Study on preparation, packaging and storage of passion fruit (Passiflora edulis flavicarpa Deg.) Nectar beverages

Introduction

Passion fruit (Passiflora edulis Sims.) is a perennial, climbing, woody vine which produces round or ovoid fruits having a tough, smooth, waxy dark purple/yellow coloured rind with faint, fine white specks. It contains orange coloured pulpy juice with large number of small, hard, dark brown to black pitted seeds. The juice is delicious with good flavour, intense aroma and sweet-acid taste and is well known for its excellent blending quality. As people are more concerned about their health, demand for passion fruit juice is increasing not only because of its exotic flavour but also for its high nutritional and medicinal properties. There is a lot of evidence that the passion fruit could be a powerful medicinal source. The juice contains very good proportion of acids, sugars, Vitamin-A, fibre, phenolic compounds, ascorbic acid (Ramaiya et al., 2012) [6] and minerals such as sodium, magnesium, sulphur, chlorides, etc. (Rao et al., 2014) [8] . The juice of yellow type is more acidic and its recovery is comparatively less (25-30%) than the purple type (35-38%) (Rao et al., 2014) [8] .

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Even though the high acidity of passion fruit limits its utilisation for table purpose, its intense flavour offers ample scope for processing into numerous value added products like fruit beverages, concentrate, etc. Fruit nectars are unfermented beverages that occupy a prominent place in the processed food sector. By far the greatest benefit of passion fruit to humankind is fruit and the delicious juice. Passion fruit juice is highly acidic due to predominance of citric and malic acid. The strong and intense flavour of passion fruit offers ample scope for processing in to a refreshing fruit nectar .In India, limited work has been done on the post harvest technology of passion fruit. So, the intervention on this aspect has better scope in processing the juice of passion fruit in to a refreshing beverage. Ascorbic acid, was estimated as per the procedure suggested by AOAC (1998), reducing, non-reducing and total sugars were determined as per the procedure suggested by Ranganna (1997) [7] . Total soluble solids (TSS) were determined by using hand refractometer. Quality of passion fruit nectar was judged by a panel of judges having different age groups for colour, flavour, taste, and overall acceptability, based on a 9 point hedonic scale rating (Amerine et al., 1965) [1] .

Methodology

Analytical Tools

All parameters were statistically analyzed by using analysis of variance technique for Factorial Completely Randomized Design as described by Panse and Sukhatme (1985) for significance by "F" test. Standard error of mean and critical differences was worked out at 5 % level of significance. The statistical analysis was carried out in Department of Agricultural Statistics, College of Agriculture, Junagadh Agricultural University, Junagadh.

Results and Discussion

Total soluble solids (TSS) of passion fruit nectar increased throughout the storage period, irrespective of storage conditions (Table 1). Nectar stored under ambient temperature showed higher rate of increase compared to those stored under refrigerated condition. Significant increase in TSS content of passion fruit nectar was not observed after first and second month of storage. Increase in TSS could be due to solubilisation of passion fruit pulp constituents during storage and degradation of complex starch into simple sugars due to hydrolysis of polysaccharides (Jawanda et al., 1978) [4] . Ascorbic acid in passion fruit nectar decreased throughout the storage period irrespective of storage conditions (Table 1). Nectar stored under ambient temperature showed higher rate of decrease compared to low temperature. The reason behind decrease in ascorbic acid could be due to oxidation of vitamin-C to furfural and hydroxyl methyl furfural (Aruna et al., 1997) [9] . Reducing, non reducing and total sugars of passion fruit nectar increased during storage irrespective of storage conditions (Table 1). However significant difference between the treatments was observed after one & two months of storage. Increase in sugar content may be due to breakdown of complex starch into simple glucose and sucrose (Selvaraj et al. 1989) [9] . Data on mean sensory scores of passion fruit nectar during first and second month of storage are presented in (Table 2). Sensory scores of passion fruit nectar declined during storage in all the treatments. The rate of decrease was faster in nectar stored under ambient condition as compared to refrigerated condition. After two months of storage, nectar developed from the juice of purple fruit stored under refrigerated condition recorded maximum sensory score while the minimum was seen in the samples from the passion fruit nectar stored under ambient condition. These results are in accordance with those reported by Ladaniya et al. (2004) [5] where in the organoleptic scores for body, taste, colour and aroma of sweetened 'Nagpur' Mandarin orange juice decreased with increase in storage period irrespective of storage conditions. However, scores for overall acceptability topped in refrigerated condition as compared to ambient temperature. Nectar stored at ambient temperature had higher microbial load than those stored at low temperature. Bacteria were not detected up to one months of storage and yeast did not survive up to one month of storage, in any treatments. Even though, fungi were not detected initially, it was found one month after storage. However, the microbial load in all the samples was within the acceptable limits (FSSAI). According to Tchango-Tchango et al. (1994) [10] the acidity in processed passion fruit juice inhibited the growth and multiplication of pathogenic microorganisms like Escherichia coli, Streptococcus or Staphylococcus, but might contain nonpathogenic fungi, yeasts or lactic acid bacteria. Sandi et al.

(2004) also reported that the passion fruit juice pasteurized at 75°C for 60 sec showed complete inhibition of microbial population, and also the juice stored under ambient condition remained microbiologically safe up to one month of storage period.

Conclusions

The storage of passion fruit nectar (17 o Brix) at ambient temperature by filling in PVC bottle which can be kept safely up to one month along with organoleptically acceptable good quality.

References

1. Amerine MA, Pangborn RN, Roessler EB. Principles of sensory evaluation of food. London: Academic Press; 1965.
2. Association of Official Analytical Chemists (AOAC). Official methods of analysis. 16th ed. Washington, DC: AOAC; 1998. p. 899.
3. Aruna K, Vimala V, Giridhar N, Rao DG. Studies on preparation and storage of nectar prepared from papaya. Beverage Food World. 1997;24(1):29-32.
4. Jawanda JS, Singh R, Kumar K. Studies on extending postharvest life of kinnow mandarin. Punjab Hortic J. 1978;18:149-153.
5. Ladaniya MS, Das AK, Khan NA, Mahalle B, Kumar A. Changes in quality of sweetened 'Nagpur' mandarin orange juice in crown corked glass bottles at ambient International Journal of Agriculture and Food Science https://www.agriculturaljournals.com and refrigerated conditions. J Food Sci Technol. 2004;41(3):344-348.
6. Ramaiya SD, Bujang JS, Zakaria MH, King WS, Sahrira MAS. Sugars, ascorbic acid, total phenol content and total antioxidant activity in passion fruit (Passiflora) cultivars. J Sci Food Agric. 2012;93:11981205.
7. Ranganna S. Handbook of analysis and quality control for fruit and vegetable products. 2nd ed. New Delhi: Tata McGraw Hill; 1997. p. 1112.
8. Rao TM, Tripathi PC, Karunakaran G, Sakthivel T, Sankar V, Kumar RS. Passion fruit cultivation in India. Technical Bulletin No. 3. Bengaluru: ICAR-Indian Institute of Horticultural Research; 2014.
9. Selvaraj Y, Kumar R, Pal DK. Changes in sugars, organic acids, amino acids, lipid constituents and aroma characteristics of ripening mango (Mangifera indica L.) fruit. J Food Sci Technol. 1989;26:308-313.
10. Tchango-Tchango J, Tailiez R, Eb P, Njine T, Hornez JP. Heat resistance of spoilage yeasts Candida pelliculosa and Kloeckera apis and pasteurization values for some tropical fruit juices and nectars. Food Microbiol. 1994;14:93-99