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Postharvest_Part-I_NCGT_2016.ppt
- 1. This presentation is Part I of the Postharvest Handling Workshop Presentation.
- 2. Postharvest Handling for Advanced Shelf Life (Part I) Support for this program is provided by the NC Growing Together Project at the Center for Environmental Farming Systems. NCGT is funded by the United States Department of Agriculture, National Institute of Food and Agriculture, grant #2013-68004- 20363. Any opinions, findings, recommendations, or conclusions expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. http://www.ncgrowingtogether.org WWW.NCGROWINGTOGETHER.ORG
- 3. Introduction Consumers are demanding local products, and wholesalers are trying to meet this demand by supporting small farms in the wholesale market.
- 4. Produce Buyers & Postharvest Education Wholesale produce buyers & institutional purchasing agents are enthusiastic about helping farmers understand postharvest needs. They see value in: Educating growers Providing packing information Extending shelf life Often, buyers will attend training workshops and other events to help clarify needs for wholesale handling and packing, meet farmers, and assist in the education of growers interested in selling into wholesale markets. Regardless of whether your farm sells wholesale or direct-to-consumer, postharvest handling methods can increase shelf life and provide valuable marketing tools for your farm!
- 5. Wholesaler Challenges Warehouse Space Shelf-life Logistics Grading/Sorting /Packing Communication
- 6. What is Quality Control (QC) Looking For? • Appearance (color, size, shape, free from defects) • Firmness • Flavor
- 7. How does this impact what they buy? • More flexibility on how much product they will buy from small farms. • Ability to pack product out into conventional product if local does not sell or before the shelf-life expires – Less Waste • Customer Satisfaction Shelf-life Grading/Sorting/Packing
- 8. Why Postharvest Handling is Important • Premium Price • Protect Food Safety • Reduce Losses • Increased shelf life and marketing opportunities
- 11. Top Causes of Reduced Shelf-Life • Temperature • Physical Damage • Pathogens (causing decay) • Relative Humidity • Contamination
- 12. How can we increase shelf-life? • Harvest early in the morning • Once harvested, keep produce out of direct sunlight or extreme temperatures. • Provide shade while transporting product. • Maintain a 100% cold supply chain whenever possible (pre-cool immediately) • Cold chains can be used as a marketing tool! Temperature Management
- 13. Pre-Cooling Methods • Room Cooling • Forced-air cooling • Hydro-cooling • Top icing or liquid method • Vacuum cooling
- 14. Sanitation • Pre-Wash handling • Water Disinfectant Options • Chlorine (organic considerations) • Ozone • Hydrogen peroxide
- 15. CAUTION…Chilling Injury Highly Sensitive • Basil • Cucumbers • Eggplants • Pumpkins • Summer squash • Sweet Potatoes Moderately Sensitive • Snap Beans • Peppers • Winter squash • Tomatoes • Watermelon
- 16. Postharvest Refrigeration • Coolers • Refrigerator • Refrigerator Truck • Walk-in Cooler • Porta-Cooler with CoolBot Technology
- 17. How can we increase shelf-life? • Relative humidity is the recommended % of moisture in the air during storage. • Raise humidity by using a humidifier. • Decrease humidity by using fans. • Temperature + Humidity = Extended shelf-life. Relative Humidity
- 18. Ethylene Ethylene Producers • Apples • Cantaloupes • Honeydew • Peaches • Pears • Tomatoes Ethylene Sensitive • Snap Beans • Lettuce • Cabbage • Cucumbers • Eggplant • Peas • Potatoes • Broccoli Consider when storing items in enclosed spaces.
- 19. Ethylene Tip for testing ethylene: Place a white carnation in a vase in the storage space overnight…if it’s brown the next morning, ethylene production is happening in your storage space!
- 20. How can we increase shelf-life? • Handle product with care to prevent any physical damage of the product. • Train employees on how to handle certain commodities; some are more fragile than others. Physical Damage
- 21. Packing • Clamshells • Boxes • Crates • Plastic Bags Carefully pack to avoid damage during transport.
- 22. How can we increase shelf-life? • Poor Employee Hygiene. • Improperly cleaning harvesting tools/containers. • Reuse of cardboard boxes (not allowed by most wholesalers or on GAP-certified farms). Avoid Contamination
- 23. Strawberries - Rejected by Buyer The result of what a wholesaler experienced within 24 hours of receiving local strawberries that have not been cooled properly.
- 24. Botrytis Rot – a.k.a Grey Mold • Caused by the fungus, Botrytis cinerea • The greatest cause of postharvest strawberry losses. • To avoid, store strawberries at 32°F within one (1) hour of harvest. • The pathogenic fungus continues to grow even at 32°F, however growth is very slow at this temperature.
- 26. Respiration and Shelf-Life • Respiration / release of heat • Respiration and shelf-life are inversely related. • The higher the respiration rate, the shorter the shelf-life of a commodity. • Example: Strawberries Temperature 32 °F 50° F 68° F ml CO2/kg-hr 6-10 25-50 50-100
- 27. Crop Respiration Rates • High Respiration • Green Onions • Snap Beans • Asparagus • Broccoli • Peas • Corn Low Respiration Apples Grapes Garlic Onions Potatoes Sweet Potatoes
- 28. Cooling & Deterioration of Strawberries Source: UC Davis, Perishables Handling #87, August 1996.
- 29. NCGT Product Specification Manual: Guidance for Summer Squash
Editor's Notes
- Share with you a story….When I graduated…..what will I do? I knew that farms had challenges getting their product to mainstream markets…….I will work for a wholesaler…they have trucks, warehouse space, and everything I need to help these small farms move product.
- Logistics: The cost of picking up small quantities on-farm or accepting and housing small deliveries at the warehouse. Shelf-life: Wholesalers need a longer shelf-life. They need time to get their product to their consumer with a shelf-life that satisfies their consumer. Grading/Sorting and Packing: Currently wholesalers are finding that the consumer is not making exceptions for lower quality product, primarily institutions at a local level, and product that is not graded out for consistent sizing. This is really important for the chefs when it comes to recipe development. Communication: Wholesalers buy their inventory at least 4 weeks in advance. If they have placed their orders prior to knowing the availability of local product, they typically cannot cancel these orders. This leaves them in a position to use local product in small quantities to fill in orders, as needed. Finally we learned how valuable their warehouse space is and how difficult it is for them to handle a case or two of a single product. Their warehouse systems are designed for industry standard pack-sizes and slots are designed to house pallets of a single product.
- Wholesalers typically have a QC team that inspects product upon arrival. - Read slide Pictured here is Turkish Orange Eggplant. This is a specialty item that is very hard to locate and does not necessarily have product specifications already in place, so typically the US#1 grade standards for Eggplant are used. We have some decay here, inconsistency in size, and ripeness variance. Because of the uniqueness of this product, the wholesaler did accept this product and felt it was marketable.
- How do these two challenges impact what the wholesaler or retailer buy? READ SLIDE…We have determined that If we can meet at least some of these challenges that affect their bottom dollar, we will open up more doors into the wholesale & retail markets.
- To help small farms to meet the industry product specifications specific to the NC Growing Together Project Partners, Foster-Caviness and MDI, we have written a Wholesale and Retail Product Specification Manual. Much of the information contained in this manual will be referenced during this webinar. We hope you will find this a useful tool. You can download an electronic version of this guide at www.ncgrowingtogther.org.
- Read Slide….We all know that the best possible quality of produce is at the time of harvest. Industry has started to temp probe product as it arrives to ensure product has been maintained at appropriate temperatures. Why are they doing this? Shelf-life is obviously one reason, but many distributors are marketing that their product as product that maintains a 100% cold supply chain sending customers the message of improved shelf-life, as well as ensuring the safety of the product. When product is not maintained at proper temperatures, harmful pathogens can thrive, not only decreasing shelf-life, but increasing the risk of foodborne pathogens. This is especially important for leafy greens and other ‘high risk” products.
- How can we increase shelf-life? Harvest early in the morning when the temperature of the produce is cooler. Once the product is harvested, place harvest boxes or bins under loose covers for shade if the produce cannot be quickly removed from the field. Produce left out in the sun absorbs heat and may also become sunburned, reducing quality and shelf life. Maintain 100% cold supply chain whenever possible. The most effective practice to maximize shelf life is pre-cooling to remove field heat. This can be accomplished by placing harvested produce in a cooling room or walk-in cooler. Good invesment…Pre-cooling provides several benefits, including slowing down the rate of respiration, minimizing susceptibility to harmful microorganisms and reducing water loss of your product, all of which affect shelf-life.
- READ HERE….Within the Product Specification Manual, we provide recommended storage temperatures, as well as relative humidity. Relative Humidity is the percentage of moisture in the air during storage. Both, temperature and humidity vary among different products. Read the rest of the slide – bullet 2.
- Must
- Here is one example of strawberries received by a local farm that was not marketable within 24 hours upon receipt of the product. The number one cause of gray mold on strawberries is that the field heat has not been pulled out of the product upon harvest in sufficient amount of time (pre-cooling methods needs to be used).
- So what is the cause of this pathological disorder in the strawberries? It is likely Botrytis cinerea, the greatest cause of postharvest strawberry loss. The strawberries here passed the initial QC inspection but did not maintain a shelf-life of 5- 7 days. The fungus was not visible during the QC inspection. READ SLIDE…Depending on the agreement that is in place with a buyer, a grower may have to incur additional costs for picking up this shipment or arranging for the wholesaler to dispose of the shipment themselves, which is usually more cost effective in a situation where the product is not marketable. If an end consumer had received this product, it would have resulted in an unsatisfied customer and the wholesaler may choose not to purchase from this same supplier in the future.
- Here is an example of the guidance provided for strawberries in the NCGT Product Specification Manual - Get manual and read through recommendations. Most wholesalers are looking for a 7 day shelf-life on strawberries.
- Fresh horticultural commodities can be seen as unique packages of water that continue living after harvest. They breath just like we do. Respiration is the process of the vegetable taking in oxygen and breathing out Carbon Dioxide. They release heat from respiration and at this time release water. Reduction of water in the vegetables is what results in shriveling and deterioration of the product. Bullet 2
- Here is a great representation of the rapidly declining marketability of strawberries based on how quickly they deteriorate postharvest. If the product is held in the field for 2 hours post harvest, the product is 10 – 20% less marketable. After 6 hours of a cooling delay, a 50% marketability is estimated. This is equivalent to a 50% loss for the grower and/or wholesaler.
- Let’s take a closer look at Summer Squash. 41-50 degrees with a 95% humidity level is recommended. CHILL SENSITIVE, so it is important not to let the temperatures fall below 41 degrees. Letting the temperature drop to this point would adversely affect the quality of the product resulting in decreased shelf-life.