The Rediscovery of Discarded Tangerine By-Products: "99% Odor Reduction"

Rural Development Administration Develops Tangerine By-Product Circulation Technology
Leachate Used for "Deodorant and Pest Attractant"
Peel and Pulp Utilized as Soil Conditioner

A technology has been developed to utilize by-products, which were previously discarded as waste after extracting tangerine juice, as eco-friendly agricultural materials such as deodorants, pest attractants, and soil conditioners.

The Rural Development Administration announced on November 6 that it has developed a tangerine by-product resource circulation technology that enables the recycling of tangerine by-products.

Kim Daehyun, Director of the Department of Horticultural Crops at the National Institute of Horticultural and Herbal Science, stated, "In Korea, about 40,000 tons of tangerine by-products are generated annually, accounting for 10% of the total tangerine production. However, most of these are either discarded or simply used as feed for livestock farms. To address this, our research team, in collaboration with industry and universities, aimed to diversify the use of tangerine by-products. We developed a technology that utilizes tangerine leachate as a deodorant and pest attractant, while the solid peel and pulp can be used as soil conditioners."

The deodorizing microbial agent is produced by sterilizing and neutralizing tangerine by-product leachate, then cultivating beneficial microorganisms such as lactic acid bacteria, Bacillus subtilis, and yeast. When this deodorant was applied to two pig manure storage tanks, the main odor components-ammonia and hydrogen sulfide-were reduced by 91% and 99%, respectively.

Director Kim explained, "Although this is similar to the effects of conventional beneficial microorganism treatments, using tangerine by-products allows for large-scale cultivation of microorganisms in the leachate, enabling mass application of deodorants. It is also more sustainable and eco-friendly than chemical agents. In practice, the liquid fertilizer produced after deodorizing manure was collected at a low cost by manure treatment companies, resulting in an annual income increase of 37 million won for a pig farm with 2,000 pigs."

The eco-friendly pest attractant is made using 'limonene,' a component generated during the tangerine juice extraction process. This attractant, created by combining limonene and pheromones, proved highly effective in attracting female larvae of the large black beetle, which damages the leaves and roots of sweet potatoes, ginseng, and pears. Compared to using pheromones alone, the attraction and capture rate of the beetle increased by about 45% (from 32.5 to 47.2 beetles). Demonstration at two farms showed that the sweet potato damage rate dropped from 52% to 15%, a decrease of 37 percentage points. The Rural Development Administration explained that utilizing limonene from tangerine by-products can reduce costs by 70% compared to purchasing commercially available limonene to produce attractants.

The soil conditioner is made from solid peel and pulp. This material, which improves soil fertility, can be customized for different crops by adjusting the nitrogen-to-carbon ratio, nutrient content such as phosphorus and potassium, and blending materials. In particular, when mixed into soil, its water retention capacity is more than 50% higher than that of conventional soil conditioners (such as perlite and bark), reducing plant water stress by about 90%.

Director Kim stated, "The resource circulation technology using tangerine by-products not only reduces disposal costs but also contributes to increased farm income and improved agricultural environments through multiple effects such as odor reduction, pest control, and soil improvement. Going forward, we will strengthen technology dissemination and industry collaboration so that this can be expanded as an innovative model for the resource utilization of agricultural by-products in Korea."

This content was produced with the assistance of AI translation services.