How do I know if milk is spoiled?
By
Dr Miguel Fernandez-Nino PhD
| Reviewed by
Dr Anny Manrich (PhD)
The contents of this article are fact-based except otherwise stated within the article.
Author bio
Dr Miguel Fernández-Niño is a food scientist with expertise in food biochemistry, Food microbiology, synthetic biology, food waste valorisation, and industrial biotechnology. He writes and reviews content on these topics.
Dr. Fernández-Niño’s Highlights:
- Colombian scientist, with a Ph.D. in Biochemical Engineering from the Jacobs University Bremen (Germany).
- Alexander von Humboldt Postdoctoral Fellow at the Leibniz Institute of Plant Biochemistry in Halle (Germany).
- Expertise in using multi-omics approaches (e.g., metabolomics, metagenomics, and metatranscriptomics) to re-engineer products and processes of relevance for the food industry.
- Expertise in designing microorganisms (microbial biofactories and starter cultures) to produce value-added products and food waste valorisation.
“My professional goal is to contribute to the education and research in Food Engineering and Food Biotechnology. The major incentive of my career is to contribute to the diffusion of scientific knowledge in society, thus promoting rational thinking and evidence-based decision-making”- Dr. Fernández-Niño’s, PhD.
Professional Experience:
Dr Fernández-Niño works as an Alexander von Humboldt Postdoctoral Fellow, at the Leibniz Institute of Plant Biochemistry, in Halle (Germany). He leads a project that aims to improve fine-flavour cocoa bean fermentation for local farmers in Colombia through controlled fermentation systems.
Previously, Dr Fernández-Niño worked as a Postdoctoral Fellow on the bio-catalytic synthesis of isoferulic acid (BMBF project) in the same institution.
Dr Fernández-Niño also worked as a Postdoctoral researcher at the Department of Chemical and Food Engineering at Los Andes University in Colombia, working on the development of a platform to produce novel aroma precursor compounds and high value-added products from analysis of cocoa fermentation.
In addition, Dr. Fernández-Niño worked on the assembly of a platform for heterologous polyphenols production in E. coli from analysis of cacao fermentation pathways, in the same institution.
Dr. Fernández-Niño has been an occasional scientific adviser of Casa Luker S.A. (leader in the Colombian chocolate market), working on projects related to the post-harvesting of fine-flavour cocoa. He also worked as instructor and coordinator of the lab course General Biochemistry and Molecular Biology II Lab (Course No. CH02-520121) at Jacobs University Bremen (Germany) and as a Resident Associate in the same institution.
Finally, Dr Miguel Fernández-Niño has experience as Part-Time Assistant Professor, Occasional Professor, and Master Teaching Assistant.
Education:
- 2009 B.Sc. Biologist at Universidad Nacional de Colombia
- 2012 Master in Science – Biochemistry (Thesis “magna cum laude”) at Universidad Nacional de Colombia
- 2017 PhD in Biochemical Engineering at Jacobs University Bremen-Germany
The main publications of Dr Miguel Fernández-Niño are:
Fabio Herrera-Rocha, Miguel Fernández-Niño*, Mónica P. Cala, Jorge Duitama, Andrés Fernando González Barrios (2023) Omics approaches to understand cocoa processing and chocolate flavor development: A review. Food Research International. https://doi.org/10.1016/j.foodres.2023.112555
Fernández-Niño Miguel* and Burgos-Toro Daniela (2022) Engineering microbial biofactories for a sustainable future. Chapter edited by Catalina Correa & Adriana Suarez-Gonzalez in the book: Genomics and the Global Bioeconomy -1st Edition-. ISBN 9780323916011. Publisher: ELSEVIER: https://www.elsevier.com/books/genomics-and-the-global-bioeconomy/patrinos/978-0-323-91601-1
Fabio Herrera-Rocha, Mónica P. Cala, Ana Maria León-Inga, Jenny Lorena Aguirre Mejía, Claudia M. Rodríguez-López, Sergio Leonardo Florez, María José Chica, Héctor Hugo Olarte, Jorge Duitama, Andrés Fernando González Barrios, Miguel Fernández-Niño* (2022) Lipidomic profiling of bioactive lipids during spontaneous fermentations of fine-flavor cocoa. Food Chemistry. Volume 397. 133845, ISSN 0308-8146. https://doi.org/10.1016/j.foodchem.2022.133845.
Díaz-Bustamante ML, Fernández-Niño M, Reyes LH and Alvarez Solano OA (2022) Multiscale Approach to Dairy Products Design. Front. Chem. Eng. 4:830314. doi: https://doi.org/10.3389/fceng.2022.830314.
Ramón E. Jaimez*, Luigy Barragan, Miguel Fernández-Niño*, Ludger A. Wessjohann, George Cedeño-Garcia, Ignacio Sotomayor, Francisco Arteaga, (2022): Theobroma cacao L. cultivar CCN 51: A comprehensive review on origin, genetics, sensory properties, production dynamics, and physiological aspects. PeerJ 10:e12676 https://doi.org/10.7717/peerj.12676.
Fabio Herrera‑Rocha, Mónica P. Cala, Jenny Lorena Aguirre Mejía, Claudia M. Rodríguez‑López, María José Chica, Héctor Hugo Olarte, Miguel Fernández‑Niño* & Andrés Fernando Gonzalez Barrios*. (2021): Dissecting fine‑flavor cocoa bean fermentation through metabolomics analysis to break down the current metabolic paradigm. Scientific Reports 11(21904) DOI: https://doi.org/10.1038/s41598-021-01427-8.
Fernández-Niño, M., Rodríguez-Cubillos, MJ., Herrera-Rocha, F., Anzola, JM., Cepeda-Hernández, ML., Aguirre, L., Chica, MJ., Olarte, HH., Rodríguez, CM., Calderón, D., Ramírez-Rojas, A., Del Portillo, P., Restrepo, S., González Barrios, A.* (2021): Dissecting on-farm industrial fermentations of fine-flavour cocoa through metagenomic analysis. Scientific Reports 11(8638) DOI: https://doi.org/10.1038/s41598-021-88048-3.
Buitrago Mora, HM., Arango Piñeros, M., Espinosa Moreno, D., Restrepo, S., Cardona Jaramillo, JEC., Álvarez Solano, OA., Fernandez-Niño, M., González Barrios, A.* (2019): Multiscale design of a dairy beverage model composed of Candida utilis single cell protein supplemented with oleic acid. Journal of Dairy Science. 102(11) 9749-9762 DOI: https://doi.org/10.3168/jds.2019-16729.
Fernández-Niño, M., Giraldo, D., Gomez-Porras, JL., Dreyer, I., González Barrios, A., Arevalo-Ferro, C.* (2017): A synthetic multi-cellular network of coupled self-sustained oscillators. PLOS ONE 12(6): e0180155 DOI: https://doi.org/10.1371/journal.pone.0180155.
Fernández-Niño, M., Marquina, M. Swinnen, S.,Rodríguez-Porrata, B., Nevoigt, E.*, Ariño, J. (2015):The Cytosolic pH of Individual Saccharomyces cerevisiae Cells Is a Key Factor in Acetic Acid Tolerance. Appl Environ Microbiol 81(22): 7813-7821 DOI: https://doi.org/10.1128/AEM.02313-15.
Swinnen, S., Fernández-Niño, M., González-Ramos, D., van Maris, AJ., Nevoigt, E.* (2014): The fraction of cells that resume growth after acetic acid addition is a strain-dependent parameter of acetic acid tolerance in Saccharomyces cerevisiae. FEMS Yeast Res 14(4): 642-653 DOI: https://doi.org/10.1111/1567-1364.12151.
Conference appearances and other speaking engagements
Selected courses delivered:
Course: Current technologies in the production of chocolates. (20 hours course). Invited as professor by the Department of Chemical and Food Engineering / Faculty of Engineering at Los Andes University-Colombia. July (2021).
Course: Design and assembly of microorganisms for the biomedical industry (20 horas course). Invited as professor by the School of Engineering and Science- Instituto Tecnologico de Monterrey (México). January 15-17 (2019)
Selected oral presentations and conferences:
Conference: Dissecting fine-flavour cocoa bean fermentation through multi-omics approaches. Speaker invited by the Organic Chemistry Department at The University of Buenos Aires -Argentina. Sep. 07 (2022).
Conference: Theobroma cacao L. cultivar CCN 51. Association of Producers of Fine Cocoa and Aroma (APROCAFA), Ecuador. March 15 (2022).
Conference: Biology of probiotics and prebiotics. Speaker invited by the Chemical and Food Engineer Department at Los Andes University-Colombia. June 27 (2020).
Conference: Pandemic food revolution. Speaker invited by the Chemical and Food Engineer Department at Los Andes University-Colombia. May 5 (2020).
Conference: Biochemistry and microbiology of cocoa fermentation. Speaker invited to the elective course: cocoa and Chocolate, organized by Casa Luker and the Department of Chemical Engineering at Los Andes University-Colombia. February 5 and 7 (2019)
Oral presentation: Lipidomic profiling of bioactive lipids during spontaneous fermentation of fine-flavour cocoa. Metabolomics 2022. Valencia, Spain. June 19-23 (2022).
Oral presentation: Exploration of Saccharomyces cerevisiae intra-species diversity for the identification of novel genetic determinants for acetic acid tolerance with the help of pooled-segregant RNA sequencing. ISSY33 International Specialized Symposium on Yeasts at University College Cork, Cork, Ireland, June 24-29. (2017)
You can view some of Dr Miguel’s work below and links to his professional profile.
https://www.researchgate.net/profile/Miguel-Fernandez-Nino
https://www.linkedin.com/in/miguel-fern%C3%A1ndez-ni%C3%B1o-4a064b168/?locale=en_US
https://scholar.google.com/citations?user=JBb1zuoAAAAJ&hl=en
https://orcid.org/0000-0002-8231-7989
https://www.scopus.com/authid/detail.uri?authorId=56123747300
https://loop.frontiersin.org/people/1296449/overview
https://www.intechopen.com/profiles/158295
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
“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
In this brief article, we are going to answer the question “how do I know if milk is spoiled?”, discuss the different methods of identifying spoiled milk and the potential health effects of drinking spoiled milk.
How do I know if milk is spoiled?
There are different easy indicators that can help you to identify whether your milk has spoiled:
Important: it is important to be careful and mindful of the potential health risks associated with consuming spoiled milk, as it can lead to food poisoning and other adverse health effects (1-3).
- Appearance: in terms of appearance, fresh milk typically exhibits a smooth and consistent texture, accompanied by a uniform color and a slightly creamy consistency.
However, when milk turns sour or spoils, noticeable changes occur. It may develop a chunky or curdled texture, appearing thick and potentially acquiring a yellowish or bluish hue.
- Smell: when it comes to the smell of spoiled milk, it possesses a distinct and easily recognizable aroma. It is often described as sour, unpleasant, and rancid.
If you detect any unusual or off-putting odors emanating from your milk, it is advisable to discard it to ensure your safety.
- Unusual color: Fresh milk typically exhibits a white or slightly off-white coloration. However, if you observe any yellowish, bluish, or any form of discoloration in the milk, it may indicate spoilage.
- Expiration date: Milk has a limited shelf life (4-5), so it is important to check the expiration date on the carton. If it expires, you should immediately discard it.
Can you get sick from drinking spoiled milk?
Yes, drinking spoiled milk can make you very sick, you should be careful as it contains harmful bacteria that can lead to food poisoning (1-3).
Food poisoning resulting from spoiled milk can lead to various symptoms, including nausea, abdominal pain and vomiting, which may manifest as an upset stomach following the consumption of spoiled milk (1-3, 6-7).
Consuming spoiled milk can also cause diarrhea, which, if left untreated, can lead to dehydration (7).
If you experience any of these symptoms after consuming spoiled milk, it is crucial to seek promptly medical attention if the symptoms persist or worsen.
What should you do if you suspect you have consumed spoiled milk?
If you suspect you have consumed spoiled milk, there are several actions that could help you to reduce the risk of illness or severe infections:
- Stop drinking the milk immediately: If you notice any signs that the milk has gone bad, such as an unusual odor or taste, stop drinking it and throw it out right away.
- Check for symptoms: Keep an eye out for symptoms described above, such as nausea, vomiting, diarrhea, abdominal pain, and fever (8-9).
- Stay hydrated: If you experience diarrhea or vomiting, it’s essential to stay hydrated by drinking plenty of fluids, such as water, clear broths, or electrolyte replacement drinks to help recovering (10).
- Seek medical attention: If your symptoms are severe or last more than a few days, seek medical attention. Your doctor may recommend over-the-counter medications or prescribe antibiotics, depending on the severity of your illness.
It is very important that you store your milk properly as it will be described in the next sections to prevent food poisoning.
How should you handle milk to prevent spoilage?
You can prevent spoilage and prolong the shelf life of your milk by following the following tips:
- Store it in the refrigerator: Milk should be stored in the refrigerator at a temperature of 40°F (4°C) or below (11). It’s important to keep milk away from the refrigerator door, as temperature fluctuations can affect its quality (11).
- Keep it covered: Milk should be kept in a covered container to prevent contamination and exposure to light.
- Don’t mix old and new milk: Don’t mix fresh milk with milk that is close to its expiration date or has been opened for several days, as this can accelerate spoilage.
- Don’t leave milk out at room temperature: Milk should not be left out of the refrigerator for more than two hours. If milk is left out for longer than this, it can quickly become a breeding ground for bacteria (12).
- Don’t return unused milk to the original container: If you have leftover milk that you didn’t consume, don’t return it to the original container, as this can introduce bacteria and contaminate the remaining milk.
- As mentioned, several times before, you should check the expiration date: Always check the expiration date on the milk carton before consuming it. Milk that has expired should be discarded.
By following these simple guidelines, you can help prevent spoilage and ensure that your milk stays fresh and safe to consume.
Conclusion
In this brief article, we answered the question “how do I know if milk is spoiled”, and discussed the different methods of identifying spoiled milk and the potential health effects of drinking spoiled milk.
References
1. Garg SK, Mital BK. Enterococci in Milk and Milk Products. http://dx.doi.org/103109/10408419109113508 [Internet]. 2008 [cited 2023 May 10];18(1):15–45. Available from: https://www.tandfonline.com/doi/abs/10.3109/10408419109113508
2. Soejima T, Nagao E, Yano Y, Yamagata H, Kagi H, Shinagawa K. Risk evaluation for staphylococcal food poisoning in processed milk produced with skim milk powder. Int J Food Microbiol. 2007 Apr 1;115(1):29–34. https://www.sciencedirect.com/science/article/abs/pii/S0168160506005137
3. Brown KL. Control of bacterial spores. Br Med Bull [Internet]. 2000 Jan 1 [cited 2023 May 3];56(1):158–71. Available from: https://academic.oup.com/bmb/article/56/1/158/388001
4. Rysstad G, Kolstad J. Extended shelf life milk—advances in technology. Int J Dairy Technol [Internet]. 2006 May 1 [cited 2023 May 10];59(2):85–96. Available from: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1471-0307.2006.00247.x
5. Barbano DM, Ma Y, Santos M V. Influence of Raw Milk Quality on Fluid Milk Shelf Life,. J Dairy Sci. 2006 Mar 1;89:E15–9. https://pubmed.ncbi.nlm.nih.gov/16527874/
6. Patel P, Komorowski AS, Mack DP. An allergist’s approach to food poisoning. Ann Allergy, Asthma Immunol. 2023 Apr 1;130(4):444–51. https://pubmed.ncbi.nlm.nih.gov/36334721/
7. Maddock EC. Food Poisoning. http://dx.doi.org/1012968/pnur199910335 [Internet]. 2014 Jun 11 [cited 2023 Apr 24];104(4344):87. Available from: https://www.magonlinelibrary.com/doi/10.12968/pnur.1999.10.3.35
8. Milaciu M V, Ciumărnean L, Orășan OH, Para I, Alexescu T, Negrean V. Semiology of food poisoning. Int J Bioflux Soc [Internet]. 2015 [cited 2023 May 10];8(2):108–13. Available from: http://hvm.bioflux.com.ro/docs/2015.108-113.pdf
9. Hurst WC, Reynolds AE, Schuler GA, Tybor PT. Preventing food poisoning and food infection [Internet]. University of Georgia; 2010 [cited 2023 May 3]. Available from: https://esploro.libs.uga.edu/esploro/outputs/9949316166102959?institution=01GALI_UGA&skipUsageReporting=true&recordUsage=false
10. McRobert GR. THE TREATMENT OF BACTERIAL FOOD POISONING. Br Med J [Internet]. 1934 Aug 8 [cited 2023 May 10];2(3841):304. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2445530/
11. Griffiths MW, Phillips JD, Muir DD. Effect of low-temperature storage on the bacteriological quality of raw milk. Food Microbiol. 1987 Sep 1;4(4):285–91. https://www.sciencedirect.com/science/article/abs/pii/S0740002087800023
12. Huis In’t Veld JHJHI. Microbial and biochemical spoilage of foods: an overview. Int J Food Microbiol. 1996 Nov 1;33(1):1–18. https://www.sciencedirect.com/science/article/abs/pii/0168160596011397
