A Review on the Potential of Organic Preservatives in the Preservation of Grains

Department of Chemistry, Centre for Food Technology and Research, Benue State University, Makurdi, Benue State, Nigeria

*Corresponding author: Nguekwagh Gabriel Aondover, Department of Chemistry, Centre for Food Technology and Research, Benue State University, Makurdi, Benue State, Nigeria, Phone: +234 808 774 6723, E-mail: [email protected]

Received Date: November 27, 2025 Publication Date: April 11, 2026

Citation: Aondover NG, et al. (2026). A Review on the Potential of Organic Preservatives in the Preservation of Grains. Nutraceutical Res. 5(1):23.

Copyright: Aondover NG, et al. © (2026).

ABSTRACT

The goal of agricultural produce preservation is to minimise post-harvest losses while maintaining food security. Grains are essential food items that are consumed by people all over the world. However, their storage and long term preservation are severely hampered by postharvest losses brought on by microbial infection, insect infestation, and environmental conditions. Synthetic chemical preservatives have historically been used to reduce these losses, but growing interest in safer, environmentally friendly substitutes is a result of the risks they pose to human health and the environment. Significant antibacterial, antifungal, and antioxidant qualities have been shown by organic preservatives, which are made from natural or organic sources like plants, microbes, and animal based products. Typical examples include plant extracts from garlic and ginger, microbiological agents like bacteriocins, and essential oils from clove, thyme, and neem. These compounds improve the safety and shelf life of grains that are stored in addition to preventing the growth of spoilage organisms. Organic preservatives provide a number of several benefits over their synthetic counterparts, such as low toxicity, biodegradability, and consumer acceptability. In regulating storage pests and spoilage fungi in grains including maize, rice, wheat, and sorghum, organic or natural preservatives can be useful, according to the results of numerous scientific studies highlighted in this study. Their widespread acceptance is still constrained, nevertheless, by problems with cost, availability, standardisation, and consistent efficacy in various environmental settings.

Keywords: Cereal Grains, Food Preservation, Organic (Natural) Preservatives, Chemical Preservatives, Post-Harvest Losses.

INTRODUCTION

To extend the shelf life of foods like grains, fruits, vegetables, prepared foods, cosmetics, and medications, as well as to maintain their quality and safety, preservatives which can be synthetic or natural (organic) are added to agricultural produce. They do this by preventing, delaying, or halting microbial contamination, fermentation, acidification, and decomposition. Many meats, such as fish and hams, are still preserved by salting. It is believed that jams and jellies contain a lot of sugar. The Eastern Civilisations of China and India also used spices to preserve their food. To preserve vegetables, pickling them in salt, vinegar, lemon juice or mustard oil was a frequent method. In the early 19th century, canning and pasteurisation changed food preservation; irradiation, filtration, and addition are examples of modern sterilisation methods [1]. Enhancing food safety and quality is essential. Since the dawn of time, humans have enhanced their diet and hunting methods, tamed plants and animals, preserved food physically, and added molecules to food to alter its flavour or prolong its shelf life [2]. Over time, many ingredients have played vital roles in a wide range of cuisines, providing an inexpensive, nutrient-dense, delicious, colourful, and safe food supply. Food additives and technological improvements have also played important roles. Their use in the food industry is essential because it makes it possible to reduce loss, improve quality, extend shelf life, develop novel formulas, and standardize all of which contribute to meeting the market's ever-increasing demands [3]. Since food preservation ensures that food products are constantly safe and edible, it is a crucial part of the food industry. Synthetic and natural (organic) preservatives have been developed and enhanced along with a variety of preservation methods, greatly increasing the shelf life of food products. Several methods, such as heating, chilling, salting, drying, and synthetic chemicals, are used to keep food safe from rotting bacteria and extend its shelf life [4]. Among the first methods for food preservation and spoiling prevention that are frequently used are chemical preservatives. The growth of bacteria and fungus that can contaminate food is inhibited by chemical preservatives. Concern over the possible health dangers of chemical preservatives is growing, despite the fact that they have effectively stopped microbial development and extended the shelf life of food products [5]. Chemically synthesised preservatives are prohibited due to their potential carcinogenicity, even though they have strong antibacterial activity. It is now more crucial than ever to find safe, effective, and natural or organic food preservatives that can protect against chronic illnesses and improve food product safety for decades. Reviewing the potential of natural (organic) preservatives in the preservation of cereal grains is the aim of this research.

LITERATURE REVIEW

Cereals

One of the most significant agricultural products in the world, cereals are used as the primary ingredient in animal feed and as nourishment for humans. Prehistoric agriculture development was closely linked to the domestication of cereal grains, and most civilisations have relied on cereals for the majority of their food supply since they were first cultivated [6]. Cereal grains make up almost 60% of the world's cultivated land and are the most widely consumed food group [7]. Over the past 50 years, global cereal output and yield have expanded to satisfy the demands of a growing global population. Maize, rice, wheat, barley, sorghum, millet, oats, and rye are the main kinds of cereal grains [8]. The air, dust, soil, water, insects, rodents, birds, animals, germs, people, storage and shipping containers, and handling and processing equipment are the main environmental causes of grain contamination. Although microbiological contamination accounts for the majority of contamination, heavy metals and industrial pollutants also contribute. Mycotoxins, or secondary metabolites made by fungi that can grow on grain, are among the most harmful substances found in a variety of food products [9]. Certain moulds have the ability to produce toxic mycotoxins, which could seriously endanger consumers' health. Moulds and mycotoxins are thought to cause 5-30% of cereal grain losses during storage, whereas insects and rodents cause 5% and 2% of losses, respectively. The average yield loss for industrialised and developing nations is 1% and 10%–30%. Grain has a great diversity of possible spoilage organisms in its microbial load, which varies depending on the climate during growing. Transport-related post-harvest contamination is also a possibility. Bacteria, yeasts, and filamentous fungus from numerous genera make up this microbial burden. Various factors influence the activity of these microorganisms during storage and, consequently, the crop's shelf life. Water availability during storage and moisture content are two of the most important factors. Since grains have a water activity of less than 0.70 and low moisture contents of 12-13%, they are typically kept using modern techniques such osmosis, salt, sugar, oil, sun drying etc.

Organic vs Inorganic Preservatives

Organic preservatives

Organic preservatives, also known as natural preservatives, are substances that come from plants, microorganisms, or animals and aid in delaying oxidation, preventing microbial growth, and preserving food items without the use of artificial chemicals. Organic preservative research has accelerated thanks to the growing demand for clean-label goods and growing health concerns about chemical additives [10]. Bioactive substances with potent antibacterial, antifungal, antioxidant, and insect-repelling qualities, including phenolics, flavonoids, terpenoids, and essential oils, are abundant in these natural agents.  Organic preservatives are used in cereal grain preservation to stop the growth of mould, insect infestation, rancidity, and mycotoxin production all of which lead to large postharvest losses. Numerous studies have demonstrated the efficacy of compounds produced from plants. For example, Aspergillus flavus and Fusarium spp., the main fungi linked to cereal spoiling, have been shown to be strongly inhibited by clove oil (rich in eugenol), neem extract (azadirachtin), and thyme oil (thymol) [11]. Additionally, it has been discovered that these bio-preservatives deter grain beetles and weevils, which are prevalent in the storage of rice and maize [12]. In a comparative investigation, Alabi et al. [13] discovered that extracts of ginger and garlic considerably decreased the fungus load in sorghum that was held for more than six months, surpassing even certain commercial chemical preservatives. In a similar vein, Adekunle and Essien [14] found that a mixture of cinnamon extract and lemongrass oil increased the shelf life of wheat that was stored by lowering the amounts of free fatty acids and mould. Organic preservatives are environmentally benign, biodegradable, and generally recognised as safe (GRAS), in contrast to synthetic preservatives [15]. But issues like instability, limited shelf life, and inconsistent efficacy across storage settings still exist [16]. In order to improve their stability and controlled release, more stable formulations have been developed, such as those involving microencapsulation and emulsification. Blending several plant extracts to provide synergistic effects has been the subject of recent advances. Similar evaluations of the application of fermented bacteriocins produced from Lactobacillus in maize storage were conducted by Chikere and Odu [17], who found notable antibacterial activity without compromising grain quality. When it comes to grain preservation, organic preservatives present viable substitutes for synthetic ones. Particularly in underdeveloped nations, better, more economical, and sustainable solutions for food security may result from further research and development of these bioactive compounds.

Synthetic preservatives

Synthetic preservatives are artificial chemical substances that are added to food and agricultural products to stop oxidation, microbiological spoiling, and quality deterioration while they are being stored. Because they are readily available, inexpensive, and highly potent, they have long been used extensively in cereal grain preservation [18]. These preservatives are essential for preserving the safety and shelf life of grains such barley, sorghum, rice, wheat, and maize. Sorbic acid, sodium benzoate, calcium propionate, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and sulphites are typical examples. These substances prevent the growth of bacteria that cause spoiling, including Aspergillus, Penicillium, Fusarium, and insects that infest grains [19]. Calcium propionate is frequently used in bread and cereal goods to stop mould growth and increase shelf life by up to 60 days [20]. Another popular preservative, sodium metabisulfite, works well to keep bacteria and fungus in milled rice and maize under control while they are being stored [21]. But because of their possible health hazards, such as cumulative toxicity, allergic responses, and carcinogenicity, synthetic preservatives have drawn more attention [22]. Numerous studies have shown that prolonged use of synthetic chemicals can cause negative side effects as dermatitis, respiratory irritation, and even disturbance of the gut microbiota [23]. In order to reduce these hazards, some nations have set maximum allowed limits (MAL) on the amount of specific preservatives in food. For example, BHT and BHA are being reviewed by the U.S. FDA and are regulated in certain food products in the European Union [24]. The global grain storage market is nevertheless dominated by synthetic preservatives despite these reservations because of their affordability, extended shelf life, and broad-spectrum activity.  According to Guan et al. [25] BHA storage of wheat produced a mould infestation of less than 2% over 180 days in tropical settings, which was a substantial improvement above untreated controls. However, recent research indicates that an excessive dependence on synthetic preservatives may result in environmental persistence and microbial resistance, which has prompted recommendations for integrated solutions that mix organic agents with lower synthetic dosages [26]. This hybrid strategy has the potential to lower chemical loads without sacrificing effectiveness. Although synthetic preservatives are effective methods for preserving grains, there are legitimate worries about their effects on the environment and human health. To ensure sustainable grain storage, their continuous usage should be governed by stringent regulations, toxicological evaluation, and perhaps supplemented with natural alternatives.

The comparative benefits of organic and synthetic preservatives are displayed is Table 1 [1].

Table 1: Comparative Advantages of Organic vs. Synthetic Preservatives.