Harvest and Post-Harvest Technologies in Walnut Production Nisão-NutVisionChișinău
The European Union and Turkey have been the leading importers, with the EU predominantly importing kernels, while Turkey opts for in-shell products. Currently the walnut prices are at their lowest levels in over two decades. With an average Californian grower receiving between 75 to 90 Cents per kilogram, the average production cost is over a Dollar, forcing them to remove loss-making old orchards in an increasing pace, especially in the South With the exception of 2012/2013 Marketing year, there has been an over production in the market for over 15 years now. With the slowing of new plantations and the extreme heat wave in California, in 2024 we are likely to see for the first time in a very long period a supply shortage to meet the increasing demand. let us compare the end-of June shipment figures of the Californian Handlers during the last 4 years. While the shipment levels have been between 85 and 92 percent of the annual
supply received by the handlers between 2021 an 2023, this figure has reached to a remarkable 97 % at the end of June 2024. With still two month of shipping to go until the next harvest, we can say that the Californian market is almost at a sold-out stage now, especially for good quality products. The largest walnut importers, The European Union and Turkey, have seen a very low levels of increase in their production levels in the last 14 years, roughly 26 % combined, while during the same period, their consumptions have increased by a staggering 79 %. Currently, they are importing over 61 % of their combined walnut demand, making them predominantly dependent on importation. Moldova is surrounded by the largest Walnut Export market in the world. Now let us try to understand the demand of the market.
We all know the the characteristics of a quality Walnut product. While your productivity depends mostly on your orchard management practices, harvest and Post-harvest activities play the most important role in determining your product quality How to improve product quality through earlier and faster harvesting: We all know that Kernel maturity occurs 3 to 4 weeks before natural harvest time. This is when kernel stops growing and it is in its highest quality level. As time passes, packing tissue, the membrane that surrounds the walnut shell gradually turns dark and the green walnut hull starts to crack open. However, not all walnuts mature at the same date, some matures earlier and some later. A precise shaker and a fast harvester allows you to begin harvesting earlier and make multiple passes without having to wait for all the walnuts to start falling down on the orchard floor. As you wait longer, both the shell as well as the kernel color starts getting darker. Furthermore, as season progresses, the increased chance
of rain may delay your harvest and the quality of the nuts on the wet orchard surface degrades significantly. Mechanical Harvesters and High Precision Tree Shakers help you begin harvesting earlier, and make multiple passes in a very short time. Harvesting the nuts that mature ealier, and preventing them to spend time on orchard surface improve shell and kernel quality significantly. Monchiero offers two advanced tree shakers both designed specifically for nut trees. While the
VL08 is a tractor-mounted shaker and the 30 one forty is self-propelled that could also be used as a tree pruner. Both systems come with the same superior characteristics, allowing to shake using programmable joystick buttons that eliminate operator errors and shake each tree with the same precision and speed. You can, also have multiple settings that could be used for larger and smaller trees simultaneosly. Integrated front sweepers prevent walnuts to be crushed by the wheels
Monchiero offers 6 different Self Propelled Harvesters designed for different sized orchards, speed and capacity. Powerful John Deere engines that come with 2 year international warranty, operate at lower RPMs, giving our harvesters superior fuel efficiency and ability to operate in difficult orchard conditions like elevation and wet surfaces. They are four wheel driven and thanks to their advanced four wheel steering system, they are extemely manouverable in tight conditions. Perhaps one of the key features that makes them stand out in the market is their large hopper sizes that allow them to make much less discharge stops. Our most popular models of 20 one forty five and 20 one twenty five come with a 3.1 cubic meters hopper while our largest model 20 two forty embodies a giant 6.5 cubic meters hopper that help Monchiero harvesters to
complete harvest much faster. They all integrate all harvest functions like sweeping, harvesting, pre-cleaning, blowing and transporting into a single machine that requires a single operator. You can use Monchiero harvesters for Walnuts Almonds Hazelnuts Macademia Nuts and easily switch from one crop to the other with the help of optional conversion kits. Walnut processing has the biggest impact on product quality. It transforms your crop into a value-added consumer product. It has several steps that need to be integrated. As you continue along the way of this transformation, your product gets closer to the final consumer and increases its value significantly. Hulling. Drying. Calibration. Storage. Packaging. and Shelling are
some of the major steps in walnut processing. Today, we will be focusing on the first four of these steps. Lets start by demonstrating a typical hulling line. Since the hulling operation generates a substantial amount of liquid and solid waste, it is usually conducted outdoors, under a shed that protects the equipment as well as the operators from sun and rain. The drainage ditch with a slight inclination, running along the concrete floor underneath the hulling line helps collect the liquid waste and transport them to a collector, usually in a small reservoir. The reception pit or a drive over depository is where harvested walnuts are discharged. With the help of elevators and conveyors, walnuts run through a series a
machinery, including a de-sticker that removes stick and leaves, a de-stoner or a floatation tank that removes the stones A pre-cleaner that starts the cleaning process of the hulls, A huller-that removes the green hulls from the shells, An aspirator that sucks and separates the empty walnuts from the rest, And finally, a sorting table where unwanted nuts are separated by manual work as well as optical sorters. Followinng all these steps, in-shell walnuts with high moisture levels are transported into the drying room with the help of an elevator. While the hulling process can be demonstrated in a very simplified presentation, the actual line looks more like this. To maximize your quality and processing efficiency, we recommend the following as the Best Practices in Harvest and Processing: One: Harvesting Speed and Hulling Capacity should be alligned, Two: Harvest all the nuts that have been shaken off the trees before the end of that work day, Three: Finish the hulling of all harvested walnut before the end of the day, Four: Begin drying all the nuts that have been hulled, before the end of the day they have been harvested. Hulling lines can be separated into two main categories: One: Californian hullers. They are integrated systems that works as a single unit. They have high capacities ranging from 10 tons to 60 tons per hour. They require very few operators. Their
hullers are designed to operate effectively under different conditions. Two: European Hulling Lines They are made of individual machines that handle a single operation, connected to each other with conveyors and elevators. Usually their speeds do not exceed 2 tons per hour. They require more labor and maintenance. You should plan very carefully When determining your hulling line
capacity, as they are difficult and expensive to upgrade. Long term capacity planning is important. Also take into account other growers in your area that would want to have their product processed in your facility. Harvesting, hulling, drying and calibration should be considered as a continuous process where capacities of each should be set taking into account the entire process. A well planned processing line should work without the needs of any of the processes to stop and wait for the other, nor require expensive buffer silos and elevators. Here is a simple demonstration of a well planned operation with matching capacities in harvesting, hulling, drying and calibration. As the walnuts start coming in to the hulling line from the harvest, the hulling line should be able to handle the speed of incoming nuts. As the nuts
go though the hulling, they are loaded into the first row of dryers that should begin drying as soon as any of them is filled. At the end of the first day, there should not be any nuts at the huller and all drying operation should be underway. beginning of the second day, the hulling line should start feeding the second drying row, while the first row should gradually begin to discharge walnuts to the calibrator. The calibrator line s operation speed should match the discharge speed of the dryers so that the first drying row is entirely discharged at the end of the second day. And the operation should continue this way thoughout the harvest period,
keeping in mind that each drying cycle will be faster due to lower incoming moisture levels, except in case of rain during the harvest period. Incoming walnuts have a high moisture level, that could be as high as 35 % wet basis. If they are not dried to a stable moisture level, which is 8 % when measure in-shell and 5 % as kernels, mold formation is inevitable.
The undustry standard in walnut drying is carried out in stationary drying bins, metal silos that are placed next to each other with a air duct that is used to pump high flow rate of pressurized, dry air underneath them. The line usually has one or multiple heaters that is used to reduce the air s relative humidity by increasing its temperature slightly. At the beginning of the line there is a blower that provides the line with the air that is pumped inside the drying bins. The effectiveness of the drying line depends on the engineering behind the air flow. The blower must
not only provide the line with the exact flow rate it needs, but also must generate in each drying bin the air pressure that is needed for the air to travel through the stacks of walnut, and remove their moisture from above. Your drying capacity will depend on your hulling line speed and your average drying cycle time. The faster it is, the lower drying capacity you can get away with. Characteristics of an effective drying line are: One: Uniformity and precision in drying, Two: Speed in drying, (should be 24 hours on average) Three: Energy and labor efficiency, autonomous operation, Four: Low temperature drying, between 30-34 degrees C Five: Automation and environmental controls Sizing: Sizing your inshell walnut transforms your nuts into a higher value commercial product European sizing standards are based on milimeter diameter of the walnuts, that runs from 28 to + 46 milimeters A good in-shell calibrator should size your walnuts in high accuracy, with less than 5 % errors, without demaging their shells Have the speed to match the discharge speed of your dryers, Weigh your walnuts while calibrating, prepare labels, handle lot numbering and should be providing reporting for the nuts handled. Walnut Storage: Storing your finished product, your most precious asset, is often not emphasized enough. Your storage method should maintain the nuts safe and fresh while should give you efficiency in expensive building space. For starters, you should not store your dryed walnuts inside your drying room that is occupied with high moisture level. The most space efficient model of storing dryed
in-shell walnuts is using the stackable boxes, made out of plastics or wood. These boxes should have free airflow on their sides. The most space efficient model of storing dryed in-shell walnuts is using the stackable boxes, made out of plastics or wood. These boxes should have free airflow on their sides. We design your entire processing plant, including your offices,
your hulling, drying and calibration lines, taking into account their upgrade potential. We establish you quality management system and operational manuals. From capacity planning and conceptual design to building and delivering turnkey solutions at proven world standards, Knee Sao is your trusted partner. With our strategic partners Monchiero and Jessee Equipment Manufacturing, we can help you achieve the highest levels of product quality and efficiency in harvest and post-harvest solutions.
2024-07-28 17:36
