≈1,200 sorghum lines were evaluated for ethanol production and were used to study the relationships of composition, grain structure, and physical features that affect ethanol yield and fermentation efficiency. Variations of 22% in ethanol yield and 9% in fermentation efficiency were observed among the 70 sorghum samples. Genotypes with high and low conversion efficiencies were associated with attributes that may be manipulated to improve fermentation efficiency. Major characteristics of the elite sorghum genotypes for ethanol production by the dry-grind method include high starch content, rapid liquefaction, low viscosity during liquefaction, high fermentation speed, and high fermentation efficiency. Major factors adversely affecting the bioconversion process are tannin content, l...

Ethanol Production from Orange Peels: Two-Stage Hydrolysis and Fermentation Studies Using Optimized Parameters through Experimental Design

Orange peels were evaluated as a fermentation feedstock, and process conditions for enhanced ethanol production were determined. Primary hydrolysis of orange peel powder (OPP) was carried out at acid concentrations from 0 to 1.0% (w/v) at 121 degrees C and 15 psi for 15 min. High-performance liquid chromatography analysis of sugars and inhibitory compounds showed a higher production of hydroxymethyfurfural and acetic acid and a decrease in sugar concentration when the acid level was beyond 0.5% (w/v). Secondary hydrolysis of pretreated biomass obtained from primary hydrolysis was carried out at 0.5% (w/v) acid. Response surface methodology using three factors and a two-level central composite design was employed to optimize the effect of pH, temperature, and fermentation time on ethanol production from OPP hydrolysate at the shake flask level. On the basis of results obtained from the optimization experiment and numerical optimization software, a validation study was carried out in a 2 L batch fermenter at pH 5.4 and a temperature of 34 degrees C for 15 h. The hydrolysate obtained from primary and secondary hydrolysis processes was fermented separately employing parameters optimized through RSM. Ethanol yields of 0.25 g/g on a biomass basis (YP/X) and 0.46 g/g on a substrate-consumed basis (YP/S) and a promising volumetric ethanol productivity of 3.37 g/L/h were attained using this process at the fermenter level, which shows promise for further scale-up studies.

Effects of growing location and irrigation on attributes and ethanol yields of selected grain sorghums.

ABSTRACT Nine sorghum cultivars (five inbred lines and four hybrids) were grown in 2006 in three locations (Mount Hope, KS, Halstead, KS, and Plainview, TX) under different irrigation conditions and were evaluated for composition and ethanol fermentation efficiency. The objective was to study, in one growing season, the effects of genotype, growing location, and irrigation on the physical and chemical properties and fermentation efficiencies of grain sorghum. Genotype had a significant effect on chemical composition, physical properties, and ethanol yield. The cultivars showed a large variation in starch (61.0–74.8%), protein (7.56–16.35%), crude fat (2.79–4.77%), crude fiber (0.58–2.57%), ash (1.25–2.26%), kernel weight (20.0–35.9 mg), kernel hardness (49.6–97.5), and kernel size (1.9–2.7 mm) and were the most important factors affecting ethanol fermentation efficiency (87.5–93.9%). Starch and protein contents were significantly affected by growing location but not by irrigation. Environment had a signif...

Antitumor activity of wheats with high orthophenolic content

The purpose of the present study is to develop in vitro assays for rapid screening of a large number of food samples that contain components that prevent tumor formation in vivo and to identify the components that contribute to this antitumor effect. Wheat samples representing numerous strains and cultivars were screened for their in vitro ability to kill a human colon cancer cell, CaCo2, in culture by trypan blue dye exclusion assay. Wheat samples were assayed for orthophenolic acid content by use of a colorimetric assay using a bathochromatic shift at 350 nm. Blood levels of specific orthophenols were determined by high-performance liquid chromatography/mass spectrometry. Wheat samples, which contained low, mid-, and high in vitro protective ability, were used to formulate balanced diets fed to Min mice. Wheat samples with high ability to kill CaCo2 cells in culture had high levels of orthophenolic acids and produced elevated blood caffeic acid levels when used in diets. These factors correlated positively with their ability to prevent tumor formation in Min mice. When fiber content was equal in diets the content of orthophenolic acids in wheats predicted the antitumor activity in vivo.

Biofuels from Lignocellulosic Biomass

Biomass feedstock, which is mainly lignocellulose, has considerable potential to contribute to the future production of biofuels and to the mitigation of carbon dioxide emissions. Several challenges exist in the production, harvesting, and conversion aspects of lignocellulose, and these must be resolved in order to reach economic viability. A broad array of research projects are underway to address the technical hurdles, however, additional research may be required to reach commercial sustainability. Gasification and enzymatic hydrolysis are the main technologies being investigated for the conversion of lignocellulosic biomass into material for the production of biofuels. While each approach has pros and cons, both are being explored to determine the optimum potential commercial method for particular feedstock situations, and to better understand the requirements for the massive scale required to contribute to biofuel volume.

Comparison of Waxy vs. Nonwaxy Wheats in Fuel Ethanol Fermentation

ABSTRACT Fermentation performance of eight waxy, seven nonwaxy soft, and 15 nonwaxy hard wheat cultivars was compared in a laboratory dry-grind procedure. With nitrogen supplements in the mash, the range of ethanol yields was 368–447 L/ton. Nonwaxy soft wheat had an average ethanol yield of 433 L/ton, higher than nonwaxy hard and waxy wheat. Conversion efficiencies were 91.3–96.2%. Despite having higher levels of free sugars in grain, waxy wheat had higher conversion efficiency than nonwaxy wheat. Although there was huge variation in the protein content between nonwaxy hard and soft wheat, no difference in conversion efficiency was observed. Waxy cultivars had extremely low peak viscosity during liquefaction. Novel mashing properties of waxy cultivars were related to unique pasting properties of starch granules. With nitrogen supplementation, waxy wheat had a faster fermentation rate than nonwaxy wheat. Fermentation rates for waxy cultivars without nitrogen supplementation and nonwaxy cultivars with nitro...

Arylcopper-Magnesium compounds

Abstract The compounds Cu4Mg(phenyl)6·Et2O, Cu4Mg(p-tolyl)6·Et2O, and Cu4Mg(p-tolyl)6·x THF (x possibly 5) have been prepared by reaction of copper(I) bromide or copper(II) bromide with the bis(aryl)magnesium in ether or THF. These compounds are quite sensitive to air, especially oxygen, but when such contamination is avoided they are remarkably stable. Molecular weight measurements and solubility properties are consistent with a discrete metal cluster unit with pendant aryl groups. Proton magnetic resonance spectra suggest the presence of at least two, and probably more, aryl group environments on the metal cluster unit. Phenyl group exchange between Cu4Mg(phenyl)6·Et2O and diphenylmagnesium in ether is also observed.

Pre-Cooked Fiber-Enriched Wheat Flour Obtained by Extrusion: Rheological and Functional Properties

Extrusion processing was utilized to pre-cook wheat flours substituted with 0, 10, 20, and 30% wheat bran in order to enhance their rheological properties and functionality with regards to production of cookies and tortillas. Two extrusion conditions, low-temperature-low-shear (LTLS), and high-temperature-high-shear (HTHS) were studied for pre-cooking the flours. Results showed that for all flours, as % bran increased, RVA peak viscosity (PV), mixograph peak time (PTM), and peak height (PH) decreased. At all bran levels, PV, and PH were significantly lower for pre-cooked flours as compared to uncooked. As the percent bran and storage time (4 to 16 d) increased, the quality of cookies (weight and spread factor) and tortillas (specific volume, rollability, and extensibility) deteriorated for both uncooked and pre-cooked wheat flours. The quality of cookies and tortillas from pre-cooked flour were either similar or inferior to those from uncooked flour.

High‐efficiency removal of phytic acid in soy meal using two‐stage temperature‐induced Aspergillus oryzae solid‐state fermentation

BACKGROUND Phytic acid of soy meal (SM) could influence protein and important mineral digestion of monogastric animals. Aspergillus oryzae (ATCC 9362) solid-state fermentation was applied to degrade phytic acid in SM. Two-stage temperature fermentation protocol was investigated to increase the degradation rate. The first stage was to maximize phytase production and the second stage was to realize the maximum enzymatic degradation. RESULTS In the first stage, a combination of 41% moisture, a temperature of 37 °C and inoculum size of 1.7 mL in 5 g substrate (dry matter basis) favored maximum phytase production, yielding phytase activity of 58.7 U, optimized via central composite design. By the end of second-stage fermentation, 57% phytic acid was degraded from SM fermented at 50 °C, compared with 39% of that fermented at 37 °C. The nutritional profile of fermented SM was also studied. Oligosaccharides were totally removed after fermentation and 67% of total non-reducing polysaccharides were decreased. Protein content increased by 9.5%. CONCLUSION Two-stage temperature protocol achieved better phytic acid degradation during A. oryzae solid state fermentation. The fermented SM has lower antinutritional factors (phytic acid, oligosaccharides and non-reducing polysaccharides) and higher nutritional value for animal feed.

Nutritional Enhancement of Soy Meal via Aspergillus oryzae Solid-State Fermentation

ABSTRACT Antinutritional factors in soy meal (SM) include trypsin inhibitor, galactooligosaccharides (GOSs), structural polysaccharides, and large-molecular-weight protein. These antinutritional factors limit the usage of SM for young monogastric animals. Aspergillus oryzae solid-state fermentation was applied to eliminate these factors, and changes in physical and chemical characteristics of SM were investigated. A. oryzae–treated SM was more nutrient dependent than oxygen dependent, which was illustrated by scanning electron microscopy. After 36 h of fermentation, the concentration of GOSs (raffinose, stachyose, and verbascose) and trypsin inhibitor decreased from an initial value of 9.48 mmol/100 g to a nondetectable level. Structural polysaccharides decreased by 59% (w/w), and the degree of hydrolysis of SM protein increased from an initial value of 0.9 to 7% (w/w) through the seven-day fermentation. Fermentation also modified nutritional factors. Protein content increased from 50.47 to 58.93% (w/w) a...