Why does coconut water turn pink?
By
Dr Rafael Frascino Cassaro (PhD)
| Reviewed by
Dr Anny Manrich (PhD)
The contents of this article are fact-based except otherwise stated within the article.
Author bio
Dr Rafael Frascino Cassaro PhD is a Chemist with expertise in Food Technology, extraction of essential oils from food sources, organocatalysis, extraction by supercritical CO2 and organic chemistry. He writes and reviews content on these topics.
Dr Rafael Frascino Cassaro’s Highlights:
- PIPE-FAPESP Project Coordinator for the company Bioativos Naturais Ltda involving the extraction of essential oils from food sources, with supercritical CO2.
- PhD in Chemistry with research in supercritical fluid reactivity.
- Bachelor of Environmental Chemistry at University of São Paulo State (UNESP)/Brazil
Professional Experience:
Dr Rafael Frascino Cassaro’s Experience:
Dr Rafael coordinated a PIPE-FAPESP Project (Company Research and Innovation Project) for the company Bioativos Naturais Ltda, involving the extraction of essential oils with supercritical CO2 from food sources such as turmeric, ginger, hops, orange bagasse, pepper rose, cupuaçu pie, among others.
Dr Rafael has worked on a project, involving studies of the influence of pre-treatment on the recovery of crude food extracts by extraction with supercritical CO2 (Supercritical Fluid Extraction or SFE) and with pressurized liquids (ethanol and water) for food sources, aimed at obtaining oleoresins; determination of global yield and chemical composition of crude extracts. As a postdoctoral fellow for the Food Engineering department at the University of Campinas/Brazil
Dr Rafael Frascino Cassaro has worked as a substitute Professor at the University of São Paulo State (UNESP) on General Chemistry and Thermodynamics II disciplines for the Food Engineering course.
Education:
- 2009 Bachelor in Environmental Chemistry at the State University of São Paulo, Brazil
- 2015 PhD in Chemistry with research in supercritical fluid reactivity University of São Paulo, Brazil
- 2017 Post Doctoral in Food Engineering Research: Influence of Biomass Pre-Treatment on Supercritical CO2 Extraction: Preservation of High Added Value Assets and Reduction of Process Costs at the State University of Campinas, Brazil
The main publications of Dr Rafael Frascino Cassaro are:
RC Bazito, RF CASSARO, LC OLIVEIRA, RA Gariani, CAO Nascimento. (2013). Proline derivatives as organocatalysts for the aldol reaction in conventional and non-conventional reaction media. Green Processing and Synthesis 2, 43-50
TS Bastos, SB Rodriguez Reartes, MS Zabaloy, RF Cassaro, RC Bazito. (2019).Phase Behavior for the System Carbon Dioxide plus p-Nitrobenzaldehyde: Experimental and Modeling JOURNAL OF CHEMICAL AND ENGINEERING DATA 64 (5), 2116-2125
GH Sakae, LM Takata, AS Paulino, RC Bazito, RF Cassaro, C Princival, .(2013). A high enantioselective Proline-based helical polymer catalyst for aldol type reaction. Blucher Chemistry Proceedings 1 (2), 214-214
You can view some of Dr Rafael’s work below and links to his professional profile.
Research Gate: https://www.researchgate.net/profile/Rafael-Cassaro-2
Fapesp: https://bv.fapesp.br/pt/pesquisador/680718/rafael-frascino-cassaro/
Google Scholar: https://scholar.google.com/citations?user=ToO7HIcAAAAJ&hl=en
Linkedin: https://www.linkedin.com/in/rafael-frascino-cassaro-4a156a37/?originalSubdomain=br
ORCID: https://orcid.org/0000-0002-3729-2858
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 guide, we will address and answer the query, “why does coconut water turn pink?”. Also, we will discuss how to preserve coconut water for it to last longer. In addition, we will answer whether it is safe to drink coconut water and if it is good for your health.
Why does coconut water turn pink?
Pink discoloration of coconut water during processing and storage primarily occurs due to the presence of naturally occurring phenolic substrates in the coconut water.
These phenolic substrates undergo enzymatic action by polyphenol oxidase (PPO), which is also naturally present in the coconut water. The activity of PPO is further enhanced by exposure to higher temperatures and metal contamination. (1)
Is pink coconut water a sign of quality loss?
Yes. The enzymes polyphenol oxidases (PPO) and peroxidases (POD) play a vital role in diminishing the storage life and market potential of coconut water.
Even under refrigerated storage conditions, the catalytic activities of these enzymes can lead to numerous undesirable effects in coconut water.
This is not restricted to the formation of pink color but also includes browning, unpleasant flavors, and odors, all stemming from the enzymatic processes and microbial activity. (2)
Is it safe to drink pink coconut water?
Yes, pink coconut water is generally safe to drink. However, the safety of pink coconut water depends on a number of factors, including the quality of the coconuts used and the method of production.
The consequence of PPO or POD activities in coconut water is discoloration. Not only pink but yellow or brown discoloration of the coconut water can occur a few minutes or a few hours after the nut is cracked. (2)
How Can You Tell If Coconut Water Is Bad?
Unpleasant flavors, and odors, all stemming from the enzymatic processes and microbial activity.
Besides changes in color, catalytic activities of food enzymes develop many unappealing effects in coconut water.
Furthermore, fresh coconut water is extremely susceptible to microbial attacks, specifically from microorganisms such as Clostridium botulinum.
Once extracted from the nut, coconut water rapidly becomes highly vulnerable to microbial contamination. This not only causes a loss of essential nutritional elements but also significantly reduces its shelf life. (2)
What are the risks of spoiled coconut water?
The consumption of spoiled coconut water carries a risk as it may contain harmful bacteria, including E. coli, salmonella, and listeria.
Ingesting these bacteria can lead to various infections, resulting in symptoms such as nausea, vomiting, abdominal cramps, and diarrhea.
Consuming coconut water that shows signs of spoilage should be avoided to prevent potential health complications. (2)
How can you prevent coconut water from turning pink?
When addressing the issue of pink discoloration in coconut water, the use of secondary direct food additives is considered by some as a potential solution to remove the phenolic substrates.
However, this approach raises concerns due to the natural/organic perception of coconut water and the potential health risks associated with chemical additives in food products.
An alternative method involves treating coconut water with food-grade resins. This approach aims to adsorb the polyphenolic constituents present in the beverage, which are subsequently removed through filtration.
It is important to note that this method does not involve the addition of any additives and, as a result, is not considered an additive itself. (1)
How long does coconut water last?
At room temperature (27 °C), coconut water has limited stability and undergoes noticeable changes in smell and taste in less than 24 hours. The acidity of coconut water, measured by its citric acid content, increases as it matures, resulting in a sour taste due to microbial spoilage.
Freshly harvested green coconuts can be preserved for 5 to 7 days when stored under ambient conditions.
To maintain the quality of tender coconut water for a longer duration, it can be stored in glass or PET bottles at temperatures ranging from -20°C to +2°C, which allows it to retain its freshness for 2-3 months.
Alternatively, if coconut water is heated to 100°C for 10 minutes, it can be stored for up to 6 months at room temperature.
Additionally, when packed in Tetra Pak or PET containers, both fresh and stabilized coconut water can remain suitable for consumption for as long as 12 months, maintaining their quality over an extended period.(3-5)
How can you preserve coconut water for long?
While contained within the coconut fruit, coconut water is regarded as the most sterile liquid. However, its natural shelf life is relatively short. Even a small crack in the coconut shell can lead to spoilage of the water inside.
Therefore, it is essential to extend the shelf life of coconut water to ensure its preservation during transportation to different regions of the country. (3)
Similar to other tropical fruits, subjecting coconut to temperatures below 12 °C can lead to chilling injury, causing the coconut skin to brown quickly.
However, when considering the whole coconut without any treatment, optimal preservation results were observed when stored for 28 days at either 12 °C or 17 °C. (6)
Conclusion.
In this brief guide, we have answered the question “Why does coconut water turn pink?” with an in-depth explanation of how to prevent coconut water from turning pink and how to preserve it for long. Moreover, we have discussed how to tell when the water has gone bad.
Hope you found this blog useful, if you have any questions, please let us know
Citations
- Garcia B., Masa D.B., Rodriguez M.J., RolleR., Control of pink discoloration in coconut water, Cord 23 67–83 2007.
- Prithviraj, V., Pandiselvam, R., Babu, A. C., Kothakota, A., anikantan, M. R., Ramesh, S. V., … Hebbar, K. B. Emerging non-thermal processing techniques for preservation of tender coconut water. LWT, 149, 111850. 2021.
- L., Sunil & Appaiah, Prakruthi & P K, Prasanth Kumar & A.G., Gopala Krishna. Coconut Water – A Nature’s miracle health drink: Chemistry, Health Benefits, Packaging, Storage, and Technologies: A Review. 1-11. 2020.
- Naik, M., C. K., S., Rawson, A., & N, V. Tender Coconut Water: A Review on Recent Advances in Processing and Preservation. Food Reviews International, 1–22. 2020.
- Aditi Mathur, Gadhe Shruthi. Market Analysis of Packed Tender Coconut Water in India. Institute Of Agri Business Management Swami Keshwanand Rajasthan Agricultural University Bikaner. 2019
- Prades, A., Dornier, M., Diop, N., & Pain, J.-P. Coconut water preservation and processing: a review. Fruits, 67(3), 157–171. 2012.
