STUDY ON PHYSICO-CHEMICAL CHARACTERISTICS OF JACKFRUIT AT DIFFERENT HARVESTING TIMES AND THEIR SHELF LIFE
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
STUDY ON PHYSICO-CHEMICAL CHARACTERISTICS OF
JACKFRUIT AT DIFFERENT HARVESTING TIMES AND
THEIR SHELF LIFE
A Thesis
By
Examination Roll No. 11Hort. JJ-03 M
Registration No. 33171
Semester: January-June 2012
Session: 2006-2007
MASTER OF SCIENCE (MS)
IN
HORTICULTURE
DEPARTMENT OF HORTICULTURE
BANGLADESH AGRICULTURAL UNIVERSITY
MYMENSINGH
May, 2012
STUDY ON PHYSICO-CHEMICAL CHARACTERISTICS OF
JACKFRUIT AT DIFFERENT HARVESTING TIMES AND
THEIR SHELF LIFE
A Thesis
By
Examination Roll No. 11Hort. JJ-03 M
Registration No. 33171
Semester: January-June 2012
Session: 2006-2007
Approved as to the style and contents by:
------------------------------------
(Professor Dr. M. A. Rahim)
Supervisor
-----------------------------------------------------
(Associate Prof. Dr. Md. Mokter Hossain)
Co-supervisor
---------------------------------------------
(Professor Dr. Md. Kamrul Hassan)
Head
Department of Horticulture
Bangladesh Agricultural University
Mymensingh
May, 2012
STUDY ON PHYSICO-CHEMICAL CHARACTERISTICS OF
JACKFRUIT AT DIFFERENT HARVESTING TIMES AND
THEIR SHELF LIFE
A Thesis
By
Roll No. 11Hort. JJ-03 M
Registration No. 33171
Semester: January-June 2012
Session: 2006-2007
Submitted to
The Department of Horticulture
Bangladesh Agricultural University, Mymensingh
In partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
HORTICULTURE
DEPARTMENT OF HORTICULTURE
BANGLADESH AGRICULTURAL UNIVERSITY
MYMENSINGH
May, 2012
ACKNOWLEDGEMENT
All praises are for the omniscient and omnipresent to the Almighty Allah
Who has kindly given the ability to complete this research work and finally
to prepare thesis in time.
The author avails the opportunity of conveying his deepest sense of
gratitude, respect, immense indebtedness and profound appreciation to his
honorable and reverend teacher and Supervisor, Professor Dr. M. A. Rahim,
Department of Horticulture, Bangladesh Agricultural University,
Mymensingh for his continuous supervision, untiring assistance, scholastic
guidance, continuous inspiration, constant help, helpful comments and
constructive criticism throughout the whole period of this research work and
in preparing this manuscript.
The author would like to express his heartiest respect, gratefulness,
Indebtedness and profound appreciation to his Co-supervisor, Dr. Md.
Mokter Hossain, Associate Professor, Department of Horticulture,
Bangladesh Agricultural University, Mymensingh for his scholastic
guidance, constructive help, far sighted suggestion and wholehearted co-
operation in completing this thesis.
The author expresses his deepest sincere thanks to the authority of Fruit
Tree Improvement Project (FTIP), BAU, funded by Swiss Agency for
Development and Co-operation (SDC), Dhaka for logistic support for the
experiment. He thankfully acknowledges for the help and co-operation of all
the stuff members of the FTIP and the Department of Horticulture.
The author desires to acknowledge his immense indebtedness to Associate
Prof. Dr. Md. Tofazzal Hossain, Head of the Department of Biochemistry
and Molecular Biology, Bangladesh Agricultural University, Mymensingh.
iv
The author also wishes to express his heartfelt indebtedness to his father and
mother, uncle, aunty, elder brother and sisters specially Sadia, Samia,
Najia, Zinia and Sonya.
Finally, the author expresses his boundless gratitude to his all friends
specially Abdur Razzak, Mansurul Haq and Mehedi Islam Khan and well
wishers for their encouragement and instant help during this study.
The Author
May, 2012
v
ABSTRACT
A study on physico-chemical characteristics of four types of jackfruit
namely Baishakhi, Khaja, Ghila and Dorosha at three different harvesting
times and their shelf life was carried out at the Bangladesh Agricultural
University Germplasm Centre (BAU-GPC) of Fruit Tree Improvement
Programme (FTIP), Bangladesh Agricultural University, Mymensingh. It
was conducted during the period of April to August 2011. The study was
conducted in a Randomized Complete Block Design (RCBD). Physical
characteristics of fruit such as size, shape and weight of fruit, number of
bulbs per fruit, juiciness of bulb, bulb and seed weight, shape and colour,
weight of rachis and rind, percentage of viviparous germination, percentage
of bulbs, seeds, rachis and rind, weight of edible and non-edible portion
were determined. Chemical characteristics such as total soluble solids (TSS),
dry matter, moisture content, total ash, pH, vitamin C, total sugar, reducing
and non reducing sugar were also determined from matured jackfruit at three
different harvesting times such as early, mid and late.
Weight of fruit, bulb, rachis and rind were varied in four types of jackfruit at
three different harvesting times. Juiciness, taste of bulb, flavour, fibre
content also varied. Considering colour, flavour, appearance and taste of
Ghila was found to be superior to others. Physico-chemical characteristics of
four types indicated that bulb weight (kg) decreases and rind weight
increases at later stages of harvesting. The bulb of Ghila was very soft at
early harvesting stage but firm at late. Edible portion was found to be the
highest (53.13%) in mid harvesting time and Dorosha type gave minimum
(45%) at late harvesting. On the other hand, Baishakhi gave the maximum
(61.11%) average percentage of edible portion followed by Khaja, Dorosha
vi
and Ghila. The fruit of late harvesting time had viviparous germination. Dry
matter, ash content of bulb was gradually increased from early to late
harvesting time. Baishakhi and Khaja type gave the highest percentage of
ash and dry matter while it was minimum in Ghila and Dorosha type. Total
soluble solid was increased at mid harvesting time and Ghila was found
comparatively higher percentage of TSS followed by Baishakhi, Khaja and
Dorosha. Early and mid harvesting time were found to be better in all the
four types of jackfruit. Incase of shelf life, the result showed that up to 150
days of storage of bulb the colour and flavour were unchanged but the
appearance of Ghila and Dorosha were found to be slightly changed after 90
days when there was no changed in appearance of Baishakhi and Khaja till
120 days at refrigerated temperature the colour of pulp of Ghila and Dorosha
was found to be changed after 4 days while the colour of pulp of Khaja and
Baishakhi remain unchanged. On the other hand, all types of jackfruit pulp
were found to be fully unacceptable at room temperature after 2 days. It was
noticed that the pattern of quality deterioration of pulp might be used for
identification of microorganism which are responsible for spoilages.
vii
CONTENTS
Chapter Title Page No.
ACKNOLEDGEMENT iv
ABSTRACT vi
CONTENTS vii
I INTRODUCTION 1
II REVIEW OF LITERATURE 4
2.1 Physical characteristics of jackfruit 4
2.2 Chemical characteristics 10
2.2.1 Taste, colour, flavour and fibre content of bulb 11
2.2.2 Moisture and dry matter 12
2.2.3 Total ash 12
2.2.4 Total soluble solids 13
2.2.5 pH of the jackfruit bulb 13
2.2.6 Ascorbic acid 13
2.2.7 Total sugar, reducing sugar and nonreducing 14
sugar
2.2.8 Storage behavior under different conditions 14
III MATERIALS AND METHODS 17
3.1 Physico-chemical characteristics of four types of 17
jackfruit at different harvesting time
3.1.1 Materials 17
3.1.2 Stages of harvesting 18
3.1.3 Experimental design 19
3.1.4 Methods 19
3.1.5 Physical parameters of fruits 19
3.1.6 Chemical parameters of fruits 20
3.2.1 Fruit weight 20
3.2.2 Size of the fruits 21
3.2.3 Shape of the fruit 21
3.2.4 Skin colour of the fruit 21
viii
3.2.5 Colour, nature, flavour and sweetness of bulb 21
3.2.6 Size of the bulb 21
3.2.7 Rind colour 21
3.2.8 Weight of different parts of fruits 22
3.3 Chemical Characteristics 22
3.3.1 Moisture 22
3.3.2 Dry matter 22
3.3.3 Total Ash 23
3.3.4 Total soluble solids (TSS) 23
3.3.5 pH of the juice of jackfruit bulb 23
3.3.6 Reducing sugar 23
3.3.7 Total sugar 24
3.3.8 Non Reducing sugar 24
3.3.9 Ascorbic acid (Vitamin C) 25
3.3.10 Colour, nature, flavor and sweetness of bulbs 25
3.4 Shelf life: Storage behaviour of three types of
jackfruit pulp and procedure of work
3.4.1 Deep freeze 26
3.4.2 Refrigerator 26
3.4.3 Room temperature 26
IV RESUILTS AND DISCUSSION 27
4.1 Physica1 characteristics of jackfruit types at
different harvesting time 27
4.1.1 Size, shape and weight of fruit 27
4.1.2 Number of bulbs per fruit, size and juiciness of
bulb 29
4.1.3 Bulb weight 33
4.1.4 Seed weight, shape and colour 33
4.1.5 Weight of rachis 34
4.1.6 Weight of rind 36
4.1.7 Percentage of viviparous seed 37
4.1.8 Percentage of bulb, rachis and rind 38
4.1.9 Rind colour of fruit 41
4.1.10 Weight of edible portion (bulb and seed) 41
4.1.11 weight of non-edible portion (axis and rind) 48
4.2 Chemical characteristics of jackfruit at different 38
harvesting time
4.2.1 Total soluble solid 39
4.2.2 Dry matter 50
4.2.3 Moisture content 51
ix
4.2.4 Total ash 51
4.2.5 Taste, colour and flavour of the pulp 52
4.2.6 Texture and fibre content of bulb 53
4.2.7 pH of the juice of jackfruit bulb 53
4.2.8 Vitamin C (Ascorbic acid) 53
4.2.9 Reducing sugar 55
4.2.10 Non-reducing sugar 55
4.2.11 Total sugar 56
4.3 Post-harvest handling 57
4.3.1 At the frozen temperature 57
4.3.1.1 Total soluble solid 61
4.3.1.2 Total sugar, reducing sugar and non-reducing
sugar of jackfruit pulp 61
4.3.1.3 Vitamin C 61
4.3.2 At the refrigerated temperature 63
4.3.3 At room temperature 64
v SUMMARY AND CONCLUSION 66
REFERENCES 69
APPENDICES 73LIST OF TABLES
Table Title Page
No.
1 Effect of types on physico-chemical characteristics of 30
jackfruit
2 Effect of treatment on physico-chemical characteristics of 31
jackfruit
3 Effect of harvesting times on the physico-chemical
characteristics of jackfruit 36
4 Effect of types on the physico-chemical characteristics of 36
jackfruit bulb
5 Effect of harvesting times on the physico-chemical 43
characteristics of seed:
6 Effect of varieties/ types on the physico-chemical 43
characteristics of seed
Effect of harvesting times on the chemical characteristics of
7
jackfruit 44
8
Effect of varieties/ types on the chemical characteristics of 44
jackfruit
9 Combined effect of treatment and variety on the
physico- chemical characteristics of jackfruit 46
10 Combined effect of treatment and variety on the physico-
46
chemical characteristics of jackfruit
xi11 Combined effect of treatment and variety on the physico-
chemical characteristics of jackfruit
49
12 Changes in physical characteristics of jackfruit pulp
54
13 Chemical characteristics of four types of jackfruit pulp
during storage at frozen temperature 54
14 Changes of different chemical characteristics of jackfruit
57
pulp (average of four types) at frozen temperature
15 Changes in physical characteristics of four types of jackfruit
pulp at refrigerated temperature 58
16 Changes in physical characteristics of jackfruit pulp at room 60
temperature
17 Chemical characteristics of four types of jackfruit pulp 62
during storage at frozen temperature
18 Changes of different chemical characteristics of jackfruit
pulp (average of four types) at frozen temperature 62
19 Changes in physical characteristics of four types of jackfruit
pulp at Refrigerated temperature (70 ± 2 0 C) 64
20 Changes in physical characteristics of jackfruit pulp at room
64
temperature (250 - 30 0 C)LIST OF PLATES
Plate Title Page
No. No.
1 Different parts of Baishakhi type jackfruit (Artocarpus
34
heterophyllus)
Viviparous germination at different harvesting times
2 38
Different parts of Khaja type jackfruit(Artocarpus
3 heterophyllus) 40
Different parts of Ghila type jackfruit (Artocarpus
heterophyllus)
4 45
Different parts of Dorosha type jackfruit (Artocarpus
heterophyllus) 47
5
xiiiLIST OF APPENDICES
Appe Title Page
ndix No.
I Monthly record of temperature, relative humidity, rainfall
and sunshine during the period from January to December,
74
2011.
II
Analysis of variance of the data on physico-chemical
characteristics of jackfruit 75
III Analysis of variance of the data on physico-chemical
characteristics of jackfruit 76
ABBREVIATONS
BAU = Bangladesh Agricultural University
BBS = Bangladesh Bureau of Statistics
DH = Department of Horticulture
FAO = Food and Agricultural Organization
FTIP = Fruit Tree Improvement Programme
GPC = Germplasm Centre
LSD = Least Significant Different
RCBD = Randomized complete Block design
TSS = Total Soluble Solid
xivDedicated
To
My Beloved Parents
and
UncleINTRODUCTION
Jackfruit (Artocarpus heterophyllus Lam.) is one of the important and
delicious fruit in Bangladesh. It has gained the position of national fruit of
Bangladesh due to its popularity and various features. Jackfruit is
economically important throughout the tropical region of Asia. It contributes
to about 18% to the total fruit production of Bangladesh. During the year of
2008-09, it ranks first in production among the fruits growing in Bangladesh
(BBS, 2009). It is growing and sold in the market almost every where in the
country. Jackfruit is the largest among the edible fruit in the world. These
large, irregular shaped oval fruits grow directly from the main branches and
the trunk of the tree on a short stem.
In Bangladesh, it ranks second in production and third in area among the
fruits. It is a member of the family of Moraceae. The family comprises of 55-
67 genera and 900-1000 species (Baily, 1949). The genus Artocarpus
contains eight species which bear edible fruit.
Jackfruit plants are very useful and important as a timber for making
furniture. The immature fruits are used as vegetable and make an excellent
dish when cooked alone or in combination. The ripe fruit is eaten fresh. It
can be made into preserve as well jams, beverage, candies and hydrated
forms are other industrial uses to which the jackfruit can be utilized (Naik,
1949). The seeds are also eaten either roasted or boiled or used in curry.
Juice of ripe fruit makes an excellent desert when mixed with rice flakes
alone or in combination with milk. The people of Bangladesh particularly
have much liking for this fruit which at times substitute/supplement their
staple food. So, it is recognized as ‘National fruit’ of Bangladesh.
The production of jackfruit in Bangladesh was 2, 67,495 tons, from an area
of 66,765 hectares (BBS, 2009). Jackfruit is cultivated in Bangladesh from
time of immemorial and it is distributed throughout the country. It seems to
1be originated from the western region of India (Samaddar, 1990) and then
spread to Malaysia and East Africa (Dutton, 1976). At present it is cultivated
in Bangladesh, India, Burma, Southern China and to a limited extent in
Queensland (Australia) and Mauritius (Morton, 1965). The jackfruit grows
well in Dhaka, Mymensingh, Rangpur and Jessore regions of the country.
Jackfruit may contribute to the nutrition of the people of the country as a
source of minerals, vitamins and sugars etc. which are essential in the daily
diet. It contains 0.99 mg minerals, 20 mg calcium, 0.5 mg iron 4700 mg β-
carotene, 11 mg thiamine.
The jackfruit is a seasonal fruit and is available from May-July. In
Bangladesh, there exist many types of jackfruits. Kamaluddin (1966) and
Samadder (1990) identified two types of jackfruit in Bangladesh namely,
Khaja with a firm and crispy pulp and Ghila with soft and juicy pulp. Haque
(1993) identified three types of jackfruit such as Khaja, Ghila and Dorosa.
The bulb of Dorosa is medium soft to soft, juicy and fairly sweet.
Anonymous (1997) identified that the texture of bulbs become crispy when
the fruits harvested in the later part of the season. Juiciness and flavour is
reduced and it turns into insipid in taste. Fruits of early harvesting time are
nearly regular in shape but late season fruits are mostly irregular. It was also
observed that dry matter, ash were gradually increased with the harvesting
time from early to late in the season. Again, TSS was135 found to be the
highest at early harvest while it was the lowest at late harvest. Weight of
fruits and number of bulbs also varied at different harvesting times.
Viviparity was found the highest in the late harvest (Azad, 1989).
Post harvest loss of fresh fruit is one of the important problems in the
tropics, which occurs at all stages of marketing chain. These losses in
quantity and quality of produce occur in all societies. Unfortunately, they
tend to be the highest in those areas where the need is the highest.
2Conservatives estimates of losses indicate that for more perishable produce
the loss exceeds 20% roots and tubers and 30% of fruits and vegetables.
Post harvest losses also waste scarce production resources such as water,
land and labour. Moreover, the waste of production resources can negatively
affect agricultural sustainability. The indigenous fruits are often picked
either when immature or at and advanced stages of maturity where inherent
physiological developments render them susceptible to injury if subjected to
rough handling during harvest and transportation (Watt, 1963). Lack of
transportation also causes uneven distribution of harvested fruit. During
harvesting, a large portion of fruit crops are wasted due to microbial
infestation, improper handling and lack of processing and promotional
activities, transportation, storage and marketing and loss of highly perishable
fruit like jackfruit may be as high as 35-50 percent (Corner, 1951).
The physico-chemical characteristics of jackfruit like shape, size of fruit,
bulb texture, seed content, edible and non edible portion, moisture, ash, TSS
etc. may vary among the types. Again they may vary with the harvesting
time. In Bangladesh, some studies on physico-cilemical changes in Ghila
type have been done by several investigators but such information on,
Baishakhi, Khaja, Ghila and Dorosa types in different harvesting time is still
lacking. Hence, the present study was undertaken to fulfill the following
objectives:
1) to study the physico-chemical characteristics of different types of jackfruit
at different harvesting times ;
2) to determine appropriate time of harvesting; and
3) to study the shelf life of different jackfruit types .
3REVIEW OF LITERATURE
The jackfruit (Artocarpus helerophyllus Lam.) belongs to Moraceae family.
Purseglove (1968) stated that jackfruit is a popular fruit in India and Ceylon.
In Philippines, it is reported to have great export potential (Corner, 1951).
Although jackfruit is one of the most important tropical fruit, limited study
has so far been made on its physico-chemical characteristics. A review of the
available information relating to the present study is presented below under
separate headings.
2.1 Physical characteristics of jackfruit
Anonymous (1997) worked with physico-chemical characteristics of Ghila
type at three different harvesting times and reported the physical
characteristics such as weight of fruit, bulb, seed, Rachis, rind and their
percentage. The characters studied at different harvesting times were varied.
The early season fruits were nearly regular and uniform in shape but fruits of
late season were mostly irregular. Again early season fruits were larger (7.32
kg) in weight while those in the late season were smaller (5.74 kg) and the
number of bulbs per fruit also varied 95.78 to 115 from early to late
harvesting. Rind content of jackfruit was 36.28, 41.31, 48.44 percent at
early, mid, late harvesting, respectively while rachis and seed constituted on
an average 0.55 kg and 0.76 kg at different harvesting time. Maximum
percentage of viviparous seeds (59.44%) was found at late harvesting. Early
harvesting time had no viviparous seed. The viviparous seeds lose their
roasting quality and become tasteless.
Azad (1989) observed that fruits of early season were larger in weight (7.1
kg) while those in the late season were smaller (4.6 kg). He stated that the
shape of fruits was also varied distinctly in different seasons. Early season
fruits were nearly regular or uniform in shape but the fruits of the late season
were mostly irregular. He further mentioned that lesser weight of fruits at the
4late season might be due to lack of adequate supply of nutrient since plants
might be exhausted of their food because of development of early season
fruits. The other reasons for lower weight of fruits at late season were lesser
number of fruit lets due to sterility or partial non availability of pollens or
lack of sufficient fertile flowers. He reported that there was effect of season
or harvest time on the quality of fruits and flavour of the fruits was found to
be degraded. Again, plants produced fruits having 48.5 percent viviparous
seed at late harvest and viviparity might be varietal characters associated
with late harvest of fruits.
Ferminger (1947) reported two types of jackfruit to be Khaja which had
green rind, firm flesh and small seeds; Ghila reddish rind, soft flesh, juicy
and sweet while Mowry (1943) identified the two principal types of Ceylon
jackfruit as the (1) Waraka distinguished by a firm fruit which was
recognized by the sound when flicked with the fingers and (2) Vela
characterized by its softer bulbs, through which the finger may be thrust
when approached ripeness. Waraka which was less sweet than the other type
vela or honey jack.
Hossain and Haque (1977) studied ten different selected jackfruit plants and
observed that the rind colour in most of the cases at ripening stages were
yellowish-green, light-green or pale green. Kamaluddin (1966) stated that
jackfruit had different colour like pale green, reddish, yellow and brownish.
Anonymous (1996) studied physico-chemical characteristics of three type of
jackfruit at different stages of ripening and during storage at different
condition and found rind colour of three types of jackfruit was varied at
different ripening stages. In case of Ghila type of jackfruit rind colour was
greenish yellow at half ripe stage and reddish yellow at ripe stage. On the
other hand, Khaja remains green at half ripe stage and it is somewhat faded
in ripe stage. Dorosha was light yellow and yellow colour at half and ripe
5stages. Corner (1951) observed that the rind of the fruit was green and it had
been yellow when ripe. Purseglove (1968) mentioned that the rind colour of
jackfruit was yellow at the ripe stage. Dutta (1956) studied the jackfruit of
Asam, India and found the colour of rind was usually pale brown and
occasionally pale green.
Kamaluddin (1966) reported that, being cross and mostly seed propagated
the jackfruit has innumerable types considering the fruit characteristics
differing in density of spikes on the rind, bearing habit, size, shape, quality
of fruit and period of maturity. He identified two principal types of jackfruit
in Bangladesh namely, the Khaja with a firm and crispy pulp and the Ghila
with soft and juicy pulp. The nature of bulb was different among varieties.
He also reported that fruit weight to be 1.86-2.7 kg to 18.6-37.2 kg. But the
normal size ranged from 5-10 kg and the fruits to be round or irregular in
shape. Singh et al. (1963) reported that the jackfruits were of different types.
Some had soft flesh considered to be mushy and sweet when ripe; those of
another types had firm or crispy flesh and more pronounced flavour; and
there was a small fruited variety called rudrakshi with a relatively smooth
rind and of inferior quality.
Khanom et al. (1994) described in “The Wealth of India” that there were two
common varieties: Kapa and Barka; the former have sweet pericarp and the
later which was considered inferior had a thin mucilaginous and sour
pericarp. He also stated that the seed content of about 5.15 percent of the
total weight of the fruit.
Dutta (1956) studied the jackfruit of Asam, India and he suggested the fruits
to be broadly divided into two groups based on pulp characters e.g. (i) Ghila
containing soft and melting pulp. Colour varies from pale yellow to dark or
golden yellow, taste is sweet. (ii) Khaja having hard pulp with apple like
consistency; pulp is sweet; pale yellow to whitish yellow in colour. In certain
6cases the edible bulb is half hard (basal end) and soft (apical end). Juice was
scanty. He also mentioned that most of the seeds are egg shaped or ovate and
smaller, medium and large in size.
Sturrock (1959) reported that the jackfruit was one of the largest fruit
ranging from 30, 48 cm to 76.20 cm long and from 20.32 cm 25.40 cm thick
but weighed varied from 9 to 13 kg. Bhatia et al. (1955) and Mowry et al.
(1953) reported the fruits to be 20.32 to 91.44 cm long and 15 to 50.80 cm
wide and weighing 4.30 to 18.00 kg or more. Purseglove (1968) reported
jackfruit to be the biggest of all cultivated fruits, 30-90 x 25-50 cm in size
and the jackfruits to be barrel or pear shaped. The edible bulb and seeds
composed about 28.7 to 30 percent and 5 percent of the fruit respectively.
Hossain and Haque (1977) studied jackfruit of ten different selected plants
having fruits ranging from 3.24 to 7.39 kg in weight and 25 x 20 to 39 x 28
cm in size. The fruit was oval, cylindrical, irregular and pear shaped. The
length of fruit ranged from 18 to 41 cm and diameter from 17 to 28 cm
having the average length and diameter 31.6 cm and 22.4 cm, respectively.
The length of bulbs varied from 4.1 to 8.5 cm, width from 2.6 to 5.0 cm and
the number of bulbs of jackfruit varied from 30 to 185. Seed content of ten
different types ranged from 6.40 to 13.67 percent having an average of
10.44. The rind content in the range of 16.48 to 70.89 percent while the
bulbs, rachis constituted on an average 9.93 to 66 and 5.83 to 1.59 percent
showing an average of 9.16 percent.
Haque (1977) made a preliminary survey on the types of jackfruit at the
Bangladesh Agricultural University campus and its surrounding villages. He
found that most of the fruits of different plants were medium in size, each
weighing in the range of 3.5 to 12.6 kg and had an average weight of 6.5 kg.
The fruit was oval, cylindrical, pear shaped and irregular. Again he found
mainly three types of pericarp namely, soft or very soft, hard and
7intermediate and the number of bulbs per fruit also varied 43 to 230. The
size of the bulbs was mostly medium to big. He also stated that there was no
relationship between weight and size with the number of bulbs per fruit.
Haque (1991) studied jackfruit trees of Bhaluka, Trishal and Kotwali Thana
of Mymensingh district and found the fruits to be 4.5 to 11.5 kg in weight.
Anonymous (1996) studied physico-chemical characteristics of three types
of jackfruit at different stages of ripening and during storage at different
condition and observed the weight of three types of jackfruit namely, Ghila,
Dorosa and Khaja were on an average 5.2, 5.267 and 5.267 kg, respectively.
The highest (108) number of bulb per fruit was found in the type of Ghila
while lowest (61) in the type of Khaja. The rind percentage was 57.17, 46.45
and 40.05 in Khaja, Ghila and Dorosa. The weight of seeds were recorded
13.42 percent in Dorosa type, 11 .37 and I 0.83 percent in Ghila and Khaja
type, respectively.
Islam (1993) stated that individual weight of seeds of Khaja and Ghila were
5.5 and 5.0 g, respectively. He made an investigation into different types of
jackfruit seeds and stated that most of the seeds are oblong in shape. Khaja
type contained 5.65 percent of seed and Ghila type contained 4.07 percent.
Again two types of fruits were found to be normal, viviparous as well as
abnormal. In Khaja 30.5 percent seeds were viviparous where as in Ghila it
was only 11.8 percent. It was also found seed size and weight was higher in
Khaja than Ghila. Hossain (1979) reported 41.97 percent viviparous seeds in
the ripe fruits.
Anonymous (1996) worked on physico-chemical characteristics and
storability of jackfruit seeds and reported that the shape of Ghila seed were
oblong, Dorosa oval and Khaja in between the two. Again the seeds of Ghila
were brownish in colour and Dorosa and Khaja were reddish. Sharma (1964)
8observed that the number of normal bulbs produced per fruits was 50 to 200,
while Haque (1994) reported it to be 100 in a single fruit.
Hossain (1976) studied ten different types of jackfruit at the Bangladesh
Agricultural University, Mymensingh and observed that size of bulb varied
among jackfruit. It was small, medium and big. The rind was 43.87 percent
and rachis was 9.16 percent. The weight of seeds was 11.50, 9.8 and 9.20
percent, respectively.
Bhatia et al. (1955) reported after their study that the bulbs and seeds
together were formed on an average about 40.2% of the fruit with a wide
range of 19.3 to 65.7% and rind constituted about 37.8% while the bulbs,
seeds and non-edible portion constituted on an average about 28.7, 11.5 and
59.1% of the fruit with a wide range of 15.2 to 49.8, 4.1 to 15.9 and 39.6 to
75.5%, respectively. The bulb varied in size i.e. length and diameter. The
size is 2.54 to 6.35 cm in length and 0.64 to 3.81 cm in diameter. He also
reported that nature of bulb was soft at early stage, intermediate at mid stage
and then firm at late stage.
Haque (1993) studied physico-chemical characteristics of three germplasm
of jackfruit at different stages of harvesting and reported that the percentage
of rind increased with delay in harvesting while bulb percentage showed the
reverse trend. In the early harvest the weight of (%) bulb ranged from 57.49
to 65.05 while it was 37.88 to 47.28 in late stage of harvest. He also reported
three clones of jackfruit; very soft, intermediate and firm pericarp which
contained 59.60, 40.14 and 41.14 percent edible portion respectively of
which the pulp contents were 48.10, 40.34 and 1.94 percent. The rind
percentages were 32.78, 43.03, 56.88 and rachis percentage was 7.22, 6.28
and 6.63, respectively.
In Asian countries the fruits ripen principally from March to June, April to
September or June to August, depending on the climatic region. Singh et al.
9(1963) and Naik (1949) reported that some off-season crops from September
to December or a few fruits at other time of jackfruit were from March to
June, the season might be extended unto September at higher elevations.
Annual progress report on Research project (Haque, 1989-90) mentioned
that the maturity of jackfruit was determined by indigenous methods. When
a fruit is hit by fingers a particular sound indicates maturity. Colour of fruit
surface, spine characteristics, latex secretion by punching fruit stalk etc. also
indicates maturity.
2.2 Chemical characteristics
In the past, only limited workers reported the chemical composition of
jackfruit. A review of the available information relating to the chemical
characteristics is given below:
2.2.1 Taste, colour, flavour and fibre content of bulb
Haque (1977) made a preliminary survey on the types of jackfruit at the
Bangladesh Agricultural University campus and its surrounding villages and
selected eleven jackfruit plants and found that the edible part (pericarp) was
variable in softness, size, colour, flavour, sweetness and fibre content. Fibre
was nearly absent in the bulb. The flavour of pericarp was varied from very
mild to strong which were mostly agreeable.
Hossain (1976) studied ten different types of jackfruit at the Bangladesh
Agricultural University, Mymensingh and observed the colour of bulb to be
light yellow, yellow and deep yellow. Samaddar (1985) observed that the
physical characteristics of jackfruit such as sweetness, acidity, flavour and
taste were varied among jackfruit types.
Anonymous (1995) reported that the Ghila contained deep yellow pulp,
Dorosha and Khaja contained yellow pulp. The pulp of jackfruit was very
sweet in case of Ghila at mid harvesting and sweet at early harvesting.
10Dorosha and Khaja were sweet at early harvesting while fairly sweet at late
harvesting. He also reported that the ripe stage of Ghila and Dorosha were
found to synthesize attractive flavour while Khaja emitted less flavour.
Anonymous (1997) worked with physico- chemical characteristics of Ghila
type at three different harvesting time and reported the chemical
characteristics such as texture, fibrousness, flavour, sweetness of bulbs were
varied at different harvesting times and reported the texture of bulb become
crispy and flavour degraded in the late harvesting time.
2.2.2 Moisture and dry matter
Anonymous (1997) observed that the percentage of moisture content was
decreased as the harvesting delayed. The bulb of early harvested fruit
contained 88.84 percent of moisture while it was 78.34 percent at late
harvesting. He also mentioned that there was gradual increase in dry matter
content from early harvesting to late harvesting.
Purseglove (1968), Bhatia et al. (1955) and Sturrock (1959) recorded
73.10%, 72.51% and 81.08% of moisture in jackfruit bulb, respectively. In
the food composition table for East Asia (FAO, 1972) moisture content of
unripe jackfruit has been listed 84.7% and that of ripe fruits 72.9%.
Haque (1993) studied three clones of jackfruits having very soft,
intermediate and firm pericarp which contained moisture 81.00, 80.02 and
80.00 percent, respectively. He also found 84% moisture in green jackfruit
bulbs and 77% in ripe jackfruit bulbs. Kamaluddin (1966), purseglove
(1968), Bhatia el al. (1955) and Sturrock (1959) recorded that dry matter
accumulated in the different types of jackfruit was 22.8%, 26.9% and
18.92%, respectively.
Hossain (1977) studied the nutritive value of jackfruits from ten selected
plants from the Bangladesh Agricultural University campus and its
11surrounding villages. This study included the contents of moisture, dry
matter, total soluble solid and ash. He reported the range of dry matter 19.54
to 28.45% and firm type content 73.95 percent moisture and very soft type
content 76.16 percent moisture, while moderately soft type was 71.55 to
85.46 percent moisture. In case of dry matter, the firm type content 26.05
percent and very soft type was 20.47 to 23.84 percent, while in moderately
soft type content 19.54 to 28.45 percent. Watt (1963) stated that the average
moisture and dry matter content of jackfruit bulbs were 76.37 and 23.63%.
Khanom et al. (1994) identified that the fresh pulp of jackfruit contain 73.3
and 77.81 percent moisture where as Dutta (1956) obtained 77.2 percent
moisture.
2.2.3 Total ash
Anonymous (1997) observed that ash content was gradually increased as the
harvesting time delayed. He found Ghila variety contain 1.08 percent ash in
late harvesting time, while it was lowest at early harvesting time 1.02, 1.04
and 1.22 percent total ash, respectively. Haque (1990) also stated that total
ash content of 1.00 percent in the jackfruit bulb of Ghila.
In the Food Composition Table for use in East Asia (FAO, 1972), unripe
jackfruit content 0.9 percent ash while 1.4 percent total ash was found in ripe
jackfruit. Khanom et al. (1994) reported that the total ash to be 0.54 percent
in fresh jackfruit pulp.
Hossain (1979) studied the nutritive value of jackfruit and reported that
jackfruit contains 1.1 percent ash. The ash content was found to vary with
selections from 0.65 to 2.14%. Watt (1963) observed that the ash content of
jackfruit bulb was 1.0% while Bhatia et al. (1995) and Purseglove (1968)
stated that the ash content of the bulb were 3.57 and 0.5%, respectively.
122.2.4 Total soluble solids
There is no available literature on jackfruit dealing with the change of total
soluble solids a various ripening stage. Haque (1993) found total soluble
solids was maximum (20%) at early harvesting stage and minimum (13%) at
late harvesting stage. He also found average total soluble to be 17.66, 16,
and 14.11 percent in very soft intermediate and firm type of pericarp. 8.18 to
15.87% of total soluble solids in mango was reported by Samad et at. (1975)
while Hossain (1976) stated 0.97% to 2.97% with a mean of 1.35%
intermediate and firm type of pericarp. 8.18 to 15.87% of total soluble solids
in mango was reported by Samad et.al (1975) while Hossain (1976) stated
0.97% to 2.97% with a mean of 1.35%.
Haque (1991) observed thirty two selected jackfruit trees and found total
soluble solid from 14 to 21.5 %. Haque (1990) stated Gila type jackfruit bulb
contains 19% total soluble solid. Anonymous (1997) found the total soluble
solid in bulbs of Gila type at early, mid and late harvesting times were 19.74,
19.64 and 19.60 percent, respectively.
2.2.4 pH of the jackfruit bulb
Hossain and Haque (1979) mentioned that the pH of the filtrates of different
types of jackfruit bulbs were in the range between 5.20 and 6.20. Samad et
al. (1975) made a study on ten varieties of Bangladeshi mango and found
that the average pH value of mango pulp was 4.42.
2.2.6 Ascorbic acid
Watt et al. (1963) observed that 8.0 mg ascorbic acid content to be 7.78
mg/100g. Hossain and Haque (1979) stated that average ascorbic acid
content of the bulb was 5.56 mg/100 g while minimum amount was 2.64
13mg/100 g. Hoque (1993) analyzed and found that Ascorbic acid 12 mg/100g
and 10 mg/100 g in green and ripe fruits, respectively.
2.2.7 Total sugar, reducing sugar and non-reducing sugar
Hossain and Haque (1979) reported that the average total sugar, reducing
sugar and non-reducing sugar content of jackfruit was 19.26%, 10.00% and
9.26%, respectively. Hossain (1976) made an experiment to determine
nutritive value of jackfruits of some jackfruit plants and found that total
sugar content of bulbs was 15.38% to 26.30%, reducing sugar 5.98 to
18.12% and non-reducing sugar 3.98 to 14.61% on fresh weight basis.
Hoque (1993) analyzed the total sugar content in green jackfruit bulb as
9.4% and in ripe jackfruit bulbs as 15%, while reducing sugar in green and
ripe jackfruit bulb were 5.2% and 6.60% and non-reducing sugar were 4.2%
and 8.40%, respectively.
2.2.8 Storage behavior under different conditions
It has been estimated that one-fourth of all produce harvested is not
consumed before spoilage (Ranganna, 1979). Spoilage of fresh fruit occurs
during storage and transport processing. It has already been stated that fruits
are living entities and undergo physiological and biochemical changes after
harvest. The loss of many perishable fruits can be prevented to a great extent
by controlling the post harvest environmental conditions of temperature,
relative humidity, atmospheric concentration of certain gases and also by
chemical treatment and irradiation.
Most of the fruits and vegetables undergo chilling injury at the low
temperature. Although no comprehensive study so far was made on jackfruit
storage and preservation in Bangladesh, the brief review of literature is given
below along with other fruits like mango, banana, apricot, litchi, peach and
straw berries etc.
14Haque (1994) made an investigation on storage of jackfruit bulb and
reported that the bulb remained edible for much longer period in the deep
freeze (-23oC). The bulbs remain edible for 4 or 5 days if it is kept in the
refrigerator (9oC). The fruit can be consumed within less than 2 days after
ripening when stored at room temperature of about 25-300C. Jackfruit having
firm flesh is suitable for preservation in freezing temperature (Haque 1993).
Khanom et al. (1994) observed the bulb of jackfruit to be acceptable with
good quality up to 75 days at frozen temperature (20 to -22oC). They also
reported that the mashed jackfruit sheath (pericarp) could be preserved for 7
days at room temperature when mixed with 80 percent sucrose and the whole
sheath could be preserved for the same temperature when emerged in 50
percent sucrose solution. The storage period of the bulbs can be extended to
135 days when stored at refrigerated temperature.
Hossain (1979) worked on storage of apricots. In this study they recorded
that the total carotene content of apricots at 30 days storage decreased to 85
percent of its original value and the carotene content was 74 per cent of its
original value. Khanom et al. (1994) observed the loss of vitamin A to be 70
percent in the frozen temperature (-20o±2oC) within 15 days and after then it
remained stable in the pulp for 4 months. They also observed that total sugar,
reducing sugar and non-reducing sugar had remained more or less same for
the storage period of 155 days.
Manjunath (1985) studied storage ability of banana and found no significant
change of total sugar, reducing sugar and non-reducing sugar at the frozen
temperature. Desrosier (1963) studied food in the freezing preservation and
concluded that there were continuous losses of vitamin C and he assessed to
be higher than any other vitamins.
Oxidation of ascorbic acid is one of the chemical changes which have been
used to detect deterioration in the quality of frozen foods (Nickerson and
Karel, 1953). Fennema (1976) studied fruits during freezing temperature
15(-18oC) and found the strawberries and peaches to lose 69 percent vitamin C
after 6 months. Desrosier (1963) also studied that there was an obvious
possibility to denature protein by freezing while Nickerson and Karel (1953)
described protein denaturation a general term for freezing at frozen
temperature.
Khanom et al. (1994) studied the subjective analysis of jackfruit stored at
155 days at a frozen temperature. The observation was confined to determine
the colour, flavour, appearance at 15 days interval and the result showed that
up to 75 days storage period the colour, flavour and appearance of jackfruit
pulp were good. After 75 days of storage, the taste of sheath was gradually
decreased and was little fibrous. It was also found that there was no change
in colour and flavour up to 135 days of storage period. But changes occurred
in the taste and appearance. No significant change of sugar content was
observed up to 120 days of storage at the same temperature. They observed
percent exude of jackfruit pulp at 30, 60, 90, 120 and 150 days were to be
5.57, 6.03, 7.10, 7.8 and 9.10 in frozen temperature (-20o±2oC), respectively.
They also recorded that total soluble solid were 16, 16.5, 18. 18.5 percent
and 19.0 per cent at 30, 60, 90, 120 and 150 days, respectively.
It was found that the self-life (in terms of colour, flavour, taste and
appearance) of candy prepared from preserved sheath was 6 months where
as, it was 3 months for candy prepared from fresh sheath (Khanom et al.,
1994). Annonymous (1995) reported a storage life of about 3-6 weeks when
the temperature ranged between 11.1 and 12.7oC, and humidity 85 to 90
percent. Samaddar (1990) observed that the stage of maturity at harvest had
great influence on its storage life.
16MATERIALS AND METHOD
The investigation was carried out during the period from April, 2011 to
August 2011. Khaja, Ghila and Dorosha type jackfruit were selected from
the Bangladesh Agricultural University Germplasm Center (BAU-GPC) of
the Fruit Tree Improvement Programme (FTIP) of Bangladesh Agricultural
University, Mymensingh and Baishakhi is selected from Charnilokkhonia at
Mymensingh sadar. The selected plants have been growing on medium high
land of old Brahmaputra flood plain soil tract of Bangladesh. Texture of soil
was sandy loam having pH 6.6. The rainfall, temperature and relative
humidity during the period of experiment according to the records
maintained by the Weather Yard, Department of Irrigation and Water
Management, BAU, Mymensingh are presented in Appendix I.
3.1 Physico-chemical characteristics of four types of jackfruit at
different harvesting time
3.1.1 Materials
A brief description of three types of jackfruit under investigation is given
below:
Baishakhi
In ripen condition, the rind of this type of jackfruit looks yellow. The bulbs
remain medium soft and elongated in nature, sweet and sometimes very
sweet. The Baishakhi type of jackfruit generally contains long size bulbs
than those of Khaja, Ghila and Dorosha. Anonymous (1997) found that
Baishakhi had soft flesh and long seeds. It can be consumed after one day or
two days once it is ripe. The spine nature is blunted and sometimes the fruit
is oval in shape.
17Khaja
In ripen condition, the rind of this type of jackfruit looks pale green. The
bulbs remain more hard and crispy in nature, medium sweet to sweet and
sometimes insipid. The Khaja type of jackfruit generally contains large size
bulbs than those of Ghila and Dorosha. Ahmad (1976) found, Khaja had firm
flesh and small seeds. Dutta (1956) reported that Khaja or Karcha had pale
brown or occasionally pale green rind and pulp was as hard as an apple. It
can be consumed after one day or two days once it is ripe.
Ghila
Ahmad (1976) found Ghila had reddish rind, soft flesh, juicy and sweet.
Dutta (1956) reported that Ghila or Ghula was usually light green,
occasionally brownish rind and had soft pulp with sweet taste. Anonymous
(1995) reported that Ghila contained deep yellow pulp. The seeds are
comparatively large. It is suitable for making juice and can be squeezed well.
Dorosha
This type of jackfruit contains medium soft to soft, juicy and fairly sweet
pulp when it is ripe (Haque, 1994). Rind is generally yellowish in colour
when fruit ripens. Anonymous (1995) reported that the pulp colour of
Dorosha is yellow.
3.1.2 Stages of harvesting
The Baishakhi type was harvested from Charnilokkhonia at Mymensingh
sadar and Khaja, Ghila and Dorosha were harvested from the BAU-
Germplasm Center (BAU-GPC) of the Fruit Tree Improvement Programme
(FTIP) of Bangladesh Agricultural University, Mymensingh at three
different times. The harvesting times are as follows:
18Early harvest: 15th April to 30th May, 2011.
Mid harvest: 1st June to 30th June, 2011.
Late harvest: 1st July to 15th August, 2011.
3.1.3 Experimental design
The study was conducted in a randomized complete block design (RCBD)
with three replications. Time and types served as different factors. Khaja,
Ghila and Dorosha type jackfruit were selected from the Bangladesh
Agricultural University Germplasm Center (BAU-GPC) of the Fruit Tree
Improvement Programme (FTIP) of Bangladesh Agricultural University,
Mymensingh and Baishakhi was selected from Charnilokkhonia at
Mymensingh sadar. Thus there were three time of harvesting and four types
of jackfruits.
3.1.4 Methods
Matured jackfruits were collected from the plant and kept at ambient
temperature for further study. Analysis was done in the laboratory of the
Department of Biochemistry and Molecular Biology, Bangladesh
Agricultural University, Mymensingh. The following physical and chemical
parameters were studied.
3.1.5 Physical parameters of fruit:
i) Weight of fruit
ii) Size of fruit
iii) Shape of fruit
iv) Weight of bulb
v) Number of bulbs per fruit
vi) Weight of seed, shape and colour
19vii) Weight of rind
viii) Weight of rachis
ix) Percentage of bulb, seeds, rachis and rind
x) Shape and colour of seed
xi) Viviparous germination of seed
xii) Weight of edible portion
xiii) Weight of non-edible portion
3.1.6 Chemical Parameters of fruit:
i) Total soluble solid
ii) Moisture content
iii) Total ash
iv) Dry matter
v) Total sugar
vi) Reducing and non reducing sugar
vii) Vitamin C
viii) pH
ix) Taste and flavour of pulp
x) Texture, juiciness and fiber content of pulp
3.2.1 Fruit weight
Four mature fruits from each type at each stage were collected to measure
the weight of fruit. The weighing was taken in Kilogram with the help of a
weighing balance (ACS System Electric Scale).
203.2.2 Size of the fruit
Length of the fruits was measured from basal to polar ends with the help of a
measuring tape and then the diameter of the fruits was determined in the
following ways:
Fruits were placed between the two hard-boards on a plane surface. The
board is perpendicular to the surface. Then the distance between the boards
were measured in centimeters.
3.2.3 Shape of the fruit
Considering the length, breadth and outer surface, shape of jackfruits was
dictated and expressed in language as made by Jagirdar et al. (1960).
3.2.4 Skin colour of the fruit
Skin color of the jackfruit was determined at ripe stage with keen
observation and expressed in language.
3.2.5 Colour, nature, flavour and sweetness of bulbs
Different parts of the fruit as for example, bulbs, rind, and axis were
carefully separated by hand with the help of a knife. Bulbs per fruit were
counted accurately. Colour of the bulbs was recorded. Consistency of the
bulbs was determined by a panel of five persons.
3.2.6 Size of the bulbs
Different parts of the fruits as for example, bulbs, rind and rachis were
carefully separated by hand with the help of a knife. Bulbs per fruit were
counted accurately and size of the bulbs was recorded.
3.2.7 Rind colour
Rind colour of the jackfruits was determined at the ripe stage with keen
observation and expressed in language.
213.2.8 Weight of different parts of fruits
Weight of rind, bulbs, seeds and rachis of jackfruit were taken with the help
of a German made balance. Percentage of rind, rachis, bulb and seed were
computed by simple calculation
3.3 Chemical characteristics
The methods followed for the estimation of moisture, dry matter total soluble
solids, ash were those of Haque(1995) and Islam (1993). The data were
analyzed on fresh weight basis for each value of nutrient.
3.3.1 Moisture
Twenty grams of the bulbs of jackfruits were taken in porcelain crucibles
and placed on a steam bath for 12 hours for evaporation. The porcelain
crucibles with its content were transferred to an oven maintained at a
constant temperature of 100oC for about one our. The crucibles with the
sample was then transferred to a desiccator containing anhydrous calcium
chloride and kept there for about 8 hours. The final weights were then taken.
Moisture content was calculated according to the following formula:
I-F
% moisture = × 100
I
where,
I = Initial weight of pulp and
F = Final weight of pulp.
3.3.2 Dry matter
Dry matter content was calculated from the data obtained for percent
moisture content.
3.3.3 Total Ash
Twenty grams of the bulbs of jackfruits were taken in porcelain crucibles
and placed into Muffle furnace at a constant temperature of 650°C for 4
22hours. The crucibles with the sample was cooled and transferred to a
desiccator containing anhydrous calcium chloride and was allowed to stand
for a period of 8 hours. The final weight was taken and ash percent was
calculated as follows:
A
% ash= × 100
I
where,
A=Weight of ash and
I= Initial weight of pulp.
3.3.4 Total soluble solids (TSS)
Total soluble solids (TSS) content was determined by refractometer (ERMA
Hand Refractometer, Tokyo). A drop of juice squeezed from the jackfruit
bulb was placed on the prism of the refractometer and percent total soluble
solids were obtained from direct reading. Temperature correction was made
as described by Ranganna (1979).
3.3.5 pH of the juice of jackfruit bulb
Fifty grams of bulb of jackfruit were blended in a warring blender in about
300 ml distilled water. The blended materials were transferred to a one-liter
volumetric flask and volume was made up to the mark with distilled water.
The content of the flask was then filtered through Whatmann No. 40 filter
paper. The pH of the filtrate was measured by Fisher, Accumet, and model
320 expanded scale research pH meters.
3.3.6 Reducing sugar
Fifty grams of the bulb of jackfruit were homogenized with water and
transferred to 500 ml beaker. It was neutralized with 0.1N NaOH and boiled
gently for 1 hour adding water to keep the volume nearly constant. The
content of the beaker was cooled and transferred to a 500 ml volumetric
23flask. Two ml of Lead acetate followed by 1.1 ml of Potassium oxalate were
added to clear the mixture and then the volume was made to 500 ml. The
mixture was filtrated and the filtrate was used to titrate against a measured
amount of Fehlings’ solution. The Fehlings solution had earlier been titrated
with standard invert solution. Percent sugar was calculated as follows:
I×D×100
% Reducing sugar =
T×W×1000
where,
I = mg of invert sugar required to reduce known volume of Feelings’
solution.
D = Dilution
T = Titre, and
W = Weight of the sample.
3.3.7 Total sugar
Samples for the estimation of total sugar were prepared according to the
method already mentioned in the case of reducing sugar. The filtrate was
used for the determination of total sugar. Hundred millilitre of NH 2 SO 4 was
taken in 500 ml. Erlenmeyer flask containing 100 ml filtrate and refluxed for
6 hours. The hydrolysate was neutralized with the filtrate through Whatman
No. 40, filter paper and then titrated against measured volume of Fehlings’
solution. Percent total sugar was calculated reducing sugar making use of
titre value obtained in determination of total sugar after inversion.
3.3.8 Non-Reducing sugar
Non-reducing sugar content was calculated as follows:
% Non-reducing sugar = % total sugar - % reducing sugar.
243.3.9 Ascorbic acid (Vitamin C)
Twenty grams of the bulb of jackfruit were blended in a warming blender
containing 100 ml of 3% HPO 3 (Metaphosphoric acid solution) for 5
minutes. The diluted sample was filtrated through Whatman No. 40 and final
volume was recorded. Ten milliliter aliquot of the filtrate was pipetted into a
small Erlenmeyer flask. It was titrated immediately with the solution of 2.6 –
dichlorophenol indophenol dye. The dye had earlier been standardized with
vitamin C solution to find an equilivolume factor for dye. The ascorbic acid
content of the samples was calculated from the following formula:
T×D×V1
mg of vitamin C per 100 g bulbs = ×100
V2×W
where,
T = Titre
D = Dye factor
V 1 = Volume made up
V 2 = Aliquouot of extract taken for estimation and
W = Weight of sample taken for estimation
3.3.10 Colour, nature, flavor and sweetness of bulbs
Bulbs were carefully separated by hand. Colour and nature of the bulbs were
recorded. Consistency of the bulbs was tested with the help of finger.
Flavour and of the bulbs were determined with the help of test of the pulp by
group five persons and expressed in language.
253.4 Shelf life: Storage behaviour of three types of jackfruit pulp and
procedure of work
3.4.1 Deep freeze (-20o ± 2oC)
In this temperature, the study was conducted up to 150 days at 30 days of
interval. The physical (in terms of colour, flavour, appearance, taste etc.) and
chemical characters of pulp were determined accordance to the methods
stated before. For the determination of exude from the frozen pulp was
carried out according to the following method. The frozen pulp was weighed
and kept it at ambient temperature. When full exude was found to be come
out, then the pulp was weighed again. The percentage of exude was assessed
by the simple calculation.
Experimental Design
The study was conducted as a factorial experiment in completely randomized
design (CRD). Types of jackfruit and days of storage were considered as two
different factors. Replication was three. Storage behavior of different types
of pulps was determined at 30 days interval.
3.4.2 Refrigerator (7oC ± 2oC)
In this storage condition, only physical characteristics of pulp were observed
at every alternate day up to 6 days as stated before.
3.4.3 Room temperature (25o - 30oC)
Physical characteristics of jackfruit pulp were observed at every alternate
day up to six days of storage.
Statistical analysis
The recorded data on different parameters for both the phases of the study
were analyzed statistically. Analysis of variance of different parameters was
performed by F variance test. The mean differences were evaluated by Least
Significance Difference (LSD) test.
26RESULTS AND DISCUSSION
The result of the study on the physico-chemical characteristics of jackfruit
type at different harvesting times are presented and discussed in this chapter.
Some of the data have been expressed in Table(s) and others in Figure(s) for
ease of discussion, comprehension and understanding. The results are
presented under the following heads.
4.1 Physica1 characteristics of jackfruit types at different harvesting
time
Physica1 characteristics of four types of jackfruit namely, Baishakhi, Khaja,
Ghila and Dorosha were studied during the harvesting season of April –
August, 2011.
4.1.1 Size, shape and weight of fruit
The result on the study of size (length x width), shape and weight of four
types jackfruit at different harvesting times are shown (Table 2). The data on
fruit weight of four types of jackfruit showed that Ghila type gave maximum
fruit weight (8.62 kg) while it was minimum (5.11 kg) in Dorosha (Fig. 1).
The weight of fruit at early, mid and late harvesting time was 6.70 kg, 7.66
kg and 6.31kg, respectively (Table 2). The present result are close to the
findings of Anonymous (1997) who reported that fruits of mid harvesting
time were larger while those in late season were smaller. Mowry et al.
(1953) described that the average weight of fruit ranged from 4.50 kg to
18.00 kg or more. Kamaluddin (1966) mentioned the weight of fruits of
some plants to be 1.86 to 2.79 kg while in some other cases it could be high
as 18.6 to 37.2 kg.
Among the different harvesting times, mid harvesting fruit gave maximum
average fruit length (52.11cm) and wide (36.78) while it was minimum at
late harvesting time. The highest length and wide were 52.11 cm and 36.78
2728
cm obtained from Ghila followed by Baishakhi, Khaja and Dorosha. The
present result are close to the findings of Bhatia et al. (1955) and Mowry et
al. (1953) who reported that the fruits to be 20.32 to 91.44 cm long and
15.24 to 50.80 cm wide. Hossain and Haque (1977) stated that the mean
length and diameter of fruits were 1.6 and 22.4 cm, respectively. The
combination effect had significant response.
It was observed that most of the fruit were ellipsoid and oval shape at early
and mid harvesting time (Table 4). But as the harvesting time the fruit
gradually losses their uniform shape. On the other hand, Khaja type fruit
shape was found ellipsoid (Plate 3c) while Ghila, Dorosha and Baishakhi
were oval, oblong and cylindrical (Plate 4a, 5b and 1a), respectively. This
result was agreed with the observation of Hossain and Haque (1977) who
stated that jackfruit to be oval, pear, cylindrical and irregular shaped.
The combined effect also had significant response. The results showed that
mid harvesting with Ghila type produced the fruits of biggest size (9.17 kg)
while it was the smallest (4.50 kg) with the combination of late harvesting
with Dorosa (Table 11). The reasons for lesser weight of fruit at the late
season might be due to lack of adequate supply of nutrients since plants
might be exhausted of their food because of development of early season
fruit.
4.1.2 Number of bulbs per fruit, size and juiciness of bulb
The size of bulb was found the highest (7.71cm x 4.89 cm) at mid harvesting
time while it was minimum (5.27 cm x 3.30 cm) in early harvesting (Table
1). The greater bulb length and diameter was found in Khaja (6.96 cm x 4.34
cm) compared to Ghila (5.67 x 3.86 cm). Bhatia et al. (1965) reported that
the bulb size is (2.54 to 6.35 cm x 0.64 to 3.81cm) (Table 1). Hossain and
Haque (1977) reported that the size of bulb was (4.1 to 8.5 cm x 2.6 to
5.0cm).
29You can also read
