Packaging Fresh-Cut Agricultural Produce Dr Alastair HicksAdjunct Professor of Agroindustry Mae Fah Luang University Thailand ProPak Vietnam, Ho Chi Minh 1-3 March 2012
Flow chart for fruits,vegetables, root crops Harvesting and Cooling Receiving and Storage Washing and Sorting Peeling, trimming, de-seeding Cutting to specific sizes Sorting for defects Washing and cooling Drying Packaging & labelling Storage and Distribution
Harvesting of fresh produce Selecting raw material with sound quality avoid produce damage and contamination workers use gloves, hair net, sanitary measures Mechanical harvesters used in large operations
Remove field heat from fresh produce Ice and water injection Chilled water baths Forced air cooling Vacuum coolers Packing with an ice-water mixture Vacuum cooling tunnel use a first-in, first out (FIFO) system
Receive and store fresh produce The receival point for fresh fruit and vegetables into a fresh-cut processing plant is a key quality check point. Large processing operations have a list of quality parameters and measurements. Usually they have an enclosed refrigerated dock facility for receiving product. Inventory of stocks begins at the receiving stage after deciding whether to process.
Quality Checklist for raw produce received at the pack houseHarvest Area (Number/ Date/Time:Field#):Harvest Crew: Supervisor:Vehicle Registration: Bin Label:Commodity Parameter Result Specifications Corrective Initials ActionsSizeBrixColourAcidityDefectsTemperature
Process flow in a fresh-cut processing plant Washing and sorting of fresh produce cut surfaces removes damaged tissues These require the use of potable good quality water Water flume for washing and transporting fruit in a large packing plant This ensures produce safety and quality
Pre-cutting whole fresh produce to extend the shelf-life Physical & Chemical pre-cut treatments Physical - mainly air pressure, Modified Atmosphere (MA), heat and low temperature treatments. Chemical – use of chemical sanitizers, chlorine, peroxyacetic acid, hydrogen peroxide, acidify sodium chloride or ozone Firming agents like calcium dip and Methylcyclopropene (1-MCP) plant growth regulator
Peeling, trimming, de-seeding fresh produce Workers in complete food safety attire,sort & cut fruit staff use knives to trim and peel fresh produce plants use abrasive peelers, trimmers high pressure air and lye and steam for peeling.
Fresh-cut produce cutting, slicing Product bin dumpers Product cutting and slicing machine
Washing, cooling of fresh produce Continuous washing of pre- cut lettuce with sprays Recycle through a filter to reduce water consumption Check temp (0 – 5C) , contact time, pH (4.5 – 5.5) chlorine level (50-100ppm) Oxido-Reduction potential (650-750 ppm).
Fresh-cut produce washing, drying Continuous fresh-cut product washing flume Pre-cut vegetables are dried with centrifugal force of spin dryers
Post- cutting treatments of fresh-cut produce Post- cutting treatments of fresh-cut produce extend shelf-life Chemical post-cutting treatments applied Physical post-cutting treatments applied
Physical post-cutting treatments Modified atmosphere and low temperature storage reduces respiration rate and deterioration of fresh-cut produce. Modified Atmosphere (MA) is passive or active Active MA - flushing package with a gas or mixture of gases different from normal air Passive MA- created in package by respiration of fresh-cut produce and package permeability
Chemical post-cutting treatments Inhibit enzymatic browning discoloration caused by enzyme polyphenoloxidase (PPO) Acidification - solutions of acetic, ascorbic, citric, tartaric, fumaric or phosphoric acid Reducing agents - Such as ascorbic acid, or erythorbate isomer of ascorbic acid Application of edible coating: using coating such as sodium caseinate-stearic acid Firming agents- Firmness of fresh-cut fruit products ismaintained by treatment with calcium compounds.
Other post-cutting treatments Low heat treatment to activate pectinesterase prior to a CaCl2 dip Drying treatment: water removed from fresh-cut produce before packaging
Fresh-cut filling, sealing, checking Auto scale with form- fill-seal packaging unit to pack produce in plastic bags Metal detectors prevent metal objects being in final product
Packaging to assure quality and safety of fresh-cut produce When fruit and vegetables are cut, spoilage is faster than with intact or packed product. Packaging protects physical damage, also chemical and microbiological contamination. Packaged fresh-cut produce is a key factor to deliver finished product intact to the end user. Refrigeration maintains package shelf life by keeping product temperature at correct level.
Packaging/labelling treatment Film, rigid plastic used for fresh-cut fruit, vegetables Packs are filled by hand in a small operation Shrink wrap machine removes air, seals bag Plastic pouches in cardboard storage, delivery boxes Automatic operations, bags formed, filled, and sealed Metal detector checks bags passing through the detector to test for metal contaminants. Finished product has a Use By date for optimum product shelf life. Codes are printed on the package.
Types of fresh food packaging film Types of packaging for fresh-cut fruits and vegetables include: Flexible film, Plastic bags Shrink wrap packaging Rigid plastic containers Oriented polypropylene (OPP) for MAP Perforated, thin, low density polyethylene (LDPE) Monolayer polyvinylchloride (PVC) Ethylene vinyl acetate (EVA)
Rigid plastic packaging Rigid plastic packaging used for fresh-cut fruit & vegetable retailing Finished product has a Use By date for optimum shelf life. Codes are printed on the package.
Flexible plastic packaging Used for fresh-cut salad vegetables Ready to eat, washed mixed fresh product Films with permeability, right area; headspace volume, known product respiration Labels printed on the plastic film, weight, price, use instructions
Fresh food packaging trends Packaging recyclability, biodegradability: large buyers are concerned about environment. Packaging variety: more than 1,500 different sizes, styles of produce packages. Packaging sales appeal: Quality graphics boost sales appeal. Multi-colour printing, distinct lettering, logos are common. Packaging shelf life: Fresh produce packaging is engineered to extend shelf life, reduce waste.
Properties of MAP packaging: Modified Atmosphere Packaging (MAP): MAP reduces respiration rate , slows senescence MAP lowers O2, high CO2 levels reduces ethylene & extends fresh-cut products shelf life. MAP delays ripening, surface browning, retard enzyme activity & microbial growth Passive MAP- a hermetically sealed container Active MAP- Flush air from package with filler gas Some limited success cases with MAP, undesirable sensory changes - colour, flavour, odour, growth of pathogenic organisms
Storage and distribution Customer demand for convenient, fresh, tasty food led to fresh-cut produce industry “Cold Chain” is key to delivering fresh wholesome fruit/vegetable products Fresh-cut plants, cold storage facilities, transport companies, wholesaler, retailer & supermarket all help the fresh product. Storage times are kept to a minimum.
Quality assurance system Quality assurance is good timely information on all the quality attributes of a product Physical, chemical, sensory evaluation of raw materials, processed products Ingredients and packaging supplies, processing parameters, finished products Microbiological analysis and control of raw materials and finished products
Quality assurance system cont’d Control of storage and handling conditions Sanitation and waste products control Assurance final products within legal limits and marketing standards. Quality, food safety used as a marketing tool Quality standards used - EUREPGAP, Good Agriculture Practices (GAPs) , International Food Standard (IFS), British Retail Consortium (BRC), Good Manufacturing & Hygienic Practices (GMP, GHP) and others.