NC State
University Department of Food Science Seafood Laboratory
The Seafood Laboratory is a component
of the Department of Food Science, College of Agriculture and Life Sciences
at North Carolina State University. Professor Frank B. Thomas established the
program in 1970 as part of NC Sea Grant College Program's Marine Extension Service.
The lab assists North Carolina's commercial and recreational fishing industries
and its citizens through seafood education, training and research in food safety,
processing technology, value-added products and regulatory compliance.
The Seafood Lab is located on the
Atlantic seaboard in Morehead City, North Carolina. Its programs and personnel
are housed in the NC State University Center for Marine Sciences and Technology
(CMAST).
Seafood Lab operational support is
provided through the North Carolina Cooperative Extension Service, NC Agricultural
Research Service and NC Sea Grant College Program. Additional program support
is obtained through grants, contracts and industry services.
Lab Mission and Function
M I S S I O N
The Seafood Lab is committed to improving
the lives of citizens by providing research, education and outreach services
to the general public, to members of the seafood industry and to food service
and regulatory personnel as it relates to seafood safety and utilization.
Seafood Lab personnel work with industry,
federal and state agencies, health professionals, extension agents, and consumers
in areas of seafood safety and quality, processing technology, packaging, regulatory
compliance, product development, and utilization. Personnel organize seafood
education and training workshops, provide consumer informa-tion, offer industry
technical services, and conduct applied research projects on important issues
in marine and freshwater fisheries. The Lab provides numerous opportunities
for internships, student training, and volunteer programs, for example, recipe
development and evaluation by the Carteret County Nutritional Leaders. The Lab
offers modern analytical laboratory and pilot processing capabilities including
microbiology, food chemistry, process engineering, test kitchen, walk-in cooler
and freezer facilities. Equipment housed at the lab includes vacuum tumbling,
packaging, fish deboner and meat strainer, batter and breading machine and nitrogen
freezer.
Information Services
Seafood handling & preparation
Product safety & quality education
Consumer & health professional
workshops
Industry Technical Services
Product safety & quality evaluation
Industry demonstrations & training
Process & facility design evaluation
Entrepreneurial assistance
HACCP training & verification
Applied Research
Product safety & quality
Process optimization & control
Packaging & shelf life determination
New product development
Quality assurance programs
Current Research Projects
roe-on scallop product evaluation;
seafood safety and preparation handbook, based on Mariners Menu research;
internet marketing of select value-added products;
blue crab sensory focus groups;
development of model scombrotoxin control procedures;
sodium chlorite for improved handling of hybrid striped bass;
heat shock treatment of oysters;
utilization of blue crab by-products.
The Seafood Lab routinely provides
students with assistantships, employment opportunities and mentorship. Interested
persons should contact Lab personnel.
Faculty and Staff
David Green, Ph.D.
Associate Professor & Director
dave_green@ncsu.edu
Barry Nash, M.S.
Seafood Technology Specialist
barry_nash@ncsu.edu
Greg Bolton, M.S.
Seafood Research Technologist
greg_bolton@ncsu.edu
Lorraine DiBella, B.S.
Public Information Assistant
lorraine_dibella@ncsu.edu
Joyce Taylor, B.A.
Seafood Education Specialist
Seafood Lab personnel collaborate
with campus©based faculty on research and extension projects of joint interest.
The Lab works cooperatively with regional programs offered through UNC Institute
of Marine Sciences, Duke University Marine Laboratory, NOAA National Marine
Fisheries Service and Carteret Community College.
Seafood Laboratory
Personnel
David Green
Associate Professor and Director
Center for Marine Sciences and Technology
Seafood Laboratory
Telephone: 252-222-6304
Telephone: 252-222-6303
Email: dave_green@ncsu.edu
As Director of the Center for Marine
Sciences and Technology (CMAST), I am responsible for oversight and management
of the CMAST facilities at Morehead City. CMAST is a multi-disciplinary research,
education and extension center with faculty from the Colleges of Physical and
Mathematical Sciences, Agriculture and Life Sciences and Veterinary Medicine.
The mission of CMAST is to serve our citizens and others who value coastal natural
resources. In addition to my administrative duties, I provide programmatic leadership
for the Department of Food Science's Seafood Science and Technology Program
located at CMAST. The Seafood Laboratory conducts applied research and extension
education programs designed to enhance the competitiveness of North Carolina's
commercial industries through innovative ways of harvesting, processing, distributing
and utilizing seafood.
My specific research interests are
centered on the physico-chemical changes that occur in post-harvest handling
and processing of aquatic muscle foods. The overall goal of this research is
to improve the safety and quality of North Carolina's fish and fishery products
through a better understanding of the physical, biological and chemical factors
affecting our wild-captured and aquaculture-based fishery resources. Applied
research studies conducted at the coastal seafood laboratory frequently involve
industry collaborators and have direct application and impact on commercial,
regulatory and economic issues of importance to our coastal communities. Students
and staff are expected to present their findings during national and regional
seafood technology and trade association meetings. In addition, I encourage
all investigators to include a technology transfer component within the stated
project goals of their applied research whenever involving our coastal seafood
program. This helps to keep our extension education programs on the cutting
edge of high priority research topics in seafood safety and quality. The NCSU
Seafood Laboratory is actively involved in a national network of seafood technologists
who regularly participate in regional, national and international fishery technology
conferences.
Barry Nash, Sea Grant Specialist
Seafood Technology & Marketing
Seafood Laboratory
Telephone: 252-222-6337
Fax 252-222-6335
Email: barry_nash@ncsu.edu
The public expects the highest quality
from their food purchases, and to the consumer, quality is synonymous with safety.
Hazard Analysis & Critical Control Point (HACCP) monitoring requires seafood
processors to prevent, eliminate or control the introduction of hazards to food
that could cause illness or injury to consumers. As a specialist of the North
Carolina Sea Grant College Program, I develop educational and applied research
programs that help coastal seafood businesses improve their compliance to rigorous
seafood safety regulations. I work cooperatively with regulatory officials from
the FDA, the North Carolina Department of Environment, Health and Natural Resources
and the North Carolina Department of Agriculture to conduct seafood safety and
plant sanitation workshops for seafood processors and environmental health specialists.
People want choice and convenience
in the foods that they buy. Strong opportunities exist in the retail market
for value-added seafood products that indulge consumers' expectations for variety,
healthfulness, taste appeal and easy preparation. I provide assistance to NC
seafood processors on new product development and marketing strategies to foster
economic growth. I also assist businesses with marketing programs that help
create brand awareness for their products.
Greg Bolton
Seafood Research Technologist
Seafood Laboratory
Telephone 252-222-6336
Fax 252-222-6335
Email: greg_bolton@ncsu.edu
As a 1994 graduate of the NCSU Food
Science Department, I joined Southern Testing and Research Laboratories in Wilson,
NC as a food microbiologist/chemist. My main responsibilities were performing
food analyses required to meet nutritional labeling laws and nutritional supplement
claims. In June 1996, I returned to the Department of Food Science to pursue
a Master of Science degree under the direction of Dr. Tim Sanders in the USDA-ARS
Market Quality and Handling Laboratory. My research focused on shelf life extension
of roasted peanuts by utilizing peanuts and peanut oil that were high in oleic
acid content.
In September, 1998, I joined the
NCSU Seafood Laboratory as a seafood research technologist. My primary responsibilities
at the Seafood Lab are conducting analytical research in support of the Food
Science Extension programs, providing technical services and information to
the NC seafood industry, and assisting with education and training programs
developed for the NC seafood industry, regulatory and consumer groups.
Lorraine DiBella
Public Information Assistant
Seafood Laboratory
Telephone 252-222-6334
Fax 252-222-6335
Email: lorraine_dibella@ncsu.edu
As PIA at the Seafood Lab, I address
inquiries from seafood consumers, educators and regulatory agents on a variety
of seafood questions and concerns. Can we eat blood clams? How long will my
catch keep in the freezer? How do we know if this seafood product is safe/fresh?
Where is the next HACCP workshop? What seafoods are safe for expectant mothers?
The questions are sourced and the information formatted to respond quickly and
accurately to each query.
Information transfer presents us
great opportunities and challenges in this age of electronic everything! Sometimes
the information we need is at our fingertips. Other times we have to dust off
a book!
And, yes, you can eat blood clams,
but you must be either very brave or very hungry!
Frank and Rachel
Thomas Food Science Scholarship
The Frank and Rachel Thomas Food
Science Scholarship is a living tribute to Frank and Rachel for their more than
80 years of combined public service as faculty at North Carolina State University.
The student scholarships and independent study stipends awarded as a result
of this endowment will serve to express appreciation for Frank and Rachel's
tireless efforts and dedication as extension specialists, councilors and friends,
and to recognize their devotion to helping students, industry members and citizens
in their personal, professional and academic development.
The Frank and Rachel Thomas Food
Science Scholarship will be used to enhance the Departments of Food Science
and Family & Consumer Sciences through the following:
(1) Award scholarships to North Carolina
students based on academic merit and financial needs in pursuing their undergraduate
degrees in Food Science or Family and Consumer Sciences with emphasis on production,
distribution and utilization of aquatic foods.
(2) Support academic and applied
research efforts in seafood technology or foods and nutrition directed at North
Carolina seafood processing industries and their communities by the awarding
of undergraduate independent study stipends.
Dr. Thomas helped to establish the
Department of Food Science's Seafood Laboratory in 1970. All donors of $250
or more have their names engraved on a commemorative plaque which is displayed
at the Seafood Laboratory. For information on this scholarship, contact the
Seafood Lab at 252-222-6334 or the CALS Foundation Office at 919-515-7678.
Seafood Laboratory
Information Services
Consumer Seafood Handling & Preparation
Is Our Seafood Safe to Eat?
Mercury (Fact sheet under construction)
Listeria (Fact sheet under construction)
Vibrios (Fact sheet under construction)
Seafood Information & Resources
Seafood Safety & Quality Education and Training
HACCP Training for Seafood Processors.
Sanitation SOP Training for the Seafood Industry.
Seafood Training for Food Service and Retail Establishments.
.......... For information, call
252-222-6337.
Extension Agents & Health Professional Workshops
Seafood Quality & Safety (a practical workshop for Environmental Health Specialists), Pine Knoll Shores, October 17-19, 2001; accredited and in cooperation with UNC-CH School of Public Health. For information, call 919-966-1104 (UNC-CH) or 252-726-6827 (NC Shellfish Sanitation).
Agent In-Service Training, Spring
2002. For information, call 252-222-6334 (Seafood Lab) or 919-515-9150 (Family
& Consumer Sciences).
Industry Technical Services
Process Validations for HACCP compliance.
New Product Development.
Entrepreneual Assistance.
For information, call 252-222-6337.
Other Interesting Seafood Science & Technology Sites
NCSU Department of Food Science
National Fisheries Institute
UC Davis Seafood Network
IS OUR SEAFOOD SAFE
TO EAT?
YES! The U.S. Food and Drug Administration's
Office of Seafood is on record as saying, "On a pound-for-pound basis, seafood
is as safe as, if not more safe than, other meat sources." Unfortunately, seafood
has suffered some bad press in recent years. Concerns about water quality and
environmental issues have led some to speculate and overdramatize reports regarding
the safety of seafood. In reality, illnesses can result from the cross-contamination
of cooked and raw foods, from contamination which occurs during preparation
or from eating seafood harvested from closed waters, but more often seafood-related
illnesses occur from eating raw or undercooked shellfish.
To gather some factual statistics
on seafood safety, the U.S. Food and Drug Administration (FDA), the federal
agency charged with ensuring the safety of our nation's food supply, studied
reports of seafood-related illnesses filed with the Centers for Disease Control
(CDC) along with other available epidemiological studies. They found the risk
of becoming sick from eating seafood to be one in 250,000, compared to a one
in 25,000 risk from eating poultry. If raw molluscan shellfish (clams, oysters
and mussels) are excluded from these numbers, the risk of eating seafood drops
to one in a million --- much less than either beef or poultry. CDC statistics
clearly show that the most serious culprits of foodborne illness are raw shellfish.
There is much average consumers
can do personally to eliminate the risks of illness and assure the wholesomeness
and safety of their seafood.
Make careful selections when purchasing seafood. Buy only from reputable dealers who are knowledgeable about their sources and products. Use your senses to determine the quality of your
product. Start by looking at the
cleanliness of the store, the display cases and the employees. Look to see that
fresh seafoods are refrigerated or properly iced and that cooked foods are not
in contact with raw foods. A fish's eyes should be clear and bulge slightly.
Only a few fish, such as walleye, have naturally cloudy eyes. The flesh of whole
fish and fillets should be firm and shiny. Fresh whole fish should have bright
red gills. The odors, if any, in your seafood store should be clean and natural,
but not strong or "fishy." Likewise, seafood should have a slight but fresh
odor.
Avoid cross-contamination. Raw seafood,
whether fresh or frozen, will normally carry some microorganisms on their outside
surfaces. This is particularly true of live shellfish. Cross-contamination occurs
when one product form contacts another form of the same or a different food
product. Common examples are when a raw product contacts a cooked product; when
a person reaches over an uncovered cooked product and lifts a raw product that
may drip onto the cooked product; or when a cooked product is stored in an unwashed
container that previously held a raw product. Much has been publicized of late
concerning the importance of handling raw poultry products. The same common-sense
approach should be taken with seafood. Wash containers, utensils, hands, cutting
boards and other surfaces when handling different products and logically, don't
let the foods contaminate one another.
These proven methods of handling
and preparation. Much can be done to delay the spoilage process in seafood.
Transporting and storing seafood.
If you've landed the catch from coastal waters or harvested it from an open
harvest area, make every effort to see that the seafood is handled properly
from the point of harvest. You may want to dress the fish completely (scale,
head and eviscerate) or fillet so that it is ready to use or freeze when you're
home. If you do not wish to dress fish before traveling, at least eviscerate
and rinse them well to maintain freshness. Pack the body cavity of large whole
fish with ice and place in a sturdy drainable cooler. If traveling a long distance,
use salt to prolong the ice (about 1/2 pound for every 5 pounds of ice). Dressed
fish and shucked shellfish should be stored in freezer bags or plastic freezer
containers; shrimp should be headed, left in the shells and placed in freezer
storage bags. Shellfish may be transported alive. The keys to success are cold
and oxygen. Place the shellfish above ice in a cooler and insulate from direct
contact with the ice using newspapers or damp towels. Tip the lid open slightly
to allow a flow of air. Maintain a minimum of 40 F. Properly cooled, clams,
mussels, and oysters will stay alive for a week or more. Discard any clams,
mussels, oysters, lobsters, crabs or crayfish that die in storage. Freshly shucked
oysters will keep for 7 to 10 days. The colder an environment you can provide
for your seafood, the longer it will stay fresh. As a general rule, refrigerate
foods at a minimum of 41 F and lower is better. Freeze fresh fish within two
days and maintain 0 F for optimum quality.
Thawing. Thaw frozen seafood in the
refrigerator (about 18 hours per pound), under cold running water (about 1 hour
per pound) or in the microwave on the "defrost" setting if the food is to be
cooked immediately. Stop the defrost cycle while the fish is still icy but pliable.
Under no circumstances should you thaw frozen seafood at room temperature or
under warm running water.
Preparing seafood. Food preparers
should wash their hands thoroughly with hot soapy water before and after handling
any raw food. Marinate seafood in the refrigerator, not on the counter. Discard
the marinade after use because it contains raw juices which may harbor bacteria.
If you want to use the marinade as a dip or sauce, reserve a portion before
adding the raw seafood.
Cooking seafood. The FDA Food Code
recommends cooking most seafood to an internal temperature of 145 F for 15 seconds.
If you don't have a thermometer, determine doneness in fish by gently flaking
the thicker part with a sharp knife. The flesh should be slightly translucent
with flakes beginning to separate. Let the fish stand three to four more minutes
to finish cooking. Shrimp turn pink and lobsters red when they are fully cooked.
The flesh is pearly opaque. Scallops turn milky white or opaque and firm. Clams,
mussels and oysters will open when they are done. Throw away any that stay closed.
Seafood is a versatile and tasty
food choice. Fish and shellfish can be baked, broiled, steamed, fried, poached,
grilled, microwaved and smoked. Seafood is easily substituted in popular recipes
calling for other meat products. Fish and shellfish are fine main ingredients
in soups, salads, sandwiches and casseroles, and are excellent in stir-fry dishes
with vegetables and in pasta offerings.
Safety First. People with certain illnesses and conditions need to be especially careful to handle
seafood safely. Certain diseases
or medications put some people at greater risk for illness or death from contaminated
seafood. These conditions include: liver disease, either from excessive alcohol
use, viral hepatitis, or other causes; hemochromatosis, an iron disorder; diabetes;
stomach problems, including previous stomach surgery and low stomach acid; cancer;
immune disorders, including HIV infection; and long-term steroid use, as for
asthma and arthritis. Raw consumption poses the greatest threat for illness
for any consumer, but if you or someone you know falls into the above at-risk
groups, put safety first and thoroughly cook all seafood.
Lorraine DiBella
Public Information Assistant
For more on seafood safety and quality,
contact:
NC State University
Seafood Laboratory
at 252-222-6334/6336/6337
www.cals.ncsu.edu/food_science/sflab/
Mercury in Mackerel
F A C T O V E R F
E A R
In March, 2000, North Carolina, together with South Carolina, Georgia and Florida, issued a joint health advisory warning of high levels of mercury in large king mackerel. A risk assessment made by NC Department of Health and Human Services, Medical Evaluation and Risk Assessment Unit advised that king mackerel over 39 inches fork-length (nose to fork of tail) not be eaten. Consumers were also advised to limit their consumption of king mackerel measuring 33-39 inches. Specifically, women of child-bearing age and children twelve and younger should eat no more than one 8-ounce portion per month. Other adults should limit their intake to one such serving per week. King mackerel under 33 inches are generally considered safe for all persons.
The U.S. Food and Drug Administration sets the guideline for limits of mercury in seafoods at 1 part per million (ppm). The 118 king mackerel sampled by the NC Division of Marine Fisheries (DMF) in the two-year study 1998-1999 had mercury levels on average greater than 1 to 2 ppm, with a maximum incidence of 3.5 ppm. Dr. Louis Daniels, executive assistant counsel with the DMF, stated, "We collected a wide range of king mackerel from both commercial and recreational fisheries. We got large and small fish, in every season, from inshore and offshore to be sure we had a representative sample of North Carolina king mackerel." The North Carolina findings were compared with studies from the other states and the conclusion was consistent --- large king mackerel contain high levels of mercury.
Mercury (Hg) is a naturally occurring metallic substance found in air, water, soil, and all living matter, both animal and vegetable. Mercury exists in a constant cycle in the environment as a result of natural and human activity. Tons of mercury are released into the atmosphere each year by the natural degassing of the earth's crust and its oceans. The U.S. Environmental Protection Agency estimates that from 1994-1995 U.S. emissions of mercury from the human sources, primarily combustion, totaled 158 tons. Calculating mercury in the environment is hardly an exact science as releases from today's human activities must be added to the mercury reservoirs already existing in land, water and air, both naturally and as a result of past human activities. Past uses of mercury, such as fungicide application for crops, must also be considered in the equation. One computer simulation brings the total annual worldwide input of mercury into the atmosphere at 5,500 tons.
In aquatic environments, inorganic mercury is converted by bacterial action to methyl mercury (meHG), a more toxic compound. Fish absorb methyl mercury by eating aquatic organisms and intake it as water passes through their gills. Larger predator fish, such as swordfish and shark, are exposed to higher levels of mercury through their diets. MeHG is easily absorbed after ingestion and has a variable half-life of 60-120 days in humans, but research shows that fish may have a half-life of up to 2 years.
The extreme toxicity of mercury has been suspected for more than a thousand years. Deaths from mercury poisoning were reported in the United States as early as 1865 in the felt hat industry; then in the scientific instrument manufacturing industry, in mining and the manufacture of drugs, cosmetics, paints, pesticides, electric batteries and a host of other products. But the risk to seafood consumers was not fully realized until an episode of poisoning in Minimata, Japan where 111 people died or became very ill from eating shellfish from waters severely polluted with mercury from a local plastics factory. The community affected had consumed seafood often daily over several years (1953-1960) before the effects were apparent. The average mercury content of the suspect fish in Minimata ranged from 9 to 24 ppm, with some levels up to 40 ppm.
The four-state king mackerel advisory was the first such notice for ocean waters off the North Carolina coast. State health officials are diligent in assuring the public that only the larger kings are unsafe. Dr. Luanne Williams, a North Carolina toxicologist, says, "Seafood is an excellent source of protein. It's healthful and good for you. People should just eat the smaller size king mackerel, not the big 17-pounders."
The advisory does not affect fishing for king mackerel. Recreational fishers in North Carolina are allowed three fish per person per day with a minimum 24-inch fork-length. Commercial fishers holding federal permits are limited to 3500 pounds per trip with a minimum 24-inch fork limit.
For more information on mercury or
other fish consumption advisories, contact any of the following: NC Department
of Health and Human Services, telephone 919-715-6429; NC Division of Marine
Fisheries, 252-726-7021; or NC State University Seafood Laboratory, 252-222-6334.
Lorraine DiBella
Public Information Assistant
NC State University
Seafood Laboratory at the
Center for Marine Sciences & Technology