Biological Engineering Commons^™

Comparison Of Lipid Extraction Methods Of Food-Grade Sorghum (Sorghum Bicolor) Using Hexane, K. L. Christiansen, Curtis L. Weller, V. L. Schlegel, I. M. Dweikat

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Much has been reported concerning sorghum phytochemicals, such as policosanols, but little literature exists on how various extraction methods might be used to optimize the recovery of such phytochemicals. The purpose of this study was to compare three extraction methods for recovery of different sorghum lipids. Lipids were extracted from whole kernel and ground Macia, a food-grade sorghum hybrid, with hexane by a Soxtec method, a refluxing method (RB), and a bench-scale recirculated solvent (RC) method. Comparisons of total lipid yield and lipid class yields extracted from the grain by each method were made. Total lipid yield for the three …

Field Slope Effects On Uniformity Of Corn Seed Spacing For Three Precision Planter Metering Systems, Corey L. Searle, Michael F. Kocher, John A. Smith, Erin E. Blankenship

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effects of field slope on planter seed spacing uniformity were evaluated for three different seed metering units (cell plate, finger pick‐up, and flat plate) operating with medium round corn seed in a laboratory using the University of Nebraska planter test stand with an opto‐electronic seed spacing sensor system. The metering units included a John Deere MaxEmerge™ Plus VacuMeter row unit with the standard cell corn plate, a John Deere MaxEmerge™ Plus VacuMeter row unit with the flat plate, and a John Deere MaxEmerge™ Plus row unit with the finger pick‐up metering system. Planter seed spacing uniformity was measured using …

Visible/Near-Infrared Hyperspectral Imaging For Beef Tenderness Prediction, Govindarajan Konda Naganathan, Lauren M. Grimes, Jeyamkondan Subbiah, Chris R. Calkins, Ashok Samal, George E. Meyer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Beef tenderness is an important quality attribute for consumer satisfaction. The current beef quality grading system does not incorporate a direct measure of tenderness because there is currently no accurate, rapid, nondestructive method for predicting tenderness available to the beef industry. The objective of this study was to develop and test a visible/nearinfrared hyperspectral imaging system to predict tenderness of 14-day aged, cooked beef from hyperspectral images of fresh ribeye steaks acquired at 14-day post-mortem. A push-broom hyperspectral imaging system (wavelength range: 400-1000 nm) with a diffuse-flood lighting system was developed and calibrated. Hyperspectral images of beef-steak (n = 111) …

Performance Evaluation Of Aluminum Test Cell Designed For Determining The Heat Resistance Of Bacterial Spores In Foods, H.-J. Chung, Sohan Birla, Juming Tang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Thermal inactivation kinetic studies are necessary to determine heat resistances of spores in the development of new thermal processes for low-acid shelf-stable products. Most currently available sample holders used in the kinetic studies take long time to reach the target sample temperature, hence fail to provide isothermal condition. In this research, novel aluminum test cells were developed to facilitate easy loading and unloading solid and liquid food samples in a hermetically sealed 1 ml cavity to evaluate the heat resistance of bacterial spores when heated at temperatures above 100 °C. Design of the test cell was governed by minimum come-up …

Characterization Of Radio Frequency Heating Of Fresh Fruits Influenced By Dielectric Properties, Sohan Birla, S. Wang, Juming Tang, G. Tiwari

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Because of its fast and volumetric nature, radio frequency (RF) heating has been looked upon as a way to overcome the problems associated with conventional heating methods used for disinfestation of fruits. But non-uniform heating within fruits is a major obstacle in adaptation of this technology. In this study, RF heating patterns influenced by dielectric properties (DPs) of fruits were investigated both experimentally and mathematically. A computer simulation model was developed using FEMLAB 3.4, a commercial software for solving Maxwell’s electromagnetic and Fourier’s heat transfer equations. Orange, apple, grapefruit, peach, and avocado fruits, selected for these studies were subjected to …

Construction, Installation, And Performance Of Two Repacked Weighing Lysimeters, José O. Payero, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Weighing lysimeters are the standard method for directly measuring evapotranspiration (ET). This paper discusses the construction, installation, and performance of two (1.52 m × 1.52 m × 2.13-m deep) repacked weighing lysimeters for measuring ET of corn and soybean in West Central Nebraska. The cost of constructing and installing each lysimeter was approximately US $12,500, which could vary depending on the availability and cost of equipment and labor. The resolution of the lysimeters was 0.0001 mV V^-1, which was limited by the data processing and storage resolution of the datalogger. This resolution was equivalent to 0.064 and 0.078 …

Variability Analyses Of Alfalfa-Reference To Grass-Reference Evapotranspiration Ratios In Growing And Dormant Seasons, Suat Irmak, Ayse Kilic, T. A. Howell, Derrel Martin, J. O. Payero, K. S. Copeland

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Alfalfa-reference evapotranspiration (ET_r) values sometimes need to be converted to grass-reference ET (ET_o), or vice versa, to enable crop coefficients developed for one reference surface to be used with the other. However, guidelines to make these conversions are lacking. The objectives of this study were to: (1) develop ET_r to ET_o ratios (K_r values) for different climatic regions for the growing season and nongrowing (dormant) seasons; and (2) determine the seasonal behavior of K_r values between the locations and in the same location for different seasons. Monthly average K_r values …

Surface Polyethylene Glycol Enhances Substrate-Mediated Gene Delivery By Nonspecifically Immobilized Complexes, Angela K. Pannier, Julie A. Wieland, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Substrate-mediated gene delivery describes the immobilization of gene therapy vectors to a biomaterial, which enhances gene transfer by exposing adhered cells to elevated DNA concentrations within the local microenvironment. Surface chemistry has been shown to affect transfection by nonspecifically immobilized complexes using self-assembled monolayers (SAMs) of alkanethiols on gold. In this report, SAMs were again used to provide a controlled surface to investigate whether the presence of oligo(ethylene glycol) (EG) groups in a SAM could affect complex morphology and enhance transfection. EG groups were included at percentages that did not affect cell adhesion. Nonspecific complex immobilization to SAMs containing combinations …

Pyrene Fate Affected By Humic Acid Amendment In Soil Slurry Systems, Y. Liang, D. Sorensen, Ronald C. Sims, Joan Mclean

Biological Engineering Faculty Publications

Background

Humic acid (HA) has been found to affect the solubility, mineralization, and bound residue formation of polycyclic aromatic hydrocarbons (PAHs). However, most of the studies on the interaction between HA and PAH concentrated on one or two of the three phases. Few studies have provided a simple protocol to demonstrate the overall effects of HA on PAH distribution in soil systems for all three phases.

Methods

In this study, three doses of standard Elliott soil HA (ESHA), 15, 187.5, and 1,875 μg ESHA/g soil slurry, were amended to soil slurry systems. ¹⁴C-pyrene was added to the systems along …