園藝專業(yè)英語第二版 教學(xué)PPT課件
園藝專業(yè)英語第二版 教學(xué)PPT課件,園藝專業(yè)英語第二版,教學(xué)PPT課件,園藝,專業(yè),英語,第二,教學(xué),PPT,課件
第六講第六講 Harvesting果實采收采后管理及果實采收采后管理及質(zhì)量控制(二)質(zhì)量控制(二)吳樹敬吳樹敬 園藝科學(xué)與工程學(xué)院園藝科學(xué)與工程學(xué)院一、果蔬質(zhì)量控制的概念一、果蔬質(zhì)量控制的概念二、果蔬成熟的指標(biāo)判斷二、果蔬成熟的指標(biāo)判斷三、果蔬三、果蔬采采收收與與儲運(yùn)儲運(yùn)Main contents1.The fruits and vegetables quality include market quality,edible quality,nutritional quality,storage quality,shipping quality,visual quality and internal quality.In the respect of one fruit or vegetable,the quality factor include appearance,texture,flavor,nutritive value,and safety.2.The indices for the right maturity of fruits.3.The importance of proper harvest and processing technology for horticultural products 4.Harvesting of horticultural productsHarvesting of horticultural productsFresh vegetables,fruits,and flowers are generally harvested by hand.Harvesters use the unique combinations of eyes,brain,and hands to harvest delicate and perishable crop with minimal loss and bruising.*combination of multiple strategies*combination of images with diverse focus using the spatial frequency*combination of multiple classifiers using local accuracy estimates*invalid combination of multiple type specifiers They can be trained to select only those fruits or vegetables of the correct maturity to reduce the amount of material that must be removed on the grading line in the packing shed.Most fruits can be detached without the use of any tools,but vegetables and some fruits(for example bananas,coconuts,strawberries,citrus fruits)are removed by cutting with some sort of knife or shears.*grading line:分揀線:分揀線*shed:廠棚、工棚:廠棚、工棚 Hand harvesting is hard work,and many devices are used to ease the work.These include ladders,picking baskets,knives and specially designed shears.Mechanical aids are often used to place pickers in the best position to carry out the harvest operation.Motorized harvesting platforms and person movers are good example.A variety of mechanical harvesters have been developed to harvest horticultural crops mechanically.They are usually used in harvesting dried products such as walnuts or perishable fruits destined for immediate processing.Mechanical harvesters are sophisticated and have a very high unit cost.They may require a smaller but more skilled labor force.Savings may be realized because the harvest can be accomplished in less time.Removal of the commodities from the plant is usually accomplished by application of shear or tensile forces,using devices such as pinch rollers,combs or rakes,shakers,beaters,or cutters.The amount of the forces required to separate the commodities from the plant can cause damage to the commodity.Fruits can be damaged by falling through the tree:small twigs can puncture the fruit,large branches can bruise the fruit,and fruit can hit each other or the surfaces of the harvester.Mechanically harvested crops are often damaged of poorer grade,more susceptible to decay,and fit only for processing.Management of harvesting and delivery to the packing house operations to maintain the commoditys quality may involve some or all of the following aspects:1.Organization,training,supervision,and motivation of the harvesting crew to achieve maximum efficiency while maintaining effective quality control.They can select fruits and vegetables of the proper maturity,discard unmarketable units,and avoid physical damage.2.Scheduling harvesting during the cooler part of the day,protecting the harvested commodity from the sun,and expediting transport to the packinghouse to reduce losses in quality due to high temperature.3.Reducing physical injuries during harvesting by ensuring that buckets,field boxes,and bins used are clean and have smooth surfaces,by using air-suspension-equipped transport vehicles,by grading roads to eliminate potholes and bumps;and by restricting speed and/or reducing tire air pressure of transport vehicle to level in order to avoid the free movement of the commodity.Manual harvesting Manual harvesting means that the fruit is separated from the plant or removed from the growth media(soil)by the hands of a harvest worker(采摘工人采摘工人).This is used for delicate and perishable commodities such as strawberries or grapes and for commodities that may naturally separate from the plant at maturity,such as most cantaloupes.Many fruits and vegetables are harvested by hand but with the use of an implement such as a knife,clippers,or prong(叉子齒)(叉子齒).Manual and Mechanical Harvest Manual harvesting has many advantages compared with the mechanical harvesting of most fruit crops.The most important advantage is visual image processing ability which enables workers rapidly to detect fruit suitable for harvest and direct their hand to the fruit selected for detachment.Lacking the necessary computer based image processing equipment,designers of mechanical harvesters (采摘機(jī)械)(采摘機(jī)械)have settled for mass removal approaches that typically results in more damage than normal when fruit is harvested individually(單個采摘)(單個采摘).Mechanical harvesting has its own set of GMP considerations.The SSOP for mechanical harvesting must include a rigorous program for the cleaning and sanitation of the harvest machine.Once a machine becomes contaminated it can spread the contamination throughout the field and onto the harvested product.Machine injury is the one problem that hindered its utilization in many fruit and crops harvesting.What is the requirement for the harvester from the healthy consideration?For example,in sweet corn harvesting,kernel injury of grade defect severity ranged from 0 to 78%among 39 loads obtained from harvesters during commercial operation in the Homestead and Belle Glade areas.The difference between sweet corn and field corn sweet corn field corn The goals of postharvest research and extension are to maintain quality and safety and minimize of horticultural crops and their products between production and consumption.Strategies for loss prevention include use of genotypes that have longer quality,and use of an postharvest handling systems that maintain quality and safety of the products.Postharvest technology Research aimed at identifying maturity and quality for a broad range of horticultural crops was continued during the past 25 years,and research on how to maintain quality and safety of fresh-cut fruit and vegetables increased greatly during the past 15 years in response to commercial development of value-added,ready-to-eat products.Strategies for delaying browning and softening of wounded plant tissues and for maintaining their safety by minimizing microbial growth have been developed,but more research is needed to enable the extension of postcutting life based on flavor and nutritional qualityProviding the optima ranges of temperature and relative humidity is the most important tool for maintaining quality and safety of intact and fresh-ct fruit and vegetables,fresh herbs,and ornamental crops.Continued research on technologies to reduce water loss,included use of polymeric films and surface coating.The use of polymeric films for packaging produce and their application in modified atmosphere package(MAP)systems at the pallet,shipping container(plastic liner,塑料墊,塑料墊),and consumer package levels continues to increase.MAP (usually to maintain 2%to 4%O2 and 8%to 12%CO2)is widely used in extending the shelf life of fresh-cut vegetable and fruit products.Use of absorbers of ethylene,carbon dioxide,oxygen,and/or water vapor as part of MAP is increasing.At the commercial level,controlled atmosphere is most widely applied during the storage and transport of apples and pears.It is also applied to a lesser extent on asparagus,broccoli,cantaloupe,persimmons,and nuts and dried fruit.Modified atmosphere is used on apples,peaches,avocados,bananas,cherries,kiwifruit,mangoes,figs,nectarines,raspberries,and strawberries.The promotion of senescence in harvested horticultural products by ethylene results in acceleration of deterioration and reduced postharvest life.Ethylene accelerates chlorophyll degradation causing yellowing of green tissues,thus reducing quality of leafy,floral,and immature fruit and vegetables and foliage ornamentals.Currently used treatments for decay control include:1)heat treatments;2)use of postharvest fungicides;3)use of biological control agents;4)use of growth regulators;5)use of 15%to 20%CO2 in air or 5%O2 in strawberries,caneberry,figs,and pomegranates,and 6)use of SO2 fumigation.
收藏