Presentation on theme: "1ST WORKSHOP PRESERVATION TECHNOLOGIES FOR FRESH FRUITS AND VEGETABLES: COLD STORAGE, MODIFIED ATMOSPHERE PACKAGING AND CONTROL ATMOSPHERE STORAGE Profª."— Presentation transcript:
1 1ST WORKSHOPPRESERVATION TECHNOLOGIES FOR FRESH FRUITS AND VEGETABLES: COLD STORAGE, MODIFIED ATMOSPHERE PACKAGING AND CONTROL ATMOSPHERE STORAGEProfª. Mª TERESA SANCHEZJanuary, 2002Istanbul, TurkeyFinancial support by the Commission of the European Union underMEDA programme is acknowledged (Thematic Network ICA3-C )
2 SPANISH FRUITS AND VEGETABLES: PRODUCTION, IMPORTATIONS and EXPORTATIONS
6 FOOD CONSUMPTION IN THE E.U. MEDITERRANEAN COUNTRIES
7 PERISHABILITY AND PRODUCE LOSES THE EMPHASIS OF ANY FRUIT ANDVEGETABLE PROGRAM IS TO:Have accurate control of temperature.Reduce microbial loading.Control and/or modify the packaging atmosphere.Deter enzymatic browning.Maintain all of the above while offering a consistent, predictable quality level for all deliveries.
8 COLD STORAGE OF FRUITS AND VEGETABLES COLD CHAINREFRIGERATED TRANSPORT
9 COOLING PROCESS 1. Reducing respiration and degradation by enzymes. 2. Reducing water loss and wilting.3. Slowing the growth of decay organisms.4. Reducing the production of ethylene, the natural ripening agent.5. Providing time for proper handling and processing.
10 The most effective way to maintain quality and safety of fresh fruits and vegetables and their products is to maintain the COLD CHAIN, including the optimum range of relative humidity, throughout the postharvest life of the commodity.MAXIMIZE THE SELF-LIFEMINIMIZE SHRINKAGE
11 REFRIGERATED TRANSPORT TEMPERATURECONTROLLED TRANSPORT
12 PROBLEMATICS OF FOOD PRESERVATION BY REFRIGERATION Requires continuous expense.The cold chain (production, transport, store, consumption) should not be broken. Problems of interruption of cooling machine power and/or shortage of cooling agent (ice, eutectic mixtures).Reduce enzymatic activity but do not kill, implies T<6 ºC for a few days but T<-18 ºC for a few months.Cooling increases relative humidity and increases surface fungi.Packed enclosure prevents it, but it asphyxiates vegetables. (Ambient humidity not relevant for frozen food.)In mixed spaces some food give odours (potatoes) and others take (dairy). Some stores require ventilation for fresh air or air treatment for controlled atmosphere.
13 CONTROLLED ATMOSPHERE STORAGE OF SELECTED FRUITS AND VEGETABLES CO2 and O2 concentrationTemperatureRelative Humidity
14 CONTROLLED ATMOSPHERE STORAGE Presence and quantity of:CO2O2EthyleneProducts in optimum conditions:TypeVarietyOriginClimatic backgroundPRODUCTS:Life can be extended by 30%Losses and diseases are reduced by %
15 Maximum concentration of CO2 and minimum concentration of O2 in AC storage Kader, 1980
16 CA MANIPULATIONS Initial low oxygen stress treatment (ILOS). High CO2 shock treatments.A range of O2/CO2 concentrations.CA combined with other treatments as a possible replacement for SO2.Better gas-tight insulation techniquesComputer control systemsLower values of O2 and CO2
17 MODIFIED ATMOSPHERE PACKAGING OF SELECTED FRUITS AND VEGETABLES PUTTING THE PRODUCT TO SLEEP
18 Produce generate their own atmosphere in plastic bags Depending on:The rate of respiration of the commodityThe properties of the filmThe storage temperature
19 Optimum CO2 and O2 concentration in MAP Optimum gas levels can vary according to:Cultivar or genotypeProduction areaHarvest maturityOther factorsBroccoli 5:2; asparagus 10:10; lettuce 2:2; peaches 6:1.5; pears 2:2; carrots 0:21; blueberries 6:1.5
20 The potential positive and negative effects MAP has on the Food Industry Davies et al., 1995
21 MODIFIED ATMOSPHERE EQUILIBRIUM M.A. PASSIVE M.A. Produced by the application of gas flushing techniquesEQUILIBRIUM M.A.The actual equilibrium MA attained within a package will also depend on factors such as the prepared form of the vegetable studied, the rate of respiration at storage temperature, the pack volume and fill-weight, and the surface areas for gas exchange.Produced naturally by respirationPASSIVE M.A.The permeability characteristics of the film determine the equilibrium gas concentration achieved in the package.
22 GENERAL EFFECTS OF MAP ON MICRO-ORGANISMS Not well studied.Gram negative bacteria (Pseudomonas) more sensitive to CO2 than Gram positive.CO2 at sufficient concentration can inhibit the growth of spoilage moulds.
23 FACTORS TO CONTROL IN MAP FOOD HYGIENETEMPERATURE CONTROLSTOCK ROTATIONQUALITY ASSURANCE TESTSMICROBIOLOGICAL TESTINGSEAL INTEGRITYGAS ANALYSISTEMPERATURE MONITORING
24 FUTURE OF MAP FOCUS AREAS OF MAP RESEARCH: OPTIMISING MAP OF A VARIETY OF FRESH PRODUCTS UNDER VARIOUS STORAGE CONDITIONS.TESTING MAP FILMS FOR CLIENTS.EVALUATING EDIBLE COATINGS.
25 ENVIRONMENTAL IMPACT OF PRESERVATION TECHNIQUES OF FRUITS AND VEGETABLES CFC’s, the predominant refrigerants used in reefer containers.Proposed restrictions on HFC’s become a reality, refrigerated transportation will face serious challenges in finding acceptable substitutes.
26 QUALITY AND CONSUMER ACCEPTANCE High quality fruits and vegetables are one of today's wonders with regard to Spanish food supply.Unfortunately, many Spanish fruit and vegetable growers believe that once a high quality product is produced, their problems are over. In reality, their troubles could be just beginning. It has been estimated that more than 40 % of perishable commodities are lost after production.Price received for produce is determined by quality at the marketplace.
27 Direct contact between the seller and the consumer results in the consumer being able to select the particular items and enabling the seller to react quickly in response to consumer demands. This ensures a high level of consumer satisfaction.
28 Variables consumers perceive as a reflection of produced quality: Texture: Crispness and freshness.Flavor and taste.Nutritive value.Price.Producers who are able to produce and package their produce in such a way to enhance these variables are the most successful in the market place.
29 How to assure the quality of a product? How to make commerce easier? (1) The quality inspection procedures that must be carried out (Commission Regulation 2251/92 of 29 July 1992),(2) What quality they must have (Common Quality Standards' that have been promulgated throughout the years), and(3) The maximum limits of pesticide residues admitted and how they should be controlled (Council Directive 76/895/EEC, 90/642/EEC and 93/58/EEC).Within the Regulation applied to foodstuffs, fruit and vegetables must fulfill the provisions on labels (Council Directive 79/112/EEC and the one that regulates the quantity of products in the packages (Council Directive 76/211/EEC).
31 1ST WORKSHOPPRESERVATION TECHNOLOGIES FOR FRESH FRUITS AND VEGETABLES: COLD STORAGE, MODIFIED ATMOSPHERE PACKAGING AND CONTROL ATMOSPHERE STORAGETHANK YOU VERY MUCHProfª Mª TERESA SANCHEZJanuary, 2002Istanbul, TurkeyFinancial support by the Commission of the European Union underMEDA programme is acknowledged (Thematic Network ICA3-C )