DEVELOPMENT OF BANANA FIGS DRIED BY DIFFERENT DRYING

TECHNIQUES AND ENROBED BY CHOCOLATE

A Project Report

Submitted
in partial fulfilment of the requirements for
award of Degree of

BACHELOR OF TECHNOLOGY
In
FOOD TECHNOLOGY
BY

A. GOWTHAMI PRIYA
BF 18-017
LINGAM SAIKUMAR Ch. BHAVISHYA
BF 18-044 BF 18-007

N. PEDA GOPI REDDY K.KRISHNAVENI

BF 18-036 BF 17-021

UNDER THE GUIDANCE OF

Dr. M. Sardar Baig
Professor & Head
Department of Food Processing Technology

ACHARYA N. G. RANGA AGRICULTURAL UNIVERSITY

Dr. N.T.R COLLEGE OF FOOD SCIENCE AND TECHNOLOGY,
BAPATLA-522 101, GUNTUR (Dist.), A.P
2021-2022

1
 ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
Dr. N.T.R COLLEGE OF FOOD SCIENCE & TECHNOLOGY,
BAPATLA

CERTIFICATE

This is to certify that this project report entitled “DEVELOPMENT OF BANANA FIGS
DRIED BY DIFFERENT DRYING TECHNIQUES AND ENROBED BY
CHOCOLATE” is a bonafide work of Ms. A. GOWTHAMI PRIYA (BF 18-017), Mr.
LINGAM SAIKUMAR (BF 18-044), Ms. Ch. BHAVISHYA (BF 18-007), Ms. N. PEDA
GOPI REDDY (BF 18-036) and Ms. K. KRISHNAVENI (BF 17-021) submitted in partial
fulfilment of the requirements for the award of the degree of BACHELOR of
TECHNOLOGY in FOOD TECHNOLOGY.

Dr. M. Sardar Baig Dr. B. John Wesley

Professor & Head Associate Dean

(Department of Food Processing Technology) Dr. NTR CFST, Bapatla
Research project advisor

2
 ACKNOWLEDGEMENT

It is a dedicated long journey for successful completion of this project. The journey
has been quite remarkable and this work paves the way which can be further explored by
many in the years to come. We express our gratitude to our Project Advisor and Supervisor
Dr. M. Sardar Baig, Professor & Head, Department of Food Processing and Technology,
under whose guidance and supervision we could successfully complete the project. We are
whole heartedly thankful for his conscientious guidance, immense patience and constant
encouragement. His enthusiasm, luminous concepts, intellectual capabilities and
dedication have been the driving force throughout this work.

It is undeniably our proud privilege to express our deepest sense of gratitude to

Dr. B. John Wesley, Associate Dean, Dr. N.T.R College of Food Science and
Technology, Bapatla for his untiring guidance and support at each step of this work.

We would like to extend gratitude to Dr. Ch. V.V. Satyanarayana, Professor and
Head, Department of Food Process Engineering, Dr. Ch. Someswara Rao, Assistant
Professor and Head, Department of Food Processing Operations, Mrs. K. Sowjanya,
Assistant Professor, Dr. Vimala Beera, Assistant Professor and Head, Department of
Food Safety and Quality Assurance, Dr. S. Blessy Sagar, Assistant Professor, Mrs. R.
Preethi Sagar, Teaching Associate for their valuable suggestions, encouragement and
genial succour during the course of this work.

Above all, we are grateful to our parents and family members for their care,
affection, encouragement, critical reviews, guidance and moral support throughout our
career.

A. GOWTHAMI PRIYA Ch. BHAVISHYA LINGAM SAI KUMAR

BF 18-017 BF 18-007 BF 18-044

N. PEDA GOPI REDDY K. KRISHNAVENI

BF- 18- 036 BF- 17- 021

Date :
Place : Bapatla.

3
 INDEX

Chapter no. Particulars Page no

List of Figures 6

List of Tables 7

List of Plates 8

Abbreviations, Acronyms, Symbols 9

Abstract 10

1 INTRODUCTION 11-14

2 REVIEW OF LITERATURE 15-17

3 MATERIALS AND METHODS 18-32
3.1 Location of raw materials

3.2 Procurement of raw material

3.3 Required raw materials

3.4 Equipments required

3.5 Processing of banana figs by different

drying techniques

3.6 Product development

3.7 Proximate and chemical analysis

3.7.1 Moisture content

3.7.2 Fat content

3.7.3 Ash content

3.74 Carbohydrate content

4
 3.8 Sensory evaluation of the developed
products

4 RESULTS AND DISCUSSION 33-40

4.1 Moisture content

4.2 Ash content

4.4 Carbohydrate content

4.5 Sensory evaluation

5 SUMMARY AND CONCLUSION 41-42

6 SUGGESTIONS FOR FUTURE WORK 43

7 REFERENCES 44-46

8 APPENDIX 47-48

5
 LIST OF FIGURES

S.NO TITLE PAGE NO

3.5.1 Flow chart showing Banana figs from hot air oven 22
drying
3.5.2 Flow chart showing Banana figs from microwave 24
drying.
3.5.3 Flowchart showing Banana figs from osmotic hot 25
air oven drying.

3.5.4 Flow chart showing Banana figs from osmo 27

microwave oven drying

4.1.1 Variation of moisture content in dried banana from 34

hot air oven
4.1.2 Variation of moisture content in dried banana from 34
osmo hot air oven
4.1.3 Variation of moisture content in dried banana from 35
microwave oven
4.1.4 Variation of moisture content in dried banana 35
from
Microwave osmotic drying
4.3 Graphical representation of fat values 37

4.4 Graphical representation of carbohydrate content 38

4.5 Graphical representation of sensory evaluation of 40

different dried bananas

6
 LIST OF TABLES

S.N.O TITLE PAGE NO

3.1 Initial characteristics of fresh ripened banana 20

4.2 Ash values of bananas from different drying 36

techniques
4.3 Fat values of banana from different drying techniques 36

4.4 Carbohydrate content of bananas from different 37

drying techniques
4.5 Results from score card 39

7
 LIST OF PLATES

S.NO TITLE PAGE

NO
3.4.1 Hot air oven 20

3.4.2 Micro wave oven 21

3.4.3 Muffle furnace 21

3.4.4 Soxhlet apparatus 22

3.5.1 Bananas dried from hot air oven 23

3.5.2 Bananas dried from microwave oven 25

3.5.3.1 Bananas soaked in osmotic solution 26

3.5.3.2 Bananas dried in hot air oven 26

3.5.4.1 Bananas after soaking in osmotic solution 28

3.5.4.2 Bananas dried from microwave drying 28

8
 ABBREVIATIONS, ACRONYMS, AND SYMBOLS

˚C centigrade

% Percentage

◦ degree

± plus or minus

μ micro

g Grams

Kg kilogram

N Normality

Fig Figure

% Percent

min Minutes

s Seconds

m Meters

cm Centimeters

mm Millimeters

9
 ABSTRACT

Banana is the most important fruit crop in the world. India is the largest producer of bananas
in the world, with a production of 297 lakh metric tonnes from 8.4 lakh hectares of land. The large
quantity of unmarketable fruits available in all banana growing regions in India wasted due to
improper postharvest handling and lack of processing technology for value addition. The waste
due to surplus banana production can be minimized by preparing banana figs. Banana figs are dried
or dehydrated banana fruits with sticky consistency and very sweet in taste. These figs are packed
in polyethylene bags or any other suitable containers. They have a shelf life of about 3-4 months
under ambient conditions.

In the present research four drying techniques are used to produce banana figs; Hot air
drying, Osmotic hot air drying, Microwave drying & Osmotic microwave drying. The temperature
for hot airdrying is 70˚C & drying time 12 hours. In Osmotic hot air drying the bananas were
soaked in 70˚B sugar solution for 12 hours and dried in hot air oven at 70˚C for 8 hrs. In Microwave
oven drying, the power used is 180 Watts (W) & drying time is 1 hour 35 min. In Osmotic
microwave drying the bananas were soaked in 70˚B sugar solution for 12 hours and dried in
microwave at power of 180W and drying time of 1 hour 5min. The bananas were treated with 1%
potassium meta bisulphite before drying. The osmotic dehydration process has been tested for
several tropical fruits soaked in sucrose solution notably papaya, mango and sweet bananas. Later
these figs were coated with dark chocolate to improve the appearance and acceptability.

Banana figs produced were characterized in terms of their composition, consumer

acceptance and storage qualities. These tests were undertaken to ascertain the suitability of the
solution for preservation of sweet bananas as added-value foods and to minimize post – harvest
losses. The composite of sugar solution improved the sensory qualities, and more importantly the
storage quality of banana figs, retarding mould development and inhibiting mould growth on the
figs surface.

This study a follow - up to a previous study on the chemical and organoleptic quality and
proximate analysis of figs from selected validates osmotic dehydration and drying as a simple and
cost-effective method of preserving bananas using sugar solution in forms of value- added figs of
improved nutrient status, storage and availability. The results of sensory evaluation, proximate
analysis and chemical analysis, the banana fig from microwave oven drying seems to be more
efficient and attracted by consumer panels and results showed best when compared to other banana
figs.

KEY WORDS : Banana , Different drying techniques, organoleptic properties, banana figs.

10
INTRODUCTION

11
 CHAPTER 1
INTRODUCTION
Banana (Musa paradisica) belongs to family Musaceae. These are plantains, grown in
every tropical region, resembles a tree, in fact it is a giant perennial herb. Banana is the largest
grown fruit in India and highly perishable and constitutes about 31-72% of total fruit production
in the world. Banana is the most important fruit crops of India with more than two hundred
commercial varieties grown over an area of about 1,60,000 hectares.

Banana is the wise fruit of India and fourth important food crop in terms of gross value
after paddy, wheat, and milk products. In terms of volume, they are the first exported fruit while
they rank second after citrus in terms of value. India comes next in rank after Brazil occupying
about 13% of total area and accounting for about 34.2% of the total world production of the fruit.
India has first position in the world in banana production while Maharashtra has the highest
productivity 58.60 metric tons against India’s average of 32.50 metric tons per hectare (UNCTAD
secretariat from FAO Statistics, 2007). Major cultivated varieties of bananas include Dwarf
Cavendish, Bhusaval Keli, Basari, Poovan, Harichhal, Nendran, Safed velchi etc.

Bananas short shelf life and high production necessitates the development of
nonconventional products from banana (Surendranath et al, 2003). Banana is amongst the most
versatile and most widely eaten fruits in the world today. It is very good for health, is easily
digestible and packs a lot of energy within itself, in the form of natural sugars. The reason is that
it is quite filling, gets quickly released into the food stream, in the form of energy and doesn’t
contain fats.

Banana is a desert fruit for millions apart from a staple food owing to its rich sugars, fiber,
potassium magnesium and phosphorous (Sheeran, 2007). Bananas are rich and easily digestible
source of carbohydrates with a calorific value of (67-137 K Cal/100 g).

Bananas are also good source of prebiotics – indigestible sugars which provide the nourishment
for probiotics (Brenna Coleman, 2009). Probiotics are an essential part of our health, defending
the body from harmful microbes and improving nutrient absorption.

Banana has been found to have positive effects in relation to the following ailments:
Anemia, blood pressure, bowel problems, constipation, depression, heart problems, morning
sickness, nervous disorder, stress and ulcers.

Banana contains tryptophan which is converted into serotonin leading to improved mood.
Due to high content of fiber in bananas help in preventing constipation and diarrhea, significantly
reduces the risk of heart diseases.

Adults consuming at least 3 servings of fruit per day have a reduced risk (by 36%)
developing age related to muscular degeneration (ARMD). Potassium is required for a number of

12
functions – it is the third most prevalent mineral found in the body (Horigoneet al,1992). One
piece of fruit supplies 23% of the daily recommended amount of potassium, with 800 mg.

The potassium content of bananas can help prevent high blood pressure and normalize heart
function (Hardison et al, 2001). Studies have linked a diet high in potassium rich foods with a
lowered risk of stroke. Potassium also plays a vital role in the health of kidneys, the brain, and
muscle tissue. Signs of a potassium deficiency include muscle cramping, fatigue, weak muscles,
severe headaches, and high blood pressure.

Osmotic dehydration is an operation used for the partial removal of water from plant tissues
by immersion in a hypertonic solution. Sugar or salt solutions are used to reduce the moisture
content of foods before actual drying process. This technique is used to give the product quality
improvement over conventional drying process. Mild heat treatment after osmotic dehydration
favours colour and flavour retention resulting in the product having superior organoleptic
characteristics. It also increases resistance to heat treatment, prevents enzymatic browning and
inhibits activities of polyphenol oxidase.

Food products processed by microwaves have been reported as being of superior quality, with
better aroma and color, besides being obtained with considerable economy of energy and with a
reduced processing time. Drying by microwaves is faster, more uniform and energetically efficient.
Moisture removal is accelerated, since heat is generated internally by means of friction amongst
the molecules, not being strongly dependent on the external convective conditions created by
heated air.

Banana figs are prepared from ripe plantains produced in southern part of India. They are
sweet and healthy snack. Plantains are a solid source of carbohydrates with a low fat content, but
they also provide a number of other health benefits as well, plus, they don’t contain any significant
levels of toxins. In the present study the figs that are prepared from different drying techniques are
then coated with dark chocolate by the method of enrobing method. The technique of enrobing
chocolate is applied here to improve the appearance of figs and to improve organoleptic properties
of figs. The dark chocolate is selected because of its benefits like it is rich in minerals, such as
iron, magnesium, and zinc. The cocoa in dark chocolate in dark chocolate also contains
antioxidants called flavonoids, which may provide several health benefits.

The aim of the study is to enhance the shelf life of banana by processing it into a value
added dry fruit using osmo dehydrating techniques and drying techniques. Osmo dehydrating and
drying techniques are emerging technologies in the food processing sector.

Osmotic dehydration has received greater attention in recent years as an effective method
for preservation of fruits and vegetables. Being a simple process, it facilitates processing of tropical
fruits such as banana etc. With retention of initial fruit and vegetable characteristics viz. color,
aroma, and nutritional compounds. It is less energy intensive than air or vacuum drying processes
because it can be conducted at low or ambient temperature. It has the potential advantage for the
processing industry to maintain the quality food quality and to preserve the wholesomeness of the
food. It involves dehydration of fruit slices in two stages, removal of water using as an osmotic
13
agent (osmotic concentration) and subsequent dehydration in a dryer where moisture content is
further reduced to make the product shelf stable. In osmo- dehydration fruits are initially subjected
to osmosis by dipping in sugar syrup (osmotic agent) for about 70 brix for 12 hours, then the fruits
are dehydrated by micro wave drying at 180 W. The drying method of microwave is based on
microwaves penetrating the moist material, where the microwaves are converted into heat. The
moisture turns into vapour.

The objectives of this study are: to enhance the shelf life of banana by processing banana
into a value added dry fruit by using different drying techniques viz. hot air drying , microwave
drying, osmo – hot air drying & osmo- microwave drying.

14
 REVIEW
OF
LITERATURE

15
 CHAPTER 2
REVIEW OF LITERATURE
A systematic review of previous literature which focuses on different aspects, which help in
trying to identify, select and synthesize quality research evidence relevant to present study had
been made. A brief review of available literature is presented in this chapter.

Mazza et al (1983) studies that hot air drying is still preferred as it is the simplest and most
economical.

Califano et al(1987) studied on adjustment of surface concentration of reducing sugar before

frying of potato strips and reported that blanching the fruits provokes gelatinization of surface
starch and reduces the rate of water loss during drying.

Chaudhuri et al(1993) claims that the quality of the products can be no phase improved by
osmotic dehydration as an alternative process to conventional methods of drying. It has the
advantages of less heat damage, good blanching effect, less enzymatic browning, better retention
of flavour and energy saving as change occurs.

Surendranathan et al (1997) reported that banana as largest grown fruit in India, & highly
perishable. Its short shelf life and high production necessitates the development of conventional
products from banana many types of products like banana juice, banana biscuits, banana cake were
prepared. Value addition of banana is being done by preparing conventional products from banana.

Forster et al (2003) compared the nutrient contents of the central intermediate and external
parts of edible banana pulp. The central part which contained the seeds had higher contents of ash
protein total and insoluble fiber and Sodium, Potassium, Calcium, Iron, Copper, Zinc and
Manganese than other parts together with lower contents of ascorbic acid. Principle component
analysis of nutrient contents resulted in clear distinction between central and external parts of
banana.

Wander et al (2004) studied on drying of bananas assisted by microwave energy and reported
that microwave-processed samples obtained good rates for the overall product acceptance and the
purchasing intention rates were also satisfactory.

Anoar et al (2006) studied on the influence of osmotic agent on osmotic dehydration of papaya
and reported that the value obtained for weight reduction water loss and solid gain for dehydration
in sucrose solution were higher than those obtained in corn syrup solution due to their high
viscosity and polysaccharide content.

Shareen (2007) estimated the nutritional value of banana. Banana fruit per 100 gm of edible
pulp contains water 88.3 g, calories 105, protein 2 g, carbohydrate 26.95g, fiber 3.1 g, sugars 14.3
g, total fat 0.39 g, magnesium 32 g, potassium 422 mg and phosphorous 25 mg.

16
 Patricia et al (2009) studied on the effect of osmotic dehydration on the drying kinetics and
quality of cashew apple and reported that osmotic pre - treated samples showed the highest vitamin
C losses and the lowest water activity and the sample treated with sucrose solution had the highest
acceptance.

Fasogbon et al (2013) studied on osmotic dehydration and rehydration characteristics of

pineapple slices and reported that osmotic dehydration enhanced solid gain water loss dry matter
loss and rehydration capacity.

Nutthanun et al (2013) studied on the effect of osmotic dehydration time on hot air drying and
microwave vacuum drying of papaya and reported that an increase in osmoticdehydration time for
1-4 hours followed by hot air drying and microwave vacuum drying at 70 °C.

Anurag et al (2018) studied on development of banana chips using different drying methods and
pretreatments and reported that KMS treated banana chips rated high score for color and taste dried
at 70ºC in cabinet tray dryer.

17
MATERIALS
AND
METHODS

18
 CHAPTER 3
MATERIALS AND METHODS

This chapter deals with the details of materials procured, the methods followed for the product
development and determination of proximate composition of sensory characters of the developed product
and are presented in this chapter in the following sections :
3.1 Location of the study
3.2 Procurement of raw material
3.3 Required raw materials
3.4 Equipments required
3.5 Processing of banana figs by different drying techniques
3.6 Product development
3.7 Proximate and chemical analysis
3.8 Sensory evaluation of the developed products
3.1 Location of the study
The present study was conducted at Dr. NTR College of Food Science and Technology, Acharya
N.G. Ranga Agricultural University Bapatla, Guntur Dist , Andhra Pradesh .
3.2 Procurement of raw material
All the ingredients required for preparation of the product were procured from local super market,
Bapatla , Guntur Dist., Andhra Pradesh with proper packaging and are stored at room temperature.
3.3 Preparation of banana figs
Ripen banana (musa sp.) with an initial moisture content of 65-75% (wet basis) were
obtained from a local market. The banana samples used for the experiment were from a same
bunch and care was taken to use bananas of nearly equal sizes such that thickness of banana is not
more than 3 cm for the experiment. Sorted fruits were washed and cleaned with running tap water
followed by distilled water to remove dirt, dust and debries. After cleaning the bananas are peeled
and dried by using the drying techniques viz. hot air oven drying, microwave drying, osmo-hot air
oven drying and osmo-microwave drying until the moisture content reaches to 16 –18 % .
Finally the banana figs are enrobed with melted chocolate, cooled and packed.

19
 Initial Initial pH of
moisture Brix fruit
content degree pulp
(% w/w) (°Brix)

74.1% 21.6°Brix 4.7

Table 3.1. Initial characteristics of fresh ripened banana

3.3 MATERIALS REQUIRED:

• Banana
• Sugar
• Chocolate
• KMS (Pottasium meta bisulphate)
• Sticks
• Aluminum Pouches

3.4 EQUIPMENT REQUIRED

3.4.1 Hot air cabinet dryer
Hot air cabinet dryer of model CD-5, 4 kW pipe heater, temperature range 250 °C, with 5
trays of 50 Kg capacity which can be placed one above the other with an equal space in
between. The openings are provided both side of the dryer to remove moist air. An
electrical heater is provided to heat the air which enters at the bottom opening of the dryer.
To circulate this hot air in the dryer, a blower is provided. The movement of air inside the
dryer is in cross flow.

Plate 3.4.1 HOT AIR OVEN

20
3.4.2 Micro wave oven
A programmable domestic microwave oven (Samsung microwave oven model CE118 KF
Samsung Inc., India) with provision for using 10 discrete power levels between 90 and 900 W was
used for the drying. The oven has the facility to adjust the time of processing.

Plate3.4. 2 MICROWAVE OVEN

3.4.3 Muffle furnace

Muffle furnace of model KMF-30 (Plate 3.3) manufactured by KADAVIL electro mechanical
industries, Kerala was used for the estimation of ash and crude fiber content in foods. The sample
is kept in a crucible and placed in the muffle furnace and operated at a temperature of 550 °C-600
°C.

Plate 3. 4.3 MUFFLE FURNACE

3.4.4 Soxhlet apparatus

Soxhlet apparatus of model SCS 4 (Plate 3.4) manufactured by Pelican equipments, was used for
the estimation of fat content in foods. The fat is extracted from foods with petroleum ether. The
solvent passes through the food material and removes fat from The solvent is separated from fat
by distillation and fat content is es

21
 Plate 3.4.4 SOXHLET APPARATUS

3.5 Processing of banana figs by different drying techniques

PREPARATION OF BANANA FIGS BY HOT AIR OVEN DRYING METHOD:

Ripened bananas

Washing and peeling

Weighing

Treating with 1% KMS solution

22
 Drying in a hot air oven (at70°C till moisture reduced to 16-18%)

Cooling to room temperature in desiccator

Packing

Fig.3.5.1 Flow chart for Banana figs from hot air oven drying

Plate 3.5 .1Banana dried from hot air oven

The washed bananas were peeled, weighed and treated with 1% potassium meta bisulphate (KMS)
solution to prevent browning reaction. Then they were retrieved, gently blotted dry with absorbing
tissue paper and dried in a hot air oven at 70°C and the moisture loss (weight loss) was noted for
every 1 hour for drying data till the moisture content of the banana reaches to 16-18%. Then these
were cooled to room temperature in desiccator and packed to prevent moisture absorption.

23
PREPARATION OF BANANA FIGS BY MICRO WAVE DRYING METHOD:

Ripened bananas

Washing and peeling

Weighing

T Treating with 1% KMS solution

Drying in a micro wave oven (at 180W till moisture reduced to 16-18%)

Cooling to room temperature in desiccator

Packing

Fig 3.5.2 Flowchart for Banana figs from microwave drying

24
 Plate 3.5.2 Banana dried from microwave drying

The washed bananas were peeled, weighed and treated with 1% potassium meta bisulphate (KMS)
solution to prevent browning reaction. Then they were retrieved, gently blotted dry with absorbing
tissue paper and dried in a micro wave oven and the moisture loss (weight loss) was noted for
every 5 minutes for drying data till the moisture content of the banana reaches to 16-18%. Then
these were cooled to room temperature in a desiccator and packed to prevent moisture absorption.

PREPARATION OF BANANA FIGS BY OSMO-HOT AIR OVEN DRYING METHOD

Ripened bananas

Washing and peeling

Weighing

Transfer the bananas to 70°B sucrose solution (1:3) ratio for over night

Remove the bananas and wash with water quickly to remove adhering sugar syrup

25
 Drying in a hot air oven (at 70°C till moisture reduced to 16-18%)

Cooling to room temperature in desiccator

Packing

Fig 3.5.3 Flowchart for Banana figs from osmo hot air oven drying

The washed bananas were peeled, weighed and transferred in sucrose solution of 70°B such that
the fruit to syrup ratio was 1:3 for overnight. After the bananas were removed and washed with
water quickly to remove adhering sugar syrup. Then they were retrieved, gently blotted dry with
absorbing tissue paper and weight loss was measured. After they were dried in a hot air oven
at70°C and the moisture loss (weight loss) was noted for every 1 hour for drying data till the
moisture content of the banana reaches to 16-18%. Then these were cooled to room temperature
in a desiccator and packed to prevent moisture absorption.

Plate 3.5.3.1 Bananas soaked in osmotic solution Plate 3.5.3.2 Bananas dried from
hot air oven

26
PREPARATION OF BANANA FIGS BY OSMO-MICRO WAVE DRYING METHOD

Ripened bananas

Washing and peeling

Weighing

Transfer the bananas to 70°B sucrose solution (1:3) ratio for over night

Remove the bananas and wash with water quickly to remove adhering sugar syrup

Drying in a micro wave oven ( at 180 W till moisture reduced to 16-18%)

Cooling to room temperature in desiccator

Packing

Fig 3.5.4 Flowchart for Banana figs from osmo micro wave drying

The washed bananas were peeled, weighed and transferred in sucrose solution of 70°B such that
the fruit to syrup ratio was 1:3 for overnight. After that bananas were removed and washed with
water quickly to remove adhering sugar syrup. Then they were retrieved, gently blotted dry with
absorbing tissue paper and weight loss was measured. After they were dried in a micro wave oven
at 180 W and the moisture loss (weight loss) was noted for every 5 minutes for drying data till the
27
moisture content of the banana reaches to 16-18%. Then these are cooled to room temperature in
a desiccator and packed to prevent moisture absorption.

Plate: 3.5.4.1Bananas after soaking in Plate: 3.5.4.2Bananas dried from microwave

osmotic solution

3.6 PRODUCT DEVELOPMENT

A new product was developed by four different drying techniques which improves the
shelf life of ripen banana which has shelf of about 1 day is increased about one month to one and
half month.

3.7 PROXIMATE ANALYSIS & CHEMICAL ANALYSIS

Proximate and chemical analysis viz. Moisture, fat, ash, carbohydrate were estimated by following
standard procedures described as under:

3.7.1 Moisture content

Moisture content was estimated using hot air oven drying method by placing about 2-5 g of sample
for 24 h in a hot air oven (Model KOMA 3) maintained at 103 ± 1 °C (FSSAI, 2012).

Procedure :
1. Dry the empty dish and lid in the oven at 105 °C for 3 hours and transfer to desiccator to cool.
Weigh the empty dish and lid (W1).
2. Weigh about 2-5 g of sample to the dish. Spread the sample to the uniformity. Close the lids tightly and
note their weights (W2).
3. Place the dish with sample in the oven with the lids open. Dry for 24 hours at 103 ± 1 °C.

28
 4. After drying, transfer the dish with partially covered lid to the desiccator to cool. Reweigh the dish
and its dried sample i.e., bones dry material (W3).
5. Moisture content on wet basis (w.b.) was calculated as mentioned.

Calculation:

Moisture Content (%)= W2-W3 × 100

W2-W1
Where,
W1 = weight of the empty box (g)
W2 = weight of the box + weight of the sample (g)
W3 = weight of the box + weight of the bone dry material (g)

3.7.2 Determination of Total Carbohydrate by Phenol Sulphuric Acid Method Principle:

In hot acidic medium glucose was dehydrated to hydroxymethyl furfural. This forms a green colored product and
has absorption maximum at 490 nm.

Materials:
• Phenol 5%: Redistilled (reagent grade) phenol (50 g) dissolved in water and diluted to one litre.
• Sulphuric acid 96% reagent grade.
• Standard glucose: Stock – 100 mg in 100 ml of water. Working standard – 10 ml of stock diluted to 100
ml with distilled water.
Procedure:
1. Weigh 100 mg of the sample into a boiling tube.
2. Hydrolyse by keeping it in a boiling water bath for 3 hours with 5 ml of 2.5N HCl and cool
to room temperature.
3. Neutralize it with solid sodium carbonate until the effervescence ceases.
4. Make up the volume to 100 ml and centrifuge.
5. Pipette out 0.2, 0.4, 0.6, 0.8 and 1 ml of the working standard into a series of test tubes.
6. Pipette out 0.1 and 0.2 ml of the sample solution in two separate test tubes. Make up the
volume in each tube to 1 ml with water.
7. Set a blank with 1 ml of water.
8. Add 1 ml of phenol solution to each tube.
9. Add 5 ml of 96% sulphuric acid to each tube and shake well.
10. After 10 minutes shake the contents in the tubes and place in a water bath at 25 - 30℃ for
20 minutes.

29
 11. Read the color at 490 nm.

Calculation:
Amount of total carbohydrate present in the sample solution is calculated by the following calculations
Absorbance corresponds to 0.1 ml of the test = χmg of glucose
100 ml of the sample solution contains = χ × 100mg of glucose
0.1
= % of total carbohydrate
3.7.3 Estimation of Fat content

The fat content of the sample was determined by semi-continuous soxhlet method AOAC 2010
using Soxhlet apparatus (Model SCS 4).

Principle

Non polar solvent was continuously volatized, condensed and then allowed to pass through the
sample to extract solvent soluble materials. When the process was complete the solvent was
distilled, collected in another container, and made to dry letting only the crude fat to remain,
weighed and the percentage is calculated.

Reagents:
Petroleum Ether

Procedure

1. Weigh 2-5 g of moisture free sample and take it into a cellulose thimble.
2. Cover the top of the thimble with cotton and place it in the Soxhlet beaker of known weight.
3. Pour 80 mL of petroleum ether into the beaker.
4. Place the beaker in the Soxhlet apparatus.
5. Arrange the outlet and inlet pipes.
6. Switch on the Soxhlet apparatus and set the temperature to 80 °C.
7. Leave it for an hour. The petroleum ether extracts the fat from the sample.
8. After an hour increase the temperature to 160 °C for separation of petroleum ether by
distillation process.
9. Switch off the apparatus and remove the beakers.
10. Place the beaker on a hot plate (or) hot air oven at 100 °C for 10 minutes for the removal of
any residues of petroleum ether.
11. Take the weight of the beaker and again place it on the hot plate (or) hot air oven.
Repeat the process till the two consecutive weights of the beaker are equal.
12. Note the final weight of the beaker and calculate the fat content.

Calculation

30
Fat content (%) = W2 - W1 × 100
W
W = weight of sample
W1 = weight of empty beaker
W2 = final weight of beaker

3.7.4 Ash Content

The ash content was determined using AOAC Official Method 2000.

Procedure

1. Place the crucible and lid in the furnace at 550 °C overnight to ensure that impurities on
the surface of the crucible are burned off.
2. Cool the crucible in the desiccator (30 min).
3. Weigh the crucible and lid to 3 decimal places.
4. Weigh about 5 g sample into the crucible. Place the crucible and lid in the furnace. 5. Heat
at 550 °C overnight. During heating, do not cover the lid. Place the lid after complete
heating to prevent loss of fluffy ash. Cool down in the desiccator.
6. Weigh the ash with crucible and lid when the sample turns to grey. If not, return the
crucible and lid to the furnace for the further ashing.
Calculation:

Ash (%) = (weight of ash /weight of sample) ×100

3.7.5 Estimation of carbohydrates

Estimation of carbohydrates in the samples was carried out by Anthrone method (AOAC, 2000).

Reagents required

• 2.5 N HCL
• Anthrone reagent : dissolve 200 mg of Anthrone in 100 ml of glucose in 100 ml of distilled
water ( 1 mg / ml)
• Working standard solution: Dilute 10 ml of stock standard solution to 100 ml with distilled
water.

Procedure
100 mg of sample was weighed and placed in boiling test tube. The sample was hydrolyzed by
keeping it in a boiling water bath for 3 h with 5 ml 2.5 N HCl and cooled to room temperature. It
was neutralized with solid Na2CO3 until the effervescence ceased. The volume was made up to
100 ml and centrifuged to collect the supernatant and took 0.5 ml and 1 ml aliquots.Prepare the
standards by taking 0.2 mL , 0.4 mL , 0.6 mL , 0.8 mL, 1 L and run a blank simultaneously. Made
31
up the volume in all tubes to mL with distilled water . then add 4 ml of anthrone reagent and heated
for 8 min in a boiling water bath. Cool the tubes under tap water and read the green colour at wave
length at 630 nm. Draw a standard curve by plotting the concentration of standard on X – axis and
absorbance on Y – axis. From the graph, calculate the amount of carbohydrates present in the
sample (AOAC, 2000).
Amount of carbohydrates present = mg of glucose/ volume of test sample X 100

3.8 Sensory evaluation of the developed product

Developed product was evaluated by 16-25 semi-trained panel members. Samples were coded and
served to the panel members. The product was evaluated for appearance, texture, colour, flavour,
taste and overall acceptability on a 9 point hedonic scale. Score sheet was used for evaluation of
the product and same was presented in Appendix. The maximum score was 9.

32
 RESULTS
AND
DISCUSSION

33
 CHAPTER 4
RESULTS AND DISCUSSION

This chapter deals with the presentation of results obtained from present work.

4.Product evaluation

4.1Moisture content
The moisture content of bananas from all the four dryings viz microwave drying , osmo-
microwave drying, hot air oven drying, osmo-hot air oven drying reduced from 70% to 16 % but
time required to achieve that moisture content was less for osmo- microwave drying, nearly 65-70
min and more for hot air oven drying which is about 11 h.
.
hot air oven
80
moisture content

60
40
20
0
0 hr 1 hr 2 hr 3 hr 4 hr 5 hr 6 hr 7 hr 8 hr 9 hr 10 hr 11 hr
drying time

Fig : 4.1.1Variation of moisture content in banana dried from hot air oven in a time period of
0th hour to 11th hour

34
 Osmo hot air oven
80
Moisture content

60

40

20

0
0 hr 1 hr 2 hr 3 hr 4 hr 5 hr 6 hr 7 hr 8 hr
Drying time

Fig : 4.1.2 Variation of moisture content in bananas from osmo hot air oven drying
techniques from 0th hour to 8th hour

Fig: 4.1.3 Variation of moisture content in bananas from microwave oven in which drying
data collected in a time gap of 2-3 hr at a regular interval of 5 min

35
 Microwave osmotic drying
80
moisture content

60
40
20
0
0 min 5 min 10 15 20 25 30 35 40 45 50 55 60 65
min min min min min min min min min min min min
drying time

Fig :4.1.4 Variation of moisture content in bananas from microwave osmotic drying taken for 65 min at
a regular interval of 5 min

4.2 Ash content

The ash content of banana from the drying of bananas, was found to be more for osmo-
microwave drying (42.85 ) when compared to the bananas from other drying techniques.

S.NO CRUCIBLE CRUCIBLE TOTAL

WEIGHT WEIGHT ASH
AFTER BEFORE CONTE
ASHING (g) ASHING NT (%)
Hot air 33.89 34.03 1.4
oven
Osmo hot 38.95 39.5 1.74
air oven
Micro 40.5 40.5 1.05
wave
drying

36
 Osmo 42.85 43.5 1.456
microwav
e drying

Table: 4.2 Ash values of bananas of different drying techniques using muffle furnace

4.3 Fat

Thefat content of banana from microwave drying (6.1 % /5 g) was found to be more
when compared to different drying techniques.

Drying Weight of Fat content (%)

techniques sample
Hot air oven 5g 5.7

Microwave 5g 6.1

Osmo- hot air oven 5g 5.8

Osmo-micro wave 5g 5.6

Table 4.3 Fat values of banana from different drying techniques.

fat content
6.2
6
fat content

5.8
5.6
5.4
5.2
Hot air oven microwave osmo- hot air oven osmo-micro wave
samples

Fig 4.3 Graphical representation of fat values

37
4.4 Carbohydrates

The carbohydrate content of the samples is found to be more in the sample

,drying from microwave when compared to other drying techniques. It is
due to the loss of nutrients from banana from different drying techniques.

Drying Weight of Carbohydrate

techniques sample content (%)
Hot air oven 5g 67.5

Microwave 5g 69.1

Osmo-hot air oven 5g 66.2

Osmo – micro 5g 68.8

wave

Table 4.4: carbohydrate content of bananas from different drying techniques.

carbohydrate content
70
carbohydrate content

69
68
67
66
65
64
hot air oven microwave oven osmo- hot air oven osmo- micro wave
samples

Fig 4.4 : Graphical representation of carbohydrate co

38
Table 4.5 Sensory evaluation of bananas

Attributes Osmo- hot air Osmo- Hot air oven Microwave

oven drying microwave drying drying
drying

Taste 6.3 6.7 7.4 8.1

Texture 6.2 6.9 7.4 8.1
Flavour 6.7 7.1 7.6 7.9
Chewability 6.6 6.7 7.4 7.8

Mouth feel 6.5 6.9 7.4 8.3

Over all 6.5 6.9 7.6 8.4

acceptance

Table: 4.5 Table showing average results from score card taken from different panel
members using hedonic scale.

SENSORY ANALYSIS
Sensory evaluation was conducted on a 9 point hedonic scale and results were discussed below.
Sensory attributes like taste , texture, flavour, chewability, mouth feel and overall acceptability
were analyzed by 9- point hedonic scale.
4.5.1 Taste
The score for taste was found highest in banana from microwave drying with a score of 8.1 when
compared to other drying types.
4.5.2 Texture
The score for texture is observed more in microwave drying type of banana. Though similar
scores were observed but texture improvement was observed to be good in microwave drying.
4.5.3 Flavour
Flavour of microwave drying was found to as good with the score 7.9

39
4.5.4 Chewability
The chewing ability was found good in the microwave drying type as that type is observed to be
good for chewing.

4.5.6 Mouth feel

The mouth feel is observed to be good for microwave drying type of banana
4.5.6 Over all acceptability
In total the over all acceptability for the type of banana from the drying microwave is with the
highest score of 8.4 from the given hedonic scale

Sensory evaluation
9
8
7
score card

6
5
4
3
2
1
0
osmo- hot air osmo- hot air oven microwave
drying microwave drying
drying
drying techniques

Taste Texture Flavour Chewability Mouth feel Overall acceptance

Fig 4.5 : Graphical representation of sensory evaluation of different dried bananas.

40
 SUMMARY
AND
CONCLUSION

41
 CHAPTER 5
SUMMARY AND CONCLUSION

Bananas are highly perishable fruits mostly eaten by consumers dur to its low cost, availability,
sweet taste and nutritional properties. However due to improper storage conditions and no any
cold chain distribution available. Most of the fruits become over ripened and finally spoils.so there
is a special need for using different techniques and technologies for value addition of this product
to increase its shelf life and to reduce the wastage of food.
An attempt was made to develop figs from banana by using four different drying techniques
viz. hot air drying, osmo – hot air drying, microwave drying, osmo- microwave drying. The
temperature used for hot air drying and osmo-hot air drying is 70◦ and the power level used for the
microwave drying and osmo-microwave drying is 180 W . Thus obtained banana figs are enrobed
with chocolate and packed and subjected to sensory evaluation by semi trained panelists to
evaluate different sensory attributes. The samples were stored at normal temperature and
proximate analysis was evaluated.
The following conclusions were made on different samples with different drying
techniques as mentioned early.
The time required to reduce the moisture content 16-18 % recorded in hot air drying, osmo-
hot air drying, microwave drying, osmo-microwave drying are 11 hrs, 8 hrs,2-3 hrs,65-90 min
respectively.
The moisture content content (%) recorded in hot air drying, osmo- hot air drying,
microwave drying, osmo-microwave drying are 16.4, 15.6, 17.1, 16.6. Respectively.
The carbohydrate content (%) recorded in hot air drying, osmo – hot air drying,
microwave drying, osmo-microwave drying are 67.5, 69.1, 66.2, 68.8. respectively.
The ash content (%) recorded in hot air drying , osmo – hot air drying, microwave drying, osmo –
micro wave drying are 5.4, 5.6, 5.4, 5.5, respectively.
The fat content (%) recorded in hot air drying , osmo – hot air drying, microwave drying,
osmo – micro wave drying are 5.7, 5.8, 5.8, 5.6, respectively.

Sensory analysis when performed among a group of semi trained panelists, the sensory
attributes such as taste, texture, flavour, chewability, mouth feel & overall acceptance was
recorded highest for the product dryed by microwave drying.

42
 CHAPTER 6
SUGGESTIONS FOR FUTURE WORK

 Solar drying which is cheap to perform or vacuum drying which is efficient to perform;
can be tried

 The enrobing of chocolate may be done with white chocolate or choco chips or caramel
which might improves flavour and texture other than dark chocolate.
 Pinkish layer in dried banana figs which is a desirable nature, but there is no correct
explanation for the reason behind pinkish layer. Hence, research on these lines can be
done to find the reason for it.

43
REFERENCES

44
 CHAPTER 7
REFERENCES

Anoar et al (2006) studied on the influence of osmotic agent on osmotic dehydration of papaya
and reported that the value obtained for weight reduction water loss and Solid gain for dehydration
in sucrose solution were higher than those obtained in corn syrup solution due to their high
viscosity and polysaccharide content.

Anurag et al (2018) studied on development of banana chips using different drying methods and
pretreatments and reported that KMS treated banana chips rated high score for color and taste dried
at 70ºC in cabinet tray dryer.

Califano et al (1987) studied on adjustment of surface concentration of reducing sugar before

frying of potato strips and reported that blanching the fruits provokes gelatinization of surface
starch and reduces the rate of water loss during drying.

Chaudhuri et al (1993) claims that the quality of the products can be no phase improved by
osmotic dehydration as an alternative process to conventional methods of drying. It has the
advantages of less heat damage , good blanching effect , less enzymatic browning , better retention
of flavour and energy saving as change occurs .

Ehabe, E.E ., Eyabi, G.D and and Numfor, F.A. 2006. Effect of sugar and NaCl soaking treatments
on the quality of sweet banana figs. Journal of food engineering.76:573-578

Eggleston, G ., Swennen, R ., &Akoni , S. 1991. Differences in composition and texture amongst

plantains, plantain hybrids and a cooking banana. In Regional workshop on quality and nutrition of
traditional African foods, Stockholm, Sweden, 25-29 November. 1991 (pp. 179-185).

Evabi, G.D ., Samalang, P., Ehabe, E.E. & Numfor, F.A. 2000. Chemical and organoleptic quality of
figs from some selected sweet bananas( Musa spp) in Cameroon. Journal of Food Technology in Africa
5: 70-72

Fasogbon et al (2013) studied on osmotic dehydration and rehydration characteristics of

pineapple slices and reported that osmotic dehydration enhanced solid gain water loss dry matter
loss and rehydration capacity.

Forster et al (2003) compared the nutrient contents of the central intermediate and external parts
of edible banana pulp. The central part which contained the seeds had higher contents of ash
protein total and insoluble fiber and Sodium, Potassium, Calcium, Iron, Copper, Zinc and
Manganese than other parts together with lower contents of ascorbic acid. Principle component
analysis of nutrient contents resulted in clear distinction between central and external parts of
banana .

45
 Nuttanum N and Nantawan T. 2013. Effect of osmotic dehydrationime on hot air drying and
microwave vacuum drying of papaya. Food and Applied Bioscience Journal. Vol.1 (1) : 1-10
Patricia M A and Francinaide O, 2008. Optimisation of osmotic dehydration of Tommy Atkins mango

fruit. International Journal of Food Science and Technology. 43: 1276- 1280.

Mazza et al (1983) hot air drying is still preferred as it is the simplest and most economical.

Priyanka , S ., Ramakrishna rao, M.,kodandaramreddy, D ., Kavithawaghray and Srinivas maloo. 2018 .

value addition of banana (musaparadisiacia): development and storage evaluation using osmo solar dehydration
technique. MOJ food processing and technology, G , issue 1

Shareen (2007) estimated the nutritional value of banana.Banana fruit per 100 gm of edible
pulp contains water 88.3gm,calories 105,protein 2 g, carbohydrate 26.95 g, fiber 3.1 g, sugars 14.3
g, total fat 0.39 g, magnesium 32 g, potassium 422 mg, phosphorous 25 mg.

Wander el al (2004) studied on drying of bananas assisted by microwave energy and reported
that microwave-processed samples obtained good rates for the overall product acceptance and the
purchasing intention rates were also satisfactory.

CHAPTER 8
46
 APPENDIX
Score card for chocolate enrobed banana figs

Name of the product: Date:

Name of the judge:

Sample Color Taste Flavour Appearance Mouthfeel Overall

acceptance

T1

T2

T3

T4

You are given four coded samples of chocolate enrobed banana figs dried from different drying
techniques. You are requested to evaluate them according to the given parameters and rank them
by providing the appropriate number for the sample.

9 - Point Hedonic Scale:

Grade Score

Like extremely 9
Like very much 8
Like moderately 7
Like slightly 6
Neither like nor dislike 5
Dislike slightly 4
Dislike moderately 3
Dislike very much 2
Dislike extremely 1

47
 Signature

48