Keywords

Morinda citrifolia L; Medicated drink; Shelf life; Chemical profile; Microbes

Introduction

Morinda citrifolia Linn is belonging to the family Rubiaceae. In India this plant is known as Indian Mulberry or Nuna whereas in Hawalli it is known as Noni [1]. The Noni plant is a small evergreen tree found growing in open coastal regions at sea level and in forest areas up to about 1300 feet above sea level. The plant is often found growing along lava flows. It’s identifiable by its straight trunk, large, bright green and elliptical leaves, white tubular flowers, and its distinctive, ovoid, “grenade-like” yellow fruit. The fruit can grow in size up to 12 cm or more and has a lumpy surface covered by polygonal-shaped sections. The seeds, which are triangular shaped and reddish brown, have an air sac attached at one end, which makes the seeds buoyant. This could explain, in part, the wide distribution of the plant throughout the Polynesian islands. The mature Noni fruit has a foul taste and odor [2,3].

After planting M. citrifolia fruits will be appeared after 9 months to 1 year time period. The unripe fruit is dark green in color and the ripe fruit has a foul taste and odor. The pulp has a light dull yellowish white color. The ripped fruit is juicy and bitter and Noni juice is prepared from ripe Noni fruit [2,4]. It has been reported to have broad spectrum of therapeutic remedies for diseases such as diabetes, arthritis, cancer, hypertension, cough, cold, pain, blood pressure, tuberculosis, malaria, intestinal worms, etc. [2,5,6].

Many value added products such as Noni juice, capsule, powder, Noni concentrates, tea, etc. are available in the market made out of different parts of M. citrifolia. Among them Noni juice is most popular for its nutraceuticals and high therapeutic values around the globe. Noni juice has been recently established in European Union as a novel food [7].

Eventhough many research work have been carried out for pharmacological investigations and chemical composition [2,3] of M. citrifolia very few studies were carried out for this plant grown in Sri Lanka. Within the same species of plant, the composition of phytochemicals can vary with the nutrient composition of the soil, climatic season, development stage of the plant, natural association with other plants, storage of raw materials and the types of processing methods such as drying and extraction procedures [8]. Therefore, an attempt was taken to evaluate the shelf life of juice of M. citrifolia grown in Sri Lanka.

Materials and Methods

Collection of plant material

M. citrifolia mature fruits were collected from Western Province of Sri Lanka during the period of August 2016 and authenticated by Senior Scientist, Botany Division, Bandaranayaka Memorial Ayurvedic Research institute, Navinna, Maharagama, Sri Lanka.

Preparation of Morinda citrifolia juice

Fruits of M. citrifolia were washed and embedded in an amber color jar and kept for 14 days under sun light. After that, filtered and filtrate was added to 4 sterile glass bottles and sealed. These bottles were kept in the room temperature (28-30°C).

Evaluation of shelf life of Morinda citrifolia juice

Shelf life was evaluated in terms of possibility of (a) decomposition of chemical compound/s (b) growth of microbes and (c) organoleptic properties of M. citrifolia juice at the initial stage and after 6 months. Possibility of decomposition of chemical compound/s in M. citrifolia juice was evaluated by means of (a) Thin Layer Chromatography (TLC) fingerprint profile and (b) phytochemical classes. Microbiological analysis was done by evaluating the presence or absence of microbes (eg. counts of aerobic bacteria, Staphytococcus aureus, yeast and moulds and Escherichia coli). Organoleptic properties such as color, odour and taste of M. citrifolia juice were checked.

Development of a TLC fingerprint profile

Noni juice was added to a separatory funnel containing dichloromethane and mixed well. Then dichloromethane layer was separated and added to a round bottom. This was repeated for thrice and evaporated to dryness. The residue was redissolved in 2 ml of dichloromethane and spotted on a TLC plate. As the mobile phase cyclohexane, dichloromethane and ethyl acetate in a ratio of 1:4:0.5 was used and observed under 254 nm and 366 nm.

Screening of phytochemical compounds

Secondary metabolites such as alkaloids, phenols, tannins, flavonoids, steroids and saponins were screened according to methods described by Goveas and Abraham [9].

Microbiological analysis

Limits of Escherichia coli, Coliforms, Salmonella, Aerobic bacteria, Staphytococcus aureus and Yeast and Moulds were determined in Noni juice according to the methods described in SLS standards [10-13].

Organoleptic properties

Organoleptic properties such as colour, smell, appearance were detected in the Noni juice.

Results and Discussion

The time duration which an active ingredient/s is expected to remain within the approved specification limits under the given storage conditions is known as shelf life of a product [14]. The storage condition of a product is the most important point when evaluating the shelf life of a product [15]. In the present study, M. citrifolia juice was kept in the room temperature (28-30°C). Moreover, TLC fingerprint profile of M. citrifolia juice at the initial stage (R_f values of 0.45, 0.60, 0.72, 0.80 and 0.88) was similar to the TLC fingerprint profile of the same juice after 6 months. Phytochemicals such as alkaloids, phenols, tannins, flavonoids, steroids, saponins were detected in the juice at both initial stage and after 6 months. More often, queries on microbial quality will arise for herbal beverages due to the complexity of chemical compounds rather than chemically define beverages [16].

Conclusion

In the present study, Escherichia coli, Coliforms and Salmonella were absent at initial stage and after 6 months respectively. Counts of Aerobic bacteria, Staphytococcus aureus, Yeast and Moulds were <1, <100 and <1 respectively in the both stages. Organoleptic properties of Noni juice was similar at the initial stage and after 6 months. In conclusion, fruit juice of M. citrifolia grown in Sri Lanka can be kept at room temperature without any chemical deterioration and microbial contamination for 6 months.

References

1. Scot C (2006) Species profiles for Pacific Island agroforestry Morinda citrifolia noni. Permanent Agriculture Resources.
2. Chan-Blanco Y, Vallant F, Perez AM, Reynes M, Brillouet JM, et al. (2006) The noni fruit (Morinda citrifolia L.): A review of agricultural research, nutritional and therapeutic properties. Journal of Food Composition and Analysis 19: 645-654.
3. Ali M, Kenganora M, Manjula SN (2016) Health benefits of Morinda citrifolia (Noni): A review. Pharmacognosy Journal 8: 321-334.
4. Dittmar A (1993) Morinda citrifolia L. use in indigenous Samoan medicine. Journal of herbs Spices and Medicine Plants 1: 77­92.
5. Whistler W (1992) Tongan herbal medicine. Isle Botanica, Honolulu, Hawaii.
6. Dixon AR, Heather M, Nina LK (1999) Ferment this: the transformation of Noni. A traditional Polynesian medicine (Morinda citrifolia, Rubiaceae). Ecological Botany 53: 51­68.
7. Europian commission, Scientific Committee on Food (2002) Opinion of the Scientific Committee on Food on new findings regarding the presence of acrylamide in food, health & consumer protection directorate general.
8. Menkovic N, Savikin-Fodulovic K, Savin K (2000) Chemical composition and seasonal variations in the amount of secondary compounds in Gentiana lutea leaves and flowers. Planta Medica 66: 178-180.
9. Goveas SW, Abraham A (2014) Extraction and secondary metabolite analysis of Coscinium fenestratum (Gaertn.) Colebr: An important medicinal plant of Western Ghats. International Journal of Pharmaceutical Sciences and Research 5: 3484-3489.
10. Sri Lanka standard 516/1:1991. Publication of Sri Lanka Standard Institute.
11. Sri Lanka standard 516/2:1991. Publication of Sri Lanka Standard Institute.
12. Sri Lanka standard 516/3:1982. Publication of Sri Lanka Standard Institute.
13. Sri Lanka standard 516/6:1992. Publication of Sri Lanka Standard Institute.
14. Dekker T (2015) Stability studies (emphasis o FPPs). Workshop on GMP and quality assurance of multisource tuberculosis medicines, Kuala Lumpur, Malaysia.
15. Ankit G, Mundeep J, Pradeep KP (2011) Shelf life of Ayurvedic dosage forms-Traditional view, current status and prospective need. Indian Journal of Traditional Knowledge 10: 672-677.
16. Anonymous (2003) Stability testing of new drug substances and products-Q1A (R2). (ICH), International Conference on Harmonization.