Why is honey, royal jelly and propolis grading important?
The quality of honeybee products produced by bees can be different due to great dependence on production environment, weather conditions, type of collection and storage.
Therefore, the best method to determine the quality of them (grading) is to perform control based on specific tests.
Bee Products Grading
| Honey Grades | A (1-50) | Very good and excellent quality |
| B (1-50) | Acceptable and general quality | |
| C (1-50) | Poor quality |
Honey grading and the reasons for choosing each test to determination of honey quality |
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| Test | Unit | Limit | Explanation |
| Polyphenols | g/100g | 0.03-0.1 (Samples greater than 0.1 are of higher quality) | Polyphenols or active compounds are mainly collected from nectar and bee’s living environment and added to honey. This factor can have a great impact on determining the quality of honey. Therefore, their type and quantity in honey can show the quality of collected nectar and plant diversity of the region. Some of laboratories use this factor and its amount in honey to determine the quality and performance of honey. Honey’s polyphenolic compounds include flavonoids, antioxidants and phenolic derivatives. The amount of polyphenol in honey has been reported in different amounts between 60-460 micrograms per 100 grams of honey. But in Iranian honeys, this number is on average between 30-100 mg per 100 grams.ols |
| Amylase | Unit/g | 10-100 (Samples greater than 0.1 are of higher quality) | The first enzyme that is evaluated as the most important enzyme for measuring honey quality is amylase or diastase. This enzyme is produced by bees and added to honey. There is almost no specific document for the specific cause and function of this enzyme in honey, but due to its importance as a biological factor in honey, it is always considered, so its activity in honey is of great importance. Compared to other enzymes in honey, diastase has the longest lifespan, which is nearly 2 years. Any reduction or absence of this enzyme in honey can be a sign of low honey quality or its destruction and inactivation by storage conditions or heat during the packaging process and so on. |
| Glucose oxidase | Unit/g | 0-10 (For typical samples) | Glucose oxidase is one of the secreted enzymes of honey bees, which causes the antibacterial effect of honey by hydrolyzing glucose into gluconic acid and hydrogen peroxide. Some honeys have more activity for the gluconic acid. This enzyme is highly sensitive to inactivation in the vicinity of heat, direct light, or energy released in microwaves. Gluconic acid is the main acid in honey and it is usually more than the acidity of honey related to this substance. |
| Reducing sugar | g/100g | >65 | More than 15 types of sugars have been identified in honey, some of them are reducing sugars. These sugars are either brought directly from nectar or processed and produced by bees from other sugars. But more than 95% of reducing sugars are mainly fructose and glucose. |
| Fructose/glucose ration | Ratio | >65 | This calculation and ratio can indicate the establishment of sugar balance in honey that is brought from nectar or produced by bees, and therefore the induction of this ratio indicates the amount of fructose in honey. |
| Sucrose | g/100g | <5 | Sucrose is one of the disaccharide sugars in honey, which can be present in honey in two natural or synthetic forms. Based on the studies of the last two decades, the idea that sucrose is the most disaccharide in honey has been changed and it has been determined that maltose, which is a disaccharide sugar and reducing sugar, can have a higher proportion in natural honey. Bees can produce different enzymes, including invertase, to reduce sucrose in honey and bring this sugar to a balanced ratio in honey. |
| Fructose | g/100g | >5 | Fructose, as the most monosaccharide sugar in honey is always an effective factor in honey evaluation. Of course, if this sugar is produced naturally from nectar or by bees, it can certainly be different from fructose that is used in the industry. |
| Glucose | g/100g | 20-35 | Glucose is a monosaccharide sugar as sweetener in honey after fructose. This sugar can be brought from the environment or from the conversion of sugars in honey (conversion of sucrose into fructose and glucose by invertase). |
| Hydroxymethylfurfural (HMF) | mg/kg (ppm) | Maximum 40 (temperate areas)
Maximum 80 (tropical areas) |
Hydroxymethylfurfural (HMF) is an indicator regarding the effect of storage or processing temperature. This factor is also very important in honey, which is caused by high temperature. The reason for the toxicity of this substance is the effect on the activity of cells and intracellular signals. This substance can be a precursor of acrylamide, both of which are reported as toxic and carcinogenic compounds. Of course, the reported LD100 for HMF is about 37 grams per kilogram, which is much less than the amount found in conventional honey. |
| Propolis Grades | A | Useful for pharmaceutical applications. |
| B | Useful for supplement applications. | |
| C | Useful for food additive and cosmetics applications. |
| Royal jelly Grades | A (1-50) | Very good and excellent quality |
| B (1-50) | Acceptable and general quality | |
| C (1-50) | Poor quality |
Royal jelly (RJ) is a nutrient-rich secretion produced by the hypopharyngeal and mandibular glands of nurse honey bees, primarily Apis mellifera. It is used to feed developing larvae and is supplied throughout larval development to queen-destined larvae. Royal jelly is therefore important for larval growth, caste differentiation, queen development, and the maintenance of the adult queen.
From a biochemical perspective, royal jelly contains several major groups of compounds:
- Nutritional components: water, proteins, peptides, amino acids, carbohydrates, lipids, vitamins, and minerals.
- Bioactive compounds: major royal jelly proteins (MRJPs), characteristic fatty acids such as 10-hydroxy-2-decenoic acid (10-HDA), antimicrobial peptides, phenolic compounds, and other biologically active molecules.
- Enzymes: including glucose oxidase and several reported protease-like activities, although the evidence for individual enzymes varies.
- Minor constituents: nucleotides, organic acids, sterols, and other compounds whose concentrations depend on the sample and analytical method.
The composition of royal jelly varies with the age and physiological state of nurse bees, larval age, season, geographical origin, colony nutrition, harvesting time, and storage conditions. Consequently, the values presented below should be interpreted as approximate ranges reported in scientific literature rather than fixed specifications for every sample.
General Nutritional and Chemical Composition
The following table summarizes the approximate composition of fresh royal jelly.
| Component | Approximate concentration in fresh royal jelly | Main constituents |
| Water | 60–70% | Water |
| Proteins | 9–18% | MRJPs, glycoproteins, and other proteins |
| Carbohydrates | 7–18% | Glucose, fructose, sucrose, and minor sugars |
| Lipids | 3–8% | Free fatty acids, hydroxy fatty acids, phospholipids, and sterols |
| Minerals and ash | Approximately 0.8–3% | Potassium, sodium, calcium, magnesium, phosphorus, iron, and zinc |
| Vitamins | Variable, generally low concentrations | Mainly B-group vitamins |
| Other bioactive compounds | Variable | Phenolics, flavonoids, nucleotides, enzymes, and peptides |
These ranges are compiled from reviews of royal jelly composition. They vary according to analytical methods, sample origin, and whether the material is fresh or dried. The percentages should not be added together as if they represented a single standardized sample.
Scientific distinction: nutritional composition describes what royal jelly contains, whereas biological activity refers to what particular components do under specific experimental or physiological conditions. Detecting a compound does not automatically establish a clinically meaningful or biologically dominant effect.
Overall Scientific Conclusions
The scientific evidence supports the following conclusions:
- Royal jelly is a complex nutritional secretion containing water, proteins, carbohydrates, lipids, amino acids, minerals, vitamins, enzymes, and bioactive compounds.
- Proline is frequently among the predominant free amino acids, but the dominant amino acid in the total protein fraction may differ.
- Glucose oxidase and several protease-like activities have been investigated directly in royal jelly. Evidence for substantial amylase activity is less conclusive.
- The lipid fraction is characterized by unusual medium-chain hydroxy fatty acids, particularly 10-HDA, which is also an important quality-control marker.
- 10-HDA has demonstrated HDAC-inhibitory activity in experimental research, providing a possible connection with epigenetic regulation. Its independent contribution to queen differentiation in living colonies remains incompletely established.
- Proteins, amino acids, lipids, sterols, and other constituents contribute to the nutritional environment required for larval development. Queen differentiation is a multifactorial process rather than the result of a single nutrient.
- For research and industrial development, the most informative approach is to combine compositional analysis, enzyme-specific activity measurements, protein characterization, and controlled biological studies.
Royal jelly should be studied as an integrated biochemical system. Its biological properties cannot be fully explained by 10-HDA, proline, MRJP proteins, or any other individual component in isolation.
