Do Raisins Go Bad?

By Dr Tayse Ferreira F. Da Silveira PhD | Reviewed by Dr Anny Manrich (PhD)

Page last updated: 05/05/2023 | Next review date: 05/05/2025

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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/

Dr Tayse Ferreira F. Da Silveira PhD

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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

Dr Anny Manrich (PhD)

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In this brief guide, we are going to answer the question “Do raisins go bad?” We will also talk about different methods to store and handle raisins.

Do Raisins Go Bad?

Yes, raisins do go bad despite being dried fruit. Raisins have a long shelf life but you can not store them forever. They degrade in quality on storing beyond their shelf life and if handled improperly.

Raisins are made from grapes that have been dried about 60% of their water content [1]. Due to this moisture reduction, sugars are also concentrated in the final product. In addition, raisins have low pH (4.0).

All of these characteristics make it hard for microorganisms to grow because most of them cannot multiply in such a hostile environment [2].

However, if stored in high-humidity surroundings, raisins can absorb moisture, which can encourage the growth of microorganisms, such as fungi and bacteria [2].

On the other hand, in low-humidity environments, raisins can lose water to their surrounding, decreasing their moisture content by half as shown in research [3].

That´s why when you get that old raisins they may seem dry and tough. Therefore, storing raisins properly is essential to keep their quality over the whole shelf life.

How Long Do Raisins Last?

Unopened, the shelf life of raisins is about 1 year, provided that they are stored properly. After being opened, the shelf life of raisins depends on the storage conditions.

If they are left in direct contact with ambient conditions, for example, unwrapped, it is possible that it loses quality faster due to moisture loss or moisture gain.

Opened and well-handled, the shelf life of raisins is of 6 months if kept in the pantry or up to 1 year in the refrigerator [4].

What Are The Signs Of Expired Raisins?

You can tell the raisins have gone bad by following the below points

– Smelling the raisins: off-odors and off-flavors in raisins may be the result of microorganisms development, such as yeasts adapted to low-moisture and high-sugar food products that produce fermentation.

– Mold: due to the characteristics of raisins (high sugar, low moisture and pH), molds are the most likely type of microorganisms developing in raisins.

However, they will multiply as a result of an increase in the moisture value, such as when the raisins are stored incorrectly.

Molds are perceived as bluish-green spots on the surface of raisins, sometimes with a cotton-like appearance. Moldy products are preferentially discarded because certain species of mold can produce toxic compounds.

– Hardness: sometimes you can feel your raisins hard to chew. It simply means that they were dehydrated. They are still safe, but not to their finest taste.

How To Store Raisins?

Raisins should be stored in a dry, cool, dark place, in an airtight container, particularly after opening, when it is recommended to store them in tightly sealed flasks to keep freshness [4].

Your pantry or a kitchen cabinet are good places for it.

You can also store raisins in the refrigerator to prolong their freshness, as long as you keep them in airtight conditions to control moisture exchange [4].

Freezing is also an alternative. According to the United States Department of Agriculture, raisins can be stored in the freezer for 1 month [4].

To keep raisins from forming huge clusters, put them evenly on a baking sheet in a single layer. These products may prevent them from forming a cluster and make them simpler to utilize.

Transfer the frozen raisins to an airtight container, then freeze the tray for one hour. Another reason is that if you’re planning to cook or bake with them, you don’t have to defrost the raisins.

In case you need to thaw them, do it by moving the frozen raisins from the freezer to the refrigerator overnight or until you notice it is defrosted.