Is Lox safe to eat? (2 risks)

By Dr Anny Manrich (PhD) | Reviewed by Dr Anny Manrich (PhD)

Page last updated: 26/10/2023 | Next review date: 26/10/2025

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The contents of this article are fact-based except otherwise stated within the article.

Author bio

Dr Anny Manrich PhD is a food Engineer with expertise in Food Technology, Natural Polymers, Edible Films, Enzymes, and Nanotechnology. She writes and reviews content on these topics.

Dr Anny Manrich’s Highlights:

Research and Technology at the Brazilian Agricultural Research Corporation
PhD in Chemical Engineering with a focus on Biochemistry at the Federal University of Sao Carlos/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany
Bachelor of Food Engineering at the University of Campinas/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany

“To solve a problem, global vision and multifactorial understanding are necessary. Therefore, in addition to expertise, one should seek multidisciplinary thinking connected with science and reality” – Dr Anny Manrich, PhD.

Professional Experience:

Dr Anny Manrich’s Experience Joining the Brazilian Agricultural Research Corporation, as soon as she completed her doctorate,

Dr Anny Manrich has worked on several projects, including the more than three-year partnership project with BRF, a major food producer in Brazil. As a postdoctoral fellow.

Dr Anny Manrich has also contributed to several business consultancies and research projects of the National Nanotechnology Laboratory System in areas such as food technology, fibres, films and coatings and Nanotechnology; in a very determined way, having a great team relationship, being creative and committed.

Growing concerns about the safe introduction of nanomaterials into today’s life emphasises the need to create regulatory documentation in front of characterising, using and testing them. Dr Anny Manrich worked for two years on a characterization project for nanoscale materials, with the aim of exploring their possible health effects.

Despite not having specific academic training in packaging or polymeric films, Dr Anny Manrich works at the Brazilian Agricultural Research Corporation in areas of edible and biodegradable films produced from agricultural waste and in the development of films with greater resistance to water, having articles published in renowned scientific journals, which demonstrates her multidisciplinary understanding and creativity.

In addition, she worked for four years as a consultant to a food company to develop a line of snacks that are healthy and that add functional ingredients, physiologically active compounds that bring health benefits, made from fruits and vegetables, enabling diet improvement, disease prevention and reduction of nutritional deficiencies.

Dr Anny Manrich participated as a member of the examination board for two Master’s exams and one PhD exam at the Department of Chemical Engineering of the Federal University of São Carlos.

Education:

2001 Bachelor in Food Engineering at the State University of Campinas, Brazil
1999 One year scholarship at the Technical University of Munich
2004 Master in Chemical Engineering at the Federal University of São Carlos, Brazil
2012 PhD in Chemical Engineering at the Federal University of São Carlos, Brazil
2010 One year scholarship at the Technical University of Munich

The main publications of Dr. Anny Manrich are:

Articles

Manrich, A., Moreira, F. K., Otoni, C. G., Lorevice, M. V., Martins, M. A., & Mattoso, L. H. (2017). Hydrophobic edible films made up of tomato cutin and pectin. Carbohydrate Polymers, 164, 83-91.

Mendes, J. F., Norcino, L. B., Martins, H. H. A., Manrich, A., Otoni, C. G., Carvalho, E. E. N., … & Mattoso, L. H. C. (2020). Correlating emulsion characteristics with the properties of active starch films loaded with lemongrass essential oil. Food Hydrocolloids, 100, 105428.

Norcino, L. B., Mendes, J. F., Natarelli, C. V. L., Manrich, A., Oliveira, J. E., & Mattoso, L. H. C. (2020). Pectin films loaded with copaiba oil nanoemulsions for potential use as bio-based active packaging. Food Hydrocolloids, 106, 105862.

Manrich, Anny, et al. Immobilization of trypsin on chitosan gels: Use of different activation protocols and comparison with other supports. International Journal of Biological Macromolecules 43.1 (2008): 54-61.

Manrich, Anny; Komesu, Andrea ; Adriano, Wellington Sabino; Tardioli, Paulo Waldir ; Giordano, Raquel Lima Camargo . Immobilization and Stabilization of Xylanase by Multipoint Covalent Attachment on Agarose and on Chitosan Supports. Applied Biochemistry and Biotechnology, v. 161, p. 455-467, 2010.

Mendes, J. F., Martins, J. T., Manrich, A., Neto, A. S., Pinheiro, A. C. M., Mattoso, L. H. C., & Martins, M. A. (2019). Development and physical-chemical properties of pectin film reinforced with spent coffee grounds by continuous casting. Carbohydrate polymers, 210, 92-99..

Milessi, T. S., Kopp, W., Rojas, M. J., Manrich, A., Baptista-Neto, A., Tardioli, P. W., … & Giordano, R. L. (2016). Immobilization and stabilization of an endoxylanase from Bacillus subtilis (XynA) for xylooligosaccharides (XOs) production. Catalysis Today, 259, 130-139.

Mendes, J. F., Norcino, L. B., Manrich, A., Pinheiro, A. C. M., Oliveira, J. E., & Mattoso, L. H. C. (2020). Development, physical‐chemical properties, and photodegradation of pectin film reinforced with malt bagasse fibers by continuous casting. Journal of Applied Polymer Science, 137(39), 49178.

Mendes, J. F., Martins, J. T., Manrich, A., Luchesi, B. R., Dantas, A. P. S., Vanderlei, R. M., … & Martins, M. A. (2021). Thermo-physical and mechanical characteristics of composites based on high-density polyethylene (HDPE) e spent coffee grounds (SCG). Journal of Polymers and the Environment, 29, 2888-2900..

Mendes, J. F., Norcino, L. B., Martins, H. H., Manrich, A., Otoni, C. G., Carvalho, E. E. N., … & Mattoso, L. H. C. (2021). Development of quaternary nanocomposites made up of cassava starch, cocoa butter, lemongrass essential oil nanoemulsion, and brewery spent grain fibers. Journal of Food Science, 86(5), 1979-1996.

Manrich, A., Martins, M. A., & Mattoso, L. H. C. (2021). Manufacture and performance of peanut skin cellulose nanocrystals. Scientia Agricola, 79.

Nascimento, V. M., Manrich, A., Tardioli, P. W., de Campos Giordano, R., de Moraes Rocha, G. J., & Giordano, R. D. L. C. (2016). Alkaline pretreatment for practicable production of ethanol and xylooligosaccharides. Bioethanol, 2(1)..

Manrich, Anny, de Oliveira, J. E., Martins, M. A., & Mattoso, L. H. C. Physicochemical and Thermal Characterization of the Spirulina platensis. J. Agric. Sci. Technol. B, v. 10, p. 298-307, 2020.

Book Chapter

Terra, I. A. A., Aoki, P. H., Delezuk, J. A. D. M., Martins, M. A., Manrich, A., Silva, M. J., … & Miranda, P. B. (2022). Técnicas de Caracterização de Polímeros. Nanotecnologia Aplicada a Polímeros, 614.

Conference Papers

Ferreira, L. F., Luvizaro, L. B., Manrich, A., Martins, M. A., Júnior, M. G., & Dias, M. V. (2017). Comparação da estabilidade de suspensões poliméricas de amido/tocoferol e quitosana/tocoferol. In: CONGRESSO BRASILEIRO DE POLÍMEROS, 14., 2017, Águas de Lindóia, SP.

Manrich, A., Hubinger, S. Z., & Paris, E. C. (2017). Citotoxicidade causada por nanomateriais: avaliação do micronúcleo. In: WORKSHOP DA REDE DE NANOTECNOLOGIA APLICADA AO AGRONEGÓCIO, 9., 2017, São Carlos. Anais… São Carlos: Embrapa Instrumentação, 2017. p. 655-658.

Manrich, Anny, et al. Immobilization and Stabilization of Xylanase by multipoint covalent attachment on Glyoxyl Agarose Support. The 31st Symposium on Biotechnology for Fuels and Chemicals. 2009.

Manrich, Anny, et al. Application of immobilized xylanase on hydrolysis of soluble wood hemicelluloses after using microwave and organosolv pre-treatments. The 32nd Symposium on Biotechnology for Fuels and Chemicals. 2010.

You can view some of Dr Anny’s work below and links to her professional profile.

Research Gate: https://www.researchgate.net/profile/Anny-Manrich-2

Scopus: https://www.scopus.com/authid/detail.uri?authorId=23103497100

Google Scholar: https://scholar.google.com/citations?hl=en&user=Ea9qpr0AAAAJ

Linkedin: https://br.linkedin.com/in/anny-manrich-20693129

Dr Anny Manrich (PhD)

View More north_east

Reviewer bio

Dr Anny Manrich PhD is a food Engineer with expertise in Food Technology, Natural Polymers, Edible Films, Enzymes, and Nanotechnology. She writes and reviews content on these topics.

Dr Anny Manrich’s Highlights:

Research and Technology at the Brazilian Agricultural Research Corporation
PhD in Chemical Engineering with a focus on Biochemistry at the Federal University of Sao Carlos/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany
Bachelor of Food Engineering at the University of Campinas/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany

Professional Experience:

Dr Anny Manrich’s Experience Joining the Brazilian Agricultural Research Corporation, as soon as she completed her doctorate,

Dr Anny Manrich has worked on several projects, including the more than three-year partnership project with BRF, a major food producer in Brazil. As a postdoctoral fellow.

Dr Anny Manrich participated as a member of the examination board for two Master’s exams and one PhD exam at the Department of Chemical Engineering of the Federal University of São Carlos.

Education:

2001 Bachelor in Food Engineering at the State University of Campinas, Brazil
1999 One year scholarship at the Technical University of Munich
2004 Master in Chemical Engineering at the Federal University of São Carlos, Brazil
2012 PhD in Chemical Engineering at the Federal University of São Carlos, Brazil
2010 One year scholarship at the Technical University of Munich

The main publications of Dr. Anny Manrich are:

Articles

Manrich, A., Martins, M. A., & Mattoso, L. H. C. (2021). Manufacture and performance of peanut skin cellulose nanocrystals. Scientia Agricola, 79.

Manrich, Anny, de Oliveira, J. E., Martins, M. A., & Mattoso, L. H. C. Physicochemical and Thermal Characterization of the Spirulina platensis. J. Agric. Sci. Technol. B, v. 10, p. 298-307, 2020.

Book Chapter

Conference Papers

You can view some of Dr Anny’s work below and links to her professional profile.

Research Gate: https://www.researchgate.net/profile/Anny-Manrich-2

Scopus: https://www.scopus.com/authid/detail.uri?authorId=23103497100

Google Scholar: https://scholar.google.com/citations?hl=en&user=Ea9qpr0AAAAJ

Linkedin: https://br.linkedin.com/in/anny-manrich-20693129

Dr Anny Manrich (PhD)

View More north_east

In this article, we will discuss whether Lox is safe to eat, the risks and benefits of eating Lox, when is Lox not safe to eat and how to handle Lox to improve its safe consumption.

Lox is the name of a traditional Jewish food that refers to brined salmon fillets. Although brined fish was originally made with other fish types, in the United States the Jews found plenty of salmon in New Yorker lakes and started making Lox (1).

Is Lox safe to eat?

Yes, Lox is safe to eat. Lox is traditionally consumed with bagels, composing one of the traditional Jewish foods (1). It is made from salt-curing of salmon fillets.

Like other brined fish products, it has a longer shelf life than fresh fish (1). However, proper handling is required for its safe consumption, as Lox can be spoiled and cause foodborne diseases (2).

In addition, due to the high concentration of salt in Lox, it may be not safe to eat for individuals who suffer from hypertension (4).

What are the risks of eating Lox?

The risks of eating Lox are foodborne diseases, including food infection and food poisoning (2, 3). In addition, the high sodium concentration in the Lox can cause negative effects on health in the long term (4).

Foodborne illnesses

Although the curing process to produce Lox, in which a 90 % salt brine is used, inhibits the development of most of the pathogenic bacteria, some microorganisms may survive and develop in the product, leading to its spoilage (2, 3, 4).

Halophilic bacteria, yeasts and anaerobic bacteria are microorganisms that typically spoil fish processed with high concentrations of salt (3).

However, studies report that, due to poor handling and improper hygienic conditions, some pathogenic bacteria including Salmonella and Staphylococcus were found in high counts in salt-cured fish products, including Lox (2).

The ingestion of contaminated fish can cause foodborne illnesses with symptoms such as diarrhoea, vomiting, nausea and lead to hospitalisations and even death. Food outbreaks were caused by the consumption of spoiled Lox in the past years (2).

Hypertension

The final salt concentration in cured salted fish products, such as Lox, is about 2 % and is considered high. Governmental Health Agencies have strived to reduce the amount of sodium in foods to promote health (4).

Excessive intake of salt can lead to hypertension, which is an important risk factor for developing cardiovascular diseases. In this way, the consumption of Lox and other salt-cured products should be moderate.

How much Lox is safe to eat?

A portion of 200 g of Lox per day is safe to eat, according to the recommended sodium intake of 2 g, which equals about 5 g of table salt per day (4). In 200 g of Lox, there are approximately 1.6 g of sodium (1, 4).

However, the recommended sodium intake of 2 g per day accounts for the whole sodium ingested in a day and not in one portion. You should then balance your diet to not exceed the daily upper limit, by including food items low in sodium.

When is Lox not safe to eat?

Lox is not safe to eat when it is spoiled. Lox can be contaminated by poor handling and cross-contamination during the preparation, packaging, transporting, cooking and serving (2).

Pathogens such as Salmonella and Listeria monocytogenes can survive in Lox and other salt-cured fish products (2, 4). Other microorganisms, such as yeasts, and salt-tolerant bacteria can develop in the Lox, causing spoilage.

Possible indications of microbial spoilage in the Lox are the presence of off-odours and off-flavours characterised as rancid, sour and putrid, the production of gas and slime, the loss of texture, the presence of pink pigments on the surface (2, 3).

Is Lox safe to eat when pregnant?

Yes, Lox is safe to eat when pregnant, when consumed moderately and prepared correctly. Fish consumption is recommended during pregnancy, as fish is a source of essential omega-3 fatty acids, which are anti-inflammatory and improve health (6).

Health concerns about eating fish during pregnancy are related to the presence of mercury and other heavy metals that contaminate fish products, as stated by the Food and Drug Administration (FDA) (5).

Although the FDA classifies Salmon as a low-mercury fish, recent studies report that a high concentration of mercury and other heavy metals as well as other contaminants were found in commercial Salmon samples in the Californian market (6).

In addition, due to the risk of hypertension during pregnancy, pregnant women should eat Lox in moderation (7).

It is important to remember that, due to the weakened immune system, pregnant women are more susceptible to foodborne diseases, and improved efforts should be taken to prevent food contamination when handling and cooking lox (5).

Cured fish is not recommended when pregnant, as it is usually not cooked (8). However, if you cook the Lox first, you can consume it when pregnant.

How to consume Lox safely?

To consume Lox safely, follow the recommendations:

Buy and consume the product within its shelf life.
Store the Lox in the refrigerator or freezer according to the recommendations given by the manufacturer.
Although the traditional way of eating Lox is uncooked with a bagel, the safest way to eat Lox is after heating and it is essential to cook or heat the Lox before eating when pregnant (5, 8).
Heat the Lox to a minimum temperature of 145 °F (63 °C) and do not keep uncooked or cooked Lox unrefrigerated.
Reject the Lox when it shows any signs of spoilage, such as off-odours and discolourations, slime or gas production.

Conclusion

In this article, we discussed the safety of eating Lox, a cured fish of the Jewish food tradition. Despite the risks of its consumption, Lox is safe to eat.

My recommendation is, due to the high salt in the Lox, it should be eaten with a food low in salt, such as unsalted rice or unsalted potatoes.

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References

1.-

Hochman L, editor. Tastes of faith: Jewish eating in the United States. Purdue University Press; 2017 Dec 15.

2.-

Olitzky I, Perri AM, Shiffman MA, Werrin M. Smoked fish as a vehicle of salmonellosis. Public Health Reports. 1956 Aug;71(8):773.

3.-

Gram L, Huss HH. Microbiological spoilage of fish and fish products. International journal of food microbiology. 1996 Nov 1;33(1):121-37.

4.-

Heir E, Jacobsen M, Gaarder MØ, Berget I, Dalgaard P, Jensen MR, Holck AL. Microbial safety and sensory analyses of cold-smoked Salmon produced with sodium-reduced mineral salts and organic acid salts. Foods. 2022 May 19;11(10):1483.

5.-

Selecting and serving fresh and frozen seafood safely [Internet]. U.S. Food and Drug Administration. FDA; 2023 [cited 2023 Oct 24]. Available from: https://www.fda.gov/food/buy-store-serve-safe-food/selecting-and-serving-fresh-and-frozen-seafood-safely

6.-

Domingo JL, Bocio A, Falcó G, Llobet JM. Benefits and risks of fish consumption: Part I. A quantitative analysis of the intake of omega-3 fatty acids and chemical contaminants. Toxicology. 2007 Feb 12;230(2-3):219-26.

7.-

Luthfita AC, Muniroh M, Bakri S, Gumay AR, Hardian H, Birawa AD, Mulyono M, Afiyani N, Farhatania L, Dewantiningrum J. High Seafood Intake During Pregnancy and Low Blood Pressure Among Coastal Pregnant Women in Indonesia. Malaysian Journal of Medicine & Health Sciences. 2020 Dec 3;16.

8.-

Dean J, Kendall P. Food safety during pregnancy. Food and nutrition series. Food safety; no. 9.372. 2004.

Food Safety