Is frozen salmon safe to eat raw? (Benefits & Risks)
By
Dr Stephen Inbaraj Baskaran (PhD)
Author bio
Dr Stephen Inbaraj is a Senior Food Researcher who specializes in Food Nanotechnology, Food Quality and Safety, Food Toxin Analysis & Treatment, Food/Agricultural Waste Valorization, Functional Food Development and Biological activity Determination, Green Extraction & Synthesis Methods, and Natural polymers/biopolymers.
Dr. Stephen Inbaraj’s Highlights
– Assistant Professor (Teaching) and Senior Researcher in the Food Science Department of Fu Jen Catholic University (New Taipei City, Taiwan).
– 20 years of research experience and 10 years of teaching experience in the Food Science and Technology field.
– Rated the World’s Top 2% Scientists by Elsevier & Stanford University (https://doi.org/10.17632/btchxktzyw.6).
– Postdoctoral Fellow in several projects in the Food Science Department of Fu Jen Catholic University (New Taipei City, Taiwan).
– PhD, Master, and Bachelor in Chemistry from Bharathidasan University (Tamil Nadu, India).
– Successfully completed many food science and technology projects funded by Indian and Taiwan funding agencies.
Dr. Stephen believes “Every person in the world deserves food – good food – quality and safer food”. With a feed of good food, a person gathers himself to work hard to lead a self-sustainable life in peace and harmony with the family and society. To attain good food, a good feed of knowledge of food science & technology is important. Sharing scientific knowledge in a simple and practical way can enlighten and unify all people to create a healthy society.
Professional Experience
Dr. Stephen Inbaraj has worked on several projects addressing key research gaps in the field of food science and technology. They include,
Analytical method development for quantification of food toxins such as polycyclic aromatic hydrocarbons, heterocyclic amines, furan cholesterol oxidation products, toxic metals and dyes.
Food toxin/contaminant removal by using novel and efficient adsorbents including an edible and natural biopolymer poly(γ-glutamic acid), functionalized magnetic iron oxide nanoparticles and waste-derived activated carbon
Isolation and analytical method development for functional/bioactive compounds such as carotenoids, flavonoids, phenolic acids, anthocyanins, ginsenosides, curcuminoids, allyl isothiocyanate and polysaccharides from fruits, vegetables, herbs, spices, and food/agricultural waste byproducts as well as marine peptides.
Nanoencapsulation of functional/bioactive compounds into various nanoformulations such as nanoemulsion, nanoliposome and nanoparticles (gold, cerium oxide, iron oxide nanoparticles).
Evaluation of biological activity of nanoencapsulated functional/bioactive compounds for antioxidant, anti-inflammatory, anticancer and antimicrobial activities as well as determination of pharmacokinetic parameters and bioavailability.
Research & Teaching Experience
1998-1999 One-year scholarship in National Tsing Hua University (Hsinchu, Taiwan).
1995-1998 Three scholarships to work on two projects in the Chemistry department of the National Institute of Technology (Tamil Nadu, India).
2001-2003 two-year project scholarship in the Chemistry department of the National Institute of Technology (Tamil Nadu, India).
2003-2004 Indian government Research Associateship in Chemistry department of National Institute of Technology (Tamil Nadu, India).
2002-2004 Worked as a Teaching Assistant at the Master’s level in the Chemistry department of the National Institute of Technology (Tamil Nadu, India).
2004-2017 Worked as a Postdoctoral Fellow on various projects funded by National Science Council (Taiwan), Ministry of Science & Technology (Taiwan) and National Science & Technology Council (Taiwan) in the Food Science department of Fu Jen Catholic University (New Taipei City, Taiwan).
2017-present (1) Assistant Professor (Teaching) in the Food Science department of Fu Jen Catholic University (New Taipei City, Taiwan)
2017-present (2) Senior Researcher in the Food Science department of Fu Jen Catholic University (New Taipei City, Taiwan).
Editorial & Review Experience in Journals
Academic Editor
– European Journal of Cancer Care (https://www.hindawi.com/journals/ejcc/editors/)
– Journal of Clinical Pharmacy & Therapeutics (https://www.hindawi.com/journals/jcpt/editors/)
– Agronomy (https://www.mdpi.com/journal/agronomy/editors?search=Inbaraj)
– Gels (https://www.mdpi.com/journal/gels/topical_advisory_panel)
Associate Guest Editor
– Frontiers in Nutrition https://www.frontiersin.org/research-topics/41943/valorization-of-food-and-agro-industrial-waste-novel-approaches-and-their-applications
– Associate Guest Editor – Frontiers in Chemistry https://www.frontiersin.org/research-topics/58227/green-and-sustainable-extraction-techniques-for-bioactives-in-food-plants-pharmaceuticals-and-cosmetics
Guest Editor
– ‘Waste and Biomass Valorization’ journal
https://www.springer.com/journal/12649/updates/25274728
– ‘Journal of Food Processing & Preservation’
https://www.hindawi.com/journals/jfpp/si/635128/
– ‘Starch-Starke’ journal
– ‘Agronomy’ journal
https://www.mdpi.com/journal/agronomy/special_issues/84Q464409C
https://www.mdpi.com/journal/agronomy/special_issues/wate_nanomaterial
– ‘Gels’ Journal
https://www.mdpi.com/journal/gels/special_issues/developments_food_gels
https://www.mdpi.com/journal/gels/special_issues/9R2L833ELB
– ‘Bioengineering’ journals
https://www.mdpi.com/journal/bioengineering/special_issues/NB1D8VR08G
Review Experience
– 2022 Has won the Outstanding Reviewer Award – ‘Foods’ MDPI journal.
– 2023 Has reviewed a total of 302 articles for 47 ‘Elsevier’ journals so far.
– 2023 Has reviewed a total of 162 articles for 30 ‘MDPI’ journals so far.
– 2023 Certified as a Trusted Reviewer of ‘IOP’ publishing journal articles.
Education
2002 PhD in Chemistry, National Institute of Technology, Bharathidasan University (Tamil Nadu, India)
1995 Master in Chemistry, Bishop Heber College, Bharathidasan University (Tamil Nadu, India)
1993 Bachelor in Chemistry, Bishop Heber College, Bharathidasan University (Tamil Nadu, India)
Publications & Citations
Journal Articles – 125
Book Chapters – 12
Conference Papers – 18
Citation on Publications – 5512
H-index – 38
Journal Articles (Some selected journal articles)
Lai, Y.W., Inbaraj, B.S., Chen, B.H. Effects of oil and processing conditions on formation of heterocyclic amines and polycyclic aromatic hydrocarbons in pork fiber. Foods 2023, 12, 3504.
Li, R., Inbaraj, B.S., Chen, B.H. Preparation of xanthone and anthocyanin nanoemulsions from mangosteen peel for studying their inhibition effects on liver cancer cells. International Journal of Molecular Sciences 2023, 24, 3934.
Bains, A., Chawla, P., Inbaraj, B.S. Evaluation of in vitro antimicrobial, antioxidant, and anti-quorum sensing activity of edible mushroom (Agrocybe aegerita). Foods 2023, 12, 3562.
Ahmed, T., Jubayer, M.F., Sharma, M., Sridhar, M., Hoque, M.M., Rana, M.R., Inbaraj, B.S. Effect of taro corm mucilage and black seed oil as edible coatings on the shelf-life and quality of fresh guava, Agronomy 2023, 13, 538.
Kandi, S., Inbaraj, B.S., Chen, B.H. An improved surface enhanced Raman spectroscopic method using a paper-based grape skin-gold nanoparticles/graphene oxide substrate for detection of Rhodamine 6G in water and food. Chemosphere 2022, 301, 134702.
Kaur, S., Sharma, P., Bains, A., Chawla, P., Sridhar, K., Sharma, M., Inbaraj, B.S. Antimicrobial and anti-Inflammatory activity of Low-energy assisted nanohydrogel of Azadirachta indica oil. Gels 2022, 8, 434.
Huang, Y.H., Kao, T.H., Inbaraj, B.S., Chen, B.H. Improved analytical method for determination of furan and its derivatives in commercial foods by HS-SPME arrow combined with gas chromatography–tandem mass spectrometry. Journal of Agricultural & Food Chemistry 2022, 70, 7762-7772.
Inbaraj, B.S.; Hua, L.H., Chen, B.H. Comparative study on inhibition of pancreatic cancer cells by resveratrol gold nanoparticles and a resveratrol nanoemulsion prepared from grape skin. Pharmaceutics 2021, 13, 1871.
Inbaraj, B.S., Sridhar, K., Chen, B.H. Removal of polycyclic aromatic hydrocarbons from water by magnetic activated carbon nanocomposite from green tea waste, Journal of Hazardous Materials 2021, 415, 125701.
Inbaraj, B.S., Chen, B.Y., Liao C.W., Chen, B.H. Green synthesis, characterization and evaluation of catalytic and antibacterial activities of chitosan, glycol chitosan and poly(g-glutamic acid) capped gold nanoparticles, International Journal of Biological Macromolecules 2020, 161, 1484-1495.
Hsu, K.Y., Inbaraj, B.S., Chen, B.H. Evaluation of analysis of cholesterol oxidation products and heterocyclic amines in duck and their formation as affected by roasting methods. Journal of Food & Drug Analysis 2020, 28, 128-142.
Chen, B.H. Inbaraj, B.S. Nanoemulsion and nanoliposome based strategies for improving anthocyanin stability and bioavailability. Nutrients 2019, 11, 1052.
Lu, P.S., Inbaraj, B.S., Chen, B.H. Determination of oral bioavailability of curcuminoid dispersions and nanoemulsions prepared from Curcuma longa Linnaeus. Journal of the Science of Food & Agriculture 2018, 98, 51-63.
Ho, N.H., Inbaraj, B.S., Chen, B.H. Utilization of microemulsions from Rhinacanthus nasutus (L.) Kurz to improve carotenoid bioavailability. Scientific Reports 2016, 6, 25426.
Inbaraj, B.S., Chen, B.H. Nanomaterial-based sensors for detection of foodborne bacterial pathogens and toxins as well as pork adulteration in meat products. Journal of Food & Drug Analysis 2016, 24, 15-28.
Huang, R.F.S., Y.J. Wei, Inbaraj, B.S., Chen, B.H. 2015. Inhibition of colon cancer cell growth by nanoemulsion carrying gold nanoparticle and lycopene. International Journal of Nanomedicine 2015, 10, 2823-2846.
Huang, R.T., Y.F. Lu, Inbaraj, B.S., Chen, B.H. 2015. Determination of phenolic acids and flavonoids in Rhinacanthus nasutus (L.) Kurz by high-performance-liquid-chromatography with photodiode-array-detection and tandem mass spectrometry. Journal of Functional Foods 2015, 12, 498-508.
Loh, C.H., Inbaraj, B.S., Liu, M.H., Chen, B.H. 2012. Determination of chlorophylls in Taraxacum formosanum by high-performance liquid chromatography-diode array detection-mass spectrometry and preparation by column chromatography. Journal of Agricultural and Food Chemistry, 60: 6108-6115.
Inbaraj, B.S., Chen, B.H. Dye adsorption characteristics of magnetite nanoparticles coated with a biopolymer poly(g-glutamic acid), Bioresource Technology 2011, 102, 8868-8876.
Wang, C.C. Chang, S.C., Inbaraj, B.S., Chen, B.H. Isolation of carotenoids, flavonoids and polysaccharides from Lycium barbarum Linnaeus and evaluation of antioxidant activity, Food Chemistry 2010, 120, 184-192.
Book Chapters (Recent 6 book chapters)
Kashyap, P., Thakur, M., Kalsi, R., Sridhar, K., Sharma, M., Kumar, S., Inbaraj, B.S. (2023) Molecular aspects on anti-SARS-CoV-2 activity of flavonols: Inhibitory on protein targets, immunomodulatory, and anti-inflammatory effects. In “Anti-SARS-CoV-2 activity of flavonoids”, J.T. Chen (Ed.), CRC Press/Taylor & Francis, In Press.
Chen, B.H. & Inbaraj, B.S. (2016). Nanomaterial-based sensors for mycotoxin analysis in food. In “Nanoscience and Food Industry”, A.H. Grumezescu (Ed.), Elsevier, USA, pp. 387-423.
Inbaraj, B.S. & Chen, B.H. (2016). Polysaccharide composition in Chinese dates (Jujubes) and health benefits. In “Chinese Dates (Jujubes): A Traditional Functional Food”, J.Y. Shi (Ed.), CRC Press, Taylor & Francis, USA, pp.177-207.
Chen, B.H. & Inbaraj, B.S. (2014). Poly(g-glutamic acid)-coated superparamagnetic iron oxide nanoparticles. In Dekker Encyclopedia of Nanoscience and Nanotechnology, S.E. Lyshevski (Ed.). Third Edition, CRC Press, Taylor and Francis Group, New York, pp 4772-4786.
Inbaraj, B.S. & Chen, B.H. (2012). Isoflavones in foods and ingestion in the diet. In Food and Nutritional Components in Focus – Isoflavones: Chemistry, Analysis, Function and Effects, Chapter 3, V.R. Preedy (Ed.). Royal Society of Chemistry (RSC) Publishers, UK, pp. 28-45.
Inbaraj, B.S. & Chen, B.H. (2012). Isoflavone ingestion by multiethnic population: implications for health. In Food and Nutritional Components in Focus – Isoflavones: Chemistry, Analysis, Function and Effects, Chapter 21, V.R. Preedy (Ed.). Royal Society of Chemistry (RSC) Publishers, UK, pp. 349-363.
Conference Papers (Recent 7 conference papers)
Lai, Y.W., Inbaraj, B.S., Chen, B.H. Inhibition mechanism of lung cancer cells by various nanoformulations prepared from Taiwan tilapia skin. International Conference on Materials Science, Engineering & Technology, Singapore, September 7-9, 2023.
Huang, R.S., W.J. Wei, Inbaraj, B.S. Chen, B.H. Inhibition mechanism of gold-lycopene nanoemulsion on colon cancer cell through passive targeting. 11th Cross-Strait Workshop on Nanoscience & Technology, Hong Kong. Dec. 14-17, 2014.
Chen, Y.J., Inbaraj, B.S., Pu, Y.S., Chen, B.H. Development of lycopene micelle and lycopene chylomicron and comparison of bioavailability. World Gene Convention, Haikou, China, Nov. 13, 2013.
Sureshbabu, K., M. Anandkumar, T.Y. Tsai, T.H. Kao, Inbaraj, B.S., Chen, B.H. Cytotoxicity and antibacterial activity of gold decorated cerium oxide nanoparticles. Materials Science & Technology Conference, Quebec, Canada, October 27-31, 2013.
Chen, B.H., Inbaraj, B.S. Synthesis, characterization and toxic metal-binding ability of poly(γ-glutamic acid)-coated superparamagnetic nanoparticles. Nanotech Conference & Expo 2012, Santa Clara, California, USA, June 18-21 2012.
Inbaraj, B.S., Chen, B.H. Color and metal removal characteristics of magnetic nanoparticles coated with a biopolymer poly(γ-glutamic acid). 9th Taiwan/ U.S. Air Force Nanoscience Workshop, Kenting, Taiwan, April 16–19, 2012.
Inbaraj, B.S., Chen, B.H. Synthesis and characterization of poly(γ-glutamic acid)-coated magnetite nanoparticles and their effects on antibacterial activity and cytotoxicity. Second World Conference on Nanomedicine and Drug Delivery, Kerala, India, March 11-13, 2011.
Professional Profiles
https://scholar.google.co.uk/citations?hl=en&user=W0lDtyQAAAAJ
https://www.researchgate.net/profile/B-Inbaraj-2
https://www.scopus.com/authid/detail.uri?authorId=57130902200
https://orcid.org/0000-0003-4301-7614
https://www.linkedin.com/in/stephen-inbaraj-baskaran-a16635298/
In this article, we will discuss whether frozen salmon is safe to eat raw and how to safely consume raw salmon, as well as the proper freezing and thawing conditions, the risks associated with improper freezing and thawing, and the signs and symptoms associated with eating spoiled raw salmon.
Salmon is popular seafood consumed in both raw and cooked forms, as it is an excellent source of various health-promoting nutrients including proteins, fatty acids, vitamins, and minerals.
Is frozen salmon safe to eat raw?
Yes, it is safe when frozen and thawed properly. Frozen salmon can be nutritious and taste as good as fresh salmon, but safer than fresh salmon (1,2).
Fresh salmon, if not properly handled by freezing at -4F (-20C) for at least 7 days, can be dangerous when eaten raw, causing foodborne illness due to parasites and microorganisms (2,3,4,5,6,7).
Equally important is the proper thawing (defrosting) of frozen salmon before eating it raw (1,2).
Which part of the world is salmon eaten raw?
Although properly handled raw salmon is consumed in the form of dishes like “sushi” and “sashimi” in Japan, it has become popular globally in various international cuisines including the United States, Norway, and Canada.
“Sushi” refers to vinegared rice combined with raw seafood, vegetables, and tropical fruits, while “sashimi” is typically a thin slice of raw fish accompanied by soy sauce, wasabi, and pickled ginger.
What are the nutritional benefits of eating salmon?
Salmon is consumed raw mainly because of its flavour, texture, and nutrition. It has high protein content, healthy fat (omega-3 fatty acids), essential vitamins (B12 and D), minerals (potassium, selenium, and iron), and other micronutrients (astaxanthin), with all of them possessing health-promoting properties (8,9,10).
Raw salmon lovers believe that flavour, texture, and nutrition are preserved in raw salmon when compared to cooked ones.
How can fresh salmon be safely consumed raw?
Properly handled fresh salmon bought from the shop should be rinsed with water, pat dried, and cooked within 2 hours for eating the same day (1,2).
You can store it in the refrigerator (40F or 4C) in a resealable zip-top bag or air-tight container for use within 2 days, while for eating within 3 months, it should be frozen rapidly (-4F or -20C) at a high freezing mode in your home refrigerator (flast or blast frozen). In this way, most of its nutrition is preserved without causing any serious health effects by parasites and microorganisms (1,2,6,11).
If you have bought raw salmon that is not properly frozen, it is important to freeze at -4F (-20C) for 7 days or -31F (-35C) for 15 hours to ensure the complete killing of all parasites and halting the growth of microorganisms (2,6,11).
What is flash or blast frozen salmon?
It refers to freezing salmon quickly reducing the temperature at a faster rate to preserve most of its flavour, texture, and nutrition.
Is thawing necessary before eating raw salmon?
Yes, it is necessary to thaw the frozen salmon before consuming it raw and four proper ways include (1,2):
- Leaving in the refrigerator (40F or 4C) overnight.
- Rinsing in running tap water.
- Placing in a sealed plastic bag and allowing to sink in room temperature water until the salmon becomes pliable (flexible).
- Microwaving in defrost mode until the thawed water is still cold.
Thawed salmon should be cooked within 2 hours or stored in a refrigerator for use within 2 days to avoid the growth of parasites and microorganisms (1,2).
What are the risks of improper freezing and thawing?
If you are buying frozen salmon from the shop, carefully look for the following and be aware of their causes (1,2,11,12):
| Appearance | Caution |
| the packaging is loose or broken | thawing process has started allowing the regrowth of microorganisms and parasites |
| ice crystal formation on frozen salmon | repeated freezing and thawing has reduced the moisture and quality |
| dry portions on the edges of frozen salmon | freezer burn has occurred |
The properly packed frozen salmon bought from the shop can be stored in the freezer with the same package if you are not using it within 2 days. If you are packing yourself, then ensure proper packing and proper functioning of the freezer before freezing.
Both improper freezing and thawing can lead to the growth of harmful parasites and microorganisms resulting in serious foodborne illnesses, as the freezing only stops their growth and does not kill them completely (1,2,6).
What are the signs and symptoms of eating spoiled raw salmon?
Strong fishy or ammonia smell, not firm, slimy, grey spots or discolouration, and filmy or white residues are some of the signs of spoiled raw salmon (2).
Common symptoms associated with eating spoiled raw salmon include nausea, vomiting, diarrhoea, fever, abdominal pain or stomach discomfort, weight loss, and anaemia. Although parasites consumed do not cause any acute effects, they grow in the body causing serious health effects over a long time (6).
Pregnant women, breastfeeding mothers, young children, and people with compromised immune systems should avoid eating raw salmon or eat in moderation to keep themselves safe (2).
Conclusion
In this article we have explored an answer to the question “Is it safe to eat frozen salmon raw?” by discussing the ways to safely consume raw salmon and properly freeze and thaw salmon to avoid risks and preserve both flavour and nutrition. In addition, we have highlighted the risks associated with consuming improperly frozen or thawed salmon as well as the signs and symptoms associated with eating spoiled raw salmon. Based on my expertise in food research, I suggest that raw salmon can be safely consumed if it is previously frozen and properly thawed.
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References
1.-
USFDA, Freezing and Food Safety, Food Safety and Inspection Service, United States Department of Agriculture, 2013.
2.-
USFDA, Selecting and Serving Fresh and Frozen Seafood Safely, United States Department of Agriculture, 2022.
3.-
USFDA, What You Need to Know about Foodborne Illnesses, United States Department of Agriculture, 2022.
4.-
USFDA, Foodborne Pathogens, United States Department of Agriculture, 2023.
5.-
USFDA, Foodborne Illness and Disease, Food Safety and Inspection Service, United States Department of Agriculture, 2020.
6.-
FDA, Chapter-5: Parasites, Fish and Fishery Products Hazards and Controls Guidance, 2011, pp.91-98.
7.-
Daschner A. Chapter 31 – Risks and possible health effects of raw fish intake. Fish and Fish Oil in Health and Disease Prevention 2016, 341-343.
8.-
Colombo, S.M., Mazal, X. Investigation of the nutritional composition of different types of salmon available to Canadian consumers. Journal of Agriculture and Food Research 2020, 2, 100056.
9.-
USDA, Finfish and Shellfish Products – Dry heat cooked wild Atlantic salmon fish, Agricultural Research Service, 2019.
10.-
USDA, Finfish and Shellfish Products – Dry heat cooked farmed Atlantic salmon fish Fish, Research Service, 2019.
11.-
1. Dawson, P., Al-Jeddawi, W., Remington, N. Effect of freezing on the shelf life of salmon. International Journal of Food Science 2018, 2018, 686121.
12.-
Nakazawa, N., Okazaki, E. Recent research on factors influencing the quality of frozen seafood. Fish Science 2020, 86, 231-244.