Microbial profile of broiler carcasses processed at a university scale mobile poultry processing unit.

Chicken and chicken products have been associated with foodborne pathogens such as Salmonella, Campylobacter, and Escherichia coli (E. coli). Poultry comprises an important segment of the agricultural economy (75 million birds processed as of 2019) in West Virginia (WV). The risk of pathogens on processed chickens has risen with the increased popularity of mobile poultry processing units (MPPUs). This study evaluated the microbial safety of broilers processed in a MPPU in WV. This study assessed aerobic plate counts (APCs), E. coli counts and the presence/absence of Salmonella and Campylobacter on 96 broiler carcasses following each MPPU step of scalding, eviscerating, and chilling. Samples were either chilled in ice water only (W) or ice water with 5 ppm chlorine (CW). The highest number of bacteria recovered from carcasses were APCs (4.21 log10CFU/mL) and E. coli (3.77 log10CFU/mL; P = 0.02). A total reduction of 0.30 (P = 0.10) and 0.63 (P = 0.01) log10CFU/mL for APCs and E. coli, respectively, occurred from chilling carcasses in CW. Overall, results show that E. coli, Salmonella, and Campylobacter were significantly (P < 0.05) reduced from the initial scalding to the chilling step. However, Salmonella frequency doubled (15.63-34.38%) after the evisceration step, indicating that washing carcasses after evisceration may be a critical control point in preventing cross-contamination by Salmonella. Proper chilling is also an important microbial mitigation step in MPPU processing. Results indicate that Campylobacter was more resistant to chilling than Salmonella. Campylobacter was not completely inactivated until carcasses were chilled in CW, whereas W was sufficient to reduce Salmonella on carcasses. The results led to the conclusion that although 5 ppm chlorine (Cl2) achieved more bacterial reductions than water alone, the reductions were not always significant (P > 0.05). Further MPPU studies are needed to verify more effective chilling and processing strategies.

Thermal inactivation of Salmonella Typhimurium and surrogate Enterococcus faecium in mash broiler feed in a laboratory scale circulated thermal bath.

This study compares kinetic parameters of Salmonella and surrogate Enterococcus faecium in mash broiler feed during thermal inactivation. Two-gram samples of mash broiler feed were added into a filtered sample bag and inoculated with nalidixic acid (NaL, 200 ppm) resistant S. Typhimurium or Enterococcus faecium, followed by vacuum-packaging and heating in a circulated thermal water bath at 75°, 85°, and 95°C for 0 to 180 s. Counts of bacterial survival were analyzed on tryptic soy agar and bile esculin agar plus 200 ppm of NaL. Microbial data and thermal kinetic parameters (n = 8, Global-Fit and United States Department of Agriculture [USDA]-Integrated-Predictive-Modeling-Program software) were analyzed by JMP software. Heating mash broiler feed at 75°, 85°, and 95°C decreased (P < 0.05) Salmonella cell counts by >6 log10CFU/g after 180, 60, and 50 s, respectively. Heating E. faecium in feed at 75°, 85°, and 95°C for 180, 120, and 70 s achieved reductions of 3, 6, and >6.5 log10CFU/g, respectively. D-values of linear, Weibull models, and z-value of Salmonella at 75°, 85°, and 95°C were 1.8 to 11.2, 4.2 to 21.8, and 28.6 s, respectively, which were lower (P < 0.05) than those of E. faecium (3.7-18.1, 8.5-34.4, and 34.1 s). Linear with Tail, Linear with Tail and Shoulder, and Weibull with tail equations revealed that E. faecium were more resistant (P < 0.05) to heat than Salmonella as shown by longer "Shoulder-time" (26.5 vs. 16.2 s) and greater "Tail" effect (4.4-4.5 vs. 2.5-2.6 log10CFU/g). Results clearly suggested that E. faecium can be used as a surrogate for Salmonella to validate thermal inactivation during feed manufacture.

Survival of Salmonella and the surrogate Enterococcus faecium in cooking of moisture enhanced reconstructed comminuted chicken patties by double pan-broiling.

This study compares kinetic parameters of Salmonella and Enterococcus faecium in moisture enhanced, reconstructed comminuted chicken patties prepared with different pump rates during double pan-broiling with various set-up temperatures. Fresh 1.5-kg chicken breast meat was course grounded, inoculated with S. Typhimurium and Tennessee, or E. faecium, followed by adding NaCl (2.0%) + Na-tripolyphosphate (0.5%) solutions to achieve pump rates of 1%, 5%, or 11.1%. Meat samples were manually manufactured into patties with the thickness of 2.1 cm and diameter of 10.4 cm. Patties were packaged with polyvinyl chloride films in the foam-tray stored at 4°C for 42 h before double pan-broiling set at 200°, 300°, or 425°F for 0 to 420 s. Counts of pathogens were analyzed on xylose-lysine-Tergitol-4 and bile esculin agars with tryptic soy agar layers. Microbial data and kinetic parameters (n = 9, United States Department of Agriculture [USDA]-Integrated-Predictive-Modeling-Program/USDA-Global-Fit software) were analyzed by the Mixed Model Procedure (SAS). Double pan-broiling reduced >5-log10 CFU/g (P < 0.05) of Salmonella after 360 (200°F), 180 to 225 (300°F), and 150 to 165s (425°F), and of E. faecium after 270 s (300°F), and 180 s (425°F) across all samples. D-values (Mafart-Weibull model) of Salmonella and E. faecium in 1% moisture enhanced samples cooked at 200 to 425°F (102.7-248.2 and 115.5-271.0 s) were lower (P < 0.05) than 11.1% samples (119.8-263.7 and 122.5-298.3 s). Salmonella were more susceptible (P < 0.05) to heat than E. faecium. "Shoulder-time" (Buchanan-Two-Phase model) of Salmonella cooking at 200° to 425°F increased (P < 0.05) from 82.3-229.0 to 116.6-246.2 s as pump rate increased from 1 to 11.1%, whereas this phenomenon was not shown for E. faecium. Results indicate that Salmonella were resistant to heat in chicken patties with greater pump rate. E. faecium can be used as a surrogate for Salmonella to validate thermal inactivation in chicken products.

Effect of κ-carrageenan on gelation and gel characteristics of Antarctic krill (Euphausia superba) protein isolated with isoelectric solubilization/precipitation.

Isoelectric solubilization/precipitation (ISP) was used to extract krill protein isolate (KPI). Due to krill endogenous proteases ISP-KPI barely forms gel which is a major hurdle in wide application of this tremendous protein source for direct human consumption. The objective was to improve gelation and elucidate interaction mechanism between κ-carrageenan and KPI. κ-Carrageenan was added to KPI at 0.00, 0.75, 1.50, 2.25, and 3.00 g/150 g and heated at 90 °C for 15 min. Added κ-carrageenan improved texture of KPI gels. However, the level of addition had minimal effect. SDS-PAGE revealed severe proteolysis of KPI even during heating. Total and free sulfhydryl were not different, while surface hydrophobicity and water-holding-capacity slightly decreased and increased, respectively with added κ-carrageenan. Fourier-transform-infrared-spectroscopy showed none-to-minimal shift of ß-sheet and α-helical protein structure; while CC and CO stretching as well as CH bending of κ-carrageenan showed the greatest shift, indicating that κ-carrageenan was mainly responsible for gel formation.

Nutritional Quality and Physical Characteristics of Soluble Proteins Recovered from Silver Carp.

The objective of this study was to evaluate the nutritional quality and physical characteristics of soluble proteins separated from silver carp at 4, 20, and 40 °C. Ground silver carp was diluted, and soluble proteins were separated by centrifugation and dried. The proximate composition (dry wt) of the protein powders averaged 82.42% protein, 3.25% lipid, and 14.50% ash. Average protein recovery yield was 11.78% with the better yields occurring at 20 °C (P < 0.05). Mineral profile revealed greater concentrations of Fe, Mg, P, and Na when compared to the initial homogenate. More saturated and monounsaturated fatty acids were recovered in the 4 °C powder and the least in the 40 °C powder (P < 0.05). Polyunsaturated fatty acids displayed a reverse trend, with the greatest concentration in the 40 °C powder and the least in the 4 °C powder (P < 0.05). The amino acid profile revealed that the protein powder met all FAO/WHO/UNO amino acid requirements for adults. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed high amounts of low and medium molecular weight (MW) proteins (10-15 and 25-50 kDa, respectively). Two-dimensional (2-D) electrophoresis indicated that the low MW proteins possessed a neutral isoelectric point relative to that of the medium MW proteins. The protein powder was significantly less soluble (P < 0.05) than whey protein concentrate 80 at every pH tested (pH 3.0 to 11.0). Similar tendencies were seen when ionic strength was shifted (0.0 to 1.1 I; P < 0.05). Soluble protein powders derived from silver carp are nutrient rich and have physical characteristics resembling whey protein concentrate. Changes in process temperature had limited effects on protein powder composition. PRACTICAL APPLICATION: Soluble proteins contribute to 20 to 40% of fish protein and are soluble in neutral salt solutions. Much of the sarcoplasmic proteins are lost when they solubilize in processing water and are discarded similarly to how whey protein was once discarded during dairy processing. When government regulations on whey disposal were implemented, the dairy industry responded by repurposing the high-quality protein for human use and it is now a billion dollar industry. The aim of this research project was to verify the composition of an otherwise overlooked protein source.

Micro-emulsification/encapsulation of krill oil by complex coacervation with krill protein isolated using isoelectric solubilization/precipitation.

This study determined feasibility of krill protein isolated with isoelectric solubilization/precipitation (ISP) as wall material to microencapsulate krill oil by freeze-drying. Effects of krill oil/krill protein ratio on properties of microcapsules were investigated. With increased ratio, crude protein of microcapsules decreased, while total lipid increased. Although microcapsule oil loading capacity increased, loading and encapsulation efficiencies decreased. Thin layer chromatography (TLC) confirmed abundance of phospholipids, which are amphiphilic; and thus, resulted in stable emulsion (emulsion stability index). Microcapsules contained ω-3 polyunsaturated fatty acids (PUFAs) at 43-60, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at 28-41 and 9-11 g/100g of total FAs, respectively. SDS-PAGE electrophoresis revealed proteolysis of ISP krill protein, probably causing reduced loading and encapsulation efficiencies. SEM showed that krill oil/krill protein ratio affected surface microstructure. ISP krill protein showed potential as a wall material to microencapsulate krill oil; and thus, expand application of krill oil/protein for human consumption.

Storage stability of egg sticks fortified with omega-3 fatty acids.

BACKGROUND: Egg sticks fortified with omega-3 polyunsaturated fatty acids (ω-3 PUFAs) were developed by replacing egg yolk with salmon, algae, and flax oils. Egg sticks were cooked before analysis. Quality indicators for storage stability under different packaging and temperature were determined throughout a 28-day storage. Egg sticks were vacuum and non-vacuum packed. Further, both packaging treatments were divided into two storage temperatures of 4 and 10 °C. Quality indicators were determined every 7 days, including pH, syneresis, texture, color, microbial growth, proximate composition, fatty acid profile, and lipid oxidation. RESULTS: Vacuum-packed egg sticks stored at 4 °C had slower degradation over time than all other treatments; however, they also had higher syneresis, harder texture, and higher anaerobic growth. Although vacuum packaging slowed lipid oxidation, it had limited effect on prevention of ω-3 PUFAs degradation; whereas refrigeration (4 °C) seemed to prevent degradation of ω-3 PUFAs better than it could slow lipid oxidation. CONCLUSION: Based on the results, it can be concluded that both vacuum packaging and refrigeration at 4 °C decrease degradation of egg sticks developed in the present study during storage. Under these conditions, egg sticks may maintain stability for at least 21 days of storage. © 2017 Society of Chemical Industry.

Calcium hydroxide as a processing base in alkali-aided pH-shift protein recovery process.

BACKGROUND: Protein may be recovered by using pH shifts to solubilize and precipitate protein. Typically, sodium hydroxide is used as the processing base; however, this has been shown to significantly increase sodium in the final recovered protein. RESULTS: Protein was extracted from black bullhead catfish (Ameiurus melas) using a pH-shift method. Protein was solubilized using either sodium hydroxide (NaOH) or calcium hydroxide (Ca(OH)2 ) and precipitated at pH 5.5 using hydrochloric acid (HCl). Protein solubility was greater when Ca(OH)2 was used compared to NaOH during this process. Using Ca(OH)2 as the processing base yielded the greatest lipid recovery (P < 0.05) at 77 g 100 g-1 , whereas the greatest (P < 0.05) protein recovery yield was recorded as 53 g 100 g-1 protein using NaOH. Protein solubilized with Ca(OH)2 had more (P < 0.05) calcium in the protein fraction, whereas using NaOH increased (P < 0.05) sodium content. CONCLUSION: Results of our study showed that protein solubility was increased and the recovered protein had significantly more calcium when Ca(OH)2 was used as the processing base. Results showed both NaOH and Ca(OH)2 to be an effective processing base for pH-shift protein recovery processes. © 2016 Society of Chemical Industry.

Nanofibrillated Cellulose and Copper Nanoparticles Embedded in Polyvinyl Alcohol Films for Antimicrobial Applications.

Our long-term goal is to develop a hybrid cellulose-copper nanoparticle material as a functional nanofiller to be incorporated in thermoplastic resins for efficiently improving their antimicrobial properties. In this study, copper nanoparticles were first synthesized through chemical reduction of cupric ions on TEMPO nanofibrillated cellulose (TNFC) template using borohydride as a copper reducing agent. The resulting hybrid material was embedded into a polyvinyl alcohol (PVA) matrix using a solvent casting method. The morphology of TNFC-copper nanoparticles was analyzed by transmission electron microscopy (TEM); spherical copper nanoparticles with average size of 9.2 ± 2.0 nm were determined. Thermogravimetric analysis and antimicrobial performance of the films were evaluated. Slight variations in thermal properties between the nanocomposite films and PVA resin were observed. Antimicrobial analysis demonstrated that one-week exposure of nonpathogenic Escherichia coli DH5α to the nanocomposite films results in up to 5-log microbial reduction.

pH shift protein recovery with organic acids on texture and color of cooked gels.

BACKGROUND: Isoelectric solubilization and precipitation (ISP) processing uses pH shifts to separate protein from fish frames, which may increase commercial interest for silver carp. Texture and color properties of gels made from silver carp protein recovered at different pH strategies and organic acid types were compared. ISP was applied to headed gutted silver carp using 10 mol L(-1) sodium hydroxide (NaOH) and either glacial acetic acid (AA) or a (1:1) formic and lactic acid combination (F&L). Protein gels were made with recovered protein and standard functional additives. RESULTS: Texture profile analysis and the Kramer shear test showed that protein gels made from protein solubilized at basic pH values were firmer, harder, more cohesive, gummier and chewier (P < 0.05) than proteins solubilized under acidic conditions. Acidic solubilization led to whiter (P < 0.05) gels, and using F&L during ISP yielded whiter gels under all treatments (P < 0.05). CONCLUSION: Gels made from ISP-recovered silver carp protein using organic acids show potential for use as a functional ingredient in restructured foods.

Physicochemical properties of surimi gels fortified with dietary fiber.

Although dietary fiber provides health benefits, most Western populations have insufficient intake. Surimi seafood is not currently fortified with dietary fiber, nor have the effects of fiber fortification on physicochemical properties of surimi been thoroughly studied. In the present study, Alaska pollock surimi was fortified with 0-8 g/100 g of long-chain powdered cellulose as a source of dietary fiber. The protein/water concentrations in surimi were kept constant by adding an inert filler, silicon dioxide in inverse concentrations to the fiber fortification. Fiber-fortified surimi gels were set at 90 °C. The objectives were to determine (1) textural and colour properties; (2) heat-induced gelation (dynamic rheology); and (3) protein endothermic transitions (differential scanning calorimetry) of surimi formulated with constant protein/water, but variable fiber content. Fiber fortification up to 6 g/100 g improved (P<0.05) texture and colour although some decline occurred with 8 g/100g of fiber. Dynamic rheology correlated with texture and showed large increase in gel elasticity, indicating enhanced thermal gelation of surimi. Differential scanning calorimetry showed that fiber fortification did not interfere with thermal transitions of surimi myosin and actin. Long-chain fiber probably traps water physically, which is stabilized by chemical bonding with protein within surimi gel matrix. Based on the present study, it is suggested that the fiber-protein interaction is mediated by water and is physicochemical in nature.

Effect of electron beam on chemical changes of nutrients in infant formula.

Infant milk formula has recently been implicated as a transmission vehicle for an emerging foodborne pathogen, Enterobacter sakazakii, resulting in high mortality rates. Electron beam (e-beam) efficiently and non-thermally inactivates foodborne pathogens, including E. sakazakii, in infant milk formula. However, the effects of e-beam on chemical changes of nutrients in infant formula have not been determined. Therefore, the objective of this study was to fulfill this gap. Dehydrated infant milk formula was processed with e-beam at 0 (control) to 25 kGy. Amino acid, fatty acid, and mineral profiles (AAP, FAP, and MP, respectively), as well as protein degradation and lipid oxidation, were determined. There were no differences (P>0.05) in FAP, AAP, and MP. SDS-PAGE electrophoresis qualitatively detected three major protein bands in all samples up to 25 kGy. Densitometry analysis of SDS-PAGE gels confirmed no size degradation (P>0.05) as a function of increased e-beam dose. Totol-volatile-basic-nitrogen (TVBN) excluded (P>0.05) protein degradation due to microbial activity. There was no increase (P>0.05) in lipid oxidation, as assessed with thiobarbituric-reactive-substances (TBARS), except in samples processed at 25 kGy. Dehydrated formula has low water activity, which likely protected nutrients from e-beam-induced chemical changes. This study demonstrates that proteins, lipids, and minerals in infant milk formula are stable when processed with e-beam up to 25 kGy at low temperature and under anaerobic conditions.

Interactions of dietary fibre and omega-3-rich oil with protein in surimi gels developed with salt substitute.

Most Western populations have insufficient intake of fibre and ω-3 polyunsaturated fatty acids (PUFAs), while sodium intake greatly exceeds the recommended maximum. Surimi seafood is not currently fortified with these nutraceutical ingredients. Alaska pollock surimi seafood was developed with salt substitute and fortified with either 6g/100g of fibre or 10 g/100g of ω-3 oil (flax:algae:menhaden, 8:1:1) or fibre+ω-3 oil (6g/100g of fibre+10 g/100g of ω-3 oil). The objective was to determine effects of the dietary fortification on physicochemical properties of surimi. Fortification with either dietary fibre or ω-3 oil alone or in combination enhanced (P<0.05) rheological and textural characteristics. The combined fortification had a synergistic effect on rheological properties. This indicates greater gelation of surimi in the presence of fibre+ω-3 oil, suggesting their interaction with surimi myofibrillar proteins. Fibre results in protein dehydration increasing protein concentration; while oil is immobilised by protein filling void spaces in the gel matrix. Differential scanning calorimetry showed that fibre and ω-3 oil did not interfere with normal denaturation of surimi proteins. Colour properties were only slightly affected (P<0.05). Fortification of surimi with fibre and ω-3 oil resulted in a quality product that could be useful in developing surimi products with nutritional benefits.

Chemical properties of ω-3 fortified gels made of protein isolate recovered with isoelectric solubilisation/precipitation from whole fish.

Protein isolate was recovered from whole gutted fish using isoelectric solubilisation/precipitation (ISP). The objective was to determine chemical properties of heat-set gels made of the ISP protein isolate fortified with ω-3 polyunsaturated fatty acids (PUFAs)-rich oils (flaxseed, fish, algae, krill, and blend). The extent of the PUFAs increase, ω-6/ω-3 FAs and unsaturated/saturated FAs ratios, and the indices of thrombogenicity and atherogenicity depended on specific ω-3 PUFAs-rich oil used to fortify protein isolate gels. Lipid oxidation in ω-3 PUFAs fortified gels was minimal, although greater (P<0.05) than control gels (without ω-3 PUFAs fortification). However, all gels were in the slightly rancid, but acceptable range. The commonly used thiobarbituric-acid-reactive-substances (TBARS) assay to determine lipid oxidation in seafood may be inaccurate for samples containing krill oil due to its red pigment, astaxanthin. Protein degradation (total-volatile-basic-nitrogen) was greater (P<0.05) in ω-3 PUFAs fortified gels than control gels. However, all gels were considerably below the acceptability threshold for protein degradation. The shear stress of ω-3 PUFAs fortified gels was generally greater than the control gels and the shear strain was generally unchanged. This study demonstrates that ω-3 PUFAs fortification of protein isolates recovered with ISP from fish processing by-products or whole fish has potential application in the development of functional foods.

Compositional characteristics of materials recovered from headed gutted silver carp (Hypophthalmichthys molitrix) by isoelectric solubilization and precipitation using organic acids.

UNLABELLED: Protein was recovered from headed gutted silver carp by isoelectric solubilization at pH 2.5, 3.0, 11.5, or 12.0 and precipitation (ISP) at pH 5.5 using acetic (AA) or a 30% formic and lactic acid combination (F&L) and 10 N sodium hydroxide. Total protein and fat recovery yields, proximate composition and mineral analyses of fractions were determined. Protein and lipid recovery yields when solubilized under basic conditions were comparable to yields reported from other studies using hydrochloric acid; however, the recovered fractions were less pure. Processing at basic pH using AA was more effective than F&L at removing impurities (P < 0.05) from the recovered protein fraction and impurities were effectively removed from recovered lipids regardless of processing pH or acid type (P > 0.05). For the most part, sodium was greater (P < 0.05) and there was less calcium, phosphorus, magnesium, and iron (P < 0.05) in the recovered protein regardless of acid used when compared to the initial paste. This research shows that organic acids have the potential to recover protein and lipid by ISP processing. PRACTICAL APPLICATION: This research presents a reliable method for extracting nutritionally valuable fish protein and oils from otherwise hard to process fish and its byproducts. Replacing the traditionally used strong acids with organic acids might further accomplish bacterial load reduction while resulting in similar to or improved protein recovery yields. Therefore, this technology may increase the commercial viability of hard to process fish.

Isoelectric solubilization/precipitation as a means to recover protein isolate from striped bass (Morone saxatilis) and its physicochemical properties in a nutraceutical seafood product.

Excessive dietary intake of Na (i.e., NaCl) contributes to hypertension, which is a major risk factor for cardiovascular disease. Normally, NaOH and HCl are used to dissolve and precipitate, respectively, fish muscle proteins in isoelectric solubilization/precipitation (ISP), therefore contributing to increased Na content in the recovered fish protein isolates (FPI). Substitution of NaOH with KOH may decrease the Na content in FPI and, thus, allow development of reduced-Na seafood products. In this study, FPI was recovered with ISP using NaOH or KOH. In order to develop a nutraceutical seafood product, the FPI was extracted with NaCl or KCl-based salt substitute and subjected to cold- or heat-gelation. In addition, standard nutraceutical additives (ω-3 fatty acids-rich oil and dietary fiber) along with titanium dioxide (TiO2) were added to FPI. Color, texture, dynamic rheology, Na and K content, and lipid oxidation of the FPI gels were compared to commercial Alaska pollock surimi gels. FPI gels had greater (p < 0.05) whiteness, good color properties (L*a*b*), and generally better textural properties when compared to surimi gels. Although the ISP-recovered FPI and surimi developed similar final gel elasticity, the proteins in FPI and surimi had different gelation pattern. A reduction (p < 0.05) of Na content and simultaneous increase (p < 0.05) in K content of FPI gels was achieved by the substitution of NaOH with KOH during ISP and NaCl with the KCl-based salt substitute during formulation of the FPI paste. Although cooking and addition of NaCl during formulation of the FPI paste increased (p < 0.05) lipid oxidation in FPI gels, TBARS values were much below rancidity levels. These results indicate that KOH can replace NaOH to recover FPI from whole gutted fish for subsequent development of nutraceutical seafood products tailored for reduction of diet-driven cardiovascular disease.

A three-prong strategy to develop functional food using protein isolates recovered from chicken processing by-products with isoelectric solubilization/precipitation.

BACKGROUND: Skin-on bone-in chicken drumsticks were processed with isoelectric solubilization/precipitation to recover muscle proteins. The drumsticks were used as a model for dark chicken meat processing by-products. The main objective of this study was conversion of dark chicken meat processing by-products to restructured functional food product. An attempt was made to develop functional food product that would resemble respective product made from boneless skinless chicken breast meat. A three-prong strategy to address diet-driven cardiovascular disease (CVD)with a functional food was used in this study. The strategy included addition of three ingredients with well-documented cardiovascular benefits: (i) ω-3 polyunsaturated fatty acid-rich oil (flaxseed-algae, 9:1); (ii) soluble fiber; and (iii) salt substitute. Titanium dioxide, potato starch, polyphosphate, and transglutaminase were also added. The batters were formulated and cooked resulting in heat-set gels. RESULTS: Color (L*a*b*), texture (torsion test, Kramer shear test, and texture profile analysis), thermal denaturation (differential scanning calorimetry), and gelation (dynamic rheology) of chicken drumstick gels and chicken breast gels were determined and compared. Chicken drumstick gels generally had comparable color and texture properties to the gels made from chicken breast meat. The endothermic transition (thermal denaturation) of myosin was more pronounced and gelation properties were better for the drumstick gels. CONCLUSION: This study demonstrated a feasibility to develop functional food made of muscle proteins recovered with isoelectric solubilization/precipitation from low-value dark chicken meat processing by-products. The functional food developed in this study was enriched with CVD-beneficial nutrients and had comparable instrumental quality attributes to respective products made of chicken breast meat. Although the results of this study point towards the potential for a novel, marketable functional food product, sensory tests and storage stability study are recommended.

Characterization of lipids and antioxidant capacity of novel nutraceutical egg products developed with omega-3-rich oils.

BACKGROUND: Cardiovascular disease has had an unquestioned status of the number one cause of death in the US since 1921. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have cardio-protective benefits. However, egg is typically a poor source of ω-3 PUFAs and, in general, the American diet is low in these cardio-protective fatty acids. Novel, nutritionally enhanced egg products were developed by substituting yolk with ω-3 PUFA-rich flaxseed, menhaden, algae, or krill oil. Experimental egg products matched composition of hen egg (whole egg). The experimental egg products, mixed whole egg, and a liquid egg product (Egg Beaters) were microwave-cooked and compared. RESULTS: Although fat, protein, and moisture contents of experimental egg products matched (P > 0.05) mixed whole egg, experimental egg products had more (P < 0.05) ω-3 PUFAs, lower (P < 0.05) ω-6/ω-3 ratio, and depending on oil added, a higher (P < 0.05) unsaturated/saturated fatty acids ratio compared to mixed whole egg. Triglycerides were the main lipid class in all experimental egg products except those developed with krill oil, which had even more phospholipids than mixed whole egg. Analysis of thiobarbituric acid reactive substances showed that lipid oxidation of experimental egg products was lower (P < 0.05) or similar (P > 0.05) to mixed whole egg, except for experimental egg products with krill oil. However, peroxide value showed that all egg samples had minimal oxidation. Experimental egg products developed with menhaden or flaxseed oil had the highest (P < 0.05) concentration of the antioxidant, ethyoxquin compared to all other egg samples. However, experimental egg products with krill oil likely contained a natural antioxidant, astaxanthin. CONCLUSION: This study demonstrated an alternative approach to developing novel, nutraceutical egg products. Instead of dietary modification of chicken feed, yolk substitution with ω-3 PUFAs oils resulted in enhancement of ω-3 PUFAs beyond levels possible to achieve by modifying chicken feed.

Physicochemical changes in surimi with salt substitute.

Protein endothermic transitions (thermal denaturation), rheological properties (protein gelation), and fundamental texture properties (shear stress and strain at mechanical fracture) of Alaska pollock surimi gels made with 0 (control), 1, 2, and 3g/100g of salt (NaCl) were determined and compared with equal molar concentration of salt substitute. Salt and salt substitute shifted the onset of myosin transition to higher temperature and resulted in larger myosin peaks (i.e., transition enthalpy). Endothermic transitions showed similar trends to rheological properties. The elastic modulus (G') increased when salt or salt substitute was added to surimi, except at the highest concentration of salt and salt substitute. Salt and salt substitute also induced the onset of protein gelation (i.e., as measured by significant increase of G') at lower temperature. Surimi gels with salt substitute and salt at equal molar concentrations had similar texture properties (shear stress and strain). Based on the present study, salt substitute can be used in the development of low-sodium surimi seafood products without significant change in gelation and texture.

Radioresistance development of DNA repair deficient Escherichia coli DH5α in ground beef subjected to electron beam at sub-lethal doses.

PURPOSE: Electron beam (e-beam) efficiently and non-thermally inactivates microorganisms in food by lethal DNA changes (direct effects) and free radicals from water radiolysis (in-direct effects). Non-pathogenic Escherichia coli DH5α (α substrain of DH5 described by Hanahan 1985 , 'DH' stands for Douglas Hanahan) is a microorganism that lacks DNA repair capability, resulting in high radiosensitivity. Studying microbial inactivation of E. coli DH5α repeatedly subjected to sub-lethal e-beam in ground beef may enhance understanding of microbial radioresistance. The objective of this study was to determine if repetitive processing with e-beam at sub-lethal doses increases D-value (e-beam dose required to inactivate one log of microbial population) of E. coli DH5α in ground beef. MATERIALS AND METHODS: Survivors from the highest e-beam dose were isolated and incubated in ground beef for the next cycle of e-beam processing. Five cycles were conducted. To acclimatise E. coli DH5α, first two cycles used low doses. D-values were determined following the third cycle. RESULTS: D-values increased (p < 0.05) significantly with each cycle. Thus, E. coli DH5α has a capability to develop greater radioresistance under these experimental conditions. Following the third cycle D-values were 0.32 ±â€Š0.006 and 0.32 ±â€Š0.002 kGy for survivors enumerated on non-selective and selective media, respectively; the fourth cycle 0.39 ±â€Š0.007 and 0.40 ±â€Š0.019 kGy; and the fifth cycle 0.46 ±â€Š0.006 and 0.46 ±â€Š0.020 kGy. D-values on non-selective and selective media were similar (p > 0.05) indicating absence of cell recovery in E. coli DH5α. CONCLUSIONS: E. coli DH5α increases radioresistance to e-beam as a result of repetitive exposure to sub-lethal doses despite its DNA repair deficiency.