Can chocolate spoil? (3 Reasons it could)
By
Dr Tayse Ferreira F. Da Silveira PhD
| Reviewed by
Dr Anny Manrich (PhD)
The contents of this article are fact-based except otherwise stated within the article.
Author bio
Dr Tayse has extensive experience in Food Science, especially through studying the chemical composition and stability of foods, as well as their bioactive properties. She writes and reviews content on these topics.
Dr Tayse da Silveira´s Highlights:
- Lecturer at the State University of São Paulo (Unesp), Brazil, for Food Engineering students
- Post-doctorate in Food Science, with a one-year training period at Cirad – France.
- PhD in Food Science, with a one-year scholarship at the University of Reading/United Kingdom.
- Bachelor of Food Engineering at the Federal University of Pará, Brazil.
“Food Science is exciting because it touches our lives in such personal and intimate ways. Understanding food systems and gaining knowledge of how to manipulate them, helps society evolve as a whole” – Dr Tayse da Silveira.
Professional experience:
In her doctorate at the University of Campinas, Dr Tayse studied the effect of emergent preservation techniques, such as high-pressure processing, on the chemical and microbial properties of foods.
After completing her doctorate, Tayse da Silveira worked as a postdoctoral fellow in the Pharmaceutical Science Department at the University of São Paulo (USP), with a one-year training at CIRAD, Montpellier, France.
During this period, Dr Tayse worked on the development and evaluation of innovative antioxidant molecules for the preservation of fatty food products.
Dr Tayse also taught in public and private universities in Brazil for Nutrition, Food Engineering, and Enology students, always on food science and food technology-related subjects, including microbiology, milk technology, and wine-making technology.
She has also been involved in a number of studies evaluating the chemical composition and bioactive properties of food products, with emphasis on the development of analytical techniques to achieve that.
Currently, Dr Tayse works at the Centro de Investigação de Montanha (MRC), Portugal. She continues to work on the study of the chemical composition of foods, with a focus on identifying and isolating molecules with potential for application as food ingredients.
In her research, she targets molecules able to provide health and nutritional improvement, and antioxidant and antimicrobial properties (natural food additives).
She regularly publishes in high-impact, specialized scientific journals in her field, and feels encouraged to expand her knowledge domain by doing new scientific partnerships.
Education
- 2017 – PhD in Food Science at the University of Campinas Brazil, with a one-year training period at the University of Reading/United Kingdom.
- 2013 – Master’s Degree in Food Science at the University of Campinas, Brazil.
- 2011 – Bachelor of Food Engineering at the Federal University of Pará, Brazil.
Relevant Published work
- Roschel GG, da Silveira TFF, Cajaíba LM, Ferrari RA, Castro IA. Combination of natural strategies to improve the oxidative stability of echium seed oil. Journal of Food Science. 2021;86(2):411-9.
- de Moraes MR, da Silveira TFF, Coutinho JP, Souza DS, Duarte MCT, Duarte RT, et al. Bioactivity of atemoya fruits and by-products. Food Bioscience. 2021;41:101036.
- Ferreira da Silveira TF, Laguerre M, Bourlieu-Lacanal C, Lecomte J, Durand E, Figueroa-Espinoza MC, et al. Impact of surfactant concentration and antioxidant mode of incorporation on the oxidative stability of oil-in-water nanoemulsions. LWT. 2021;141:110892.
- da Silveira TFF, Cajaíba LM, Valentin L, Baréa B, Villeneuve P, Castro IA. Effect of sinapic acid ester derivatives on the oxidative stability of omega-3 fatty acids rich oil-in-water emulsions. Food Chemistry. 2020;309:125586.
- Roschel GG, da Silveira TFF, Cajaiba LM, Castro IA. Combination of Hydrophilic or Lipophilic Natural Compounds to Improve the Oxidative Stability of Flaxseed Oil. European Journal of Lipid Science and Technology. 2019;121(5):1800459.
- da Silveira TFF, Cristianini M, Kuhnle GG, Ribeiro AB, Filho JT, Godoy HT. Anthocyanins, non-anthocyanin phenolics, tocopherols and antioxidant capacity of açaí juice (Euterpe oleracea) as affected by high pressure processing and thermal pasteurization. Innovative Food Science & Emerging Technologies. 2019;55:88-96.
- da Silveira TFF, de Souza TCL, Carvalho AV, Ribeiro AB, Kuhnle GGC, Godoy HT. White açaí juice (Euterpe oleracea): Phenolic composition by LC-ESI-MS/MS, antioxidant capacity and inhibition effect on the formation of colorectal cancer related compounds. Journal of Functional Foods. 2017;36:215-23.
You can view some of Dr Tayse´s work below and links to her professional profile:
ResearchGate: https://www.researchgate.net/profile/Tayse-Ferreira?ev=hdr_xprf
Scopus: https://www.scopus.com/authid/detail.uri?authorId=55901968900
Google Scholar: https://scholar.google.com/citations?user=l4zi0d8AAAAJ&hl=pt-PT
Linkedin: https://www.linkedin.com/in/tayse-ferreira-a2311947/
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 guide, we will answer the question “Can chocolate spoil?” We will discuss the reasons which make chocolate spoil and discuss the shelf lives of some common chocolates as well.
Can chocolate spoil?
Yes, chocolate can spoil. Factors that can cause the quality of chocolate to decline can be fat bloom, sugar bloom, substandard ingredients, perishable ingredients, or improper storage and handling [1].
Whether or not chocolate is more prone to spoilage depends on the content of cacao in a bar, the moisture or milk content, and the presence of non-cacao ingredients.
Components such as cream, butter, nuts, caramels, raisins, wafers, and other wet fillings can contribute to chocolate spoilage.
These products can be a source of contamination, as well as they easily absorb moisture under inadequate storage conditions, favoring microbial development and quality loss [1].
In general, the low moisture content of chocolate products makes them less perishable foods, with a shelf life of a few bonus years [1]. However, the span of chocolate also depends on how you handle and store it.
Improper storage, processing, and packaging – for example, poor hygiene and moisture gain – may encourage microbial contamination and growth.
What does make chocolate spoil?
Chocolate spoils if its ingredients go bad, or if it is stored or packed improperly. Raisins will dry out, and nuts become rancidity and gain moisture, as well as wafers.
According to reports in research, adequate storage humidity and temperature are key factors to protect chocolates from many quality-associated issues, such as sugar crystallization, melting, and fat bloom [1].
Last but not least, the package must serve as a barrier to water vapor permeability. In the absence of an effective wrap for chocolate, products will tend to lose or soak up moisture.
The buildup of moisture on the surface of chocolates could then lead to mold growth on products [1].
How long do some commonly eaten chocolates last?
Have a look at the table ahead for the shelf life of some chocolate products [1].
| Chocolate type | Typical shelf life |
| Dark chocolate | 24 months |
| Milk and white chocolate | 16 |
| Chocolate-coated fondant | 18 |
| Milk chocolate-coated peanuts Chocolate bars with raisins Chocolate-coated wafer Chocolate shells with soft caramel center Chocolate shells with praline center | 12 |
As you can see, the presence of non-cacao ingredients shortens the shelf life of chocolate, which happens for several reasons. For instance, extra ingredients can be a source of contamination for chocolates.
Furthermore, they can be more or less prone to chemical reactions due for example to nuts that may undergo fat oxidation; to moisture loss, due to raisins; or to moisture absorption, as is the case of chocolate-coated wafers [1].
How to know that chocolate has gone bad?
Here are the main transformations taking place when dark chocolate goes bad.
- Fat bloom: visibly recognized as a whitish superficial layer on chocolate accompanied by loss of surface gloss, the fat bloom is nothing more than fat crystallization on the surface of the chocolate.
Factors leading to fat bloom include storage at temperatures higher than 18°C, melting of chocolate followed by recrystallization, and inadequate processing conditions [2].
- Sensory changes: chocolate is high in fat, so one sign that it has gone bad is rancidity caused by fat oxidation. Although dark chocolate is rich in antioxidants, over time, fat oxidation is inevitable.
Other sensory changes comprise stale favor, hardness, crumbliness, and loss of superficial gloss.
Chocolates incorporated with nuts may experience extra rancidity because nuts are usually rich in unsaturated fat. They can also lose texture due to moisture pickup.
- Sugar bloom: means the crystallization of sugars on the surface of the chocolate, and is caused by moisture absorption.
Any of these signs can harm your health, they are just quality markers.
Although microbial growth is unlikely, incorrect storage conditions may somehow promote it. Therefore, upon any manifestation of mold, which shows a cotton appearance on the surface of the chocolate, discard the chocolate immediately.
How to store chocolate?
- Chocolates should be kept in a dark, cool, dry area.
It’s OK to keep it in the cupboard or a kitchen cabinet; it doesn’t need to be refrigerated. After you’ve opened the bag, make sure it’s properly wrapped before putting it away.
Adequate stock conditions protect the chocolate from heat (which promotes melting, fat bloom, and fat oxidation); moisture (which causes texture loss and sugar crystallization; and light (which can favor fat oxidation).
- The optimum shelf life is at temperatures of about 18 °C or less [1,2]. According to studies, in general, the lower the temperature, the lower the bloom risk [2].
if the temperature rises to 30°C, it isn’t a huge problem, but the chances to occur fat bloom are increased.
Above this temperature, chocolate is partially melted, and upon recrystallization, the fat bloom is very likely to take place [2].
- Hold the bar far from any heat sources while storing it, since heat may melt the chocolate.
- After you’ve opened the bar, cover the chocolate in the aluminum foil that came with it, or seal up the bag if it’s resealable.
Can I eat expired chocolate?
- Unopened packs: chocolates usually come with a best-before date, which means that after the date printed on labels, the quality of the product is no longer guaranteed, but it is still safe, according to the US Department of Agriculture [3].
Therefore, if your chocolate is sealed, has been stored properly, and does not show any sign of spoilage, it is supposed to be safe because the low moisture content of chocolate makes it a hostile environment for microbial growth.
However, the quality of the chocolate can have dropped significantly past the best-before date. For instance, you may find the chocolate stale, the nuts rancid, or the wafer soft.
So the best thing to do is to analyze case to case before deciding whether to eat the chocolate or not.
- Opened packs: if you find a forgotten slice of chocolate in your pantry that has been previously opened but not finished before the best-before date, I do not recommend eating it, even if it looks ok.
Although chocolate is considered a stable product due to its low moisture content, Morasi and others [4] highlighted that pathogens like Salmonella ssp. can survive in adverse ambient of low-moisture foods, including chocolate.
The authors also drew attention to the contamination of chocolate ingredients, such as nuts, peanuts, and almonds, which could take pathogenic microorganisms to chocolates.
In these products, the surviving bacteria will wait until favorable conditions come up, such as moisture increase due to water absorption from the surroundings, after which they will develop quickly.
Therefore, it is not a good idea to eat chocolate that has been opened for a long time and expired, or that you obviously see has been badly stored, for instance, exposed to moisture or mild heat.
If contaminated, these conditions could encourage salmonella and other pathogens to grow.
Conclusion
In this brief guide, we answered the question “Can chocolate spoil?” We discussed the reasons which make chocolate spoil and the shelf lives of some common chocolates.
Citations
1. Subramanian P. The Stability and Shelf Life of Confectionery Products. https://www.sciencedirect.com/science/article/pii/B9781845697013500256.
2. Lonchampt P, Hartel RW. Fat bloom in chocolate and compound coatings. European Journal of Lipid Science and Technology. 2004;106(4):241-74.
4. Morasi RM, Rall VLM, Dantas STA, Alonso VPP, Silva NCC. Salmonella spp. in low water activity food: Occurrence, survival mechanisms, and thermoresistance. Journal of Food Science. 2022;87(6):231
