Christina A Mireles DeWitt

Oregon State University | OSU · Department of Food Science and Technology

Given the growing global demand for seafood, it is imperative to conduct a comprehensive study on the prevalence and persistence patterns of pathogenic bacteria and viruses associated with specific seafood varieties. This assessment thoroughly examines the safety of seafood products, considering the diverse processing methods employed in the indust...

Fish production is one of the most important solutions to tackle the great challenges of the 21st century, such as how to feed people in the context of a growing population. However, pathogens such as bacteria, including antimicrobial-resistant populations and viruses, can be present in the water column and fish (also including shellfish) threateni...

Pacific whiting (PW) is an inexpensive, protease rich fish which make it an excellent candidate as a source for fish sauce. However, fish sauce fermentation requires elevated ambient temperatures (20–35 °C) for 12–18 mo. Ambient temperature where PW is harvested ranges from 1 to 20 °C and therefore external heating would be required. To make fish s...

High pressure processing (HPP) at ultra-low temperatures was conducted against Listeria monocytogenes and Salmonella enterica in frozen pink salmon fillets. Quality changes, such as drip loss, color and odor attributes were recorded in non-inoculated pollock, pink salmon and tuna fillets. Pressures at 250 and 400 MPa were applied from 0.5 to 10 min...

Vibrio parahaemolyticus infections in the United States have been linked to consumption of raw oysters. Depuration has the potential to reduce contamination in live oysters after harvest. This study investigated the impact of depuration flow rate to reduce V. parahaemolyticus in raw oysters. Pacific oysters (n = 35 per trial) were inoculated with a...

Practical application: Texture softening in fish has typically been addressed by diverting product to lower-value minced applications where ingredients can be blended-in to counteract softening caused by enzymes. Investigations demonstrate feasibility of brine injection of protease inhibitor ingredient, dried egg white, to preserve protein integri...

Vibrio parahaemolyticus causes acute human gastroenteritis and is often linked to consumption of raw oysters. Previous investigations indicated that refrigerated seawater depuration at 12.5°C could significantly reduce V. parahaemolyticus contamination in Pacific oysters; however, further optimization is necessary to achieve the regulatory target o...

An exploratory study was conducted to determine if multineedle injection technology could deliver protease inhibitor ingredients into fish fillets at sufficient levels to inhibit protease activity. Pacific whiting is used as a model in this study. Fillet treatments ( n=8 /treatment) included noninjection (C), injection of base brine containing 3% s...

Parameters for chilling fish using nano‐sized ice crystals (NI) made from 3.6% salt water were investigated. Flake ice mixed with salt water (CS) was utilized for comparative purposes. The effect of ice : fish ratio (2:1, 1.5:1, 1:1) on chilling rates and on time, at, or below threshold temperatures (lowest achievable, 0 °C, and 4 °C) were investig...

Odor-active compounds from two canned tuna (albacore and skipjack) were fractionated and studied by gas chromatography/olfactometry-mass spectrometry (GC/O-MS). Aroma compounds were isolated using solvent extraction followed by solvent-assisted flavor evaporation and fractionation. A total of 51 odorants were identified. The sulfur-containing compo...

This review aims at summarizing the findings of studies published over the past 15 years on the application of modified atmosphere (MA) systems for shelf life extension of fish and fishery products. This review highlights the importance of CO2 in the preservation of seafood products, and underscores the benefits of combining MA technology with prod...

Pacific whiting is a fish that produces a poor quality cooked fillet due to proteases that exhibit high activity during cooking. Brine injection technology is being investigated for its ability to deliver a protease inhibitor to improve cooked fillet texture. Previous studies with brines containing dried potato extract and dried egg white demonstra...

By-products obtained from winemaking processes still contain large amounts of phenolic compounds, especially phenolic acids, flavanols, flavonols, stilbenes, and flavonoids. Enzymatic hydrolysis was used for determination and characterization of phenolic acids, flavanols, flavonols, and stilbenes. Characterization of the flavonoids was achieved usi...

This study aimed to determine the interactions among salt (NaCl), sodium phosphate (SP) and mild high pressure processing (HPP) in brine-injected beef. Beef strip loin segments were injected to 10% over initial weight with solutions containing water and various levels of salt (0, 2 or 4% of solution) and/or SP (0 or 4% of solution). Pieces from the...

High pressure–low temperature (HPLT) processing was investigated to achieve Escherichia coli O157:H7 inactivation in non-intact, whole muscle beef while maintaining acceptable quality characteristics. Beef semitendinosus was internally inoculated with a four strain E. coli O157:H7 cocktail and frozen to − 35 °C, then subjected to 551 MPa for 4 min...

Phenolic acids, flavanols, flavonols and stilbenes (PAFFS) were isolated from whole grapes, juice, or pomace and purified using enzymatic hydrolysis. Only anthocyanin mono-glucosides and a few of the oligomers from Cynthiana grape (Vitis aestivalis) were analysed. Flavonoid-anthocyanin mono-glucosides (FA) were isolated using methanol/0.1% hydrochl...

By-products obtained from winemaking processes still contain large amounts of phenolic compounds, especially phenolic acids, flavanols, flavonols, stilbenes, and flavonoids. Enzymatic hydrolysis was used for determination and character-ization of phenolic acids, flavanols, flavonols, and stilbenes. Characterization of the flavonoids was achieved us...

Value-added seafood products are becoming increasingly important in satisfying the demands for safe, high-quality seafood throughout the world. While both capture fisheries and aquaculture have supplied fresh fish and shellfish to many markets, the exploration of value-added opportunities in the marketplace present expansion possibilities for the s...

This study was conducted using response surface methodology to predict fluid loss from injected beef strip steaks as influenced by levels of salt and sodium phosphates (SP) in the injection brine. Also, a beef-based dehydrated beef protein (DBP) water binding ingredient was evaluated. Paired U.S. select beef strip loins were quartered before being...

Seafood, defined here as marine and freshwater fish and shellfish, is recognized as a healthy food choice because it is a low‐fat protein source that provides long‐chain omega‐3 fatty acids important for early development along with eye and heart health. However, seafood is also known to contain certain contaminants, such as methylmercury and persi...

Unlabelled: Muddy and/or musty off-flavors in farmed-raised catfish occur as a result of the absorption of geosmin (GEO) and 2-methylisoborneol (MIB), compounds produced by algae. Previous research suggests the acid pH-shift method may be able to reduce off-flavors to produce a consumer acceptable product. The objective of this research was to eva...

A dehydrated beef protein (DBP) was evaluated as a replacement for the phosphate added to beef injection brines. U.S. Select strip loins (n=20) were injected to 110% of their initial weight with a brine containing 3.6% salt and 4.5% sodium phosphate (CON) or 3.6% salt and 5% dehydrated beef protein (DBP). DBP loins had less fluid loss after 30 min....

Paired U.S. Department of Agriculture Select strip loins were injected with either a conventional brine (4.5% potassium and sodium polyphosphate blend [Brifisol 750], 3.6% NaCl, 1% Herbalox seasoning HT-S, and 90.9% ice water) or an ammonium hydroxide (AH) brine (1% AH, 3.6% NaCl, 1% Herbalox seasoning HT-S, and 94.4% ice water). The steaks were sl...

Select beef loin pairs (n = 10) were injected (10% pump) with brine containing either 4.5% sodium-based phosphates, (CON), or 1% ammonium hydroxide treatment (AHT). Both brines also contained 3.6% NaCl and 1% Rosemary Herbalox. Steaks cut from loins were high oxygen (80% O(2)/20% CO(2)) modified atmosphere packaged, stored 4 d at 4 °C in the dark t...

The impact of 2 different brines on the palatability and tenderness of select beef strip loin steaks was evaluated. Brines were differentiated by the type of alkaline agent, 4.5% sodium-based phosphate (control brine; CON) or 1% ammonium hydroxide (ammonium hydroxide treatment; AHT), incorporated into the formula. Injected steaks were placed in hig...

The purpose of this study was to judge the feasibility of gasification for the disposal of waste streams generated through salmon harvesting. Gasification is the process of converting carbonaceous materials into combustible "syngas" in a high temperature (above 700 degrees C), oxygen deficient environment. Syngas can be combusted to generate power,...

Paired USDA Select beef strip loins (n = 10), aged 2 d, were injected with either an alkaline-based (3.6% sodium chloride, 1% Herbalox seasoning, adjusted to pH 10 with ammonium hydroxide [approximately 0.1%, FFC grade]) or a phosphate-based (3.6% sodium chloride, 1% Herbalox seasoning, 4.5% sodium tripolyphosphate) brine. Steaks were evaluated for...

Story in Brief USDA Select, paired beef strip loins aged for 2 d were enhanced to 110% of original weight with either a high pH solution containing 3.6% sodium chloride, 1% Herbalox seasoning and adjusted to pH 10 with ammonium hydroxide (~.1%, FFC grade) or a phosphate based solution (pH 8.45) prepared using 3.6% sodium chloride, 1% Herbalox seaso...

Catfish fillets were minced and acid (pH 3.0) solubilized in dilute conditions (1:9). Insolubles were removed by centrifugal force (3000 xg) and the soluble protein was recovered by isoelectric precipitation (pI approximately 5.4). Moisture and NaCl of the batters were equilibrated to 78% and 2%, respectively. Samples were stuffed into casings, coo...

Conditions that optimize 2-methylisoborneol (MIB) and geosmin reduction by protein solubilization were evaluated in channel catfish. For both MIB and geosmin spiked fish, acid and alkaline solubilizations effectively (p < 0.001) reduced off-flavor. Average MIB and geosmin levels for untreated, unprocessed fish were 1.396 and 1.992 ppb, respectively...

Previous research has demonstrated that vitamin E (tocopherol) applied to muscle foods using an oil carrier targets the neutral lipid fraction (NLF: triacylglycerols) instead of the polar lipid fraction (PLF: phospholipids) and therefore does not act as an effective antioxidant. This paper demonstrates that δ-tocopherol (TOH) applied using a polar...

Select grade strip loins (n = 10) were enhanced 10% with either a phosphate or an acid solubilized protein solution. Color score, aerobic plate count, lipid oxidation, purge loss, cook yield, Warner-Bratzler shear force, and sensory analysis were measured to characterize storage quality. The phosphate injection consisted of 4.5% phosphate, 3.6% sod...

Incorporation of δ-tocopherol using an ethanolic carrier to control lipid oxidation in impingement and ohmic cooked beef patties was evaluated, and quality characteristics were determined. Ethanolic δ-tocopherol delayed oxidative deterioration of cooked beef patties in both cooking methods. Ohmic cooked samples developed significantly higher (P < 0...

Beef heart (BH), a low water binding meat, was treated by acid-solubilization isoelectric-precipita-tion (SIP), and functional and textural properties were compared with untreated BH and BH treated by a surimi-type process. The effect of salt, 0% or 2% NaCl, on gel attributes was also evaluated. Acid-SIP BH without salt exhibited higher gel attribu...

Byproduct disposal from food processing operations is an increasing problem. Gasification is an alternative, value-added process for handling some food processing byproducts. A low-cost, pilot-scale, updraft, batch gasifier was designed, fabricated, and tested at the Oklahoma State University to test feasibility of gasification of food processing b...

The recovery of myofibrillar protein from beef heart using nonthermal acidic solubilization was evaluated. Postmortem time, 3 or 24 h, did not affect protein solubility (p > 0.05). Protein solubility and yield were detrimentally affected by salt addition. Recovery of extracted protein (yield) was maximized with 0 mM NaCl (60.8 ± 3.9%). SDS-PAGE con...

Recovery of bioactive compounds, such as proteolytic enzymes, from waste streams is a means to both recuperate value and reduce environmental pollution. Previously optimized lab-scale parameters for the recovery of a stable crude protease fraction from Pacific whiting (Merluccius productus) surimi wash water were tested using pilot plant equipment....

Proteases are important bioactive compounds that have many applications in food processing. In this study, laboratory scale experiments were performed to establish conditions for recovery of a heat stable, acid protease from Pacific whiting (Merluccius productus) surimi process water. Reduction of proteinaceous solids and recovery of protease activ...

HACCP was implemented in the U.S. in December, 1997. A survey from the FDA Office of Seafood, after the first 6 months, showed mixed results regarding successful implementation. Four major issues have developed from the initial FDA inspections. They include: parasites in seafood, histamine monitoring, lethality of cook, and Clostridium botulinum in...

Edible coatings prepared using proteins and polysaccharides can help retain high preservative concentrations on food surfaces to retard microbial surface growth which limits the shelf life of many products. Coating effectiveness is affected by coating formulation, food water activity, food pH and storage temperature. Microstructure determinations b...

Story in Brief Many catfish producers are burdened with the chronic management problem of producing off-odor/flavor catfish. Off-odor/flavor catfish results from two compounds, 2-methylisoborneol (MIB) and geosmin, that can reside in the water in which catfish are raised. The resulting off-odors/flavors decrease profit margins for producers because...

The objective of this study was to develop a protocol for the production of the non-pathogenic recombinant sheep prion protein (RecShPrPC) using a bacterial expression system and confirm its production using Western Blot and Immuno-PCR. Prion protein is the causative agent of many neuro-degenerative diseases including Bovine Spongiform Encephalopat...

Typescript (photocopy). Thesis (M.S.)--Oregon State University, 1994. Includes bibliographical references (leaves 72-77).