Far-Infrared Drying Technology for Efficient Strawberry Drying

Strawberries are delicious and highly nutritious, but due to their delicate nature, they are not easy to preserve fresh. To store them for a longer period, they need to be dried immediately after harvesting. Dried strawberries are also popular among women in various regions. Today, we will compare the far-infrared drying technology with traditional drying methods for drying strawberries.

Traditional drying methods include natural air drying, which largely depends on weather conditions. In rainy weather, strawberries can spoil, leading to low production efficiency, making it unsuitable for mass production and more appropriate for small-scale operations. Industrial drying methods include hot air drying, microwave vacuum drying, microwave freeze drying, and heat pump drying. Each method has its own drying effects, such as significant nutrient loss, high energy consumption, uneven drying, and lengthy processing times. Therefore, developing new drying technologies for strawberries is a major research direction in the field of dried strawberry processing.

Far-infrared drying uses grijaći elementi od karbonskih vlakana as the infrared radiation source. Utilizing the thermal effect of infrared and the principle of selective absorption of radiation by substances, the infrared radiation reaches the surface of the material, where the substance absorbs energy in specific infrared wavelengths. This accelerates the vibration and collision of internal molecules or atoms, increasing the temperature and driving internal moisture to diffuse outward, achieving rapid drying. Far-infrared drying features low drying cost, fast speed, good quality, and low energy consumption. It has already been successfully applied in drying vegetables, herbs, and agricultural products.

Before the experiment, the strawberries were de-stemmed and placed in a far-infrared drying box using carbon fiber heater elements as the heat source. Samples were taken out every 10 minutes for weighing and size measurement. The drying process ended when the weight difference between two consecutive measurements was less than 0.01g. Drying temperatures were set at 40°C, 60°C, and 80°C. For the rehydration test, the dried strawberries were soaked in distilled water in a refrigerator for 72 hours, with weight measurements taken every 24 hours to determine the rehydration rate.

During the drying process, the moisture content of strawberries gradually decreased, and higher drying temperatures resulted in shorter drying times: 24 hours at 40°C, 10 hours at 60°C, and 7 hours at 80°C. The drying time using infrared drying was significantly shorter than that of hot air drying. Related experiments indicated that hot air drying at 75°C took over 20 hours, and at 60°C took more than 40 hours.

The rehydration rate results showed that with increased rehydration time, the rehydration rate gradually increased. For example, at 60°C drying, the rehydration rate increased from 4.0 to 5.0 as the rehydration time extended from 24 to 72 hours. At 80°C, it increased from 7.0 to 7.9. Higher drying temperatures resulted in higher rehydration rates. This conclusion indicates that higher temperatures lead to more hydrophilic groups inside the strawberries, enhancing the rehydration rate.

The appearance of dried strawberries varies with drying temperatures. At 60°C, the dried strawberries had good quality, with a complete surface, elasticity, and gloss. At 40°C, the surface had wrinkles and moderate hardness. At 80°C, the surface turned black, became severely deformed, too hard, and lost elasticity.

Discover how our innovative far-infrared drying technology, using carbon fiber heater elements, enhances the quality and efficiency of strawberry drying. Contact us at contact@globalquartztube.com or visit our web stranica for more information.