stephen morris - postharvest fresh - the storage and handling of fruits and vegetables

The storage and handling of fresh foods , including fruits and vegetables

Dr Stephen Morris Postharvest Fresh

The challenges for quality during storage and impact on nutritional content.

New technologies and quality monitoring systems for optimal storage and handling

Regulatory changes and issues quality and safety

• Postharvest science provides benefits to the supply chain and reduces waste, therefore making better use of existing resources

• 15-75% of fresh produce is lost - tropical regions and developing nations is higher due to lack of technology & inadequate infrastructure

• More than 66% of value after farm gate (can be up to 90%) , therefore loss in postharvest is more economically significant

• In developed countries, produce has higher ‘value’ • Distance to market is a big factor - modern supply chains span the globe


The challenges for quality during storage and impact on nutritional content.

New technologies and quality monitoring systems for optimal storage and handling

Regulatory changes and issues quality and safety

What is the Postharvest Goal?

Postharvest life and quality


How

High

How

Fast

http://www.pbase.com/daves88/feeling_blue

Causes of Postharvest Losses



– major factor leading to wastage

– results in lower market prices

Physical Damage

TYPES OF DAMAGE

Impact

- sharp blow, ie. falling on a hard surface or against another fruit - a fingernail or cutting blade - mechanical harvester - hail etc


during storage, tendency is for

water to move from produce to

atmosphere

Water loss results in:

• shrivelling

• softening

• loss of appearance

• loss of saleable weight

• toughening

% water loss resulting in quality

loss varies with produce type

Desiccation


Postharvest diseases

Rhizopus rot Brown rot (Monilinia fructicola)

Blue mould

(Penicillium

expansum)

Anthracnose (eg.

Colletotrichum spp.)

http://images.google.com.au/imgres?imgurl=http://pics.davesgarden.com/pics/Thaumaturgist_1061427785_804.jpg&imgrefurl=http://davesgarden.com/pf/showimage/23387/&h=640&w=480&sz=54&hl=en&start=3&tbnid=e_nJ5hVahBIgVM:&tbnh=137&tbnw=103&prev=/images?q%3Danthracnose%2Bmango%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG

http://www.inra.fr/hyp3/images/6033451.jpg


Physiological disorders

water soaked

appearance of flesh

flesh does not ripen

colour does not change

pitting

of skin

bitter pit

- low

calcium


Postharvest Handling Techniques How Can We Reduce Postharvest Losses?


Postharvest Handling Techniques


Postharvest Processes - Harvest

Transport to packing house


Marketing Functions - Australia Packing

Washing

Fungicide


Grading and Quality Control Packing Grading


Pre-cooled fruit loaded into

refrigerated truck

International transport by sea

Reefer

container

- Reefers are insulated

containers with own

refrigeration units

- Can have CA or MA

Refrigerated Transport


Quality Management

Definition of Quality Producer

grade


Wholesalers Retailers

Definition of Quality


Consumers

Definition of Quality


External quality

Appearance


Appearance can be improved by:


Quality components of fruit and vegetables - internal

Main Factor Component


Quality components of fruit and vegetables - internal

Main Factor Component

Organic produce


Minimise time to market

Minimise metabolic activity (respiration rate)

Minimise physiological activities

Minimising Quality Losses


Changes in acidity and soluble solids in grapes during ripening

0

2

4

6

8

10

12

14

Red/green Red Purple Black Dull black

So

lub

le s

olid

s (

%)

0

1

2

3

Tit

rata

ble

ac

idit

y (

%)

Soluble solids

Titratable acidity

Adapted from Kays, 1991


Change in aromatic compounds during ripening of banana fruit

0

200

400

600

800

1000

1200

2 4 5 6 8 10 11 12 13 14 15 16 17 18 19 20 21Days

Co

nc

en

tra

tio

n u

g/1

00

g

400

700

1000

Ca

rbo

n d

iox

ide

mg

/kg

/24

h

CO2 Methyl-3-butyl acetate

2-Pentyl acetate

n-Butyl acetate

Hexyl acetate

Isopentyl alcohol

Adapted from Kays, 1991


Colour

light reflected from rotating fruit measured by

photoelectric cells

Images captured and analysed by software, fruit sorted

into defined classifications using colour, diameter and

shape


Brix determination (automated, non-destructive) Indication of taste (sweetness)

No damage to fruit

Brix = % of soluble solids

per given weight of juice

www.compacsort.com


Quality Management Systems


Increased Consumption of Fresh Produce and the Occurrence of Foodborne Disease

Sivapalasingam et al., Journal of Food Protection., Vol 67, No. 10, 2004, pp 2342-2353


Pathogens & Spoilage Organisms

•

•

Disease:


Vulnerable Persons Food Safety Scheme Manual Policy and information to help businesses comply with the Food Service to Vulnerable Persons Food Safety Scheme under the Food Regulation 2004

Foods that are normally potentially hazardous include:

• Raw and cooked meats or foods containing raw or cooked meat such as

casseroles, curries, lasagne and meat pies.

• Dairy products and foods containing dairy products such as custard and dairy

based desserts.

• Seafood and foods containing seafood

• Processed fruits and vegetables , for example salads

• Cooked rice and pasta

• Foods containing eggs, beans, or other protein rich foods, for

example Quiche

• Foods that contain any of the above, for example sandwiches


Australian Experts Name Foods Most Likely to Cause Food Poisoning Rachel Creasey, 28 Nov 2013 (Australian Food Safety News)

The Seven Foods Most Likely to Give You Food Poisoning

Rice – Once rice cooked Bacillus cereus can start to grow – keep refrigerated and eat promptly

Poultry – Problem can occur due to Salmonella & Campylobacter. Killed if properly cooked but when

raw can contaminate other surface surfaces and foods.

Eggs – Problem with Salmonella on surface of egg shells. Cooking thoroughly can kill them. But when

uncooked, Salmonella with time, can penetrate shell and eventually reach the yolk, with then a huge

increase in bacteria concentration.

Deli Meats – Risk of Listeria, which can grow down to about 2C

Fruit – Problem when grown on ground ie melons, also other fruits. Only ever problem from

contamination usually from water or surfaces containing some trace of faeces. Listeria cannot cross

the skin, but a problem when cut.

Vegetables (especially leafy) and Tomatoes – Salmonella and Listeria can be a problem,

from ground and water splash/ irrigation.

Sprouts – Unfortunately, the ideal temperature and conditions for growing sprouts are also ideal

for bacteria. Keep refrigerated, eat promptly don’t touch if any sign of bacteria.


Three Quick Examples of Problems and Solutions

Apples – Benefits and Problems of Technol0gy


1-MCP

Combination of CA and 1-MCP


Apples in Summer


Potatoes – Unusual History


Developed ‘Safe’ use of potatoes.


Potatoes Adoption


Potatoes – Critical Food for Hazaras in Afghanistan



Eggs – Problem of Compromised Immune System

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60

Hu

ag

h U

nit

s

Estimated Days After Laying

Australia Survey Egg Quality 2008

Brisbane

Melbourne

Sydney

Perth

USDA Grade AA

USDA Grade A

USDA Grade B

Previous Aust, Std


Eggs – Problem of Compromised Immune System • Eggs have three strong barriers against bacteria • Egg shell and waxy bloom • Egg white strongly discourages bacterial growth • Membrane around yolk is a strong physical and chemical barrier, breaks down after about 3 weeks at room temperature


Eggs – Problem of Compromised Immune System


Eggs – Simple temperature and handling protocol would guarantee extra safe and extra fresh eggs for consumer • With current cheap stick on temperature labels can readily

ensure temperature kept below 8C • Label eggs with laying date and use by date 2.5 weeks under

refrigeration below 8C • Ie Three spot label – first changes after 8 h above 8C, second

after 1 day above 8C and third after 48h above 8C • Have monitored cooling and transport protocol • Have special cooking and handling protocol – ie check label

from fridge < 24 h above 8C and cook within 2 hours from fridge.

stephen morris - postharvest fresh - the storage and handling of fruits and vegetables

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