LEMON PACKING PROCESS
After receiving fruit from the fields, our lemons are washed and scrubbed thoroughly using a gentle soap and chlorinated water. Then, food-grade storage wax is then applied to prevent shrinkage and preserve quality. Next, the lemons are sorted. We use Sunsort® grading technology developed by the Sunkist, a leader in optical lemon-grading equipment. After stringent inspection, the lemons are then grouped by size and grade and sent to storage.
While in storage, the fruit is kept at 50-52 degrees F with 90-95% relative humidity. High volumes of air fill the lemon storage rooms, where they develop their flavorful, bright yellow color before being packed.
Once the fruit is market ready, it is delivered from storage to be washed and rinsed a second time and receives an application of food-grade pack wax designed to safeguard the lemon during transit. The fruit is passed through a second set of optical lemon-grading equipment and is examined by skilled employees for quality. The fruit is then sized and placed into packaging tailored to our customers’ orders.
Once placed into the proper packaging, the lemons are palletized and placed into pre-coolers set between 40-45 degrees before being loaded into trucks arranged by Sunkist. From there, our fruit is transported to the various domestic and international markets.
SETTING THE STANDARDS IN THE CITRUS INDUSTRY
Our top priority at Saticoy Lemon is the health and safety of our consumers. The Food Safety Program we have in place ensures the safest and highest quality fruit leaves our facilities. Saticoy Lemon employees receive training in food safety and safe handling procedures.
We are strong advocates within the citrus industry for improving food safety initiatives. Our commitment promises to use every resource possible to ensure the highest quality, cleanest, safest and most wholesome fruit in the world.
Levels of respiratory gases which promote ripening, such as ethylene as well as carbon dioxide, should be kept as low as possible. If ventilation is inadequate, storage damage, such as a bitter flavor and peel scab, may occur. The supply of fresh air must thus be constant in order to dissipate these gases.
LEMON PACKING SYSTEMS
There has been much discussion in the Florida Fresh Citrus Industry about the possibility of handling lemons in a conventional packing house. The advantages of keeping idle machinery and key people productive in the summer months are obvious if the special problems of handling this variety can be overcome.
This can be done and is being done successfully by two Florida Packing Houses, Golden Gem Growers, Inc. in Umatilla and Gracewood Fruit Company in Vero Beach.
This concept requires a few specific facilities which are not found in all Florida packing houses but are present in many. This paper will discuss these facilities plus others which are desirable if available.
To further discuss this subject I would like to break it down into several points which I consider important in the handling of fresh lemons in a conventional packing house. The first four points are absolutely essential. The remaining points are certainly desirable, but not as important as the first four.
LEMON PROCESSING AND PACKING
After harvest, fruits and vegetables need to be prepared for sale. This can be undertaken on the farm or at the level of retail, wholesale or supermarket chain. Regardless of the destination, preparation for the fresh market comprises four basic key operations:
1. Removal of unmarketable material,
2. Sorting by maturity and/or size,
Any working arrangement that reduces handling will lead to lower costs and will assist in reducing quality losses. Market preparation is therefore preferably carried out in the field. However, this is only really possible with tender or perishable products or small volumes for nearby markets. Products need to be transported to a packinghouse or packing shed in the following cases: for large operations, distant or demanding markets or products requiring special operations like washing, brushing, waxing, controlled ripening, refrigeration, storage or any specific type of treatment or packaging.
These two systems (field vs. packinghouse preparation) are not mutually exclusive. In many cases part field preparation is completed later in the packing shed. Because it is a waste of time and money to handle unmarketable units, primary selection of fruits and vegetables is always carried out in the field. In this way products with severe defects, injuries or diseases are removed.
Lettuce is an example of field preparation where a team of three workers cut, prepare and pack (Figure 22). For distant markets, boxes prepared in the field are delivered to packhouses for palletizing, precooling, and sometimes cold storage before shipping. Mobile packing sheds provide an alternative for handling large volumes in limited time. Harvest crews feed a mobile grading and packing line (Figure 23). On completion of loading, the consignment is shipped to the destination market and replaced by an empty truck. In mechanized harvesting, the product is transported to the packhouse (Figure 24) where it is prepared for the market. In many cases, harvest crews make use of an inspection line for primary selection on the field.
Figure 22: Lettuce field preparation for the fresh market.
Figura 23: Mobile packing shed for market preparation of celery.
Figure 24: Mechanized harvest of tomato.
2.2 The packhouse
A packinghouse allows special operations to be performed. Another advantage (over field preparation) is that products can be prepared continuously for 24 hours regardless of the weather. With its capacity to process large volumes, farmers associations, cooperatives, or even community organizations can take advantage of these opportunities.
After working out the details of the building layout, it is important to prepare a diagram for the movement of product throughout the packinghouse and activities to be undertaken for the entire operations. Handling must be minimized and movement of product should always be in one direction without crossovers. It may be possible to undertake operations concurrently, such as working simultaneously on different sizes or maturity stages.
2.2.2 General considerations about lemon packing operations
Preparation and packing operations should be designed to minimize the time between harvest and delivery of the packaged product. Reception is one area where delays frequently occur (Figure 27) and the product should be protected from the sun as much as possible. Product is normally weighed or counted before entering the plant and in some cases samples for quality analysis are taken (Figure 28). Records should be kept, particularly when providing a service to other producers.
Preparation for the fresh market starts with dumping onto packinghouse feeding lines. Dumping may be dry (Figure 29) or in water (Figure 30). In both cases it is important to have drop decelerators to minimize injury as well as control the flow of product. Water dipping produces less bruising and can be used to move free-floating fruits. However, not all products tolerate wetting. A product with a specific density lower than water will float, but with other products salts (sodium sulfate, for example) are diluted in the water to improve floatation.
Figure 25: Lighting at eye level causes blinding and eye fatigue. Lighting fixtures should also be covered to prevent glass shattering over produce if broken.
Water dipping through washing helps to remove most dirt from the field. For thorough cleaning, more washings and brushing are required. Water rinsing allows produce to maintain cleanliness and be free of soil, pesticides, plant debris and rotting parts. However, in some cases this is not possible. This is because of insufficient water. If recirculated water is used, this needs to be filtered and settled dirt removed.
Figure 26: Elevated administration offices allow process supervision.
Chlorination of dumping and washing waters with a concentration 50-200 ppm of active chlorine, eliminates fungi spores and bacteria on the surface of diseased fruits. This prevents the contamination of healthy fruit. In addition to this, bruising should be avoided since this is the entry for infection by decay organisms. At depths greater than 30 cm and for periods of time longer than 3 minutes, water tends to penetrate inside fruits, particularly those that are hollow such as peppers. Water temperature also contributes to infiltration. It is recommended that fruit temperature is at least 5 °C lower than liquid.
Figure 27: Delays should be avoided either at reception or delivery, particularly when produce is exposed to the sun.
188.8.131.52 Removal of lemon rejects in the lemon packing process
Figure 38: Dynamic quality grading system. Sized onion bulbs continuously flow on inspection tables where defective products are removed. Final inspection is performed before bagging (right hand side).
It is also possible to prevent some postharvest physiological disorders with chemical treatments. For example, calcium chloride (4-6%) dips or sprays for bitter pit in apples. Other methods include dipping or drenching fruits in chemical solutions to avoid storage scalds or other disorders. Similarly, the addition of low concentrations of 2.4-D to waxes assists in keeping citrus peduncles green.
184.108.40.206 Temperature treatments
Cold can be used in low temperature tolerant fruits (apples, pears, kiwifruit, table grapes, etc.) and other potential carriers of quarantine pests and/or their ovipositions. Exposure to any of the following combinations of temperatures and time is provided in the following recommendations (Table 4).
Heat treatments like hot water dips or exposure to hot air or vapor have been known for many years for insect control (and for fungi, in some cases). When restrictions were extended to bromine based fumigants, however, heat treatments were reconsidered as quarantine treatments in fruits such as mango, papaya, citrus, bananas, carambola and vegetables like pepper, eggplant, tomato, cucumber and zucchinis. Temperature, exposure and application methods are commodity specific and must be carried out precisely in order to avoid heat injuries, particularly in highly perishable crops. On completion of treatment, it is important to reduce temperature to recommended levels for storage and/or transport.
Hot water immersion requires that fruit pulp temperature is between 43 and 46,7 °C for 35 to 90 minutes. This depends on commodity, insect to be controlled and its degree of development (U.S. E.P.A., 1996). Dipping in hot water also contributes to reduced microbial load in plums, peaches, papaya, cantaloupes, sweet potato and tomato (Kitinoja and Kader, 1996) but does not always guarantee good insect control (U.S. E.P.A., 1996). For the export of mangoes from Brazil, it is recommended that dipping is performed at 12 cm depth in water at 46,1 °C and for 70-90 minutes (Gorgatti Neto, et al., 1994).
Table 4: Combinations of temperature and exposure time for fruit fly quarantine treatments.