A simple cup of applesauce is the accumulation of the work of many different types of engineers: from the mechanical engineer who designed the machine that puts the applesauce in the cup to the electrical engineer who built the system that records the weight and physical appearance of each apple. By working to improve their designs, engineers have significantly changed the production of applesauce over the past 10 years.
Believe it or not, the process begins with the preparation of the apple tree’s soil. Chemical engineers determine the soil’s pH to ensure that healthy trees produce healthy apples. Farmers run annual soil tests to keep the pH level near a 6.0 by adding nutrients and tilling the soil (Berkett). Young apple trees are planted by hand. Farmers take care of the tree until it produces fruit, which depending on the species can take many years (Berkett)
Seasonal workers pick the apples by hand. One apple-picker can pick approximately 5,000 lbs. of apples per day, and these apples are then trucked to processing plants (Mott’s).
Although apple picking is a seasonal event, advanced technology now allows applesauce production to go on year-round in atmosphere controlled processing plants. First apples are inspected, sometimes manually or with food-sorting machines. Sorters use cameras to detect defected apples, and pressurized air ejection systems to suck up and remove bad apples (Dunkley). Many machines also weigh the apples. The information gathered from the cameras and scales are used to sort the apples into different machines that are calibrated specifically for the apple’s size (Compac). A software engineer programs these sorting machines.
Processing plants transport the apples from one step to the next by conveyor belt, elevator, or a water-powered flume channel system. The transport system delivers the apples to a washing machine. Jiangsu Kuwai Machinery manufactures a machine that rotates the fruit while cleansing them with highpressured water. A mechanical engineer designs the roller body that spins the machines and integrates it with the water cleaning system.
Next, the apples are peeled and cores are removed. Atlas Pacific Engineering Company manufactures an “Apple Peeling System” that does both of these steps. First, the apples arrive at the orienting table from a feed system. Spindles move to orient the apples upright and as the orienting table rotates, the properly-aligned fruits are picked up by a rotating peeling column and the other apples fall back to be reoriented. While on the peeling column, special care must be taken so that overripe apples do not squash and immature apples do not crack off the spindles. This machine uses a Sensor Peel head to control the pressure of the peeler and ceramic guards that guide the peeler around the outside of the apple to maximize fruit production regardless of the maturity of the fruit. The peeler peels 130 apples per minute; this is equivalent to one ton of average-sized apples per hour (Atlas Pacific).
The rotating peeling column is also used to remove the core of the apple. This column has interchangeable core tubes that can be adjusted for apples of different sizes. The column cuts through the center of the apple and releases it onto the feed system when it is peeled (Atlas Pacific). Apple processors can choose between a Hydro Feed or Dry Feed system to transport the apples onto the apple peeling orientating table. The Hydro Feed system uses waterpower to float apples to the orienting table. The Dry Feed system reduces water usage by using a conveyor and a sensor to regulate apple flow into the machine (Atlas Pacific). While the Hydro Feed system is gentler, it requires another machine to clean excess water before returning it to the river. An environmental engineer will calculate the effects of the polluted water on the river, and will collaborate with a mechanical engineer to build this machine. Since this system adds an extra cost, many companies prefer Dry Feed (Anonymous). The Host Monitoring System monitors the flow of apples through each step of the apple-peeling machine. The measurements are displayed on a computer screen so that maintenance workers can quickly identify any errors and fix them before there are more problems (Atlas Pacific). An electrical engineer designs the software for this machine.
Atlas Pacific talks to apple processors at service seminars. If their engineers can provide a solution to the processors’ complaints then they improve their machines. Generally, the complaints of customers are centered on maximizing and budgeting production. For example, the Dry Feed system was an improvement on the Hydro Feed system in reducing the costs associated with water (Anonymous). The switch from aluminum to stainless steel is another recent improvement. In the past, all apples were cooked after they were peeled, killing bacteria in the process. In the past 7 years however, some companies have stopped cooking their apples, instead opting to use the more sanitary stainless steel (Anonymous).
Currently, Atlas Pacific is working to improve their orienting tables. While some varieties of apples like Granny Smith and Fuji work well on the machine, others such as Golden and Red Delicious do not. Deformities in these apples present trouble on the orienting table. Apples that are not completely symmetrical are difficult to stand upright with the orienting spindles, so industrial and mechanical engineers are working to fix this problem (Anonymous).
After the apples are peeled and cored, they go to the dicer. This machine slices them into strips. Crosscutting knives then dice them into cubes. Finally, the cubes travel through a set of blades configured to chop the apple into the size needed for the applesauce texture (Martin). Carried by conveyor belt, the apple cubes are brought through a metal detection scanner. Shards of metal from blades that cut the apple may be left behind. Any apple that contains metal is rejected (ADS). Now the apple chunks can be cooked into applesauce. Knouse’s Musselmans Applesauce is cooked with a “live steam injection system rotary cooker.” This system uses pressurized water and air to heat a rotating machine that cooks the sauce at a high temperature. A filter purifies the steam before it comes in contact with the applesauce. Cooked applesauce is strained with a stainless steel mesh screen to remove any defects. At this point, any flavorings or sweeteners that a chemical engineer has created are added to the sauce before it is packaged (McDannell).
Applesauce is then fed into a machine that squirts it into cups as they move along on a conveyor. Precut aluminum lids are heat-sealed onto the cups at the lid station (Oystar). Recently, processing plants have switched to using plastic cups rather then glass jars. Plastic cups are more popular with consumers, as kids can easily toss them into their lunch boxes. Interestingly, using plastic cups allows companies to use applesauce that is lower in visual quality. In the past, jars were clear and the consumer could see any impurities, but consumers can no longer see the difference in opaque plastic cups (Anonymous).
After the applesauce is sealed and packaged into cups, it must be sterilized. The applesauce and its container are heated to a high temperature, and then cooled down. A chemical engineer will have calculated the level of heat that most efficiently sterilize the applesauce without heating the plastic cup so much that it gives off dangerous gasses (McDannell).
The applesauce is now ready to be coded, cased, and shipped. A code is printed onto each cup, including expiration date and a tracking number in case of an FDA recall. Next, several cups are placed into each of the cardboard sleeves sold in stores. These sleeves are packed into a coded box where they are stored until they get to the grocery store. The most common methods of printing codes on cups and boxes are with Thermal Transfer, Hot Foil, or Laser Coding (Allen). An industrial engineer designs each cup, sleeve, and box to enclose a maximum amount of product.
Lastly, cartons are lifted onto a pallet designed by civil engineer to withstand the weight of the boxes. A forklift then carries these pallets to a truck that transports them to a warehouse where they get ready to be shipped to your local grocery store (McDannell).
Fifty years ago applesauce was still a relatively new product at the grocery store – Motts did not add it to their product line until 1930. Back then machines were less efficient, and production was more labor-intensive. Customers bought applesauce in glass jars that were heavy, fragile, and expensive. Now, customers find cheaper applesauce in lightweight plastic cups. Applesauce, which was once a specialty item, is now a mass-produced snack. Different types of engineers have created these innovations through their hard work.