MSc

Passion fruit (Passiflora edulis Sims.) is the fruit of exotic passion flower. Purple and yellow are the two main types of passion fruit grown commercially all around the world. The fruit is valued for its powerful medicinal property and high antioxidant activity. The juice exhibits pronounced flavour and aroma which help in producing high quality beverages and also in flavouring several other products. It is quite delicious, nutritious and liked for its excellent blending property. Even though passion fruit is having many such advantages, its utilization is limited in processing sector mainly due to the short shelf life, minimum juice recovery and intense acidity.
Hence, to overcome these limitations, a study on “Value addition of passion fruit (Passiflora edulis Sims.)” was carried out in the Department of Processing Technology, College of Horticulture, Vellanikkara, with three main objectives viz., to characterize passion fruit accessions for nutritional and biochemical attributes, to extend shelf life through packaging and to impart value through processing.
Passion fruit accessions (yellow and purple) from various localities of Kerala and Kaveri, the only variety of passion fruit released in India by the Central Horticultural Experiment Station (CHES), Chettalli, a sub station of the Indian Institute of Horticulture Research (IIHR), Bengaluru, were collected and characterized based on physico-morphological, nutritive and biochemical parameters. Considerable variation in physical composition, fruit length, fruit diameter, fruit girth, rind thickness and fruit weight was observed among the accessions. Juice recovery was higher in purple types as compared to the yellow ones. Brilliant yellow was the commonly observed colour of the juice in majority of the accessions, followed by vivid yellow and light orangish yellow, based on the descriptor of the Royal Horticulture Society (Universal Colour Language).
Nutritional and biochemical characteristics also varied significantly among passion fruit accessions. Purple types had comparatively higher TSS, reducing
sugars, total sugars and vitamin C whereas, titratable acidity, non-reducing sugars, total carotenoids, total phenols, total flavanoids and antioxidant activity were higher in yellow types.
Mature fruits of a yellow accession grown at the Cashew Research Station (CRS), Madakathara were used at the turning stage for the evaluation of shelf life and assessment of changes in quality through shrink wrap packaging, using polyolefin films of 15, 19 and 25μ thickness, in two methods viz., shrink wrapping of individual fruits and shrink wrapping of areca plates containing fruits. Observations on changes in quality of fruits were recorded at weekly intervals during storage at ambient temperature.
Individually shrink wrapped passion fruit with 25μ polyolefin film gave highest shelf life (26.66 days) whereas the lowest shelf life (7.00 days) was observed in control in which fruits were kept unwrapped. Fruits wrapped in areca plates became unmarketable after two weeks of storage, irrespective of the film thickness. Physiological loss of weight (PLW), total soluble solids, reducing, non reducing and total sugars increased, while, titratable acidity, vitamin-C and total carotenoids decreased in all the treatments during storage. Total phenols and total flavanoids increased during the first week and decreased during second and third week of storage. Sensory quality of passion fruit increased throughout the storage period in all the treatments.
Nectar developed from yellow and purple fruits separately and also by blending juice of yellow and purple fruits in 1:1 ratio with 20% juice and 200 Brix was used for storage studies to evaluate the changes in quality under ambient and low temperature conditions for three months.
Total soluble solids, non-enzymatic browning, reducing, non reducing and total sugars increased while, titratable acidity, vitamin-C, total carotenoids, total phenols and total flavanoids decreased during storage of nectar, irrespective of treatments and storage conditions. Qualitative changes in passion fruit nectar were more conspicuous under ambient conditions than under low temperature storage.
Microbial load in all the samples were within the acceptable limits even after three months of storage.
It may be concluded that there exists considerable variation in passion fruit accessions collected from various parts of Kerala. Shelf life of passion fruit can be prolonged through shrink wrap packaging and fruit nectar having 20% juice and 200 Brix is organoleptically acceptable. Storage of nectar at low temperature helps to retain quality.