Peanuts

Peanuts are technically legumes, belonging to the Fabaceae family, which also includes plants like common beans, lentils, and chickpeas. The peanut plant, Arachis hypogaea, is an annual herbaceous plant that grows up to 50cm tall and wide, with leaves composed of four oval-shaped leaflets. The flowers are small and colorful, and after pollination, the stalk elongates to bury the seed pods underground, a process known as 'geocarpy'. Peanuts are a rich source of proteins, healthy fats, vitamins, and minerals, and they have been domesticated for over 7,500 years, originating in South America[1][2].

In terms of food and beverages, peanuts are incredibly versatile. They are commonly eaten as a snack, either raw, roasted, or boiled. Peanut butter, made from dry-roasted peanuts, is a popular spread used in various dishes, including the classic peanut butter and jelly sandwich, and it is also added to hummus, yogurt, and stir-fries. Peanuts are used in savory dishes to make sauces served with meat and are a key ingredient in many global cuisines, such as in mole sauces and Thai peanut sauce. Additionally, peanut oil is widely used for cooking, and peanuts are processed to produce peanut milk. In bars, salted peanuts are often served with drinks because the salt enhances the taste of the alcohol and increases thirst, prompting patrons to order more drinks[3][4][5].

The process of creating peanuts involves several meticulous steps, starting from the cultivation stage. Peanuts are planted in soft, well-worked soil, typically between November and January, just a few centimeters below the surface[1]. After the peanuts mature, they are harvested and undergo a pre-cleaning process to remove foreign materials such as dirt, rocks, and sticks. This is followed by drying, either on the farm or at the factory, using drying silos that blow hot and dry air through the peanuts to reduce moisture and prevent mold[1].

Once dried, the peanuts are transported to a processing plant where they are shelled. The shelling process involves several stages, including the removal of sand, dirt, rocks, and other foreign materials using sieves, gravity separators, and aspiration. The shells are then smashed off, and the loosened shells are sucked away by a fan. The shelled peanuts are further cleaned and graded by size using screens, shakers, rollers, color sorters, X-ray machines, and magnets to ensure quality and purity[1][2].

After grading, the peanuts can be either sold as raw product or sent to the blanching plant. Blanching involves running the peanuts through a low-temperature roaster/dryer to make the skin easy to remove, followed by passing them over abrasive rollers that strip away the skins. The blanched peanuts are then sorted using color sorters and X-ray machines to remove any unblanched or foreign material. Finally, they are packed into bulk bags or smaller packs after passing through metal detectors[3][1].

Safety Profile for Human Consumption of Peanuts

Peanuts can be a nutritious and healthy addition to the diet when consumed in moderation, but they also come with several safety considerations. One of the most significant concerns is the risk of peanut allergy, which can cause symptoms ranging from mild reactions like itchy hives and nausea to severe, life-threatening anaphylaxis. Even for those not allergic, consuming too many peanuts can lead to digestive problems such as diarrhea, belly cramps, and vomiting. Additionally, peanuts are high in calories, with a single serving of dry roasted peanuts containing about 180 calories, making moderation crucial to avoid weight gain. It is recommended to limit daily consumption to about 1 ounce or 35 peanuts. Furthermore, some peanut products may contain added salt and sugar, which should be monitored by reading labels carefully[1].

Potential Contamination Risks

Peanuts are susceptible to various contamination risks that can impact their safety for human consumption. One of the most critical risks is the contamination by harmful pathogens such as Salmonella and the fungus Aspergillus flavus, which can produce aflatoxins. Aflatoxins can cause acute symptoms like vomiting, abdominal pain, and long-term health issues such as liver cancer. The risk of aflatoxin contamination is higher under conditions of water stress, high temperatures, and poor crop management[2]. Additionally, peanuts can be contaminated with heavy metals like mercury, cadmium, lead, and arsenic, which can accumulate in the crop due to environmental factors and have severe health implications, including kidney damage, nervous system damage, and increased risk of certain cancers[3][2]. Pesticides and herbicides used in peanut cultivation also pose a risk if not applied according to regulatory standards, potentially leaving residues on the peanuts that can be harmful to consumers[2]. Regular monitoring and adherence to safety guidelines are essential to mitigate these contamination risks.