How to preserve rice

By Dr Anny Manrich (PhD)

Page last updated: 11/05/2022 | Next review date: 11/05/2024

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)

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In this brief guide, we are going to answer the question, “how to preserve rice” and discuss the different methods of preserving rice.

How to preserve rice

According to FAO statistics, 755,473,800.00 tonnes of paddy rice were produced in 2019. If we examine the production share of paddy rice by region (average, 1994–2019) we see that Asia produced 90.6% followed, at a great distance, by the Americas (5.2%), Africa (3.5%), Europe (0.6%), and Oceania (0.1%). Within the Asian region, China is the main producer with almost 200,000,000.00 tonnes followed by India with almost 150,000,000.00 tonnes and Indonesia with about 50,000,000.00 tonnes (1).

Rice can be preserved by :

Raw rice: Utilizing proper storage conditions. Storing in a closed container, away from pests.
Rice flour: Utilizing proper storage conditions. Storing in an air-tight container away from pests.
Cooked rice: Refrigerating and freezing.

Rice varieties and dishes

Rice is a common crop in Asia with over 6000 varieties. The most common varieties of rice include red rice, brown rice and Basmati.

Rice grains are generally brown. When the husk is removed by milling, they are known as white rice.

Rice is a nutrient-filled grain that can be prepared in a multitude of ways. Many Asian cuisines include rice in their daily diet and some cuisines use rice as their staple food. Some world-famous rice dishes include Sushi from Japan, Risotto from Italy, Nasi Goreng from Indonesia, Paella from Spain and Biryani from India.

Shelf-life of rice

Rice is one of the best foods for long term storage.

Raw white rice can be stored for 25-30 years under the proper storage conditions (3).
Raw brown rice has a shelf-life of about 6 months under the proper storage conditions. Since the husk of brown rice retains moisture and attracts microbes, it spoils faster (2).
Cooked rice: Cooked rice will stay fresh in a fridge for about 36 days. Cooked rice can also be frozen for up to 6 months, according to the USDA.

The brown rice has a short shelf life due to the presence of high lipid percentage in the bran layer resulting in quality deterioration due to lipid oxidation. Moreover, microbial load was observed higher in brown rice in contrast to white rice due to the lipid rich bran layer which is susceptible to microbial attack (2).

Preserving raw rice

Storage conditions such as moisture, temperature, and atmospheric conditions influence the rice quality. Controlled stored conditions are required to enhance the shelf life of rice for reducing the oxidation acceleration. The packaging of rice in modified atmospheric conditions such as carbon dioxide flushing and under vacuum slows down the quality deterioration in rice (2).

Raw rice is very shelf-stable and is one of the best goods for long term storage. Raw rice is preserved for the longest time by (2,3):

Inspecting rice before storage: Raw rice must always be inspected to make sure it is free from insects. Storing rice infested with insects will only shorten the shelf-life.

Storing away from dust, contaminants and insects: Raw rice is very prone to infestation by termites and bugs. Raw rice must be kept in a closed, pest-free container in a cool, dark place.
Storing at the optimum conditions: The best temperature for storing raw rice is 40°F or below.
Storing in oxygen-free containers: Rice has the longest shelf-life when stored in oxygen-free containers. Rice can be preserved for up to 30 years when stored in an oxygen-free container at a cool temperature.

Preserving cooked rice

Cooked rice must be either refrigerated or frozen to preserve it. Cooked rice has a high moisture content which will encourage the growth of microbes. So it is necessary to refrigerate or freeze cooked rice as soon as it reaches room temperature.

Refrigerating cooked rice: Cooked rice can be refrigerated for up to 4 to 63 days, according to the USDA. Cooked rice must be refrigerated in a zip-lock bag with the air squeezed out or in an air-tight container. Being exposed to air will make the cooked rice hard and chewy.

Freezing cooked rice: Cooked rice can be frozen for up to 6 months. Cooked rice must be frozen either in a ziplock bag or in an air-tight container.

How to eat frozen cooked rice

Frozen cooked rice can be directly added to dishes such as stews and risottos. Frozen rice can also be thawed and eaten on its own in the main dish such as rice and curry or fried rice.

Thawing of the foods is an important process when the term «food safety» is taken into account. Incorrect thawing of high-risk foods will enable the growth of harmful microorganisms. It is known that safety risk increases if the foods involved are not processed in some way such as by cooking but rather are consumed as are as ready to eat items. It is advised that frozen foods should be thawed in the refrigerator, put under cold running water, or in the microwave oven (5).

To thaw frozen rice:

Remove from the freezer and transfer to a suitable container for reheating.
Sprinkle some water on the top of the rice. The rice grains will be stuck together and dried and the water will allow them to loosen up.
Place the container on a stovetop at medium heat.
Stir the grains without mashing.
The rice can also be reheated in a microwave at medium power. Make sure to stir the rice every 30 seconds.

Preserving rice-flour

Flours have lower shelf stability than their respective grain forms due to the increased surface area available for moisture adsorption and other deteriorative changes often influenced by storage time and environmental conditions. Flours will have decreased shelf life when stored in high moisture and high oxygen environments and at higher temperatures (5).

Rice is easily ground into flour which is then used in recipes such as string-hoppers and hoppers.

Rice flour must be stored in an airtight container in a cool, dry place.

To make rice flour :

Wash raw rice.
Soak rice in water.
Let the rice air dry.
Grind the dried rice into fine flour.

Rice flour can also be made from roasted rice.

The detailed method of preparing rice flour can be found here.

How to identify if the rice has gone bad

Raw rice: Most common method of spoilage for raw rice is pest infestation. If any insects such as bugs and termites are visible, it means that the rice is unsuitable for cooking and must be discarded. Raw rice may also discolor when it is spoiled. Brown rice may suffer lipid oxidation, which leads to the formation of off-odors.
Cooked rice: Cooked rice will smell foul and feel sticky to the touch when it’s gone bad. Rice,once cooked, is perishable. The spoilage of boiled rice is found to be associated with the presence of Gram-positive CoccoBacilli. At room temperatures, rice becomes inedible after 29 h due to the development of off-flavors and off-odors (6).

Other FAQs about Rice that you may be interested in.

What can I substitute for cilantro in rice?

How Much Brown Rice is per Person

How long does rice last in the fridge?

Can you live off beans and rice?

Conclusion

In this brief guide, we answered the question, “how to preserve rice” and discussed the different methods of preserving rice. We also discussed the different rice varieties and dishes and how to identify if the rice has gone bad.