Introduction
The olive tree, also known as the “tree of eternity,” is an ancient Asian fruit crop with a documented history of 8000-6000 years. It thrives well in sub-tropical regions, preferring semi-arid, warm conditions. Olives thrive best in well-drained, fertile, deep, loamy soil with an alkaline pH, and can’t tolerate humid conditions.
Olive belongs to family Oleaceae and genus Olea. The tree is evergreen small woody shrub having twisted trunk. The color of leaves and flowers are greyish-white and white respectively.
The fresh olives have bitter taste, therefore they are not consumed fresh. The bitter taste is due to presence of oleuropein. However, the green olives are generally used for table purpose. As the olives are rich in oil, that’s why over 90% are used for extraction of oil. Moreover, olive oil is also used for baking, frying and as salad dressing.
Nutritional Composition
1: Carbohydrate
Among all edible fruits, olives have lower content of carbohydrates. The major sugar is glucose while fructose comes next to glucose. Inositol is also present in trace amount.
2: Protein
Olives have lower amount of protein, less than 1%. But the quality of protein is high due to presence of all essential amino acids. Predominant amino acids are aspartic and glutamic acids.
3: Dietary Fibre
The content of fibre in olives is also quite low but the quality is high in terms of its digestibility.
4: Lipid
Olives are rich source of fats. The predominant fatty acids are oelic acid, palmitic acid and linolenic acid. Pericap of fruit contain 96-98% of oil. However, the seeds also have 2-4g/100g of oil.
5: Phytochemicals
Olive fruit contain more than 30 phenolics. The predominant phenolic alcohols are oleuropein or hydroxytyrosol and p-hydroxyphenylethanol.
6: Vitamins
Olive fruit contain different amino acids including vitamin A, vitamin E, Vitamin B6, Vitamin B3 and tocopherol.
7: Minerals
Olives contain different essential minerals including iron, calcium, potassium, phosphorous, zinc, selenium, and copper. The predominant are zinc, iron and calcium.
Health Benefits
1: Anti-ageing effect
Vitamin B present in olives protect skin from harmful effects of UV radiation, thereby maintaining the smoothness of skin. In addition, hydroxytyrosol guard the skin from damage by ROS.
2: Neuroprotective activity
Phenolic content of olive counteract the neuronal loss by causing inhibition of lipid peroxidation, nitric oxide and prostaglandin E2 production and improving the concentration of glutathione.
3: Body weight
Oleic acid have an important role in maintaining the weight of body.
4: Anti-cancerous activity
Phenolic compounds present in olives especially terpenoids and squalene are important anti carcinogens. Vitamin E also have chemoprotective effect due to its role in radicle scavanging.
5: Anti-microbial activity
Polyphenols in olives possess anti-microbial as well as antifungal activity. These phenolic compounds have inhibitory effects on growth and reproduction of bacteria which are pathogenic. Polyphenols form bonding with bacterial cell membranes and cause the death of cell. Moreover. These polyphenols makes iron unavailable for microbial cells which are essential for their survival. Olive consumption also help in improving gastric health.
6: Anti-inflammatory activity
Olives have anti-inflammatory activity. Oleocanthal is a polyphenol present in olives, responsible for anti-inflammatory activity.
7: Anti-oxidant activity
Olives also have antioxidant activity.
Conclusion
Olive, also known as “ fruit of eternity” is an important fruit having unique nutritious composition. They are rich in fats, mainly the monounsaturated. The cholesterol content in olives ranges from only 1-1.5 percent. They also contain carbohydrates, proteins, dietary fibre, vitamins and minerals. This composition makes olives beneficial for health. They possess anti-oxidant, anti-inflammatory, anti-cancerous and anti-microbial activities. Moreover, they also have neuroprotective and ant-aging effects. The Olives are used for the extraction of the oil.