Assessment Of Proximate Mineral, Phytochemicals And Vitamin Contents Of Banana Subjected To Ripening By Artificial Methods

Description

 

ABSTRACT

Ripening of fruit is a natural process in which the fruits go through various physical and chemical changes and gradually become sweet, colored, soft and palatable. This study was carried out to examine the effects of using artificial ripening processes which include calcium carbide, wood ash and ripening in the dark on plantain fruit. This study was conducted using standard phytochemical assay procedures and the atomic absorption spectrophotometric methods. The result of the phytochemical screening showed the presence of alkaloids (3.53 ± 0.64 and 3.4 ± 0.38 g/100 g), flavonoids (0.16 ± 0.05 and 0.13 ± 0.02 g/100 g), tannins (2.18 ± 0.63 and 3.22 ± 0.82 g/100 g) and terpenoids (1.88 ± 0.24 and 1.83 ± 0.19 g/100 g) in unripe and ripe plantain peels, respectively. Freshly harvested green matured plantain bunch were used for the determination of proximate analysis and mineral content [iron(Fe); potassium(K); zinc(Zn), and calcium (Ca)]. Calcium carbide samples had the highest Fe, K and Ca (3.05 mg/100g, 50.0 mg/100g and 3.48 mg/100g) respectively, and also the least content of protein, ash, fibre and fat (3.90%, 1.53%, 0.18% and 0.43%) respectively and significantly different when compared to other ripening methods.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE STUDY
• PROBLEM STATEMENT
• AIM AND OBJECTIVE OF THE STUDY
• SIGNIFICANCE OF THE STUDY
• SCOPE OF THE PROJECT
• LIMITATION OF THE STUDY
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• DESCRIPTION OF BANANA
• OVERVIEW OF RIPENING
• RIPENING PHYSIOLOGY
• BANANA RIPENING

CHAPTER THREE

METHODOLOGY

• SAMPLE COLLECTION AND PREPARATION
• DATA COLLECTION
• MINERAL ANALYSES
• PHYTOCHEMICAL SCREENING
• STATISTICAL ANALYSIS

CHAPTER FOUR

• RESULT AND DISCUSSION

CHAPTER FIVE

• CONCLUSION
• REFERENCES

CHAPTER ONE

1.0                                            INTRODUCTION

1.1                               BACKGROUND OF THE STUDY

One of the most important crops of the tropical and subtropical plants is banana. It belongs to the Musaceae family, genus Musa and specie acuminata (Danlami, Ijoh, & David, 2015). In Africa, it is an important staple fruit. Fruit ripening is a naturally occurring process(physical and chemical changes) that fruits go through to become, coloured, soft, edible, nutritious and palatable(Brady, 1987). The main reason for artificial ripening is for commercial purposes. Banana is estimated to provide 60 million people in Africa with more than 200 calories per day(Onwuka & Onwuka, 2005). The many forms in which they are consumed also indicate the long association between man and the crop(Baiyeri, Aba, Otitoju, & Mbah, 2011). The over-ripened, are often processed into local wine called ’agangidi’(Onyeka, 2005). As a result of rising population and need to meet the growing demand of the population, different ripening agents are used to initiate the ripening process of the plantain fruits. Ripening is defined as a biological process involving series of physiological changes in colour, flavour, aroma and texture (M. Li, Slaughter, & Thompson, 1997; X. Li et al., 2008; Singh, Bal, Singh, & Mirza, 2018; Sogo-Temi, Idowu, & Idowu, 2014), and fruits gets softened, firmness decreases and starch is converted into sugar(Prabha & Bhagyalakshmi, 1998).

One essential part of fruit business is commercial ripening and this involves the use of ripening agents such as glycol, ethereal, calcium carbide, African bush mango fruit and leaves, palm nut, cassia leaves, yellow pawpaw leaves, torch light battery, calcium carbide, potash, ash, and Neubouldia leaves(Adewole & Duruji, 2010; Ojetayo, Bodunde, & Odeyemi, 2018) to fasten the process. Artificial ripening of fruits speeds up the rate of process but the nutritional quality, sensory and safety of the fruits are affected (Hossain, Akhtar, & Anwar, 2015; Nura, Dandago, & Wali, 2018). The use of acetylene as ripening agent is a common practice in some countries but due to high cost many developing(Chowdhury & Alam, 2008) countries including Nigeria, use low cost-calcium carbide. The consumption of calcium carbide ripened fruits is extremely hazardous to health, because it affects the nervous system. The aim of this study is to assess the quality assessment of plantain (Musa paradisiaca) as affected by different ripening process (calcium carbide, wood ash and ripening in the dark) commonly adopted.

1.2                                 PROBLEM STATEMENT

In Nigeria, the contamination of food through poisons is on the increase. Reports of death as a result of food poisons is alarming(Adewole & Duruji, 2010). The National Agency for Food and Drug Administration and Control issue a public alert on the dangerous practice of sale and consumption of fruits artificially ripened with calcium carbide(NAFDAC, 2018). This study was carried out to determine the proximate mineral, phytochemical and mineral contents of banana subjected to three artificial ripening methods which at the end of the study will make the reader understand the effect of artificial ripening on banana.

1.3                   AIM AND OBJECTIVES OF THE STUDY

The main aim of this work is to investigate the phytochemical and mineral contents of plantain and to examine the effects of three ripening process which include calcium carbide, wood ash and ripening in the dark on plantain fruit. The objectives are:

1. To carry out an assessment of proximate mineral, phytochemical and mineral contents of banana subjected to three artificial ripening methods
2. To study the effect of artificial ripening on banana.

1.4                          SIGNIFICANCE OF THE STUDY

This study will shade light on the effect of artificial ripening on banana and also make the reader to understand the need of allowing banana to ripe naturally.

1.5                                  SCOPE OF THE STUDY

Artificial ripening promotes the ripening process and cause color changes in the fruits. Even if the appearance of the artificially ripened fruits improve, the properties like taste, smell, and touch are found to be weak and the worst of it is that the nutrient levels reduces. This study was carried out to determine the effect of artificial ripening on banana. The assessment was based on proximate mineral, phytochemical and mineral contents of banana subjected to three artificial ripening methods. In this study, three different method of fruit ripening method was discussed – calcium carbide, wood ash and ripening in the dark.

1.7                            LIMITATION OF THE STUDY

As we all know that no human effort to achieve a set of goals goes without difficulties, certain constraints were encountered in the course of carrying out this project and they are as follows:-

1. Difficulty in information collection: I found it too difficult in laying hands of useful information regarding this work and this course me to visit different libraries and internet for solution.
2. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).

Time Constraint: The researcher will simultaneously engage in this study with other academic work. This consequently will cut down on the time devoted for the research work.

1.8                                              PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work,   chapter two presents the literature review of the study. Chapter three describes the methods applied in this chapter. Chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.

CHAPTER TWO

2.0                                  LITERATURE REVIEW

2.1                              DESCRIPTION OF BANANA

A banana is an elongated, edible fruit – botanically a berry (Armstrong, 2011) – produced by several kinds of large herbaceous flowering plants in the genus Musa.[ Merriam-Webster Online Dictionary, 2013] In some countries, bananas used for cooking may be called “plantains”, distinguishing them from dessert bananas. The fruit is variable in size, color, and firmness, but is usually elongated and curved, with soft flesh rich in starch covered with a rind, which may be green, yellow, red, purple, or brown when ripe. The fruits grow in clusters hanging from the top of the plant. Almost all modern edible seedless (parthenocarp) bananas come from two wild species – Musa acuminata and Musa balbisiana. The scientific names of most cultivated bananas are Musa acuminata, Musa balbisiana, and Musa × paradisiaca for the hybrid Musa acuminata × M. balbisiana, depending on their genomic constitution. The old scientific name for this hybrid, Musa sapientum, is no longer used.

Musa species are native to tropical Indomalaya and Australia, and are likely to have been first domesticated in Papua New Guinea. They are grown in 135 countries, primarily for their fruit, and to a lesser extent to make fiber, banana wine, and banana beer and as ornamental plants. The world’s largest producers of bananas in 2017 were India and China, which together accounted for approximately 38% of total production [Picq, 2010].

Worldwide, there is no sharp distinction between “bananas” and “plantains”. Especially in the Americas and Europe, “banana” usually refers to soft, sweet, dessert bananas, particularly those of the Cavendish group, which are the main exports from banana-growing countries. By contrast, Musa cultivars with firmer, starchier fruit are called “plantains”. In other regions, such as Southeast Asia, many more kinds of banana are grown and eaten, so the binary distinction is not useful and is not made in local languages.

The term “banana” is also used as the common name for the plants that produce the fruit. This can extend to other members of the genus Musa, such as the scarlet banana (Musa coccinea), the pink banana (Musa velutina), and the Fe’i bananas. It can also refer to members of the genus Ensete, such as the snow banana (Ensete glaucum) and the economically important false banana (Ensete ventricosum). Both genera are in the banana family, Musaceae.

2.2                               OVERVIEW OF RIPENING

Ripening is a process in fruits that causes them to become more palatable. In general, fruit becomes sweeter, less green (typically “redder”), and softer as it ripens. Even though the acidity of fruit increases as it ripens, the higher acidity level does not make the fruit seem tarter. This effect is attributed to the Brix-Acid Ratio. Underripe fruits are also fibrous, less juicy, and have tougher outer flesh than ripe fruits (Kimball, 2011).

Ripening is a genetically programmed highly coordinated irreversible phenomenon which includes many biochemical changes including tissue softening, pigment changes, aroma and flavour volatile production, reduction in astringency, and many others. Banana is one of mostly consumed fruit crops in the world. Since banana is a climactic fruit, induced ripening is essential in commercial scale banana cultivation and distribution to assure good flavour, texture, and uniform peel colour. Ethylene gas, acetylene gas liberated from calcium carbide, and ethephon are some of the commercial ripening agents used successfully in the trade and they have been widely studied for their effectiveness on initiating and accelerating the ripening process and their effect on fruit quality and health related issues. Lauryl alcohol was also shown as a ripening agent for bananas. Most studies suggest that there is no difference in biochemical composition and sensory quality in bananas treated with chemicals that induce ripening from naturally ripened bananas.

2.3                                                 RIPENING PHYSIOLOGY

The life of a fruit can be divided into three phases: fruit set, fruit development, and fruit ripening. Fruit ripening is the initiation of fruit senescence which is a genetically programmed highly coordinated process of organ transformation from unripe to ripe stage to yield an attractive edible fruit [Perotti et al, 2014]. It is an irreversible phenomenon involving a series of biochemical, physiological, and organoleptic changes [Joshi et al, 2017]. These changes include changes in carbohydrate content, increment of sugar content, changes in colour, texture, aroma volatiles, flavour compounds, phenolic compounds, and organic acids.

Respiration is a process of breakdown of complex material in cells to simpler molecules giving energy and some specific molecules which are used in different cellular reactions. Thus respiration is a good indicator of cellular metabolic activity, and respiratory pattern is characteristic of the stages in the life cycle of a fruit such as development, ripening, and senescence [Tripathi et al, 2016]. Fruit ripening is closely linked to ethylene, a phytohormone that can trigger initiation of ripening and senescence. Based on regulatory mechanisms leading to fruit ripening, fruits can be divided into two groups: climacteric and nonclimacteric fruits. In climacteric fruits, as ripening proceeds there is a strong respiratory peak with high level of ethylene production. While in nonclimacteric fruits respiration rate is almost constant or shows a steady decline until senescence occurs, with little or no increase in ethylene production [Bouzayen, 2010]. Therefore, climacteric fruits are referred to as ethylene dependent fruits and they have the capability to ripen after the harvest, often with the help of exogenous ethylene. However it is generally claimed that nonclimacteric fruits ripen only if they remain attached to the parent plant [Pathak, 2010].

2.4                                         BANANA RIPENING

When bananas are ripening, they release carbon dioxide which will build up in a ripening room. The CO2 production begins as the fruit ripens enters the “climacteric” phase, or the period when bananas release ethylene and and have an elevated rate of respiration (along with a great deal of other physiological changes). Respiration involves the uptake of oxygen, the release of carbon dioxide, and the breakdown of starches. Carbon dioxide concentrations above 1% (10,000 ppm) will retard ripening, delay the effects of ethylene and cause quality problems. Therefore, it is recommended to vent rooms by opening the doors for 20 minutes every 12 hours, after the first 24 hours of ripening. Other venting methods are by automatic fan or “flow-though” (constant) ventilation.

Banana ripening rooms are very important, not just any room will suffice. A proper ripening room must have the following:

• The room must be as air tight as possible to prevent too much of the ethylene from leaking out.
• The room must be properly insulated to be able to control the temperature within a few degrees.
• The room must have adequate refrigeration. Bananas produce large quantities of heat when they are ripening. The refrigeration equipment must have the capacity to accurately control the pulp temperature.
• The room may need heating equipment in order to maintain proper room temperature in cold weather. Electric heating elements have proven the most satisfactory and are often a part of the cooling system. Open flame type heating should never be used.
• The room must have adequate air circulation. Because uniform pulp temperatures throughout the load are essential for even ripening, the refrigerated air in the room must circulate at all times and uniformly throughout the load. The room should be constructed so that the air flow path from the refrigeration system, through the load and back to the refrigeration system is unobstructed. Proper air flow patterns are of the utmost importance.

Pressurized Ripening Rooms

Perhaps the most important advancement in fruit ripening since the advent of the banana box is the development of Pressurized Ripening Rooms. The key feature of these rooms is that conditioned air is forced through the product rather than the product just being stored in a temperature controlled room. The system passes air though each pallet or series of pallets before returning to the evaporator. Therefore, any “air-stacking” or “cross-stacking” of boxes is not necessary, and the result is less handling of the fruit and improved product quality. For non-pressurized rooms, the boxes of bananas should be “air stacked”. That is, the boxes should be offset to allow the air to circulate among all the boxes since a non-pressurized room design will not pass air through boxes but around them.

Avoid “chilling” or “cooking” the fruit. Bananas are very sensitive to temperatures. Chilling will occur if the fruit is subject to temperatures below 56° F. for several hours. It causes the peel to have a smoky, dull gray appearance. This may not show up for 18 to 24 hours after chilling occurs. Cooked bananas result from excessively high temperatures. The peel will have a brown to orange appearance. The fruit may be soft and have a short shelf life.

Maintain proper humidity levels. For best ripening results, humidity should be 85 to 95%. If the humidity is too low, install a humidifier; wetting the floor of the room with water may increase the humidity but may cause sanitation issues.