Cactus Fruit Plucker

By: Pragati, Ganesh, Parul, Sarath, Shiyas, Shubham and Shubhangi

May 2016

Problem Statement

Traditional method of cactus fruit plucking involves use of a wooden stick/ stick with hook and container. Ripe fruits are hit lightly with a stick and are collected in the container. Ripe cactus fruits easily fall in a container.

The objective is to develop an efficient tool for plucking cactus fruits which has following features:

  • Easy and safe to use

  • Similar or improved time efficiency

  • Cost effective

  • Require less physical efforts

Field Visit

To know about current methods employed, problems face by farmers, areas of improvement, market analysis - Chital, Amreli, Lalavadar and Jasdan in Gujarat were visited. Fruits were available in both of these areas and people have tried out different techniques to pluck fruits. But people in Chital harvested fruits for daily purposes and had no market was available forany source of income while people in Lalavadar plucked fruits on order basis and earned from cactus fruit picking. Chital on one side was well developed village while Lalavadar on the other side had relatively poor economic conditions. Cactus fruit is found in very dry areas. There were two types of cactus plant we saw during field visits and fruits were available in one specific variety of plant. This plant has padded leaves and not circular as we generally see in cactus plants cactus 1 People generally do not grow these fruits but use these plants as fencing for their farms and houses. Therefore, these plants are generally found on roadside, around farms and in forests In spite of various advantages of this fruit, people are generally not aware of its features. Only people harvesting them and people living nearby are aware of its uses and features This fruit can be used for various purposes like making juice, jellies, candies, jam, and in dye production. Its seed are used in curing diabetes, and for increasing iron content in human body Plants are grow densely and it is not easy to access fruits Thorns on plant and fruits are different. Plant has big thorns but fruits have very soft and small thorns (glochids). These glochids can leave fruit during light wind Cactus fruit is grown on the edges of the padded leaf and size varies from 4-8 cm (in diameter). Ripe fruits are generally red in colour and can be plucked easily with a small jerk cactus 2 Thorns on the fruit should not be ignored and thus without gloves they should not be touched at all which makes handpicking impossible Edible part of this fruit is very less and major chunk of it gets wasted while peeling the fruit It has large number of seeds which are not edible in raw form Table life of these fruits is generally 3-5 days and can increase upto a month if kept in refrigerator.

 

Traditional methods:

1. Using stick and container:

For fruits at small and medium heights people use stick to jerk off the ripe fruits and container to collect the falling fruits.

Advantages:

  • Easily available and easy to handle

  • No repair cost

Problems associated:

  • This method requires both hands and is unsafe

  • They can’t reach to fruits at heights

  • During collecting, thorns might prick your hands and/or body

  • Fruits which fall due to thejurk can’t be collected as they fall in dense thorny bushes

2. Using L shape pipe:

This method requires a device in which a L shape is attached to a long hollow PVC pipe. This device can be reached to fruits, orient towards it and plucked by giving a twist (to the pipe) and they gets collected in the pipe only which is closed at the other end.

Advantages:

  • No need of separate container

  • Can be extended by attached a separate pipe with a connecter to reach different heights

Problems associated:

  • Fruits may fall outside of the pipe and become unrcoverable

  • It doesn’t have any cutter or groove to pluck and twist fruits from the plant. One has to do it manually which in current case needs long experience and practice

3. Using Chinese clamp:

In this method, big scissors with bowl at the top is employed. Fruits are hold using the bowl through the scissors and pulled to pluck them.

Advantages:

  • More than a single fruit can be plucked from this method which is not possible in any of the method developed so far

  • Easy to use as it is in the form of scissors

  • More fruits can be reached than stick and container method

Problems Associated:

  • One need to bring the fruits down after each step and thus require more physical work

  • Very inefficient method as it is time consuming

Improvements made by farmers:

1. Use of hook to pluck more fruits

2. Use of extendable container instead of stick

Lilaben demonstrating hook mechanism

Chaganbhai demonstrating use of extendable container

Market and demand:

Chital: In Amreli, primary purpose of cactus fruit harvesting is for house hold use and by small children. They can’t earn any livelihood as there is no market demand for the fruit. Therefore, these people do not have any interest in any device for plucking fruits.

Lalavadar: People in this area are more seriously involved in this field. During season, they harvest fruits and sell them raw as well as after processing (juice) the fruits.

 

Key observations:

  • They work on order basis and harvest when they receive order

  • Earnings from this vary from Rs. 50000-600000 per annum amongst farmers from cactus fruit harvesting

  • Raw fruits are generally sold Rs. 30 per kg to supplier which further sells at Rs. 160 per kg in areas nearby

  • Half litre juice bottle is generally sold up to Rs. 150

Field testing of locally made device:

During visit to Chital, we found a device made by Upendrabhai. It has bike brake mechanism attached with a spring and a clutch attached. It was capable of holding fruit by applying brake which can be plucked either by twisting or pulling the fruit.

Testing 1:

Normally Closed Device @Chital

Advantages:

  • It was capable of holding fruit and plucking

  • Use of simple brake mechanism which can be repaired easily

  • Very cost efficient; can be made in Rs. 200

Problems:

  • The device was not long enough.

  • Spring was not strong enough to have a grip on the fruit

Improvement Done:

Clutch was reversed so that when one press brake, clutch holds the fruit and spring was replaced to make it strong

Testing 2:
Normally Opened Device at Lalavadar

Advantages:

  • It was relatively easy to hold fruits before improvement

  • It could be used to pick up the fallen fruits as well

Problems:

  • It was difficult to orient for every fruit

  • Clutch was strong which sometimes was tearing the fruit

  • It was not a comfortable instrument as suggested by Chaganbhai

  • Need to bring device down after picking every fruit

 

Mind Mapping

Around the world prickly pear fruits are found in South America, Australia, USA, India and Mexico is largest producer. In India majority of these species are found in desert prone regions which include Gujarat, Rajasthan and Maharashtra etc. Primary use of cactus bushes is fencing around their crop fields. Usually famers/ labourers and women self-help groups are involved in harvesting of cactus fruits.

 

Literature Review:

We performed prior art search to find information on available literature about prickly pear fruit uses, harvesting and devices available for plucking fruits. Following databases are used for search:

Nonpatent database: Google (books, news, images),techpedia database, IEEE explore, Elsevier, Scopus, Springer, Taylor & Francis, citeseer, pubmed, research gate, Conference proceedings, Youtube videos

Patent database: Google patents, USPTO, Espacenet, Thomson, free patents online The information obtained is used as preliminary data to create mind map for the cactus fruit harvesting.

Problems identified from literature:

1. Cactus bushes are dense and thorny. Cactus fruits also have nubs which make plucking of fruits difficult.

2. Nubs of the fruit enter into skin which is difficult to remove because of their microscopic size.

3. Big thorns on the pads around the fruit.

4. Due to the thorny foliage at the lower level, it is difficult to pick fruits from the ground level.

5. Existing devices don’t offer reach to fruits ( in terms of height adjustability, dense bushes, position of fruits and thorns on the fruit)

 

Mind Map 1.0: Cactus Fruit

Mind Map 2.0: Evolution of mind map after field visit

 

1) Uses of cactus fruit:

Before starting our research, we were interested in knowing uses of cactus fruits, various products made up of cactus fruit and market available for cactus fruit. Cactus fruit is used in food processing industry to make juice, jellies, candies and ice-cream. Another area of usage of cactus fruit is for medicinal purpose. During field visit we realized that people make milk-cold drink and juices from cactus fruit pulp. It was also sold in medical shops for iron deficiency syndrome.

 

2) Cactus fruit harvesting/ plucking:

This is the key area to be explored. The various relations connecting to this area are as below:

Traditional fruit picking methods

1) Traditional method with stick and bowl is time consuming and tedious

2) PVC pipe with L channel at the end allows continuous collection but there are problems with the orientation and fruits falling while picking.

3) Chinese model of plucker offers pick and drop of 1-2 fruits at a time which is again a tedious process.

4) Locally developed plucker is low cost design but again offers pick and drop of 1 fruit each time. Sometimes it damages fruit during clamping.

 

3) Cactus fruit processing:

During first mind map we had assumed that fruit peeling process is carried by industries as farmers sell fruits to dealer. But during field visit we observed that fruit processing is a real challenge faced by small scale or household level cactus fruit processing businessses.

Fruit peeling process:

Conventionally fruit peeling is done using knife or scissors. Women wear plastic bags in hand to prevent injuries from cactus nubs. During field visit we found that fruits processing (peeling+ pulping+ seed removal) is very tedious and tales more time. This was a new problem found during the process.

 

4) Stakeholders:

The important stakeholders in the process are farmers, labourers and self-help groups. The stakeholders such as brokers, large scale processing industries, shopkeepers and users are now part of the mind map 2.

 

5) Problems:

List of problems observed during field visit are as follows:

Fruit plucking process:

1. Picking fruits in dense areas at heights more than human body

2. Attaching container to the device to improve time efficiency with no interruptions

3. Cost effective as current devices are as cheap as Rs. 200

4. Weight of the device should be less

5. Protecting users from the thorns on plants and fruit

6. Preventing fruits from falling down during plucking

7. Preventing fruit damage while holding fruit during plucking

8. Orientation of device for plucking fruits

9. Safe to use and preventing them people from getting exposed to thorns

10. Designing holder to hold fruits with different sizes

Fruit processing:

1) Removing thorns and peeling of outer layer of fruit is tedious process. Removing thorns results in injuries as well.

2) Peeling process which is currently followed involves use of scissors or knife and there is wastage of fruit pulp in this process.

3) Filtering of pulp to remove seeds is again a manual process.

4) Another problem is storage and preserving cactus fruit juice for longer duration.

 

6) Opportunities: Functional requirements characteristics for new design are as follows:

Fruit Plucker

1) The new design should allow continuous fruit collection to improve collection efficiency.

2) Allow for reaching heights of 10-12 fts

3) Size and weight constraints for ergonomic considerations

Fruit processor:

1) Manually operated machine for fruit processing and process layout

2) Work on cactus fruit juice preservation

Proof of Concept & Feedback on concept

Discussion with Mr Kodar Patel

We explained our design ideas about cactus fruit plucker.

Suggestions/ feedback given is as follows:

  • Pipe opening in 90 degree bend should have cutting edge/ ring to stuck fruit inside.

  • Outer sliding pipe should have collars to locate on the inner pipe.

  • Suggestion to use pulling operation compared to twisting operation for ergonomic consideration and fatigue.

Cactus fruit processing:

  • Find parameters of fruit dimensions (min-max) such as-fruit size (length, diameter), stem size, fruit covering thickness.

  • Suggestion to use mesh inside a metal box to remove thorns on the fruit.

  • Suggestion about use of circular box with cutters inside to peel the fruit

  • Improvements suggested on the idea of removing pulp from the fruit directly without peeling the fruit.

  • Mesh type shaker machines for removing thorns on the fruits.

  • An idea of using brushes for removing thorns appeared during the discussion.

  • Suggested to try peeling a few fruits with lathe type turning idea and then proceed for mechanism.

Discussion with Mr Sachin Panchal:

Cost effectiveness is major concern for our design hence the discussion was based majorly about material selection for design and availability of readily available components.

Material of the pipe of the fruit pluckier could be made from:

  • Aluminium sheet: as it is light in weight and cost effective.

  • UPVC: this is thicker and heavier than regular PVC material

  • PVC

  • Plastic pipe: as it corrosion resistant, lighter in weight then aluminium sheet, more cost effective then aluminium sheet, but it may not be strong enough.

Mr. Panchal also gave insights on material to be used for scooping the pulp out of the fruit.

  • He suggested using a 10mm metal scoop of “J” shaped.

  • Even plastic could be used as a scooping device material to remove pulp from the fruit.

 

Prototyping

The device was developed for pulping the fruit. The device consisted of a metal cuboidal box with several circular opening ranging from 2 to 5 centimeter on its top. A small part of the fruit is cut from its base and pressed against the matching circular opening to separate the pulp from peel.

 

User feedback

Modified Prototype

Plucker Top:

Two different shapes (six sided star and a square) are cut out on the PVC cap of 3 inches which could be fitted on all of the above mentioned pluckers.

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