Food Science and Technology Project Topics

Evaluation of Oil Obtained From Pawpaw Seed

Evaluation of Oil Obtained From Pawpaw Seed

Evaluation of Oil Obtained From Pawpaw Seed

Chapter One

Objective of the Study

            The aim of this work includes

  • Extraction of oil from papaya seed
  • Determine the physicochemical and phytochemicals properties and the quality of oil extracted from papaya seeds.


REVIEWS ON PAWPAW (Carica papaya)

Brief Introduction to Carica papaya and its Seed

Papaya belongs to a small family caricaceae having four genera in world. The genus carica L. is represented by four species in India, of which Carica papaya L. is the most widely cultivated and the best-known species (Jean et al., 2011). It is commonly known as Papaya Melon tree, Pawpaw or Papau, Kapaya, Lapaya, Papyas, Papye, Tapayas, Fan mu gua, papita, arand- kharpuja, papayabaum and papaya (Bhattachrjee, 2001). The taxonomical classification includes Kingdom (Plantae), Order (Brassicales), Family (Caricaceae), Genus (Carica) and Species (papaya). Papaya is probably originated in southern Mexico and Costa Rica, subsequently got introduced in Australia, Hawaii, Philippines, Sri Lanka, South Africa, India and all tropical and subtropical regions. It is growing both commercially and in home garden (Marotta et al., 2006). A study conducted by University of Florida researchers Nam Dang and colleagues in Japan has documented papaya’s powerful anticancer properties and its impact on numerous lab-grown-tumors.

The papaya seed contain fatty acids, crude protein, crude fibre, papaya oil, carpaine, caricin, glucotropaeolin, benzyl glucosinolates, benzyl Isothiocyanate, benzyl thiourea, hentriacontane, ß-sitostrol, caressing and an enzyme myrosin. The seeds and the pulp of Carica papaya contain benzyl glucosinolate which can be hydrolyzed by myrosinase to produce benzyl isothiocyanate. Seed extracts have profound bactericidal activity. The seeds of unripe fruits are rich in benzyl isothiocyanate, a sulphur containing chemical that has been reported to be an effective germicide and insecticide. These substances are important for plant natural defense mechanisms (El Moussaoui et al., 2001). Medicinal uses of papaya seed are carminative, anti-fertility agent in males, counter irritant, as a paste in the treatment of ringworm, psoriasis, emmenagogue, vermifuge, liver cirrhosis and abortifacient. Seed juice is used for bleeding piles, enlarged liver and pectoral properties. Seed paste is used as anthelmintic, stimulation of menstruation or abortion.

Carica papaya seeds were approved and confirmed in some studies for their effective anthelmintic properties against nematodes found in animals (Chota, 2010). Chinoy et al., (2006) proved the anti-fertility, anti-implantation and abortifacient properties of extracts from papaya seeds. It has been established in males that the seeds of C. papaya are potential anti-fertility drugs (Lohiya et al., 2005). Pawpaw seeds are used to produce an indigenous Nigerian food condiment called ‘daddawa’, the Hausa word for a fermented food condiment (Dakare, 2004). Fermented seeds have no effects on litters of rats (Abdulazeez et al., 2009), whereas, those effects were apparent when the unfermented extract was administered (Abdulazeez, 2008). Anthelmintic activity of papaya seed has been predominantly attributed to carpaine (an alkaloid) and carpasemine (later identified as benzyl thiourea). Carpaine has an intensively bitter taste and a strong depressant action on health.

 Composition of Carica papaya

Researchers have found that differences in cultivars, growing location, sunlight exposure, agricultural practices, stage of ripeness and postharvest handling have significant effects on the chemical composition of the fruits (De-Rosso and Mercadante, 2005; Wall, 2006; Ornelas-Paz et al., 2008; Gayosso-García et al., 2011). For instance, the progression of fruit through different maturity stages results in physiological and biochemical changes that modify fruit composition and enables its consumption (Pereira et al., 2009). The loss of fruit firmness is a consequence of changes in plant cell wall constituents that lead to weak cell-to-cell links and thus lose of rigidity and firmness. The softening indicates ripening. These changes can be observed in papaya fruit tissue by means of microscopic examination (Pereira et al., 2009). For commercial production papaya fruit maturity is often based on the changes of skin colour of the fruits.

Papaya fruits have a good nutritional health profile being an excellent source of provitamin A and ascorbic acid. They rank as one of the top fruit for ascorbic acid content. There is no significant variation of the ascorbic acid content of different cultivars of the fruits but there is a large variation in the provitamin A content between the red and yellow-fleshed papaya cultivars (Chandrika et al., 2003; Wall, 2006) as well as a variation due to the level of ripeness of the fruit (Gayosso-García et al., 2011). The ripening process begins when the chlorophyll is degraded, which coincides with carotenoid synthesis and results in significant colour changes from green to yellow-orange colour. Moreover, during ripening, the content of esterified carotenoids increases, which allows esterified carotenoids to integrate more quickly into the membranes. This in turn increases the color of the fruit and its accumulation in chromoplasts (Andersson et al., 2008; Yahia and Ornelas-Paz, 2010).

Many tropical fruits such as mango have similar behaviour as papaya in that the colour is conferred by the carotenoid level. Carotenoids like β-cryptoxanthin, and β-carotene are found in all types of papaya cultivars. However, contradictory results are found on lycopene availability in yellow fleshed fruits. Lycopene in yellow-fleshed fruits was not detected or found in a low amount compared with the red-fleshed fruits (Wall, 2006; Marelli de Souza et al., 2008; Gayosso-García et al., 2011). Colour intensity resulting from carotenoid content plays a vital role in fruit acceptability by consumers (Yahia and Ornelas-Paz, 2010). Red-fleshed cultivars such as ‘Solo’ often outweigh the yellow-fleshed fruits in consumer preference. However, the former has excellent flavor but very poor shape and appearance, whereas the latter has very good appearance (Drew, 2005).

Papaya is one of the few examples known of a plant containing both glucosinolates and cyanogenic glucosides (Bennett et al., 1997; Olafsdottir et al., 2002). Generally, plants producing glucosinolates are not cyanogenic, however, a few plant species have been positively identified as containing both glucosinolates and cyanogenic glucosides. Benzylglucosinolate was found to be detected in all of the tissues of papaya (Aruna and Subrata, 2008; Jiao et al., 2010; Tripathi et al., 2010). Nonetheless, in papaya fruits, the amount detected was very low compared to other parts of the plant such as leaves and seeds (Bennett et al., 1997s). In addition, the leaves also contain alkaloids (including carpain and pseudocarpain), enzymes (papain, chymopapain, cystatin), tocopherol, ascorbic acid, flavonoids, tannins, nicotinic acid, saponins and phenolics (Bennett et al., 1997; Seigler et al., 2002; Duke, 2011).





Whole papaya fruits were procured from local market of Owo. Most of the chemicals used in this investigation were of analytical grade. They were obtained from Department of Food Science and Technology, Rufus Giwa Polytechnic, Owo, Ondo State. The equipments were obtained from Department of Food Science and Technology, Rufus Giwa Polytechnic, Owo, Ondo State.


Preparation of Carica papaya Seeds

Mature Carica papaya fruits were procured from the local market in Owo. The fruits were cut into two longitudinal halves and the seeds were removed by hand. The testae of the seeds were removed by squeezing the seeds between two fingers. The seeds were dried in an oven at 60ºC. The dried seeds were stored at -4ºC until required for analysis.




Table 1: Reference Table for Edible Oil





            It was concluded that both the seed and the extracted oil can provide daily requirement in terms of either fortification or enrichment of food because it is a good source of protein and tangible percentage of dietary fibre. The oil is benefit nutritionally and health wise to treat degenerative diseases, its antimicrobial activities poses it activities against bacteria and fungi. It also has ability to act as a biofuel.


Based on the finding, the following are recommended for further knowledge and utilization of the oil.

  1. Before being considered adequate for food applications, toxicological studies need to be carried out to ascertain whether or not this oil is safe
  2. Information provided by the present study is of great importance for further chemical investigations of papaya seed oil and industrial utilization of the papaya seeds as a raw material to foods and cosmetics.


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  • Abdulazeez, M.A. (2008). Effect of fermented and unfermented seed extract of Carica papaya on implantation in Wistar rats (Rattus norvegicus). Thesis submitted to Department of Biochemistry, A.B.U Zaria.
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