HANDOUT - INTRODUCTION TO PHV - PART 1 AND 2 - 17.5.2018 (1)

5/18/2018 POST HARVEST TECHNOLOGY OF FRESH FRUITS AND VEGETABLES -Introduction- Dr Dương Thị Ngọc Diệp NLU, May 2018 LEARNING OBJECTIVES At the end of the lesson, the learners are expected to: define post harvest technology; determine its importance and objectives; explain the causes of post harvest food losses and the prevention measures; and determine the pre-harvest factors affecting the post harvest life and quality aspects 5/18/2018 LESSON OUTLINE Definition of Postharvest Technology (PHVT) Importance and Objectives of PHVT Causes of Post Harvest Food Losses and the Prevention Measures; and Pre-Harvest Factors Affecting the Post Harvest Life and Quality Aspects What is Post-Harvest Technology? Post-harvest technologies constitute an interdisciplinary science and techniques applied to agricultural commodities after harvest for the purpose of preservation, conservation, quality control/enhancement, processing, packaging, storage, distribution, marketing, and utilization to meet the food and nutritional requirements of consumers in relation to their needs 5/18/2018 What is Post-Harvest Technology? Post-harvest technology stimulates agricultural production by:  prevents post-harvest losses;  improves nutrition;  adds value to agricultural products;  opens new marketing opportunities; and  generates new jobs What is Post-Harvest Technology?  Postharvest handling specifically involves the movement and the operations that commodities undergo from harvest to the time immediately before meal preparation 5/18/2018 What is Post-Harvest Technology? Its main concern is to keep commodities in an acceptable state from harvest until it reaches the consumer since most commodities are transported in their perishable state Postharvest Flow Harvest Handling Packaging Transportation Distribution Manufacturer Consumer 5/18/2018 What is Post-Harvest Technology?  In addition, postharvest handling aims to minimize losses at the least possible cost  The existing postharvest environment requires appropriate technologies to maintain quality of commodities  Poor handling of agricultural commodities can result in quality deterioration and losses 5/18/2018 Objectives of Post-Harvest Technology? The three main objectives of applying postharvest technology to harvested fruits and vegetables are: 1) to maintain quality (appearance, texture, flavor and nutritive value) 2) to protect food safety, and 3) to reduce losses between harvest and consumption Why is the study of postharvest physiology and technology so important?  Vegetable and fruits products are usually of high value (compared to grains) and need to be handled carefully in order to preserve that value  Vegetables and fruits are living commodities and deteriorate in quality very quickly 5/18/2018 Why is the study of postharvest physiology and technology so important?  A lot of money and other resources is invested in growing the crop  To get the best price possible for the crop, it must be looked after appropriately until it reaches the consumer  Vegetables and fruits are rich source of vitamins, minerals, plant proteins and medicinal substances - proper care helps maintain nutritional and pharmacological value REMEMBER!!!  Fresh fruits, vegetables, and flowers must be in excellent condition and have excellent quality if maximum shelf life is desired  The best possible quality of any commodity exists at the moment of harvest  From that point on, quality cannot be improved, only maintained  Remember that shelf life begins at harvest 5/18/2018 POST HARVEST LOSS??? POST HARVEST LOSS??? This means that one-tenth to one- half of all the land, inputs, and labor used to produce the commodities goes to waste When expressed in monetary terms, this could amount to millions of dollars 5/18/2018 POST HARVEST LOSS??? Globally, food losses and postharvest waste are estimated at 30 to 40% of production Losses of perishable foods such as fruits and vegetables can be even higher during the postharvest period, depending upon the weather, access to storage or distance from markets POST HARVEST LOSS??? Utilizing improved postharvest practices often results in:  reduced food losses,  improved overall quality and food safety, and  higher profits for growers and marketers 5/18/2018 Objectives of Post-Harvest Technology? The three main objectives of applying postharvest technology to harvested fruits and vegetables are:  to maintain quality (appearance, texture, flavor and nutritive value)  to protect food safety, and to reduce losses (both physical and in market value) between harvest and consumption  THE BASICS OF POSTHARVEST TECHNOLOGY Actual postharvest losses of selected perishable crops 10 5/18/2018 COMMON CAUSES OF POSTHARVEST LOSSES IN VIETNAM  Rough handling  Inadequate cooling and temperature maintenance  Lack of sorting to eliminate defects before storage  Inadequate packaging materials further add to the problem  COMMON CAUSES OF POSTHARVEST LOSSES IN VIETNAM In general,  minimizing rough handling,  sorting to remove damaged and diseased produce and  effective temperature management  will help considerably toward maintaining a quality product and reducing storage losses 12 5/18/2018 Storage life will be enhanced if: the temperature during the postharvest period is kept as close to the optimum as feasible for a given commodity 13 5/18/2018 EFFECT OF TEMPERATURE ON POSTHARVEST  The ideal temperature often depends on the geographic origin of the product  Tropical plants have evolved in warmer climates and therefore cannot tolerate low temperatures during storage Plants from tropical origins must be stored above 12°C  This is in contrast to plants which have evolved in temperate, cooler climates which can be stored at 0°C  EFFECT OF TEMPERATURE ON POSTHARVEST The rapid cooling after harvest is so important: If the temperature is lowered and the harvested products are put in refrigerated storage, water and quality loss can be reduced Fresh produce is alive, living and breathing The general term for all the processes going on inside a living organism is called metabolism 14 5/18/2018 EFFECT OF TEMPERATURE? Temperature has a big effect on the rate of metabolism of the product When the temperature of the product rises, so too does the rate of metabolism EFFECT OF TEMPERATURE? One of the main processes of metabolism is respiration which is the process of Temperature management for fresh produce is the key to quality Lowering the temperature as quickly as possible after harvest will slow the rate of metabolism and therefore extend the product’s shelf life 15 5/18/2018 EFFECT OF TEMPERATURE?  High temperatures accelerate ripening and the speed at which rots develop 10 oC increase in temperature will cause fruit and vegetables to deteriorate twice as fast, as well as encouraging disease organisms to grow twice as fast as well A Major quality loss reactions Microbiological Enzymic Chemical Growth or Hydrolytic Oxidative presence of reactions rancidity toxinogenic catalyzed by microorganisms lipases, protease… Physical Mass transfer, movement of low MW components Growth or Lypoxygenase Oxidative and Loss of presence of reductive texture infective discoloration microorganisms Growth of spoilage microorganisms Enzymic browning Non-enzymic Loss of flavors browning Freeze-induced Nutrient losses damage 16 5/18/2018 Assessment of post harvest losses Causes of post-harvest losses of fresh fruits and vegetables:  use of uncertified seeds  excessive use of fertilizer,  poor irrigation system  poor harvesting practices,  supply exceeding demand  limited access to loan  handling: poor transport and storage  diseases and pests Assessment of PHV losses for leafy vegetable • Producers are aware that quality of produce is affected by: – Delay weeding – Water management – Fertilizer & pesticide use – Disease and pests 17 5/18/2018 F&V PRODUCTION IN VIETNAM 2017 - The Year of the Vegetable Industry !!!! Disasters, severe diseases… But, with the efforts, the whole agriculture industry in 2017 has achieved success beyond expectations, especially in export, with export turnover estimated to reach $ 3.5 billion, up to 40% over 2016, Vegetables continue to affirm that agricultural products will be the great power of Vietnam in the future F&V PRODUCTION IN VIETNAM Updated data from the General Department of Customs showed that in January 2018, the value of vegetable and fruit exports was $ 320 million, up by 37% over the same period last 2017 18 5/18/2018 F&V PRODUCTION IN VIETNAM  Vietnam’s F&V are mainly exported in the form of fresh fruits, so the value added is low and affected by technical barriers such as plant quarantine, fruit quality decreases rapidly, short shelf life due to lack of skillful labor and advanced preservation technology and food hygiene and safety F&V PRODUCTION IN VIETNAM  Exportation on: dragon fruit, products from coconut, pomelo, longan  Processed products: puree, concentrated, dried, frozen  China  America  Japan  Korea: biggest markets of Viet Nam F&V 19 5/18/2018 F&V PRODUCTION IN VIETNAM Post harvest loss of 20-25% Small-scale production Hand-operating Behind-time technology Fresh consumption tradition 20 5/18/2018 Wrong harvesting INDICATORS Wrong LOGISTICS Wrong PESTICIDE APPLICATION (RESIDUES)  GOOD PLANNINGS ARE REQUIRED ON:  PRODUCTION  PRESERVATION AND PROCESSING  Comprehensive understanding of compositions, physiological processes, physicochemical processes  Different F & V needs different handling technique 21 5/18/2018 THANK YOU! 22 5/18/2018 PROCESSING OF FRUITS AND VEGETABLES - introductionDr Dương Thị Ngọc Diệp NLU, May 2018 Why fruit and vegetable processing? - All fruits & vegetables lose their quality at some rate after harvesting The principal quality loss reactions are: - microbiological - chemical - enzymic - physical 5/18/2018 Processing of fruits and vegetables is for: Preservation: by slowing down the natural processes of decay caused by microorganisms, enzymes and other factors such as heat, moisture and sunlight Food diversification: attractive and in demand by consumers Table Major quality loss reactions Microbiological Enzymic Chemical Physical Growth or Hydrolytic presence of reactions toxinogenic catalyzed by microorganisms lipases, protease… Oxidative rancidity Growth or Lypoxygenase presence of infectous microorganisms Oxidative and reductive discoloration Growth of spoilage microorganisms Non-enzymic Loss of flavors browning Freeze-induced Nutrient losses damage Enzymic browning Mass transfer, movement of low MW components Loss of crispy texture 5/18/2018 Table Consequences of quality loss Nature of quality loss Consequence Presence of toxin Hazard to the consumer Presence of pathogenic microorganisms Microbial spoilage Potential microbial hazard Unacceptable rate of oxidation Unacceptable change in texture Development of rancidity Color change Flavor loss Texture change Poor color, flavor, texture Loss of food Inability to distribute & market product Limitation of self life Increased packaging and distribution cost Low quality of marketed food ... different handling technique 21 5 /18 /2 018 THANK YOU! 22 5 /18 /2 018 PROCESSING OF FRUITS AND VEGETABLES - introductionDr Dương Thị Ngọc Diệp NLU, May 2 018 Why fruit and vegetable processing? - All fruits... Viet Nam F&V 19 5 /18 /2 018 F&V PRODUCTION IN VIETNAM Post harvest loss of 2 0 -2 5% Small-scale production Hand-operating Behind-time technology Fresh consumption tradition 20 5 /18 /2 018 Wrong harvesting... crops 10 5 /18 /2 018 11 5 /18 /2 018 COMMON CAUSES OF POSTHARVEST LOSSES IN VIETNAM  Rough handling  Inadequate cooling and temperature maintenance  Lack of sorting to eliminate defects before storage