Bulk Lecithin is used in various fields such as food, medicine and cosmetics. The phospholipid components contained in its structure play an important role in human health. In particular, it is involved in cell membrane construction, nervous system maintenance, and lipid metabolism. Although lecithin shows relative stability in its chemical structure, prolonged exposure to air may cause many unfavourable changes. Oxygen and humidity in the air can, under certain conditions, cause lecithin to break down, impairing its quality and function. The length of time lecithin can be stored after opening is affected by many factors. Generally speaking, it can be stored for about 1-2 months if properly preserved, but the exact length of time varies depending on the type of product, preservation conditions, etc. The following is an overview of how lecithin can be stored.
Basic properties and structural stability of lecithin
Lecithin is a kind of phospholipid. It contains unsaturated fatty acids and phosphate in its chemical structure. It is usually amphiphilic. It acts as a good emulsifier in oil-water mixing systems. Lecithin behaves as a more stable substance in air. However, it is susceptible to oxidation due to the unsaturated fatty acids in its structure. This property can affect the preservation and stability of lecithin.
The oxidative stability of bulk Lecithin is strongly influenced by its unsaturated fatty acid chains. When exposed to air, the unsaturated bonds of lecithin react readily with oxygen to form peroxides and other oxidation products. This oxidation phenomenon gradually leads to the deterioration of lecithin and loss of function. In addition, humidity in the air is also one of the key factors leading to lecithin deterioration. In a humid environment, molecules of lecithin may absorb water and undergo hydrolysis. This ultimately generates free fatty acids and other by-products that exacerbate the chemical instability of lecithin.
EEffects Of Prolonged Air Exposure On Lecithin
● Oxidation
The unsaturated fatty acid chains in lecithin undergo oxidation in air. Oxidation is especially likely to occur at higher temperatures. Oxidation leads to breakage of the fatty acid chains and changes in the chemical structure, resulting in a gradual decrease in the activity of lecithin. The peroxides and other by-products resulting from oxidation not only affect the nutritional composition of lecithin but may also alter its organoleptic properties such as colour and odour. This further affects its function as a food additive or pharmaceutical excipient.
● Hydrolysis
In addition to oxidation, humidity in the air can also adversely affect lecithin. When exposed to high humidity for long periods, lecithin molecules may absorb water and undergo hydrolysis. Hydrolysis results in the splitting of phosphate groups in the lecithin structure to form lecithinylinositol, free fatty acids and other small molecules, which in turn disrupts its emulsification and hydrophilicity. Hydrolysis usually occurs in environments with high humidity and temperature fluctuations. Keeping lecithin in dry storage is therefore essential to minimise the occurrence of hydrolysis.
● Changes in crystalline properties
The crystalline nature of lecithin may change during prolonged exposure to air. Particularly in environments where temperature and humidity are unstable, changes in the molecular structure of lecithin can affect its crystalline form. This alters its properties such as solubility, emulsification and dispersion. For example, when the temperature changes dramatically, lecithin molecules rearrange themselves and may form new crystalline forms. These structural changes may affect the performance and effectiveness of lecithin in applications.
● Deterioration Reactions
Prolonged exposure of bulk lecithin to air can also lead to deterioration. Deterioration is not just a superimposed effect of oxidation and hydrolysis, but may also be the result of a combination of other chemical and physical changes. Under inappropriate storage conditions, lecithin may gradually lose its nutritional value, organoleptic properties and applied functions. Once this deterioration occurs, it can make it difficult for lecithin to continue to be used in demanding food, pharmaceutical or cosmetic production. Therefore, how to extend the shelf life of lecithin and prevent its deterioration is an important issue in storage and use.
Methods to maintain the stability of lecithin
In order to maintain the stability of lecithin in the air, especially in laboratory and industrial production, it is necessary to take appropriate protective measures.
● Avoiding oxygen exposure
To minimise the occurrence of oxidation reactions, measures can be taken to isolate lecithin from oxygen. In the laboratory, lecithin manipulation is usually carried out using inert gases such as nitrogen to minimise exposure to oxygen. Nitrogen effectively isolates oxygen and prevents oxidation of lecithin molecules, thus prolonging their stability. In addition, the use of vacuum packaging technology during industrial production is also an effective way to extend the shelf life of lecithin by reducing the amount of oxygen inside the package and inhibiting the occurrence of oxidative reactions.
● Appropriate storage conditions
Storage temperature and humidity of lecithin have a significant effect on its stability. Generally, it is recommended to store lecithin in a cool, dry environment to minimise the effects of heat and humidity on its stability. Ideal storage conditions can be a dry environment with a temperature below 25°C and humidity below 40%. This can effectively inhibit the occurrence of hydrolysis reactions. In addition, try to avoid frequent fluctuations in temperature and humidity, which may cause changes in the structure and crystalline form of lecithin.
Judgement of deterioration
● Appearance:
Normal lecithin powder, bulk Lecithin granules or lecithin bulk soft capsules are of uniform colour without obvious discolouration. If it is found to be darkened, yellowed or with black spots, etc., it is likely that it has been spoiled and should not be consumed any more.
● Odour:
Fresh lecithin has a slight soya odour or no odour. If there is a pungent, harry smell and other odours, it indicates that lecithin has been oxidised and rancid. And its nutrients and quality have been seriously affected, so it can no longer be used.
● Texture:
Granular lecithin should be kept loose and dry without lumps. If there are lumps, sticking or softening, etc., the bulk lecithin may have absorbed too much water or has deteriorated and is not recommended for consumption.
Recommendations for the application of lecithin
Due to the various sensitivities of lecithin, users are advised to strictly control its storage environment in practical applications. For example, in food production, care should be taken to minimise exposure to air to avoid oxidative deterioration of lecithin. In the pharmaceutical field, it should be ensured to be in a dry, low-oxygen state before use to enhance its biological activity and efficacy. In cosmetics, the storage environment for lecithin requires a higher degree of stability. Oxidation of lecithin is particularly problematic in emulsions containing high oil content.
Although lecithin is relatively stable, prolonged exposure to air can lead to oxidation, hydrolysis, changes in crystalline properties and deterioration. Oxygen and moisture in the air are the main factors responsible for the destabilisation of lecithin, so appropriate protective measures should be taken during storage and application. Guanjie Biotech is a bulk lecithin supplier. our lecithin bulk powder, bulk lecithin liquid and lecithin wax are stored in proper situations. If you need to buy lecithin bulk products, welcome to enquire: info@gybiotech.com.
