Nutritional Evaluation of Fruits of Gynochthodes umbellata ( L . ) Razafim . & B . Bremer – An Underutilized Edible Fruit Plant

Objective: The present investigation aimed to assess the nutritional, mineral profiling and anti-nutritional analysis of Gynochthodes umbellata (Syn. Morinda umbellata), an underutilized edible plant belongs to the family Rubiaceae. Literature perusal reveals that, there are no previous reports on nutritional studies for this valuable fruit. Methods: Nutritional, mineral profiling and anti-nutritional analysis of fruits were carried out. Results: In nutritional analysis, carbohydrates (6.98 g/100g fw), protein (2.68 g/100 g fw), crude fat (0.13 mg/g dw) and crude fibre (32.58%) content were detected. The fruits of G. umbellata, Vitamin C (25 mg/100g fw) was higher when compared to other three vitamin evaluated, Four macro elements and 6 micro elements were also quantified. Conclusion: Nutritional and Antinutritional analysis reveals that, the G. umbellata fruits could be used as a source of protein, vitamin and minerals and highly recommended for consumption as they contain low amount of the anti–nutrients analysed. This is the first report on nutritional analysis of G. umbellata fruit.


INTRODUCTION
Fruits are widely accepted as a good and important source of nutrients and supplement for food in a world faced with problem of food scarcity.Fruits are very vital portion of an adequate diet and they serve as food supplement, and an appetizer.Wild fruits are potential source of antioxidants, vitamins and minerals and they act as an important source of nutrient to the rural population, and can be act as a source of micronutrients, so knowledge about composition of fruits and their nutrient potentials is imperative. 1 In most developing nations, numerous types of edible wild plants are exploited as sources of food to provide supplementary nutrition to the inhabitants. 2The plants, which are neither grown commercially on large scale nor traded widely, may be termed as underutilized plants.These plants are cultivated or grown wild, traded and consumed locally.] The plant selected for the present study was Gynochthodes umbellata (syn: Morinda umbellata) belongs to the family Rubiaceae is an underutilized plant (Figure 1).Plant distributed in India, Srilanka, China, Japan and North Australia.6] This plant produces large number of fruits which are edible and used in curries in younger stage. 7Morinda citrifolia fruit (noni) is the major edible close relative of G. umbellata.M. citrifolia has long history of use as a food in tropical regions throughout the world and has been reported to have a broad range of health benefits. 8In recent years, the noni fruit juice has received much attention because of its nutritional and antioxidant properties and has been now accepted widely as a nutraceutical and marketed worldwide.Noni juice is also claimed to relieve inflammation.0][11] Extensive research has been carried out on M. citrifolia (noni), there is a lack of information on the other related species like G. umbellata (Syn.M. umbellata).G. umbellata produces large number of edible fruits but the conception of fruit is very rare.Literature perusal reveals that there is no literature regarding the nutritional analysis of its fruit.Hence the present study on the nutritional value of fruits of G. umbellata is very important as it will definitely help in popularising this underutilized crop from a nutraceutical point of view.Thus the major objectives of this study were nutritional, anti-nutritional and min-eral composition analysis as indication of nutritional values of the fruit of G. umbellata.

Fruit collection and storage
The ripened fruits were collected during April-May from wild grown plant from Kariyavattom Campus of University of Kerala, Thiruvananthapuram, Kerala.The fruits were washed and cleaned with distilled water to remove the surface residues and blotted with tissue paper and one part of fresh ripened fruits were stored at 4 o C for the evaluation of total carbohydrate, total protein, vitamins, pH of the juice.The other portion of the ripened fruits was dried in a hot air oven for 24 hours at 45 o C. Then the dried fruits were ground well in a mixer grinder and kept in an air tight bottle and stored at 4˚C in a refrigerator for the evaluation of crude fibre, fatty acid, crude fat, mineral profiling and anti-nutritional analysis.All chemicals used in the study were of reagent grade, unless otherwise stated.

Nutritional analysis
The proximate composition including the moisture content and crude fibre were estimated as per the method given by Association of Analytical Chemists. 12Total carbohydrates were estimated by the method given by Sadasivam and Manickam 13 , Total protein content were quantified using the method by Lowry et al. 14 Vitamin A, vitamin C, vitamin B 1 and vitamin B 12 determined using standard procedures by Deepak. 15rude fibre content and crude fat was estimated by the method given by AOAC 12 and for fatty acids quantification the procedure given by Akinyeye et al., 16 were also evaluated in fruits of G. umbellata.pH of fruit juice were determined using a pH meter (Cyberlabs, USA).Total carbohydrate, total protein, vitamins, pH of the juice were evaluated in fresh fruits and crude fibre, fatty acid, crude fat were conducted in dried fruit powder of G. umbellata.

Mineral profiling (macro and micro elements)
The powdered dried fruit sample was digested using nitric acid-perchloric acid mixture (4:1) for 24 hours.This was then filtered using Whatman No. 42 filter paper and the filtrate was used to determine the mineral content using Atomic Absorption Spectroscopy (AAS). 17Four macro elements, Magnesium (Mg), Sodium (Na), Calcium (Ca), Potassium (K) and six micro elements like, Iron (Fe), Copper (Cu), Manganese (Mn), Zinc (Zn), Lead (Pb), Cadmium (Cd) were quantified in ripened fruit of G. umbellata.

Anti-nutritional analysis
The method described by Day and Underwood 18 was used for the determination of oxalate content.The method described by Cataldo et al., 19 was adopted in the determination of nitrate.The method reported by Reddy and Love 20 was used for the determination of phytate.Measurement of saponin concentration of the extract was based on the method described by El-Olemy et al. 21All the anti-nutritional parameters were conducted in fresh fruits of G. umbellata.

Anti-nutrient to nutrient molar ratios
Anti-nutrient to nutrient molar ratios of G. umbellata fruit were also determined by using compare the critical values reported by Hassan et al. [22][23] Anti-nutrient to nutrient molar ratio helps to predict the effect of anti-nutrient on the bioavailability of mineral elements.

Fruit collection and storage
Young fruits of G. umbellata are green in colour (Figure 2), when mature it becomes orange red in colour (Figure 3).The change of fruit skin colour and firmness of fruit which ripen naturally on the plant is represented in Table 1.Fruit contain numerous seeds and were small.The average number of seeds/ fruits were 13.43 ± 4.43.The size of the fruits range with an average length of 3.93 ± 0.84 cm, a width of 2.35 ± 0.50 cm.The fully ripened fruits were collected for the analysis (Figure 4).

Nutritional analysis
The nutritional analysis results of G. umbellata were listed in Table 2.The moisture content in fresh fruits (58.32%) was low when compared to other fruits like Banana (74.91%),Mango (81%) and Morinda tinctoria (78.34). 24Desai et al., 25 studied the proximate composition and some physicochemical properties of the two species of Morinda fruits, and observed that the moisture content in M. citrifolia was 63% and M. pubescens was 22%.The low moisture content in the fruit suggests that the levels of other nutrients might be high. 26arbohydrates are one of the most important components in many fruits.The total carbohydrate content in fresh fruits of G. umbellata was cal cascade mechanisms. 38The results of mineral analysis of G. umbellata are depicted in Table 3.Out of four macro elements quantified, potassium (956 mg/100g dw) was higher followed by calcium (450 mg/100g dw).The value of potassium is much greater than the popular potassium enriched fruit, banana, with only of 348-370 mg/100g. 39In addition the fruit also contain substantial amount of Magnesium (245 mg/100g dw), Iron (3.4 mg/100 g), Manganese (14.1 mg/100g) and Zinc (1 mg/100g).The Fe and Zn content of the tropical and sub-tropical fruits ranged from 0.09-3.4mg/100 g and 0.06-0.64respectively. 39Brett 27 reported 214.34 mg/100 g potassium in fresh fruit juice of M. citrifolia.All the elements quantified were higher in G. umbellata than the Morinda citrifolia. 27This difference in mineral elements is due to the difference in experiment materials used and the difference in plant species.Anuradha et al., 37 reported the difference in nutrient content in fresh and dry fruits of M. tictoria were different.

Anti-nutritional analysis
Fruits are important sources of minerals, fibre and vitamins, which provide essential nutrients to the human body.But it is known that some fruits have so-called anti-nutritional factors that diminish nutrient bioavailability, especially if they are present at high levels. 40The high content of these anti-nutrients exert negative effects on the bioavailability of some mineral nutrient. 4198g/100g.This value is comparable with total carbohydrate content reported by Brett 27 in M. citrifolia fruit (7.21g/100g).The protein is another important nutritional factor.G. umbellata fresh fruit have 2.68g/100g protein.Protein is a major source of energy, as well as containing essential amino acids which are important for human being. 28Lewis et al., 29 reported M. citrifolia fresh fruit have 5.98g/100g protein.The M. citrifolia juice reported to have a lesser amount of protein (0.4g/100g).30 This reduction in protein may be due to the processing of fruit for the preparation of juice.Crude fat (0.1316 mg/g) and fatty acid (0.1053 mg/g) were detected in dried fruits of G. umbellata.In M. citrifolia the crude fat content were reported by various authors, as 0.10g/100g 27 and 0.14g/100g 31 were comparable with this result.Low fat foods are considered as preferable.32 High fibre content (32.58%) was detected in G. umbellata dried fruit.High amounts of fibre were also reported in M. citrifolia (33%) and M. pubescens (48%).33 Fibers in diet help the digestion process and aid absorption of trace elements in the intestine. Italso reduces the absorption of cholesterol and helps in efficient elimination of wastes.34 The Vitamin content of the fresh fruit of G. umbellata reveals high content of Vitamin C (25 mg/100g). Viamin A (1.29 mg/100g), Vitamin B 1 (0.023 mg/100g) and Vitamin B 12 (0.014 mg/100g) were detected in fresh fruit of G. umbellata (Table 2).European Commission 35 reported M. citrifolia fruit juice contains 3-25 mg/100g vitamin C. The pH of fruit juice of G. umbellata was 4.80.Similar pH (4.76) was reported in M. citrifolia fruit juice 36 and this pH fall outside the range that incidentally favours bacterial growth.

Mineral profiling
The mineral composition is an important for reliable nutrient information and its pivotal role in human life provides healthy growth. 37Minerals are essential for normal cellular function and provide additional protection to the human body and act as second messenger in some biochemi- In G. umbellata oxalate content detected (1.12 mg/g) is higher than phytate (0.01 mg/g) and nitrates (0.018 mg/g).The saponin is absent in G. umbellata fruit (Table 4).Levels of all the anti-nutritional factors in the fruits of G. umbellata were lower than the value what can cause mal-absorption of other nutrients, so the consumption of other nutrients should be encouraged when available. 1

Anti-nutrient to nutrient molar ratios
Anti-nutrients to nutrients molar ratio are used to predict the effect of oxalate and phytate on the bioavailability of important macro and micro elements. 23The Anti-nutrient to nutrient molar ratios were listed in Table 5.All the Anti-nutrient to nutrient molar ratios are below the critical level except [Ca] [Phytate]/[Zn].This indicate that bioavailability of Ca and Zn may be effected by the phytate content which can overcome by little processing of fruit before their consumption.

CONCLUSION
The present study showed that the underutilized G. umbellata fruits could also be used as a potential source of protein, vitamin and minerals with some of them being even better than M. citrifolia and other popular fruits.Anti-nutrient to nutrient molar ratio suggest that little processing is needed before the consumption of G. umbellata fruit.This study suggests more scientific studies should be conducted to identify the nutritional and functional compounds present in G. umbellata fruits and explain their mechanisms of action in order to determine the real potential of this fruit and the technological processes that preserve these.This information is also pertinent to help underutilized and neglected species for better health and nutritional status of the rural communities of the country.The present study also reveals that this fruit can be a substitute for noni.