Lemon is a citrus fruit rich in vitamin C and flavonoids that have a powerful antioxidant function. The juice contains 5% citric acid, giving lemons a sour taste. Lemon is added to various foods to enhance the flavor. Lemon trees produce fruit all year round and the top five producing countries are China, India, Mexico, Argentina, and Brazil.
Ripe lemon contains a high percentage of water, which will cause the growth of microbial and eventually shorten the shelf life of lemons. Drying is a process of decreasing the moisture content to preserve fruits by preventing microbial growth. It increases shelf life, reduces weight and volume thus reducing storage and transportation cost. Besides, it increases food diversity, which promotes the consumption of foods.
Dried lemon slices can be added to water, iced tea, or hot tea. They can be added to baked goods such as cakes and muffins. Dried lemon slices are also added to a variety of recipes. They are excellent for adding to potpourri mixes.
Lemon peel, the "zest" portion of the lemon, can also be dried for consumption. Lemon peel has a high content of essential oil and is rich in calcium, Vitamin C, and fiber. Dried lemon peel powder is used in baked goods like cakes, muffins, cookies, and bread. The peel is sprinkled on salad and also added to herbal teas.
There are various methods that have been used for drying lemon slices and peels, such as open sun drying, solar drying, hot air drying, microwave drying, infrared drying, and freeze-drying.
Open sun drying requires low investment costs. However, it poses some problems such as contamination by dust and animals and spoilage due to a humid climate, Also, the required drying time can be quite long, which often causes deterioration of quality.
Solar drying has a shorter drying time compared to open sun drying with an improved quality of the dried product. The drying process is carried out in a closed system which prevents the products from contamination.
Lemon could be dried by hot air in a hot air dryer. Air is blown into the electric heater or radiator by the fan, heated and passed to the drying chamber of hot air drying machine. Forced ventilation and adjustable air distribution plates ensure the temperature balance in the oven, the materials can be dried evenly.
Water polar molecules in the food tend to re-orient themselves in the rapid reversal of the electromagnetic field. Due to the friction heat is generated, which results in rapid evaporation of water, achieving the aim of drying. Microwave drying allows the transmitted heat energy to be absorbed by the whole lemon slices, having a short drying time.
By infrared drying, lemon is dried directly by the absorption of infrared energy. It has high energy efficiency and short drying time. The dried product has high quality. However, it is attractive only for surface heating applications.
Freeze-dried lemon adopts vacuum freeze-drying technology. Lemon is pre-frozen and then the water converts directly from a solid-state to a vapor (sublimation) under low pressure. Freeze-dried lemon has good rehydration capability and could keep the original shape, color, and taste after rehydration.
The lemon powder is used to make a lemon drink, and can also be used for making candy fillings, desserts, yogurt, ice cream, smoothies, jellies, marinades, sauces, fish dishes, baked goods such as cakes and cookies, etc. The lemon powder is also used for functional food.
Spray dried lemon powder is extracted from fresh lemon juice through spraying technology by spray drying machine. Spray-dried powder has good reconstitution characteristics. As the powders contain fruit sugars and acids that make them difficult to dry due to the low glass transition temperature, commonly a drying aid such as maltodextrin is added as a carrier, which increases the glass transition temperature, enhances the properties and stability of the powder.
Seagate freeze-dries whole lemons(the skin, pulp, seeds, and juice) to make lemon powder. They pre-grind the whole lemon in a grinder and then freeze the ground lemon in the freezer-dryer under vacuum. The flavor, color, and nutrients in the fresh fruit are retained in this process. L'Epicerie produces freeze-dried lemon powder by freezing whole lemons in a refrigerated vacuum drier before powdering.
1. Place the lemon slices on dehydrator trays.
2. Dehydrate at 135 degrees for 10 hours.
3. Once lemons are completely dry, store in an airtight container.
1. Preheat your oven to its lowest setting.
2. Lay the lemon slices on the baking sheets covered in parchment paper.
3. Place the sheets in the oven for 4 hours. Flip the slices every hour so they would dry evenly.
4. When the lemons are completely dry, turn the oven off and let them sit in the oven overnight.
5. Remove from the oven and store in an airtight container.
Here are three methods for you to dry lemon peels at home.
1. Place the lemon peel on a plate, leave them to dry in a warm and dry spot for a couple of days until dry and crispy.
2. Lay the peels on a dehydrator tray, put the tray in the dehydrator and dry at 100 degrees Fahrenheit for about 24 hours until dry and crispy.
3. Spread the peels on a parchment-lined baking sheet, place the sheet in the oven at the lowest setting for about two hours until completely dry.
Grind the dried zest into powder in a spice grinder, mortar, and pestle, coffee grinder or blender. Store in an airtight container in a cool location.