Skip to content
HOME / ARTICLES / PLANT-ORIGINATED NATURALLY OCCURRING TOXINS (NOTS) IN FOOD PROCESSING
ARTICLES

Plant-Originated Naturally Occurring Toxins (NOTs) in Food Processing

Introduction to Naturally Occurring Toxins (NOTs)

Among the 300,000 plant species, approximately 2,000 species contain Naturally Occurring Toxins (NOTs), which are considered a chemical hazard in the food industry. When consumed in large quantities, these toxins pose serious health risks. Understanding their impact is crucial for food industry consultants, food technology consulting firms, and food processing consultants.

Chemical Composition of Plant-Based Foods

Intrinsic vs. Extrinsic Components

Plant-derived foods are complex chemical mixtures that fall into two categories:

  • Intrinsic Components: Naturally occurring compounds inherent to plants.
  • Extrinsic Components: Chemicals introduced through external sources such as food additives, pesticides, pollutants, and packaging materials.

Key Intrinsic Components in Plant-Based Foods

  1. Macronutrients and Micronutrients: Proteins, fats, carbohydrates, vitamins, and minerals that define nutritional value.
  2. Anti-Nutrients: Compounds like protease inhibitors and phytates that hinder nutrient absorption.
  3. Inherent Plant Toxicants: Toxic secondary metabolites such as glycoalkaloids and cyanogenic glucosides, which pose health risks.

Understanding Naturally Occurring Toxins (NOTs)

Naturally Occurring Toxins (NOTs) are low molecular weight endogenous toxins secreted by plants as a defense mechanism against predators, insects, microorganisms, or extreme climate conditions. These toxins vary in structure, biological function, and toxicity levels. To date, over 500 types of NOTs have been identified in food products, making their control a priority for food safety consultants and food processing consultants.

Major Plant-Based Naturally Occurring Toxins

1. Glycoalkaloids

  • Found in sprouted and sun-greened potatoes.
  • Unsafe levels result from light exposure during storage.
  • The FDA limit: 20–25 mg/100 g of fresh potatoes.
  • Cooking does not destroy glycoalkaloids, so store potatoes in a dark, cool, dry place.

2. Furocoumarins

  • Act as natural pesticides aiding plant defense.
  • Found in citrus fruits (Rutaceae family), parsnips, parsley, celery, and carrots (Umbelliferae family).
  • Phototoxic and photo-mutagenic properties.
  • The FDA limit: 1.31 mg/day.

3. Hydrogen Cyanide

  • Found in raw cassava, bamboo shoots, and pit fruits.
  • Toxicity results from cyanogenic glycosides breaking down into cyanide.
  • The lethal dose for humans: 0.5-3.5 mg/kg body weight.

4. Lectins

  • Also known as hemagglutinins, these glycoproteins cause RBC agglutination.
  • Found in black beans, soybeans, lima beans, kidney beans, lentils, and grains.
  • Can cause severe stomach pain, vomiting, and diarrhea if consumed raw.
  • Soaking for 5 hours and boiling for 10 minutes neutralizes toxicity.

5. Oxalic Acid

  • Found in rhubarb leaves.
  • Symptoms of poisoning: Muscle twitching, cramps, slow heart rate, vomiting, and even coma in severe cases.

6. Cucurbitacins

  • Found in zucchini (courgette) and summer squash.
  • Causes bitter taste, vomiting, stomach cramps, diarrhea, and collapse if consumed in excess.

 

Why This Matters for Food Industry Consultants

Effective control of naturally occurring plant toxins is vital for:

  • Food manufacturing consultants designing safe processing protocols
  • Food consultancy services developing regulatory compliance strategies
  • Food technology consultants creating toxin-removal solutions
  • Consultancy for the food industry ensuring consumer safety and industry compliance

Final Thoughts

Recognizing and managing Naturally Occurring Toxins is essential for anyone involved in the food supply chain. By partnering with expert food consulting firms, businesses can minimize risk and ensure food safety standards are upheld throughout the production cycle.

Frequently asked
What exactly are Naturally Occurring Toxins and why are they treated as a chemical hazard?
Naturally Occurring Toxins (NOTs) are low molecular weight endogenous toxins secreted by plants as a defence mechanism against predators, insects, microorganisms or extreme climate conditions. They vary in structure, biological function and toxicity level. Of roughly 300,000 plant species, about 2,000 contain NOTs, and over 500 types have been identified in food products, so they are classified as a chemical hazard in the food industry.
How do we keep glycoalkaloids in potatoes within limits during storage?
Glycoalkaloids build up in sprouted and sun-greened potatoes, with unsafe levels resulting from light exposure during storage. The FDA limit is 20–25 mg/100 g of fresh potatoes. Cooking does not destroy glycoalkaloids, so process control has to happen upstream: store potatoes in a dark, cool, dry place, and manage sprouting and greening rather than relying on thermal treatment to remove the toxin.
Can beans and pulses be made safe from lectins in processing?
Yes. Lectins, also called hemagglutinins, are glycoproteins that cause red blood cell agglutination and are found in black beans, soybeans, lima beans, kidney beans, lentils and grains. Raw consumption can cause severe stomach pain, vomiting and diarrhoea. Soaking for 5 hours followed by boiling for 10 minutes neutralises the toxicity, so soak-and-boil parameters should be fixed and verified in the process protocol.
Which raw materials carry hydrogen cyanide risk?
Hydrogen cyanide risk arises in raw cassava, bamboo shoots and pit fruits, where cyanogenic glycosides break down into cyanide. The lethal dose for humans is 0.5–3.5 mg/kg body weight. Any line handling these raw materials needs incoming material controls and processing steps aimed specifically at reducing cyanogenic glycoside content before the product moves downstream.
What is the difference between intrinsic and extrinsic components in plant-based foods?
Plant-derived foods are complex chemical mixtures. Intrinsic components are naturally occurring compounds inherent to the plant, including macronutrients and micronutrients such as proteins, fats, carbohydrates, vitamins and minerals, anti-nutrients like protease inhibitors and phytates, and inherent plant toxicants such as glycoalkaloids and cyanogenic glucosides. Extrinsic components are chemicals introduced externally through food additives, pesticides, pollutants and packaging materials.
Are there regulatory limits we must design against for furocoumarins?
Yes. Furocoumarins act as natural pesticides aiding plant defence and are found in citrus fruits of the Rutaceae family and in parsnips, parsley, celery and carrots of the Umbelliferae family. They have phototoxic and photo-mutagenic properties. The FDA limit is 1.31 mg/day, which should be factored into recipe formulation and raw material selection for products using these crops.
CITE THIS

PMG Engineering. (2020). Plant-Originated Naturally Occurring Toxins (NOTs) in Food Processing. PMG Engineering. https://pmg.engineering/Article/57/plant-originated-naturally-occurring-toxins-nots-in-food-processing/