Banana ( <i> Musa </i> spp.) is an important ingredient of several dishes and its nutritional and other biochemical composition at different stages is yet to be scientifically studied. In the present study the most popularly cultivated species of Nendran, Nijali poovan and Robusta banana in Southern India are selected. Variations in the nutritional and biochemical compositions associated with ripened and unripened stages of banana fruits were studied. Proximate composition, mineral and phytochemical compositions of ripened and unripened banana flours were analyzed and the total soluble sugars in unripened banana rang e from 1.70 to 2.15 mg/100g of the samples and that of ripened banana rang e from 37.5 to 43.8 mg/100g of the samples. Mineral compositions show that they are rich sources of calcium, phosphorus and iron. In addition to this they are rich sources of antioxidant potential phytochemicals such as polyphenols, flavanoids, vitamin C and lesser in quantity of anti nutritional factors such as phytates and oxalates. The current study revealed the variations of biochemical compositions of three varieties in unripened and ripened stages. This will be useful for the exploitation of these crops to obtain and formulate the value added products.
Banana is one of the most popular desert fruit, in terms of per capita consumption as well as the most widely traded fruit in the world. India is the largest producer of banana accounting for 17.8% of world share followed by Barzil [
Fruits and vegetables are rich sources of various health beneficial phytochemicals, such as vitamins, minerals, carbohydrates, flavanoids and phenols [
The development of new product is a strategic area at the food industry. Consumers demand foods mainly of two reasons, one in deal with the traditional nutritional aspects of foods, whereas the second feature is that the additional health benefits accepted from its regular ingestion and such kinds of food products are called nutraceutical foods [
Banana fruits are rich source of nutrients and their biochemical composition varies with growth stage and maturity [
The ripe and unripe varieties of Musa AAA Spp. (Robusta), Musa AAB Spp. (Nendran) and Musa AB Spp. (Njali poovan) were collected from Kasaragod district of Kerala. The fresh ripe and unripe bananas were peeled, cut into thin slices and dried in an electric oven at 60˚C for 12 h. Dried samples were ground, sieved and stored at room temperature (25˚C ± 2˚C) in air tight containers and the powdered sample were used for the analysis of chemical compositions. The varieties of unripe banana are represented as Un-Nendran, Up-Njali poovan, Ur-Robusta and ripe banana varieties are represented as Rn-Nendran, Rp-Njali poovan and Rr-Robusta respectively.
The moisture, ash and protein content in the samples were determined according to methods described in AOAC [
The pH of the sample was determined by methods given by Berwal et al. [
Phytic acid was determined by the method of Davis and Reid [
Total phenolic contents were estimated with the Folin-Ciocalteu Reagent (FCR) colorimetric method [
Total flavanoids were estimated by the method of Marinova et al. [
Oxalic acid was estimated by the method of Raghuramulu et al. [
Mineral compositions such as calcium, phosphorus and iron were estimated from acid digested samples. Reagents-diacid mixture: Nitric acid and perchloric acid were mixed in the ratio of 5:1. Finely ground samples (1 g) were taken in conical flask containing 25 mL diacid mixture and kept overnight. The following day, the samples were digested by heating till a clear white precipitate settled down at the bottom. The crystals were dissolved by the addition of deionized water. The contents were filtered through Whatman no.42 paper. Final volume was made up to 50 mL with deionized water and used for the determination of individual minerals.
Calcium in the digested solution was estimated by the method of Raghuramulu et al. [
The iron content was estimated by the method of Raghuramulu et al. [
Phosphorous content was estimated by the method of AOAC [
Experiments were carried out in three replicates and presented as means ± standard deviation of three replicates. One way ANOVA was carried out to examine whether the difference in the chemical components present in the different samples were significant or not. SPSS software (version 17) was used for the analysis.
Three different varieties of unripened and ripened bananas were dried separately in an electric oven at 60˚C for 12 hrs. It was observed that 100 gm of fresh ripened banana subjecting to oven drying yielded Rn (37.5 g), Rp (30.22 g) and Rr (24.5 g) respectively (
The result of the proximate composition of the three different varieties of unripened and ripened bananas are given in
The moisture content was ranged from 39.40% to 60.06% in unripened and 66.23% to 75.25% in ripened banana respectively. The bananas generally contain 60% - 68.6% of moisture as they ripen; it gradually increases from 68.6% - 78.1% [
Sample (100 g) | Oven drying (60˚C for 12 h.) |
---|---|
Wt (g) | |
Un | 45.14 |
Rn | 37.50 |
UP | 39.78 |
Rp | 30.22 |
Ur | 30.60 |
Rr | 24.50 |
Un―Unripened Nendran, Rn―Ripened Nendran, Up―Unripened Njali poovan, Rn―Ripened Njali poovan, Ur―Unripened Robusta, Rr―Ripened Robusta.
Samples | Un | Rn | Up | Rp | Ur | Rr |
---|---|---|---|---|---|---|
Moisture content (%) | 54.86 ± 0.29 | 66.23 ± 0.26 | 60.06 ± 0.13 | 70.53 ± 0.48 | 39.40 ± 0.39 | 75.25 ± 0.20 |
Ash (mg/100g) | 1.55 ± 0.04 | 1.61 ± 0.02 | 1.90 ± 0.07 | 2.22 ± 0.04 | 1.66 ± 0.06 | 2.07 ± 0.02 |
Proteins (g/100g) | 2.00 ± 0.41 | 3.75 ± 0.20 | 2.25 ± 0.20 | 4.95 ± 0.04 | 1.75 ± 0.20 | 3.25 ± 0.20 |
Lipids (g/100g) | 1.63 ± 0.30 | 1.77 ± 0.66 | 1.38 ± 0.11 | 0.66 ± 0.05 | 2.51 ± 0.32 | 2.59 ± 0.04 |
Crude fiber (g/100g) | 4.03 ± 0.06 | 1.58 ± 0.03 | 2.30 ± 0.08 | 1.85 ± 0.04 | 2.78 ± 0.02 | 2.42 ± 0.04 |
Total soluble sugars (g/100g) | 1.80 ± 0.04 | 37.50 ± 0.40 | 2.15 ± 0.04 | 43.80 ± 0.65 | 1.70 ± 0.08 | 40.50 ± 0.40 |
Fructose (g/100) | 0.415 ± 0.004 | 9.15 ± 0.12 | 0.477 ± 0.002 | 11.50 ± 0.08 | 0.49 ± 0.01 | 11.95 ± 0.12 |
Reducing sugars (g/100g) | 0.68 ± 0.05 | 16.75 ± 0.20 | 1.31 ± 0.05 | 18.15 ± 0.02 | 0.56 ± 0.08 | 19.12 ± 0.10 |
Non reducing sugars (g/100g) | 1.11 ± 0.01 | 20.75 ± 0.20 | 0.84 ± 0.01 | 25.30 ± 0.85 | 1.12 ± 0.13 | 21.37 ± 0.31 |
The protein content shows that a significant difference among the Njali poovan and Robusta variety 1 - 2.5 g/100g present in unripened and ripened fruits. A gradual increase was observed under ripening condition (3 - 4.95 g/100g) of Rn, Rp and Rr. The protein content of banana fruit varied from mature fruit (1% to 2.5%) to ripened fruit (3.8% to 4.2%) depending up on genome type, variety, altitude and climatic conditions [
The lipid content ranges from 0.66 - 2.59 g/100g in ripened fruits, whereas in unripened fruits it ranges from 1.38 - 2.51 g/100g. Banana’s with low lipid and high energy contents make them very useful for the manufacturing of low fat diet formulations [
The crude fiber content was highest in unriped fruits (2 - 4 g/100g) compared to ripened fruits (1 - 2.42 g/100g). The food value of crude fiber is greater, which helps to regulate certain physiological functions. The highest crude fiber content was observed in unriped nendran banana (4 g/100g). The crude fiber composition of unriped banana was observed to be high and it later dropped at the ripened stage [
The total soluble sugar content shows highest in ripened stage (37 - 43.8 g/100g) compared to unripened banana (1.7 - 2 g/100g). Increase of total soluble sugars while ripening is an important trait of hydrolysis of starch into soluble sugars such as glucose, sucrose and fructose [
Banana contains rich sources of mineral nutrients and it could serve as mineral element supplement in diet for both humans and animals [
The observed value of Ca (mg/100g) in unripened banana samples ranged from 23.04 mg to 38.57 mg/100g, whereas in ripened fruits ranging from 31 mg to 52.6 mg/100g of the samples. The calcium content was highest in ripened Robusta fruits (52.6 mg/100g).
Phosphorus in Un, Up, Ur was found to be 34.37, 56.25 and 50 mg/100g respectively. In Rn, Rp and Rr samples it was shown to be 75, 81.25 and 78.13 mg/100g respectively. An increase in the phosphorus content was observed upon ripening. Morton [
The iron content of the samples Un, Up and Ur showed 1.25, 1.25 and 1 mg/100g respectively. Whereas, in Rn, Rp and Rr was 1.5, 1.75 and 1 mg/100g respectively. In comparison Ur and Rr, contains same amount of iron (1 mg/100g) whereas, the unripened and ripened Nendran and Njali poovan varieties showed slight increase in their iron content during their maturation stage. The gradually increasing in the mineral contents of banana fruits during ripening stages is already reported [
Polyphenols are the biggest group of phytochemicals found in plant based foods and the structure of natural polyphenols varies from simple molecules to highly polymerized compounds. Majority of polyphenols existed as glycosides with different sugar units and acylated sugars at different positions of the polyphenol skeletons [
Sample | Calcium | Phosphorus | Iron |
---|---|---|---|
Un | 23.04 ± 1.63 | 34.37 ± 2.55 | 1.25 ± 0.00 |
Rn | 31.06 ± 0.81 | 75.00 ± 5.10 | 1.50 ± 0.20 |
Up | 27.05 ± 0.81 | 56.25 ± 0.00 | 1.25 ± 0.00 |
Rp | 41.08 ± 0.81 | 81.25 ± 5.10 | 1.75 ± 0.00 |
Ur | 38.57 ± 0.40 | 50.00 ± 0.00 | 1.00 ± 0.20 |
Rr | 52.60 ± 0.41 | 78.13 ± 2.55 | 1.00 ± 0.20 |
Samples | Polyphenols | Flavonoids | Vitamin C | Phytates | Oxalates |
---|---|---|---|---|---|
Un | 400.00 ± 20.41 | 112.00 ± 0.81 | 0.73 ± 0.01 | 0.088 ± 0.04 | 2.95 ± 0.04 |
Rn | 600.00 ± 20.40 | 115.00 ± 0 | 0.72 ± 0.01 | 0.077 ± 0.01 | 2.15 ± 0.04 |
Up | 431.25 ± 45.92 | 118.00 ± 0 | 0.66 ± 0.012 | 0.0375 ± 0.0004 | 2.90 ± 0.08 |
Rp | 625.00 ± 40.82 | 110.50 ± 0.40 | 0.67 ± 0.01 | 0.0315 ± 0.0004 | 3.15 ± 0.04 |
Ur | 506.25 ± 15.30 | 131.00 ± 0.81 | 0.55 ± 0.01 | 0.0377 ± 0.0002 | 3.15 ± 0.04 |
Rr | 725.00 ± 20.41 | 126.00 ± 20.41 | 0.54 ± 0.004 | 0.3175 ± 0.0002 | 2.77 ± 0.02 |
total polyphenol content in the ripe pulp compared to the green pulp of all plantain and cooking banana cultivars. Among the three varieties of ripe and unripe banana Ur and Rr showed a high values of polyphenols (506.25 mg and 725 mg/100g). Whereas, the other two varieties ranged from 400 - 431.52 mg/100g to 600 - 625 mg/100g as they ripened. The total polyphenol composition of the banana cultivars are determined by their genetic factors and could have been modified by oxidative reactions during storage. Many of the phenolic compounds of the banana are being both good browning substrates and good antioxidants [
The flavanoids content of the samples Un, Up and Ur are 112, 118 and 131 mg/100g respectively and that of Rn, Rp and Rr are 115, 110.5 and 126 mg/100g respectively. In all the analyzed samples the flavanoids content shows that decreasing order from unripened banana to ripened fruit, except in the Nendran banana sample (Un-112mg and Rn-115mg). Fathemeh et al. [
Vitamin C is an anti-oxidant and it acts as a good scavenger of several reactive oxygen species [
Phyticacid is a natural plant inositolhexaphosphate commonly found in seeds and represents the principle form of stored phosphate [
The oxalate content of sample Un, Up and Ur was ranging from 2.90 to 3.15 mg/100g of samples, whereas in ripened fruits Rn, Rp and Rr ranged from 2.15 to 3.15 mg/100g. The oxalate content ranged from 0.64% - 0.88% for several plantain and banana cultivars [
Sample | pH |
---|---|
Un | 5.97 ± 0.016 |
Rn | 4.50 ± 0.08 |
Up | 5.78 ± 0.06 |
Rp | 4.63 ± 0.04 |
Ur | 5.92 ± 0.02 |
Rr | 4.55 ± 0.040 |
The present study reveals that the nutritional compositions are affected by various growth stages of banana. The findings of this study indicate that the ripening effects on the proximate composition, mineral contents, phytochemical content and anti-nutrients factors of the flours. The moisture content, total soluble sugars, crude protein, ash, Ca, P, Fe and pH of the samples increased with ripening stages. The crude fiber contents of the flours decrease with increasing the ripening process. The levels of oxalate and phytate in all the samples were low and may not hinder the bioavailability of essential nutrients in the flours. The results revealed that the nutritional quality of unripened and ripened banana flour helps to understand the chemical changes associated with ripening may form the basis for expanding the utilization of bananas to various food products. Exploration of antioxidant potential of the unripened and ripened banana flour will help to know the nutraceutical benefit of these varieties. The outcome of this research will help the food industry to optimize the nutritional compositions while designing new products that utilize the banana varieties discussed in the paper.
Support received from Department of Sustainable Living, Maharishi University of Management, Fairfield, Iowa is gratefully acknowledged. The Authors are grateful to School of Biotechnology, National Institute of Technology, Calicut, India for their help.
The authors declare no conflicts of interest regarding the publication of this paper.
Kookal, S.K. and Thimmaiah, A. (2018) Nutritional Composition of Staple Food Bananas of Three Cultivars in India. American Journal of Plant Sciences, 9, 2480-2493. https://doi.org/10.4236/ajps.2018.912179