Wild Fruit Pulping Machine

International Conference on Mechanical and Industrial Engineering (ICMIE'15) July 14-15, 2015 Harare (Zimbabwe)
Wild Fruit Pulping Machine
Manditsera Dickson
Thus the need for alternative sources of food and nutrition
has resulted in the production of food supplements used to
correct nutritional deficiencies or maintain an adequate intake
of certain nutrients [4]. However in some cases excessive
intake may be harmful and have adverse effects such as liver
damages and other diseases. So the need for a 100% safe
alternative source to compliment agriculture is still a problem
which can be solved by providing organic natural sources of
nutrients and vitamins from wild fruits which is an excellent
and rich source.
Abstract--- The need for alternative safe means and sources of
food and nutrition has been the major preoccupation of the
development and scientific communities. Purpose of the study is to
design a wild fruit pulp processing machine to harness Baobab and
Parinari Curatellifolia fruit contents for the benefit of the local
populace, the goal being to enhance food security and income
generation through fruit pulp products and new tastes. The operating
principle is to convey the fruits by auger screw against a stationary
sieve, due to frictional and shear forces the fruit pulp will be
separated from the seed (peeling principle). The results of the project
will be based on the prototype output and efficiency of the concept.
Keywords—Baobab, fruit pulp, Parinari Curatellifolia, auger
III. PROBLEM STATEMENT
screw
I.
The deficiency of vital micronutrients and vitamins in the
dietary system are a form of hidden hunger. In many countries
health problems related to dietary inadequacy are an ever
increasing threat, in fact malnutrition and foodborne diseases
(Ebola) are becoming a double burden [5]. Therefore the
extraction of wild fruit pulp and value addition fruits will help
alleviate poverty.
Purpose of this study is to design and manufacture a pulp
processing machine for Chrysobalanaceae (Parinari
Curatellifolia) and Adanasonia Digitata (Baobab fruits)
INTRODUCTION
T
HE design project is a hybrid machine that uses peeling
principles to mechanically separate fruit pulp through
shear by pressing the fruit against a sieve. The project is aimed
at utilizing the available indigenous wild fruit through the
extraction of the much needed vitamins and nutrients with the
goal of enhancing food security (eradicating hunger),
nutrition, new tastes and income generation.
II. BACKGROUND OF THE PROBLEM
IV. LITERATURE
The world today faces urgent food and nutritional crisis, in
1996 FAO [1] estimates reported that as many as 840 million
people face chronic or perpetual hunger, however in 2009 the
number exceeded 1 billion [2], which implies that one-sixth of
the world’s population is facing acute hunger. A major
preoccupation of the development and scientific communities
since 1935 (first account of hunger and malnutrition in the
world) has been how to resolve the conflict between
increasing demand for food and the degradation of the
environment due to climate changes. Zimbabwe for instance is
facing severe and widespread food shortages, the ZimVAC
report identified approximately 6 percent of the rural
population (560 000 people) will be in need of food assistance
at the height of lean season between January and March 2015
[3].
The objective of the project is to design a means to harness
macronutrients and vitamins from wild fruits, however due to
vastness of the resource the project limits its focus on small
scale extraction of pulp from Baobab and Parinari
Curatellifolia fruits. Nutritional analysis to assess the potential
of these wild fruits has proven that they are rich in
macronutrients and vitamins that help solve the great central
issues of the world economic, health and environmental
development. The focus was on the fruit’s relevance to the
three biggest needs for human survival and social security
which are Nutrition, Food Security and Income Generation.
Although pertinent wild fruit nutritive information is often
poorly available, it can be concluded that all African fruits are
useful sources of nutrients particularly Vitamin C. They offer
substantial levels of calcium, phosphorus, potassium and iron.
For instance Baobab fruit contains six times as much Vitamin
C as oranges, twice calcium as milk and packed with B
Vitamins [7] while Parinari contains proteins, fats, Vitamin C,
calcium, magnesium, zinc and iron [6].
The words “Food Security” imply the concept of access to
sufficient safe food at all the time. The fruits’ most vital use is
to provide food security to those who cannot buy their way out
of hunger and overall to the world in times of hunger and bad
harvest. For this purpose the pulp can be beaten into pancakes,
Dickson T Manditsera, Harare Institute of Technology, Zimbabwe, Email
id: manditserad@gmail.com
11
International Conference on Mechanical and Industrial Engineering (ICMIE'15) July 14-15, 2015 Harare (Zimbabwe)
which when dried can be stacked and stored for months and
even years.
For purposes of relieving local poverty (income
generation) in most rural and urban areas, wild fruits are
powerful tools. The food and beverage industry searches
constantly for new flavors, so wild fruits offer an
advantageous opportunity and good market share earner.
Possibly there is no long term answer more basic or more
beneficial of merger local empowerment than this ancient food
source.
production. The variations are the means of human effort
application and output required by end user, mostly
considering the fruit types.
b. Electrical Pulping Machines
These are much faster than manual machines and are
powered by means of an electric motor. The type ranges from
crushing machines to pulp extractors varying due to the means
and the idea of operation.
c. Baobab Fruit pulp processor
The design of a baobab fruit pulp machine is different from
other machines because of the fruit structure and components,
which is not juicy but powdery. Apart from mechanisms that
where latterly designed the rural means of extracting the pulp
is still practiced nowadays in most area.
i.
Traditional Baobab Pulp processing
This is a method practiced for many years and in some parts
of Zimbabwe is still existing, the use of continuous repeated
pounding of the seed and pulp then separated by a food sieve.
However despite the method yielding results there is risk of
contamination of the pulp due to handling and also the process
is very slow.
ii.
Electric power Baobab pulp Machine
The design emphasize on simplicity, productivity and ease
to use. Conveniently the energy of the machine is provided by
a pedal or an engine, connected to the tubes inner shafts that
separate the pulp from its seed and fiber. The combination
consist of a tube and mesh wire, the tube is hooked up to the
motor causing it to rotate with milled grooves grinding against
a stationary mesh grinding baobab fruit into pulp.
Fig. 1 Baobab fruit
 Project material requirements
For the machine pulping components material with high
corrosive, oxidation and ordinary rusting is required therefore
stainless family is more advantageous for the machine internal
components (screw, sieve and the covers),while the frame
requires a material that is easy to weld and less costly.
The design project (machine) estimate cost price in the
market is to be $600 from bill of material and costing, which
is an affordable price to locals and small food processor in
Zimbabwe.
Fig. 2 Parinari Curatellifolia
V. METHODOLOGY
 Existing machines
All the existing machines principles for fruits with or
without seeds is based on crushing, however the project is to
bring a new dimension to the industry by concentrating on
smart means of separating the pulp from the seed. By the
adaptation of conveying screw, the pulping will be done due to
the friction and shearing effect between the screw and a
stationary sieve.
a. Manual type
These are slow means of extracting pulp by human
interaction with the machine. These range from small kitchen
utilities for making pulp for example tomatoes, fruit juices
from fruits etc. to small scale productions such as coffee
In order to achieve the objective of the project, the
methodology was based on the project development life cycle
concept, utilizing three major steps planning, implementation
and testing. Planning stage was centrally rooted on data
collection, which was collected in two forms primary data
(experiments) and secondary (investigations).
VI. EXPERIMENTS
The experiments were done in real life setting rather than
laboratory (Field experiment method).
12
International Conference on Mechanical and Industrial Engineering (ICMIE'15) July 14-15, 2015 Harare (Zimbabwe)
Experiment 1: Determination of the relative of easy pulp
removing (Parinari Curatellifolia)
Objectives: To determine the principle to pulping Parinari
Curatellifolia and also determine the best preservation method
for easy pulping.
Apparatus: Grater (6mm and 4mm), Slicer/Peeler (5mm),
Perforated bowl holes screen (9mm)Stop watch ,Vernier
caliper
Fruit Conservation and treatment: Unripe fruits collected
where stored for maturity which took about 10 days from the
day collected to mature and to ripen. For experiment purpose
the fruits where stored using different methods both collected
ripe and unripe. Thus some were refrigerated, some stored
under room temperature and the rest were buried underground.
Thus all ripe and unripe were treated separate in storage to
observe the differences in the pulp behavior due to storage
method. This is done because the fruit is seasonal and it will
be subjected to storage before pulping and also to review the
easy state to preserve the fruit for easy pulping.
Tests: The experiment was to determine the changes of the
fruit pulp and skin in accordance with method of preservation
and time from collection. The tests were done under time, with
different tools (Grater (6mm and 4mm), Slicer/Peeler (5mm),
Perforated bowl holes screen (9mm)), under approximately the
same variables (temperature, force) and the time was recorded.
Three individuals for each test where timed. Using the same
tool to remove the pulp, also the behavior of the skin and pulp
structure was observed and noted. For each tool the two tests
were done, for each collection criteria used.
Conclusion: Basing on the experiment results and
observations it can be noted that the capacity of any pulping
machine for Parinari Curatellifolia is dependent on the
preservation method and size of mesh wire holes used, thus
the relative ease of pulping in all cases depended on the peeled
area on the fruit (capacity). The pulping force was determined
through shear.
were left without pulp. The fruit sizes were not distinct so the
quantity measure was used for the tests (20g, 50g and 70g).
Results: The pulp removed depends on the method and
individual’s ability and expertise in using the tool. However
the pounding technique is bit slower and tedious than the
sieving method. Also from results and observations the pulp
from pounding is not completely removed from the seed
implying the crushing principle is tricky in pulping Baobab.
VII. PROJECT DESIGN CONSIDERATIONS
The machine feed mechanism consists of a feeding chute
that regulates the amount of material input to the pulping
system. Due to the machine inclination (10º) the material does
not require external energy but will flow due to gravitational
acceleration. Also at the heart of the process there is an auger
screw which consists of several blades of helix shape welded
to the rigid shaft which is rotated in a fixed sieve to feed and
convey the fruit through the pulping process. The screw
creates a translational movement so that fruits are pulped due
to collision and frictional resistance. The sieve was designed
to offer shearing perforated holes to help separate the pulp
from the conveyed fruits, the hole size were determined from
fruit peel resistance tests. The sieve is treated as a thin walled
cylinder which is subject to internal pressure from the pulping
effect.
However the machine efficiency is highly dependent on the
screw-sieve gap, machine’s speed and fruits’ (Parinari
Curatellifolia) ripeness state. The gap was designed based on
the Baobab fruit, and also Baobab requires higher speed to
increase collision and inertia (increase shear force).
Screw and sieve due to stresses involved are made from
stainless steel, type 304 because of its excellent forming and
welding characteristics, thus it is readily roll formed into a
variety of parts. The covers are made from type 430 because
corrosion resistance is not so demanding while the frame is of
mild steel.
Design Calculations
Screw pitch: The pitch ranges between 0.5 and 1 times
diameter and bigger for light material. From the data the
largest fruit measured is 35mm.
……………………(1)
Screw diameter (D): Screw diameter is taken to be 4-12 times
bigger than the diameter of the material particles being
transported (homogeneous material) and 2- 4 times bigger
than the bigger diameter of the material particles being
transported (heterogeneous material)
……………………(1)
A smaller clearance is needed to prevent the jamming of the
fruit material being sheared. Therefore the clearance will be
taken as the diameter of the smallest fruit seed which is the
baobab seed of 6mm.
Sieve filled area (S):
Experiment 2: determine best pulping techniques for
Baobab
Objectives: To determine how best to separate Baobab Fruit
pulp from the seed.
Apparatus: Sieve, Pounding equipment, Scale, Tap
measure, Vernier Calipers
Procedure and Methods: Also the experiment was done in
real world setting. The experiments were considered on two
traditional methods of pulping Baobab used by locals, which
water and physical means of removing the pulp. However the
water was screened out as it reduces the pulp’s shelf live and
destruction of other nutrients. Thus the experiment was done
using physical methods.
Tests: Two tests were done, using the pounding method and
using a food sieve to separate the pulp from the seed. Time
taken by the individuals was recorded, three tests for each
method. Pounding method is where the fruit pulp is removed
by continuous beating, using traditional means (duri and
mutswi) while the sieve method the fruit will be rubbed
against a food sieve mesh wire continuously until the seeds
…………...(2)
13
International Conference on Mechanical and Industrial Engineering (ICMIE'15) July 14-15, 2015 Harare (Zimbabwe)
Screw capacity (Q): The capacity of a screw depends on the
screw diameter, screw pitch, speed of the screw and the
loading efficiency of the cross sectional area of the screw. The
capacity of a screw conveyor with a continuous screw:
…………………………...(4)
VIII. FIGURERS
=21.38kg/hr
Sieve: Sieve was treated as a thin walled cylinder which is
subject to internal pressure to internal pressure form the
pulping effect. The stress in the sieve include
Circumferential stress: The sieve is fixed on both end and the
pressure on end plates were assumed negligible
p internal pressure,
- circumferential stress, d sieve internal
diameter , t sieve thickness
F- is the rotational inertia force of each fruit against the
sieve given by the formula
Where r = 42mm
m- mass of the fruit
F = 17.64 N
Is the area where were the fruits exerts the force, assuming a
square area concentrated by one Parinari fruit, given that the
largest fruit size is 35mm therefore
A=
=
Thus the internal pressure is 0.0144 ⁄
⁄
=
The sieve was also tested for thickness in finite analysis.
Frame: Frame design parameters were obtained from finite
element analysis, the consideration being to come up with the
best stress bearing section. However considerations of the
members were treated as struts and subjected to a vertical
pressure.
By Euler formula
IX. CONCLUSION
The project aims to bring a new dimension to the industry
by concentrating on the smart means of separating the pulp
from the seed, saving energy and providing an alternative
source of food supplements and taste. Also the machine cost
is relatively cheap to produce and maintain. By the adoption of
the expelling and screw conveying concepts the pulping will
be done due to the friction and shearing effect between the
screw and the sieve (peeling principle)
- is the Euler buckling load, E- modulus of elasticity, ISection moment of area
For the test in finite element analysis the struts where
assumed one end fixed and the other end pinned.
=
-is the length of the strut.
14
International Conference on Mechanical and Industrial Engineering (ICMIE'15) July 14-15, 2015 Harare (Zimbabwe)
APPENDIX
ACKNOWLEDGMENTS
Parinari Curatellifolia experiment results
The following individuals provided the much needed
support, in every aspect of the project and their assistance in
gratefully acknowledged, Eng. R Masike, Eng. L Masiyazi,
Eng. M Dzanya and Mr Topotsa.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
Baobab experiment results
λ Value (handbook)
Type of load
Λ
heavy and abrasive
0.125
heavy and little abrasive
0.25
light and little abrasive
0.32
light not abrasive
0.4
1. Ψ Value data sheet
Type of material
Ψ
Abrasive material
0.12 - 0.15
Mildly abrasive material
0.25 - 0.5
Abrasive free flow
0.4 - 0.45
15
Shah. M, Strong .M, (1999) Food in the 21st Century: From Science to
Sustainable Agriculture. Washington DC, CGIAR System Review
Secretariat, World Bank.
World Summit on Food Security, Declaration Of The World Summit On
Food Security, pg 1, note 2,Rome 16-18 Nov 2009 Retrieved from
http://www.fao.org/fileadmin/templates/wsfs/Summit/Docs/Final_Decla
ration/WSFS09_Declaration.pdf
World
food
programme:
Zimbabwe
,
Retrieved
from
https://www.wfp.org/countries/Zimbabwe/Overview
European Food Safety Authority: Food Supplement. Last updated: 2
October
2013
,Retrieved
from
http://www.efsa.europa.eu/en/topics/supplements.htm
World
Health
Organization:
Food
Security.
http://www.who.int/trade/glossary/story028/en/
Benhura .M.A.N, Muchuweti.M, Gombiro.P.E, Benhura. C (September
2013) Properties of Fruits (Parinari Curatellifolia/Hacha/Chakata)
from different parts of Harare, Zimbabwe, Vol 13, Issue 4, pg. 8004.
African Journal of Food, Agriculture, Nutrition & Development.
Dr. Wilkinson, Dr. Matt.H. Baobab: The Baobab Fruit Pulp Powder
Benefits, retrieved from http://www.baobab.com/category/englishlanguage/baobab-health-benefits/