Basic Operations for Fruits and Vegetable Processing

Dr. Rakesh K. Singh Professor and Head

Department of Food Science &Technology The University of Georgia

India’s Fruits & Vegetable Industry

Export (average 20% but 50% for mangoes):

Processed Fruit and Vegetable export increased to US$ Million 555.07 in 2006-07.

Mango Pulp (Rs. 505.83 Crores) (US$ Million 112.21),

Dried and Preserved Vegetable (Rs. 424.06 Crores) (US$ Million 94.07),

Pickles and Chutneys (Rs. 293.59 Crores) (US$ Million 65.03),

Other Processed Fruits and Vegetables (Rs. 508.15 Crores) (US$ Million 112.72),

Pulses (Rs. 770.65 Crores) (US$ Million 170.95)

• World production around 370 MT

• India is #1 producer with annual output of 32 MT (growth rate 3.9%)

• Major Indian fruits consist of:

mango, banana, citrus fruits, apple, guava, papaya, pineapple and grapes.

• The fruits are processed into various products such as fruit juices & concentrates,

canned fruit, dehydrated fruit, jams & jellies etc

Increase in processing of fruits/vegetables:

Frozen 121%

Dehydrated 24%

Source: Government of India – Department of Commerce

Source: Government of India – Department of Commerce

Vegetable Production

Use furrow or ditch irrigation

Courtesy of Trevor Suslow

Use clean well water to wash fresh produce

Potable water is drinking water that is wholesome and

clean and does not cause illness. It is free from any

micro-organisms and parasites and from any substances,

that in numbers and concentrations, constitute a

potential danger to human health.

Harvesting

Clean Harvest Containers and Tools Daily

Evaporative Field Cooler

• A squirrel-cage fan pulls dry air through a water-saturated pad to cool the air, which is forced through vented produce cartons to remove field heat

• See UGA Extension bulletin for instructions to build a simple cooler system

ORGANIZED CHAOS: Fresh produce mixes with rotting

vegetables in Bangalore's Krishnarajendra Market

Different levels of acidity in fruits

Fruits are more acidic than vegetables which affects pathogen growth

Very acidic fruits pH<3.7

Moderately Acidic fruits pH3.7-4.5

Less acidic fruits pH >4.5

Grapefruit Lemon Lime Orange Tamarind Tangerine

Guava Mango Passion fruit Pineapple Strawberry Tomato

Banana Breadfruit Melon Papaya Squash

Assuming all fruits are fully ripe, from ‘The Composition of Foods’, Paul, A.A. and Southgate, D.A.T., Elsevier, 1985

Time before spoilage starts in selected fruits and

vegetables

A few days A few weeks 1-2 months

Fruits Banana (dessert) Cantaloupe melon Guava Mango Papaya Passion fruit Pineapple Strawberry Watermelon

Vegetables Cauliflower Cucumber Green bean Leek Lettuce Okra Peppers Spinach Spring onion Tomato

Fruits Avocado Banana (cooking) Breadfruit Grapefruit Jackfruit Vegetables Cabbage Capsicum Chickpea Cowpea Lima bean/Navy bean Pigeon pea Pumpkin Soybean Squash

Fruits Gourd (bottle) Lemon Lime Orange Tamarind Tangerine Vegetables None

Time available between harvest and processing before spoilage begins

Ideal Location for Processing Facility

• Near production area and main road

• Good roads

• Reliable electricity

• Adequate supply of potable water

• Access for workers & staff

• Availability of other supplies

• Other facilities, e.g., schools, shops, etc

Fruit & Vegetable Processing Building

Should be hygienically designed and easily cleaned to prevent contamination

• Movement of food should not cross paths

• Should have enough space to separate raw, processed, packages

& ingredients

Food movement

Processing

area

Office/

Lab Packaging

Washing

Product

Raw

Basic rules for hygiene and sanitation in fruit

and vegetable processing

Facilities required in the processing room

• A changing room where clothing and shoes that are not worn for

work can be stored.

• Separate hand-washing facilities for staff, with soap, clean water,

nail brushes and clean towels.

•Toilets, which should be separated from the processing room by

two doors or located in a nearby building.

• First aid materials.

• Protective aprons or coats washed regularly, hats/hairnets and if

necessary, gloves and shoes.

• Cleaning chemicals, stored away from the processing room.

Pulped

FRUITS & VEGETABLE PRODUCTS

Fruits Vegetables

Whole fruit Pulped Extract Whole vegetables Fresh-cut

Pectin Papain Dried Packed Chutneys/

Pickles

Fruit peels Dried

(Adapted from: Fellows, 1997)

Bottled Salted/

Pickles/

Chutneys

Sauces Juices

Extracted Juice Whole pulp

Fermented Juices Squashes/

Syrups Jellies/

Marmalades

Jams Nectars Pastes/

Purees/

Fruit

‘cheese’

Fruit

‘leathers’

Sauces

Wine

Second

Fermentation

Vinegar

Distilled

Spirits

Fruit and vegetable of desired quality

Receiving roller conveyor

Washing machine

De-stoning/De-podding

Peeler remover

Inspection / sorting conveyor

Elevator

Cutting machine/cubing machine

Vibro distributor Transporting conveyor

Blanching

Hydraulic conveyor

Pre cooling

Process flow diagram for mango cubes, fruits and vegetables

cubes, sweet corn and baby corn etc.

Selection table

Shredding and Slicing: Vegetables: Spinach,

Cabbage, Gourd

Fruits: mangoes, pineapples

Grating Vegetables: Most hard vegetables, e.g. potatoes, carrots, turnips, sweet potatoes Fruits: Apples,

Manual Graters - stainless steel graters . Mechanized graters - food processors

Weighting Shredded veg are then weighted

to a standardized measurement and packed

in either plastic bags.

Packaging The packaging is then sealed using a bar sealer

Manual Operation for Small Scale Fresh-cut Process

Fresh-Cut

Optimal gaseous environment (for

respiration control)

Temperature control

Sanitizing treatment

Package design

Sensory and consumer testing

Marketing Fresh Blueberries

Calculate Raw Materials & Ingredients

• Decide the amount of product to make

• Calculate from a recipe

Recipe Calculation Amount needed to make 50kg

Mango 500 g (500/803.5) x 50 31.1 kg

Sugar 300 g (300/803.5) x 50 18.7 kg

Ginger 0.5 g (0.5/803.5) x 50 31.1 g

Mustard 0.5g (0.5/803.5) x 50 31.1 g

Chillie 1.0 g (1.0/803.5) x 50 62.2 g

Garlic 0.5 g (0.5/803.5) x 50 31.1 g

Salt 1.0 g (1.0/803.5) x 50 62.2 g

Total 803.5 g 50.0 kg

Example: Mango chutney 50 kg/day

Note: Losses are not included

Typical Losses During Processing of Fruits and

Vegetables

Stages in a Process Typical Losses (%)

Washing fruits/vegetables

Sorting

Peeling

Slicing/dicing

Batch preparation/weighing

Boiling

Drying

Packaging

Machine washing

Accidental spillage

Rejected packs

(does not include evaporation

losses)

0-10 5-50 5-60 5-10 2-5 5-10 10-20 5-10 5-20 5-10 2-5

(Source: Fellows, P., Midway Technology Ltd, Bonsall, UK), 1997

Example: Calculating the weight of fruit after drying

Taking 15.5 kg of fresh fruit, initially the fruit contains 75% water and 25% solids.

Therefore 15.5 kg of fruit contain 11.6 kg of water and 3.9 kg solids

After drying the weight of solids has not changed (only water is removed) and the moisture

content is reduced to 8%.

Therefore the solids content is (100 - 8) = 92%

If 3.9 kg solids is 92%, then the total weight of product = (100 /92) x 3.9 = 4.2 kg

Therefore (15.5 - 4.2) = 11.3 kg water is removed

There were also losses of 200g due to rejected dried fruit. Therefore 4 kg of product is

available for sale.

It is in the interests of the processor to reduce product losses as much as possible

Example: Calculation of boiling losses:

The solids content in the mix of ingredients before boiling is found as follows:

Ingredient Weight Solids content Weight of solids

(kg) (%) (kg)

_____________________________________________________________

Mangoes 31.1 15 4.67

Sugar 18.7 100 18.7

_____________________________________________________________

Total 49.8 23.37

Total after 10%

wastage 44.8 kg 21 kg

% solids in batch before boiling = (21/44.8) x 100 = 46.9%

So 21 kg equals 46.9% of the batch before boiling. After boiling there is no loss of solids

(only water is removed) but the solids content has been increased to 70%.

Therefore 21kg equals 70%.

Therefore the total weight of the batch after boiling = (100/70) x 21 = 30 kg

And boiling losses are (44.8 – 30) = 14.8 kg

Packaging When selecting packaging materials, the processor should consider:

• technical requirements of the product (for protection against light, crushing, air,

moisture etc.)

• the design (for promotional and marketing requirements) and

• the relative cost and availability of different types of packaging.

The daily production rate is used to calculate the numbers of packages required.

Example: Calculation of number of packs required and time to fill and seal them

If 25 kg of dried fruit is produced per day and packed into 100 g bags and there are 50

bags in each cardboard distribution box:

the number of bags required = 25 x 1000/100 = 250 bags

and the number of boxes = 250/50 = 5 boxes

If on average it takes a worker 45 seconds to fill and seal a bag,

the time required = 250 x (45/60) min = 188 min (3 hours, 8 min)

or if 4 people are working together, the time required is just over ¾ hour.

Record Keeping

1. Financial records 2. Production records

Recipes

Raw materials and ingredients received and

suppliers

Wastage % at different stages of the process

Stock levels for each ingredient

Production volumes and measurements

Maintenance programs and schedules

Income from sales

Costs of all process inputs

Staff records

Cash flow

Profit/loss

Tax records

Bank statements

3. Quality assurance records 4. Sales records

Target amounts of ingredients and

any changes made to recipe

Measurements made at process

control points

Batch numbers and product code

numbers

Cleaning procedures and schedules

Names of customers and amounts sold to each

Weekly and monthly sales volumes

(Source: Fellows, P., Midway Technology Ltd,

Bonsall, UK), 1997

Dried Products Dried fruits, vegetables, herbs and spices are low-volume, high-value foods

Blanching: Hot water blanching for vegetables. Steaming can protect nutrients.

1% Sodium bicarbonate in blanch water protects green color

2% Calcium chloride solution firms soft vegetables

Blanching times for vegetables

Food Blanching time (min)

Steam Boiling water

Leafy vegetables Sliced beans Squashes Cabbage Peas Carrots Cauliflower Potatoes

2 - 2.5 2 - 2.5 2.5 2.5 3 3 - 3.5 4 - 5 6 - 8

1.5 1.5 - 2 1.5 - 2 2 3.5 3 - 4 5 - 6 8 - 12

(Source: Fellows, P., Midway Technology Ltd, Bonsall, UK, 1997)

Sulphuring and sulphiting

• Sulphur dioxide protects the natural color of some fruits (banana, pineapple

etc)

[Caution: Do not use on red fruits, it bleaches color]

1. Burning sulphur

Place cut fruits on trays, and 350-400g sulphur are burned per 100 kg

fruit for 1-3 hours

2. Solution of sodium sulphite, sodium metabisulphite or potassium

metabisulphite (1 g/L solution)

Fruits are dipped for 5-10 minutes, or add in the blanch water for

vegetables

• Other treatments: Salting for limes to used in pickles

Process for Dried Fruits and Vegetables

Essential step Optional Notes

Fruit Harvest carefully to reduce bruising and other damage.

Inspect

Wash

Remove mouldy, rotten, and damaged fruit. Also remove all

foreign material: leaves, stems, stalks, sticks and stones. Use

wash tanks or washers with clean, potable water to remove

contaminants, e.g., pesticide residues, insects, soil or dirt, etc

Sort/grade

Uniform size and maturity are important to get uniform drying

times for all pieces. Over-ripe fruits are easily damaged and

difficult to dry. Under-ripe fruits have poorer flavor, color and

appearance.

Peel

Core

Cut/slice

Blanch

Allows faster blanching, sulphur dioxide treatment and drying.

Peel by hand using knives or peelers, or peeling machines.

Check that all traces of peel are removed. Depending on the type

of fruit/vegetable, cut by hand using sharp stainless steel knives,

corers etc. or using choppers, cutters, slicing or dicing machines.

Check for uniform sized pieces.

For vegetables, using a boiling pan, heater, wire basket or

steamer. Check water temperature, time of heating.

Acid dip

Can be used to prevent browning of light coloured fruits and

vegetables. It involves dipping fruit in 2% citric acid, lemon or

lime juice for 5-10 minutes. Equipment required includes

weighing scales or scoops and food-grade plastic tank.

Process for Dried Fruits and Vegetables [continued]

Essential step Optional Notes

Treatment with sulphur

dioxide

Sulphuring cabinet or a food-grade plastic tank for

a sulphite dip. Other equipment includes weighing

scales or scoops. Check weight of sulphur or

concentration of sulphite and time of exposure.

Dry

Pack

Time needed for drying depends on the

temperature, humidity and speed of the air, the type

of dryer and the size of the food pieces. Check for

mould growth, insect contamination and the

temperature and time of drying.

Using an electric heat sealer to produce moisture-

proof, airtight plastic bags. Check fill-weight and

seal.

Label

Store

Check that label is correct for type of product.

Store in a cool dry place away from sunlight.

Protect fragile foods from crushing.

Flour can be made by grinding the dried fruit in a hammer mill before packaging.

Process for chutney

Stage in Process Notes

Fruits/Vegetables

Inspect

Fruits should be picked carefully to reduce bruising and checked for full maturity but not over-

ripe. Vegetables should be fully mature.

Remove mouldy, rotten, and badly damaged fruits and vegetables.

Also remove all foreign material.

Wash Use clean, potable water in a wash tank to remove contaminants, e.g., pesticide residues, insects,

dirt and soil, etc.

Sort/grade

Peel

Sort by hand on a sorting table to get similar colour or maturity

Most fruits and vegetables require peeling, but some chutneys include un-peeled fruits. Peel by

hand using sharp knives or peeling machines that are made for some types of fruits. Check that

all traces of peel are removed.

Cut/slice/core Cut into thin strips or small cubes by hand using knives, or slicing or dicing

machines. Pieces should be similar in size to produce uniform mixtures and allow faster

penetration of sugar syrup into the pieces. Check for uniform sized pieces.

Mix ingredients Weigh ingredients and mix in a stainless steel or food grade plastic mixing bowl.

Heat

Boil the mixture in a stainless steel boiling pan with constant stirring, until it is thick and

concentrated. Check the time and temperature of boiling. An optional check can be made of

sugar content (68-70%) using a refractometer.

Fill & Seal Hot fill using a filler into pre-sterilised jars (boiled in water or in an oven at 100C for 10-15

min). Seal lids and check fill-weight and properly sealed lid. An optional bottle rinser can be

used to save time If jars are not obtainable, plastic pots or bags can be used,.

Cool

Label

Store

To room temperature, either by lying jars on their side on a table or using a bottle cooler .

Label and check that the correct label is used and that label quality is satisfactory.

Store in cool dry place away from sunlight

Equipment

Size of equipment

• One large, several small or

multiple batches?

• Jam making 36 kg/day

• Time available to boil the 36 kg

fruit/sugar batch = 3 h

• Boiling throughput = 36

3 = 12

kg/h

• A batch should be boiled in 20

min to maintain quality, 2

batches/h?

• Either one pan with 12 kg size, or

a pan with 6 kg capacity but use

two batches

Type of equipment

• Mixing of ingredients

• Heating burners

• Boiling pan

• Filling & Packaging

• Labeling

• Cleaning

Hot air drying

Blueberries

Carrots

Vacuum belt drying of blueberries

Capsule sealer

Bottle cooler

Boiling pan/pasteuriser

Hygiene and Sanitation

• Raw material should be suitable for its intended

purpose

• Processing facility should be in sanitary condition

• Equipment (must be cleanable and kept clean)

• Persons handling food and their responsibilities to

protect it from contamination

• Building design and construction including water

supplies, drainage, toilet facilities, wash-hand basins,

provision of first aid facilities, places to store clothing,

facilities for washing food and equipment, lighting,

ventilation, protection against infestation by rats and

insects and removal of wastes.

Display of fruits and vegetables