The antioxidant capacity of lemon –
Lemon is a worldwide consumed citric with huge antioxidant potential. But do you think you know all about this fruit?
Check our blog if you want to discover lemon’s great potential to solve current problems in a wide range of different fields, from health, to animal nutrition or cosmetics.
Origins and interest:
The true origins of lemon (Citrus limon) are nowadays unknown certainly yet, but the main opinion is that it could come from the northwestern part of India. Nowadays is consumed worldwide. Despite the chemical composition of lemon is well known, daily consumers usually do not know its antimicrobiological or even its antioxidant properties. Nevertheless, in the last decade, the interest in that topic has considerably increased, that is why numerous studies of lemons antioxidant properties have been carried in the last years.
Antioxidant properties:
Antioxidant activity is a foundation of many biological functions, such as anti-cancers, anti-inflammation and anti-aging. Moreover, the prevention of many chronic diseases, such as cancer, diabetes and cardiovascular disease, has been suggested to be associated with the antioxidant activity.
Citrus fruits are rich sources of useful phytochemicals, such as vitamins A, C and E, mineral elements, flavonoids, coumarins, limonoids, carotenoids, pectins, and other compounds. These phytochemicals, consumed through fresh fruits or their derived products, have been suggested to have a wide variety of biological functions including antioxidant, antiinflammation, antimutagenicity, anticarcinogenicity and anti-aging to human health. There are more than 170 antioxidants from Citrus fruits that have been reported in the current literature.
The whole fruit contains a great number of bioactive compounds with antioxidant properties. One of the most important ones are the flavonoids: Citrus lemon fruit has the highest level of eriocitrin in comparison to other Citrus species – as well as important quantities of phenolic acids (ferulic acid or synaptic acid ) which are localized mainly in the juice. Finally the most known is Ascorbic Acid, commonly known as Vitamin C, which highlights as a powerful antioxidant molecule and an effective free radical scavenger.
Due to the high antioxidant power those chemicals have, is interesting to measure the total antioxidant capacity of lemon’s fruit. Sometimes, depending on the research objectives, is necessary to make an extraction. In order to optimize the antioxidants extraction researchers have recently developed a method that combines solid-liquid extraction using ethanol-water solutions, cLC-DAD, and chemometrics.
For the measurement of the antioxidant capacity there are many different tests and techniques. In fact, this lack of a standardized and global method leads to the existing discrepancies between the different methods used, which has led the scientific community to recommend using several of them, to have a more global vision of the oxidative status.
For exmaple, it can be used a β- carotene/linoleic acid bleaching test; however, more used and universal are the DPPH, ABTS or FRAP Antioxidant Capacity tests. All of those techniques to determine the Total Antioxidant Capacity (TAC) work as Electron transfer methods. In this assays the sample is added to a solution that contains an oxidized ion. Then the antioxidants reduce that molecule and a change of color takes place. Finally, the new Absorbance is measured by a spectrophotometer.
Bioquochem offers a wide variety of these assays, as well as a new methodology, the eBQC-LAB, a portable device based on electrochemistry, that allows together with the measurement of the TAC, the differentiation between fast and slow-acting antioxidants.
Lemon’s antioxidants applications and uses
Nowadays a lot of applications has been found for this fruit:
– UV light damage restoration: Researchers have found elevated concentrations of hesperidin in several citric fruits peel, this compound allows high protection levels against UV light. Moreover, It has been demonstrated that lemon flavonoids can increase the activity of catalase and superoxide dismutase while decreasing the levels of interleukins and other necrosis factors.
– Ischemia stroke treatment: Flavonoids contained in lemon’s fruit, increase oxidoreductase enzymes activity in the affected área, while disabling oxidative processes in the affected cells. This is a crucial factor for effective reperfusion and better response.
– Treat acrylamide affected áreas: In the last decades the intake of processed fast food has risen, this implies higher levels of acrylamide ingestión which can lead to several diseased tumors or even hormonal disorders. Researchers have probed that lemon intake can improve TAC levels at an acrylamide damaged área. Moreover, levels of tumoral markers like MDA or TNF-α drop considerably.
– Acne treatment: Lipid peroxidation of sebum creates an adequate environment for Propionibacterium acnes to grow. Nevertheless, lemon’s high ascorbic acid levels prevent that oxidation process, playing an important role as a Propiobacterium acnés grow inhibitor.
– Animal feed supplement as a solution to antioxidants lack in the diet at intensive poultry farms. Different heat or drying treatments applied to feed cause antioxidant compounds destruction. As a consequence of that, many animals suffer from gastrointestinal diseases. It can be found a solution by adding Citrus waste products that contain elevated levels of flavonoid compounds, in particular hesperidin and naringin which can be highly assimilated by poultry.
