Paul H. Patterson

Pulsed UV light inactivation of Salmonella Enteritidis on eggshells and its effects on egg quality.

The majority of Salmonella Enteritidis outbreaks have been related to the consumption of raw or undercooked eggs or egg-containing foods. Therefore, the U.S. Department of Agriculture mandates egg washing for all graded eggs by use of a detergent solution and sanitizer. These agencies and the egg industry have been investigating alternative decontamination techniques, which could better serve the public, minimize costs, and benefit both the public and the industry. Pulsed UV light is an emerging technology that is used to inactivate microorganisms quickly. In this study, the effectiveness of pulsed UV light was evaluated for the decontamination of eggshells. Eggs inoculated with Salmonella Enteritidis on the top surface at the equator were treated with pulsed UV light 1 to 30 s, at a distance of 9.5 and 14.5 cm from the UV lamp in a laboratory-scale, pulsed UV light chamber. Three eggs were used per treatment in each repetition, except for quality measurements, which involved six eggs per treatment in each repetition. A maximum log reduction of 5.3 CFU/cm2 was obtained after a 20-s treatment at 9.5 cm below the UV lamp at a total dose of 23.6+/-0.1 J/cm2, without any visual damage to the egg. After a 30-s treatment at 9.5 and 14.5 cm, the temperature of eggshell surfaces increased by 16.3 and 13.3 degrees C, respectively. Energy usage increased up to 35.3+/-0.1 and 24.8+/-0.1 J/cm2, after 30-s treatments at 9.5 and 14.5 cm, respectively. The effect of pulsed UV light treatments on egg quality was also evaluated. Pulsed UV-light treatments for 3, 10, and 20s at either 9.5 or 14.5 cm did not change the albumen height, eggshell strength, or cuticle presence significantly (P<0.05). This study demonstrated that pulsed UV light has potential to decontaminate eggshell surfaces.

Screening of phenylpyruvic acid producers and optimization of culture conditions in bench scale bioreactors

Alpha keto acids are deaminated forms of amino acids that have received significant attention as feed and food additives in the agriculture and medical industries. To date, their production has been commonly performed at shake-flask scale with low product concentrations. In this study, production of phenylpyruvic acid (PPA), which is the alpha keto acid of phenylalanine was investigated. First, various microorganisms were screened to select the most efficient producer. Thereafter, growth parameters (temperature, pH, and aeration) were optimized in bench scale bioreactors to maximize both PPA and biomass concentration in bench scale bioreactors, using response surface methodology. Among the four different microorganisms evaluated, Proteus vulgaris was the most productive strain for PPA production. Optimum temperature, pH, and aeration conditions were determined as 34.5xa0°C, 5.12, and 0.5 vvm for PPA production, whereas 36.9xa0°C, pH 6.87, and 0.96xa0vvm for the biomass production. Under these optimum conditions, PPA concentration was enhanced to 1,054xa0mg/L, which was almost three times higher than shake-flask fermentation concentrations. Moreover, P. vulgaris biomass was produced at 3.25xa0g/L under optimum conditions. Overall, this study demonstrated that optimization of growth parameters improved PPA production in 1-L working volume bench-scale bioreactors compared to previous studies in the literature and was a first step to scale up the production to industrial production.

Decontamination of Shell-Eggs with Pulsed UV-Light

Currently, most methods used by the food industry to decontaminate shell-eggs involve washing the egg surface with various chemical solutions. In this study, the effectiveness of pulsed UV-light was evaluated for the decontamination of shell-eggs. Samples inoculated with Salmonella Enteritidis on top surface on the equator were treated with pulsed UV-light for 1, 3, 5, 10, 15, 20, and 30 seconds at 9.5 and 14.5 cm from the UV-strobe in a chamber. An input voltage of 3,800 V was used to generate a 1.27 J/cm2/pulse of radiant energy at 1.5 cm below the lamp surface, producing a polychromatic radiation in the wavelength range of 100 to 1100 nm, with 54% of the energy being in the UV-light region. Log reductions in microbial population were determined after treatments. A maximum log10 reduction of 5.3 (CFU/cm2) was obtained after 20-s treatment at 9.5 cm without any visual damage to the egg. The temperature and total energy absorbed at each treatment condition was determined using a K-type thermocouple and a radiometer, respectively. Temperature and energy increased with higher treatment time and shorter distance from the UV-lamp. A maximum temperature increase of 10.5 ±1.6°C and a maximum energy of 35.3±0.1 J/cm2 were observed after 30-s treatment at 9.5 cm. This study demonstrated that pulsed UV-light has potential to decontaminate shell-egg surfaces.

Enhanced phenylpyruvic acid production with Proteus vulgaris in fed-batch and continuous fermentation.

ABSTRACT Phenylpyruvic acid is a deaminated form of phenylalanine and is used in various areas such as development of cheese and wine flavors, diagnosis of phenylketonuria, and to decrease excessive nitrogen accumulation in the manure of farm animals. However, reported phenylpyruvic acid fermentation studies in the literature have been usually performed at shake-flask scale with low production. In this study, phenylpyruvic acid production was evaluated in bench-top bioreactors by conducting fed-batch and continuous fermentation for the first time. As a result, maximum phenylpyruvic acid concentrations increased from 1350 mg/L (batch fermentation) to 2958 mg/L utilizing fed-batch fermentation. Furthermore, phenylpyruvic acid productivity was increased from 48 mg/L/hr (batch fermentation) to 104 and 259 mg/L/hr by conducting fed-batch and continuous fermentation, respectively. Overall, this study demonstrated that fed-batch and continuous fermentation significantly improved phenylpyruvic acid production in bench-scale bioreactor production.

Supplementation of Poultry Feeds with Dietary Zinc and Other Minerals and Compounds to Mitigate Nitrogen Emissions—A Review

One of the environmental challenges that the poultry industry has been faced with is ammonia emission from manure. One way to reduce nitrogen excretion and emissions is supplementing dietary trace minerals to inhibit the activity of microbial uricase, a key enzyme converting nitrogen compounds in the manure into ammonia. Several dietary minerals are commercially available as economic alternatives for reducing ammonia emissions in poultry. In this review, we discuss different mineral elements including zinc as feed amendment minerals that could be used to reduce ammonia emission. Issues discussed include potential for inhibiting microbial uricase, dietary supplementation levels, growth performance, toxicity, their influence on manure nitrogen emission, and potential mineral accumulation in soil. In addition, we discuss other minerals and compounds that have the potential to reduce ammonia volatilization by inhibiting microbial uricase and growth of uric acid-utilizing microorganisms.

Reduction of nitrogen excretion and emission in poultry: A review for organic poultry

ABSTRACT Organic poultry is an alternative to conventional poultry which is rapidly developing as a response to customers demand for better food and a cleaner environment. Although organic poultry manure can partially be utilized by organic horticultural producers, litter accumulation as well as excessive nitrogen still remains a challenge to maintain environment pureness, animal, and human health. Compared to conventional poultry, diet formulation without nitrogen overloading in organic poultry is even more complicated due to specific standards and regulations which limit the application of some supplements and imposes specific criteria to the ingredients in use. This is especially valid for methionine provision which supplementation as a crystalline form is only temporarily allowed. This review is focused on the utilization of various protein sources in the preparation of a diet composed of 100% organic ingredients which meet the avian physiology need for methionine, while avoiding protein overload. The potential to use unconventional protein sources such as invertebrates and microbial proteins to achieve optimal amino acid provision is also discussed.

The effects of disproportional load contributions on quantifying vegetated filter strip sediment trapping efficiencies

Vegetated filter strips (VFSs) are a best management practice (BMP) commonly implemented adjacent to row-cropped fields to trap overland transport of sediment and other constituents present in agricultural runoff. Although they have been widely adopted, insufficient data exist to understand their short and long-term effectiveness. High inter-event variability in performance has been observed, yet the majority of studies report average removal efficiencies over observed or simulated events, ignoring the disproportional effects of loads into and out of VFSs over longer periods of time. We argue that due to positively correlated sediment concentration-discharge relationships, disproportional contribution of runoff events transporting sediment over the course of a year (i.e., temporal inequality), decreased performance with increasing flow rates, and effects of antecedent moisture condition, VFS removal efficiencies over annual time scales may be significantly lower than reported per-event averages. By applying a stochastic approach, we investigated the extent of disparity between reporting average efficiencies from each runoff event over the course of 1 year versus the total annual load reduction. Additionally, we examined the effects of soil texture, concentration-discharge relationship, and VFS slope in contributing to this disparity, with the goal of revealing potential errors that may be incurred by ignoring the effects of temporal inequality in quantifying VFS performance. Simulation results suggest that ignoring temporal inequality can lead to overestimation of annual performance by as little as <xa02% and to as much as >xa020%, with the greatest disparities observed for soils with high clay content.

Modifying Protein in Feed

Abstract Protein and amino acid (AA) nutrition for laying hens has become increasingly precise to ensure that pullet growth, hen maintenance, and egg production and quality are optimized. Bird AA requirements, once considered only on a total dietary AA basis, are now looked at on a digestible basis and in relationship to other AA. The goal is for no AA to be deficient in the diet or fed in excess of requirements, which can lead to negative consequences. Dietary protein and AA requirements of mature birds decrease with age for both laying hens and other commercially relevant avian species (e.g., ducks and quail). However, good quality protein ingredients (either conventional or organically approved in organic systems), with consistent composition and low cost (e.g., soybean meal), are needed throughout the life of the bird. Optimizing protein and AA nutrition is critical for maintaining adequate egg production, size, and quality for laying hens.

Ammonia emission and productivity of laying hens fed diets containing distiller dried grains.

Laboratory and field studies of diets containing distiller dried grains with solubles (DDGS) have reported reduced ammonia (NH3) emissions from egg laying hen manure. The study reported here was conducted on-farm in Pennsylvania, one of the major egg producing states. The goal was to document any changes in egg quality and gas emission improvements through the use of DDGS diets while maintaining or improving hen productivity. Three isocaloric, amino acid balanced diets containing 10% corn DDGS with or without the probiotic Provalen™ were compared to a corn-soybean based control diet. Hens were 20-65 wk of age with each diet provided to two of six rows of stacked manure-belt cages (six decks high) in one house. Feed intake, water consumption, hen body weight, egg production, egg case weight, mortality, feed cost, and egg income were provided weekly by the cooperating egg company. Replicated monthly data, including hen body weight, hen-day egg production, egg weight, albumen height, Haugh units, yolk color, shell strength, and shell thickness, were determined from collected eggs. Ammonia gas measurements utilized a non-steady state flux chamber method coupled with photoacoustic infrared gas analyzer. Results indicated that including 10% DDGS with or without Provalen probiotic had economical benefits on a commercial scale. The 10% DDGS diet improved egg production, albumen height and yolk color. DDGS diet ammonia flux from belt manure in the hen house was variable and offered no consistent improvement.

Efficacy of electrolyzed oxidizing water for the microbial safety and quality of eggs during in-vitro and pilot scale egg washing

During commercial processing, eggs are washed in an alkaline detergent and then rinsed with chlorine to reduce dirt, debris, and microorganism levels. The alkaline and acidic electrolyzed oxidizing (EO) water have the ability to fit into the two-step commercial egg washing process if proven to be successful. Therefore, the efficacy of EO water to decontaminate Salmonella Enteritidis and Escherichia coli K12 on artificially inoculated shell eggs was investigated. For the in-vitro study, eggs were soaked in alkaline EO water followed by soaking in acidic EO water at various temperatures and times. Treated eggs showed a reduction between =0.6 and =2.6 log10 CFU/g shell for S. Enteritidis and =0.9 and =2.6 log10 for E. coli K12. Log10 reductions of 1.7 and 2.0 for S. Enteritidis and E. coli K12, respectively, were observed for detergent/sanitizer treatments, whereas log10 reductions of =2.1 and =2.3 for S. Enteritidis and E. coli K12, respectively, were achieved using the EO water treatment. For the pilot scale study, EO water was compared with the detergent/sanitizer treatment using E. coli K12. Log10 reductions of = 2.98 and = 2.91 were found using the EO water treatment and the detergent/sanitizer treatment, respectively. The effects of treatments on egg quality were investigated. EO water and detergent/sanitizer treatments were found to have no significant effect on albumen height and eggshell strength; however, there were significant affects on cuticle presence. All these results indicate that EO water has the potential to be used as a sanitizing agent for the egg washing process.