WHAT IS PASSION FRUIT?

Passiflora is a species of flowering plants. Most of these plants are vines, with a few of them being shrubs or herbs. The fruit that grows on the Passiflora plant is known as the passion fruit.

The scientific name of passion fruit is Passiflora edulis, which is purple in colour. The yellow-coloured variant or form of passion fruit is named Passiflora edulis var. flavicarpa or Passiflora edulis f. flavicarpa.

This fruit is cultivated in those geographical areas where the climate is warm and frost-free.

Description of Passiflora plant

The Passiflora plant is a vine. It rises above the ground by means of tendrils. The leaves are tri-lobed, long, and deep-green. On the leaves, tinges of red and purple are also seen, depending on the variant of the fruit. These leaves are glossy on the upper surface, and dull on the lower surface. The vine grows to a length of about 15 to 20 feet.

Description of Passion Fruit

Passion fruit develops from the passion flower. The fruit has a circular or an oval shape. It is about 7 cm wide. The outer skin (rind) is extremely tough, and possesses a smooth, waxy texture. The rind possesses a thickness of 5 mm, and adheres to a layer of pith having a thickness of about 5 mm, which is white in colour. When the fruit is cut open, membranous sacs are seen which are double-walled and highly aromatic. These sacs are filled with aril (pulp) and juice. Around 200 seeds are present in each fruit. The fruit possesses a rich and musky flavor. When the fruit becomes mature, the outer skin turns purple or yellow in colour.

Based on the exterior appearance of the fruit, the two main variants are -

• Passiflora edulis - This is the purple-coloured variant of the passion fruit (it can also be red-coloured). The red or purple-coloured passion fruit is less acidic, and possesses richer flavor and aroma, as compared to the yellow-coloured variant. Therefore, the juice of the purple-coloured variant is sweeter to taste than the juice of the yellow-coloured variant. Its small size notwithstanding, the red or purple-coloured variant yields around 35% more juice as compared to the yellow-coloured variant. Seeds are black in colour.

• Passiflora edulis var. flavicarpa - This variant is bright yellow in colour. It is bigger in size as compared to the purple-coloured variant, and can be as large as a grapefruit. The yellow-coloured variant has a much higher content of citric acid as compared to the purple-coloured variant. The texture of the rind is glossy. The vine of the Passiflora plant yielding the yellow-coloured variant is stronger than that of the purple-coloured variant. Seeds are brown in colour.

Owing to its rich aroma and flavor, the juice of the passion fruit is often mixed with the juices of other fruits for aroma and flavor enhancement.

Other types of variants have been cultivated by crossing and hybridization. But these variants are highly prone to rotting, and do not yield the same quantity of juice or possess the same kind of aroma, as compared to the naturally-occurring variants.

HEALTH BENEFITS OF PASSION FRUIT

Both variants of passion fruit have numerous health benefits, described as follows -

• Improving digestive and intestinal health - Passion fruit is a rich source of dietary fibre, both soluble as well as insoluble. Insoluble dietary fibre improves bowel movements, and helps in cleaning the digestive system. This prevents digestive disorders such as constipation.

Research has shown that consumption of dietary fibre in a diet completely devoid of dietary fibre improves intestinal health and functioning by enhancing the activity of the enzyme intestinal amylase, which helps in the digestion of carbohydrates.

Consumption of insoluble dietary fibre also helps in lowering the pH and ammonia content of the caecum. A lower caecal ammonia content and pH are highly conducive for the existence of intestinal bacterial flora. These bacteria aid in the process of digestion and, after birth, play a key role in the development of immunity provided by the intestinal mucosal glands. Chances of colonic tumours are also reduced to a great extent as a result of consumption of insoluble dietary fiber.

Research has also shown that dietary fibre sourced from the rind of the yellow-coloured passion fruit may act as protection against diverticular disorders.

• Asthma remedy - Research has shown that the extract of the peel of the purple-coloured passion fruit has been found to reduce symptoms associated with asthma such as wheezing, coughing, and shortness of breath. This peel extract may act as alternative medication so as to reduce the clinical symptoms of asthma.

• Anti-cancer activity - In cell cultures, the juice extract obtained from the yellow-coloured passion fruit displays anti-cancer properties. Passion fruit juice is rich in phytochemicals such as carotenoids and polyphenols, which are responsible for this anti-cancer action.

Research indicates that passion fruit juice is responsible for the induction of the enzyme caspase-3, which is instrumental in carrying out the process of apoptosis or programmed cell death in normal cells. When caspase-3 gets induced in cancerous cells, the cells commit themselves to apoptosis, and get destroyed in the process.

Research shows that the polysaccharide fraction extracted from Passiflora edulis (PFCM) using hot water displays tumour-inhibitory effects on sarcomas in vivo.

• Anti-inflammatory activity - The aqueous and methanolic extracts of the leaves of Passiflora edulis comprise of triterpenoid steroids and saponins. Tannins and flavonoids are also present in the methanolic extract. The anti-inflammatory effect of these extracts was studied in Wistar rats in which oedema had been induced in the left paw using carrageenan. It was found that the methanolic extract showed a reduction in the inflammation at a dosage of 100 mg/kg and the aqueous extract showed a reduction in inflammation at a dosage of 200 mg/kg. It may be concluded that this anti-inflammatory activity is due to the presence of steroids, flavonoids, and other compounds, present in the leaf extracts of Passiflora edulis.

• Antioxidant activity - Passion fruit is a rich source of nutrients such as Vitamin C and beta-carotene, as well as polyphenols such as flavonoids, piceatannol, and scirpusin B, all of which have been found to possess strong antioxidant properties.

Using techniques such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and photochemical analysis, it was found that the ethanolic leaf and stem extract of Passiflora edulis displayed strong antioxidant activity with both assays.

Using quantitative High Performance Thin Layer Chromatography (quantitative HPTLC), it was found that the rind of a healthy, disease-free passion fruit contained a greater amount of isoorientin as compared to the rind of the passion fruit which was infected with Passion fruit Woodiness Virus (PWV). Isoorientin is a flavone compound which possesses antioxidant properties. Therefore, the rind of a disease-free passion fruit can be said to be a rich source of antioxidants.

• Improving cardiac function - Passion fruit is a good source of potassium (348 mg of potassium per 100 grams of fruit). Low potassium levels can affect the functioning of the heart, leading to arrhythmias (or irregular heart beat). Consumption of adequate amount of potassium in the diet is extremely critical for proper functioning of the heart. Also, passion fruit is a completely "cholesterol-free" food. Passion fruit plays a crucial role in maintaining and improving cardiac health.

Antioxidants present in passion fruit improve cardiovascular health by preventing plaque formation and artery blockages due to accumulation of cholesterol and other substances in the blood vessels.

It has been found that the extract of the peel of the purple-coloured passion fruit reduces cardiovascular risk factors in type 2 diabetics. Upon administration of the passion fruit peel extract, there was a reduction in the systolic blood pressure and fasting blood glucose seen in type 2 diabetics.

• Anti-fungal activity - Seeds of Passiflora edulis are a source of Passiflin, a dimeric protein that possesses anti-fungal properties. It has a molecular weight of 67 kDa. It has been found that the growth of fungal mycelia of Rhizoctonia solani (a plant pathogen) can be blocked by Passiflin.

Another anti-fungal peptide has been isolated from the seeds of the passion fruit called Pe-AFP1, having a molecular weight of 5 kDa. Assays performed in vitro suggest that Pe-AFP1 displays an inhibitory effect against various filamentous fungi such as Fusarium oxysporum, Aspergillus fumigatus, and Trichoderma harzianum. However, no inhibitory effects were seen against other fungal species such as Candida albicans, Rhizoctonia solani, and Paracoccidioides brasiliensis.

Passiflin and Pe-AFP1 possess great potential to be further developed as antifungal products, with applications in the fields of medicine, plant biotechnology, and agriculture in the near future.

• Anxiolyitc and Insomnia treatment - The aqueous extract of Passiflora edulis has been shown to possess hypnotic and sedative properties as indicated through research on rodents and humans.

Aerially-growing parts of the Passiflora edulis f. flavicarpa plant were extracted using various solvents such as ethanol, ether, ethyl acetate, water, etc. These extracts were shown to possess anxiolytic and sedative effects on Swiss albino mice using the elevated plus-maze (EPM) and spontaneous activity (SA) assays. Anxiolytic effects were seen at low dosages and sedative effects were displayed at high dosages. Flavonoids and other compounds present in passion fruit can be said to be responsible for these effects.

It has been shown that decocted dried leaves of Passiflora edulis increased sleep in diazepam-induced mice.

• Reduction of iron-deficiency anaemia - Among fruits, passion fruit is one of the best sources of iron (3.78 mg of iron in a serving size of 1 cup). Passion fruit is also a rich source of Vitamin C (70.8 mg of Vitamin C in a serving size of 1 cup). In the diet, when iron is consumed along with Vitamin C, absorption of dietary iron by the body increases to a great extent. Passion fruit is a rich source of both iron and Vitamin C. Therefore, iron-deficiency anaemia can be reduced to a great extent due to the consumption of passion fruit.

• Reduction of osteoarthritis - The peel extract of Passion fruit consumed orally has been found to reduce pain and stiffness associated with osteoarthritis of the knee in patients suffering from this disorder. This can be attributed to the presence of antioxidants in the passion fruit peel which possess anti-inflammatory properties.

• Improved vision & immunity - Passion fruit is a rich source of Vitamin A and Vitamin C. Vitamin A plays an important role in the visual cycle by producing rhodopsin (or visual purple), which aids in dim light vision. Vitamin C increases immunity against illnesses, and also helps in dietary iron absorption. Therefore, dietary consumption of passion fruit improves vision and immunity.



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