Lemons have been the primary commercial source of citric acid for many years; this was before the technological development of fermentation-based processes.
Lemon juice can be used to clean surfaces and oily skin.
Half a lemon immersed in salt or bicarbonate is used to polish the metal, more precisely the copper. This is due to the corrosive action of the acid that dissolves the opacification of scratches and abrasions that occur during the cleaning process.
Lemon juice plays a multi-purpose role in kitchen sanitization; it deodorises, degreases, removes bleach stains and disinfects.
Mixed with sodium bicarbonate, lemon juice helps to remove stains from plastic food containers.
Lemon peel oil is also used in many different applications. For example, as a detergent for enamelled wood (that of furniture); in fact, lemon peel oil has a discreet solvent power that facilitates the removal of old surface wax, fingerprints and dirt in general. Lemon oil and orange oil are also used as a non-toxic insecticide treatment.
Half a lemon is used as a finger humidifier, especially by office staff who continuously handle sheets of paper.
Lemon oil is frequently used in aromatherapy. This does not affect the immune system of the human being but can improve the mood.
The acidic pH of lemon juice makes it antibacterial and, to this end, in India is part of the remedies of traditional Ayurveda medicine.
Lemon juice is sometimes used as an acid in educational scientific experiments. In addition, it can be used as a simple invisible ink, highlighted by heat.
Lemon peel for slimming
Some people argue that certain foods such as lemon or grapefruit or green coffee etc. may promote body slimming. Sometimes, these beliefs are based on interesting chemical and biological principles; in other cases, they are real "fairy tales".
For example, in the 90s there were rumours that the acids of certain citrus fruits could facilitate weight loss due to their solvent effect on fats, a real fandonia.
However, as far as lemon is concerned, some researchers have made an interesting discovery. To be clear, the study was carried out on mice and not on humans; this is a very important detail because, while it is true that the two species share a large part of the genetic heritage, it is also true that many pharmacological interactions are completely different between one and the other organism.
In this case, then, it is not the lemon juice, but the extracts of the skin, rich in polyphenols (antioxidant molecules) and with very few organic acids.
The study dates back to 2008 and is entitled "Lemon Polyphenols Suppress Diet-induced Obesity by Up-Regulation of mRNA Levels of the Enzymes Involved in beta-Oxidation in Mouse White Adipose Tissue".
The aim was to evaluate the effect of the polyphenols contained in the lemon peel:
On obesity induced by a diet with a high fat content
On the regulation of genetic expression in lipid metabolism.
The sample consisted of mice, which were divided into three groups and fed for 12 weeks with:
- A low-fat diet (LF)
- A diet rich in fat (HF)
- A high-fat diet supplemented with 0.5% lemon peel polyphenols (LP).
It was found that the group of mice taking the lemon polyphenols underwent a significant reduction in: weight gain, increase in adipose diapers, development of hyperlipemia, development of hyperglycemia and development of insulin resistance.
In the LP group, the lemon peel polyphenol supplement increased the level of mRNA for the proliferation of peroxisome activated receptor-alpha (PPARa) in the liver compared to the LF and HF groups in the liver.
In addition, compared with the LF group but not the HF group, mice with LP increased the level of mRNA for acyl-CoA oxidase (ACO) in the liver and white adipose tissue.
The diet enriched with lemon polyphenols therefore suppressed weight gain and body fat by increasing peroxisomal expression of PPARa and ACO in liver and white adipose tissue.