Bioactive compounds in banana and their associated health benefits – A review

Highlights

• Banana contains several bioactive antioxidant compounds.

• These compounds include phenolics, carotenoids, biogenic amines and phytosterols.

• These are highly desirable in the diet exerting positive effects on the human health.

Abstract

Banana is a very popular fruit in the world market and is consumed as staple food in many countries. It is grown worldwide and constitutes the fifth most important agricultural food crop in terms of world trade. It has been classified into the dessert or sweet bananas and the cooking bananas or plantains. It is either eaten raw or processed, and also as a functional ingredient in various food products. Banana contains several bioactive compounds, such as phenolics, carotenoids, biogenic amines and phytosterols, which are highly desirable in the diet as they exert many positive effects on human health and well-being. Many of these compounds have antioxidant activities and are effective in protecting the body against various oxidative stresses. In the past, bananas were effectively used in the treatment of various diseases, including reducing the risk of many chronic degenerative disorders. In the present review, historical background, cultivar classification, beneficial phytochemicals, antioxidant activity and health benefits of bananas are discussed.

Introduction

Fruits are sweet or sour fleshy structures of a plant that are edible in the raw state. These are rich sources of vitamins and sugars, along with bioactive compounds (including fiber and phenolic compounds) and have been associated with reducing the risk of major chronic degenerative diseases (Singh, Kaur, Shevkani, & Singh, 2015). The World Health Organization (WHO) recommends eating at least 400 g of fruits per day (Who & Consultation, 2003).

Banana is a very popular fruit in the world market ranking next to rice, wheat and maize in terms of its importance as a food crop. The word ‘banana’ refers to the fruit of evergreen monocotyledonous, perennial, giant herb, exclusively subtropical belonging to the genus Musa from the family Musaceae (Lassoudière, 2007). It is grown in over 130 countries; mostly in the tropical and subtropical areas and has a center of origin from South-East Asia. Economically, it is the fifth agricultural food crop in terms of world trade, after coffee, cereals, sugar and cacao; and is an important fruit crop in the world apart from grapes, citrus fruits and apples (Aurore, Parfait, & Fahrasmane, 2009). India, China, Philippines and Ecuador are the main banana producing countries of the world (FAOSTAT, 2014). Most of the bananas are consumed in the countries where they are grown and only 20% are exported to other countries. Ecuador is the largest banana exporter and USA is the major banana importing country in the world (FAOSTAT, 2014).

Edible bananas evolved from the wild species by parthenocarpy and seed suppression. These are diploid, triploid or tetraploid hybrids, having A and B genomes. Musa acuminata was a progenitor of the A-genome, while the B-genome was derived from Musa balbisiana (Osuji, Okoli, Vuylsteke, & Ortiz, 1997). These two species are diploids with genomes AA and BB, respectively. Hybrids of M. acuminata and M. balbisiana arose as a result of human intervention (Lejju, Robertshaw, & Taylor, 2006). Hybridization of A and B genomes occurred when AA cultivars were brought from Southeast Asia to South Asia. AA, AAA, AAB and ABB cultivars are available in the domesticated areas of the world. Banana fruits are parthenocarpic berries, made up of peel and edible pulp, that have a high nutritional value. The ovules shrivel early and can be seen as minute brown flecks in the central part of the edible pulp. It is a climacteric fruit which develops without pollination from the inferior ovary of the female flower (Forster, Rodríguez, Martín, & Romero, 2003). It is eaten raw as a dessert or sweet fruit by millions of people worldwide and is often categorized as the dessert/table banana or as a staple food by cooking (frying, boiling, roasting or baking) and referred to as the plantain. Banana can also be processed in various other forms, such as juice, puree, flour; so that it can be stored for longer periods and utilized for other purposes. Banana chips made by deep-frying thin slices of unripe fruits are also common. Ripe bananas can be easily sliced, dried and stored without adding preservatives for longer durations. Banana purée can be used as an ingredient in bakery items, drinks, dairy desserts, sausages and many other processed foods.

Banana fruit is a rich source of important phytonutrients, including vitamins and phenolic compounds (Lim et al., 2007, Wall, 2006). It is also notably enriched with minerals, such as phosphorus, sodium, potassium, calcium, magnesium, iron, copper, zinc and manganese (Forster et al., 2003). Utilization of banana as an ingredient in different food products exerts a beneficial effect on human health. The incorporation of banana in the recipes of many food products improves the total dietary fibre, resistant starch, total starch and some essential minerals (phosphorus, magnesium, potassium and calcium). Banana is a staple food in many countries and due to its high nutritive value has a positive effect on the health and well-being of many people. Several researchers have evidenced that bananas are an important source of health promoting phytochemicals (Davey et al., 2007, Someya et al., 2002). There is no collective information in the form of a review available in the literature, reporting the important phytochemical compounds in banana fruits and their antioxidative potential as well as health benefits. The aim of this review is to re-examine the information on the beneficial phytochemicals of bananas and provide some useful information to the people about the health benefits and the potential application as a natural antioxidant in food.