Passion to Profession: A review of Passion fruit Processing

Passion fruit (Passiflora edulis) is a nutritious tropical fruit that belongs to the family Passifloraceae. The purple passion fruit is local from southern Brazil through Paraguay to northern Argentina. For a long time, India has appreciated a moderate collection of purple passion fruit in the Nilgiris in the south and various parts of north India. The Passion fruit has a good amount of antioxidants, flavonoids, anti-inflammatory, anti-bacterial, anti-fungal, and antiaging properties. This fruit has huge economic importance as all the parts of this fruit (seed, peel, flower, pulp) are rich in medicinal and therapeutic properties. The fruit is a fantastic wellspring of dietary fiber, nutrients, Vitamin C, and Vitamin A. Being a decent laxative, it likewise secures the colon mucosa by diminishing openness time to harmful substances in the colon and clearing off the malignant growth causing poisonous substances from the colon. Passion fruit has several medical advantages and hence requires diverse processing and preservation methods. Here we are going to review a portion of these methods.

Passiflora quadrangular is L. : It is commonly known as Giant granadilla and Barba dine and native of tropical South America. Widely distributed in tropics where it is grown for fruits. xii.
Passiflora tripartite (Juss) Poir: It is native of Ecuador and cultivated for fruits. It is commonly known as Tasco.

Varieties
Passion fruit has two distinct forms , the standard yellow (Passiflora edulis f. flaavicarpa Deg.) and the purple (Passiflora edulis f. edulis). The yellow are more acidic and less starchy while the purple are less acidic and more starchy. Both two form viz., purple passion fruit (P. edulis) and yellow passion fruit (P. edulis var.flavicarpa) are of commercial importance. The hybrids of these two have also been developed for cultivation. The most popular passion fruit cultivated for their edible fruits have been discovered, which can vary in size and color. These most commonly available varieties are.

Purple Passion Fruit
Vines are productive at higher elevations. Fruits are 4-5 cm in diameter, deep purple when ripe each weighing 35-45 g. The juice content varies from 31-35 per cent. The variety is known for its quality in terms of flavor and nutrient content. Seeds are black in color. The variety is susceptible to leaf spot, collar rot, attack by trips and nematodes. The juice content of the fruit varies from 35-38% and has a better flavor and aroma as fresh, canned and frozen juice or pulp than the yellow one. The seeds are black in color. The commercial cultivars of the purple form are Ouropretano, Muico, Peroba, Pintado etc. in South America. In India, there is no standard cultivar. The local lines such as Ooty Purple, Coorg Purple Moodabidri Purple, Thrissur Purple, Cher punji Purple, Thalipramba Purple, Ambalavaval Purple etc. are cultivated by the growers [12].

Giant Granadilla
The hybrids of yellow and purple form have been developed for combining the desirable characteristics of both the forms of passion fruits. Several hybrid varieties have been developed in Brazil, Australia ,south Africa, etc. In India, a hybrid "Kaverii" of purple and yellow form was developed at Central horticultural Experimental Station, Chattily, Coorg, Karnataka. This variety is a high yielding hybrid developed from Central Horticultural Experiment Station, Chattily in 1986. This is a cross between purple and yellow varieties. The fruits are ovoid to round and purple dotted in color. The average fruit weight ranges between 90-100 g. Each plant bears 40-60 fruits per annum. The average yield of a grown up orchard is around 60-70 tons per year. Its fruit yield is around 200 tons per ha over a three-year cropping period. Fruits contain 25-30 per cent juice, 11.5-12.0 percent sugars and 3.0-3.5 mg citric acid/100ml of Juice. This is tolerant to Alternaria leaf spot, Fusarium collar rot and nematodes. This variety is popular in Karnataka, Kerala, Tamilnadu and North Eastern States.

Importance of Passion Fruit
Passion fruit is a good source of nutrients, especially fiber, vitamin C and vitamin A. Raw passion fruit is 73% water, 22% carbohydrates, 2% protein and 0.7% fat (table) [13]. In a 100 gram amount, fresh passion fruit supplies 97 calories, and contains 36% of the Daily Value (DV) of vitamin C, 42% dietary fiber, B vitamins riboflavin (11% DV) and niacin (10% DV), 12% iron and 10% phosphorus (table) [14]. It's also rich in beneficial plant compounds, including carotenoids and polyphenols [15]. Passion fruit is a high acid food (pH~ 3.2) due to the predominance of two acids, citric and malic acid. It is also rich in minerals like K, P, Ca, Fe, Na, Mg, S, Cl and protein (Table 1) [16]. Passion fruit is also known as a nutritionally dense fruit, based on the level of nutrients present. The high amount of vitamin A, C and B2 in passion fruit is the primary driver of such nutritional scores. Nutritional composition of passion fruit per 100g is enumerate in Table 1 [17]. The fruit has a high content in nutraceuticals, as phenolic acids, where anthocyanin's and flavonoids are the majoritarian compounds of this group; carotenoids and β-carotene appear to be the principal component, with consequently increased pro vitamin A activity. These nutraceutical compounds have biological activities in the health, protective effect against degenerative and chronic diseases and act as mutagenesis and carcinogenesis inhibitors. Also, these compounds have been associated with antiviral, anti-allergic, antiplatelet and anti-inflammatory activities [18] [19] [20] [21].
The presence of pythoconstituents like Alkaloids, phenols, glycosylic flavonoids and cyanogenic compounds make this fruit beneficial for the treatment and prevention of diseases such as anxiety, diabetic, cardiovascular diseases, sedative, convulsive, asthma, osteoarthritis and cancer. In several preclinical experiments, P. edulis extracts have exhibited potential effects for the treatment of inflammation, pain, and insomnia as well as for attention-deficit hyperactivity disorder, hypertension, and cancer. The juices extracted from pulps of P. edulis, P. maliformis and P. quadrangular is possessed a rich source of fiber, protein and carbohydrate content. A cup of 247 mL Passiflora fruit juices provided ~24% of K, 60-80% Mg, >80% P and 90% Fe of recommended dietary allowance of minerals [22]. Several mechanisms, including the inhibition of proinflammatory cytokines, enzyme (myeloperoxidase) and mediators (bradykinin, histamine, substance P, nitric oxide) release and/or action, appear to account for P. edulis actions. The leaves and stems of P. edulis have shown anti nociceptive, antitumor, antimicrobial, and antioxidant activities. This plant-based, traditional medicine system still acquires an important place in the health care system. The pulp of the fruit acts as a stimulant and tonic. Many practitioners actually use P. edulis extracts alone or in combination with other herbal medicines to treat depression and insomnia in a wide range of patients [23] [24].

Post-Harvest Management of Passion Fruit
Passion fruit has various little hard seeds which makes it troublesome as a table leafy foods its business significance exists in preparing, processing and value addition. There is an immense interest for blended fruit juices in Indian just as abroad business sectors, passion fruit juice or its mix with different fruits and vegetables have an extraordinary potential to drift in the market. The first harvesting is done after 1-2 years of planting and a healthy plant produces about 150-180 fruits per year. Passion fruit is manually picked by chopping or clipping the fruit from the vine. To help avoid water loss and fungal growth, a small piece of stem, around 4 cm (1.5 inches) in length, should be left attached to the fruit [26]. The storage of purple passion fruit at 10±2°C and 75% RH is recommended for the three maturity stages tested because of the absence of chilling injury and better keeping quality during the shelf life period [27].

Cleaning
Depending upon the volume of fruit to be cleaned, the cycle should be possible manually or automatically. Automatic operations utilize overhead splash wash framework to clean to the fruit. To evade the spread of disease, the water utilized for washing should be consistently cleaned by keeping a 150 ppm sodium hypochlorite concentration and a water pH of 6.5. Subsequent to washing, the fruit should be air dried prior to grading or sorting.

Grading/Sorting
The Pre-sorting of fruit should be carried out in the field, and additional grading performed at the packing area to remove fruit that does not meet market requirements. The fundamental qualities utilized in grading passion fruit are size, skin color and uniformity, shape, firmness, and the amount of surface blemishes. Three different grades have been established by the National Bureau of Standards for domestic marketing of passion fruit (Grade 1, Grade 2, and Grade 3).

Grade 1
Fruits are firm with shiny appearance; indication of wilting will be absent, free from visible evidence of insects, disease, and surface imperfections. These fruit types are most superior.

Grade 2
These passion fruits should be of acceptable quality, although 10% of the fruit in this grade may be soft or give indications of withering, and won't have a shiny appearance

Grade 3
These passion fruit don't meet all requirements for consideration in the higher evaluations, yet ought to be clean, mature, free from pests and diseases, will have similar color, shape, and size.
Passion fruit should be divided into 3 diverse size classifications from 4 to 9 cm in diameter and 4 to 12 cm long. The average diameter for fruit classified as small size is 5 cm (2 inch), for medium size is 6.5 cm, and for large size fruit is 8 cm.
External color tone is another significant quality characteristic utilized in sorting passion fruit. Prior to packing it is important to look for uniformly colored fruit in each container. The fruit should have a minimum of 75% of the surface area coloured to type (i.e. yellow or purple). Internal fruit quality should be checked on randomly selected fruit. Soluble solids content (SSC) of marketable fruit should range between 10% and 18% for yellow passion fruit and between 10% and 20% for purple passion fruit. Acidity of the pulp should range from 3% to 5%. ■ 54

Waxing
Passion fruit may benefit from a postharvest wax application. Much of the fruit's natural wax is removed during washing, so it should be replaced. Waxing enhances the shine and external appearance of the fruit, reduces postharvest weight loss, minimizes shriveling, and extends market life. A carnauba-based wax is preferred for passion fruit. A liquid paraffin wax dip may also be used, but it is costlier and does not impart a shine on the fruit surface. After waxing, the fruit is packed for market.

Packing
A well-ventilated containers capable of being stacked without damaging the fruit is used for packing of passion fruit. Passion fruit are packed typically in large synthetic mesh sacks for export market and wooden containers or durable plastic crates are preferred for the domestic market. Ventilation holes are desired for horizontal air movement and efficient cooling. During shipment the carton should also have vents for vertical air flow.

Processing of passion fruit
The main objective of processing technique is to enhance the keeping quality of perishable fruit and minimize the qualitative and quantitative deterioration of the fruit and its products.

Fruit pulps and juices
Pulp or juice of passion fruit is extracted by straining the seed from the fruit content. With the help of additives, the juice can be stored from six months to more than year. During off seasons, the stored juice can be utilized for making different variants of beverages for consumption.

Dehydrated products
It is a less difficult technique for preparing and expansion of storage life by physical removal of water, by hot air drying, which is affordable on commercial scale. Here the fresh material is dried to residual moisture of about 5% and depending upon the required retention of pigmentation, flavor and taste, pre-treatment need to be ascribed. The dried material can be rehydrated using water. The storage life of dried material can be of a half year at room temperature. This process provides the scope for better storage and transportation due to reduction in bulk weight. Osmodehydrated and intermediate moisture products of ~25% water content can be used for direct consumption without the need of re-hydration.

Freezing of pulps
In order to expect least or no changes in the stored fruit pulp, it is advisable to hold the fruit pulp prepared in a hygienic condition, in frozen condition at -30°C. The storage life would be minimum of six months. The frozen pulp after thawing can be reconstituted to obtain RTS drinks.

Aseptic packaging
Here the fruit pulp or juice is passed through computerized equipment with set temperature, duration and flow rate for processing and filling into sterile containers for storage and transport. The principle behind is high temperature short time (HTST).

Micro-filtration
After suitable dilution or the juice extracted is passed through ceramic membrane with micro pores. In fact, this technique can also serve to render stability to the product if operated under strictly sterile conditions. The greatest advantage of this process is a high degree of juice clarification and also prevention of discoloration over a course of storage life.

Jam, jelly and marmalade
Using pectin as a setting agent, fruit pulp can be converted to jam, whereas juice can be transformed into jelly under definite conditions of sugar and pectin concentrations. Marmalade represents a product like jelly including a bitter principle, usually as bits of citrus peel.

Pickles
Raw fruit can be converted into pickle after mixing in salt along with chili powder, followed by seasoning in hot oil of saturated fatty acids to overcome the rancidity during prolonged storage. To avoid the freight charges of wet pickle and convenience of handling, salting and dehydration into "instant pickles" can be packed along with chili, salt and spice powder. Upon reconstitution in water overnight the dry pickle can be converted into wet pickle.

Bakery products
Fruit pulp or its dehydrated product can be utilized for preparation of biscuits, cookies, fruit cake and muffins. After juice extraction, fruit pomace can be utilized in amalgamation with bakery flour to give bakery products better functionality due to balanced ratio of soluble/insoluble fiber, better hydration properties, and confer better sensory properties.

Value Addition
Value is added to the fruit by changing their form, color in order to increase the shelf life of perishable fruit. In the current scenario, there is an urgent need to increase the level of value addition and to improve the quality of value added fruit products for domestic and export market. Passion fruits are primarily used for food, in the form of value added products like juices, jams, jellies, ice creams and liquors. It is known for its sedative property, but its attractive aroma and flavor make the passion fruit an important product for the industry. The leaves and juice contain pass florin, a natural sedative, and tea prepared with leaves has a diuretic effect. It also shows purgative, sedative and anti-inflammatory properties. The seeds act as anthelminthic. It is popularly believed that the tea leaves, besides acting as a sedative, are also an effective antipyretic and help to treat skin inflammation, but these two uses are based on popular beliefs.

Byproducts and Waste Management
The processing of fruits leads to large amounts of by-products that may have functional properties. The waste resulting from passion fruit processing consists of more than 75% of the raw material. The rind constitutes 90% of the waste and is a source of pectin (20% of the dry weight). Passion fruit seed oil is rich in linoleic acid (65%). Nearly 40% of passion fruit production is directed to the juice industry. Large amounts of by-product (seeds and peels), that contains functional substances, are carried in passion fruit juice processing. The rind can be utilized for pectin production which is one of the major additive in confectionery industries whereas the seeds which represent about 6% to 12% of the total fruit weight can be utilized for oil extraction. The oil yield from the dry seeds of passion fruit reaches about 25%. One hectare can produce approximately 480 kg of dry seed, which equals 96 kg of oil when using cold extraction.

Conclusion
Considering the above factors, it is possible to infer that the cultivation and processing of passion fruit is technically feasible and can be expanded in the region. The first and most important step to be taken is to raise public interest and provide widespread publicity by various channels, followed by the development of coordinated initiatives among all potential stakeholders, such as farmers and government agencies, research institutions and other agencies. Strategies such as proper post-harvest management, the development of proper storage facilities, the development of improved packaging for transportation, the improvement of transportation facilities, the establishment of new processing units, and the strengthening of existing processing units will undoubtedly increase passion fruit production in the region.