Here’s what they’ve discovered after over a decade of research and 50+ patents later…
My visit to Khon Kaen University to meet with Dr. Duanpen Wongsorn and a handful of students was eye opening to say the least. With their mission to explore and develop new fields of insect research, it was the perfect stop that opened many doors for more my interest in edible insects. There, at the Insect Pathology Lab, they have focused on one specific animal for the past decade due to it’s increasing potential, the Eri Silkworm (Bombyx Mori). Dr. Duanpen Wongsorn and a handful of students in the Division of Entomology were kind enough to show me what they’ve been working on, and even taste some of the products they’ve developed. They even translated some of their studies into English so I could better understand what they’ve been working on in a broader scope and what’s in store for the future. With their permission, below is a synopsis included years of intensive research on what I consider a superhero of an animal, the Eri Silkworm.
An Outstanding Food Product
The Eri silk has been developed as an Outstanding OTOP (One Tambon One Product) food product, which is delicious, easy to produce, and high in nutrition. In addition, the analysis of processed silkworms and pupae fed with cassava leaves are safe from toxic chemicals, heavy metals and hydrocyanic acid (Sirimungkararat et al, 2010).
Sources of Raw Material
The food by-products from Eri culture are acceptable and valuable to consumers. In addition to their value, a high demand of Eri raw materials in the form of Eri silkworms and pupae has been of interest for both domestic production and export. Moreover, consumers and entrepreneurs are needed for commercial production. Meanwhile, the country’s edible insect supply is decreasing, and the Food and Agriculture Organization (FAO) and European Union (EU) report that the current world’s food is entering a crisis situation. Insects imported from neighboring countries are not able to control production quality from toxic chemicals such as insecticides and carcinogens, thus causing loss of profit from the country. Thailand’s insect trade has turnover about 40 million Bat (1.2 million USD) per year. Presently, the insect food has been needed more and more in other countries. Therefore, the Thai Eri silk is one of the preferred choices, and truly has commercial potential.
Value and Commercial Potential
Based on its properties and various outstanding characteristics, the Eri silkworm has become of great interest and has been supported for further research. This includes conscious technical transfer by many agencies, in terms of both handicraft and factory industries for export. Khon Kaen University established the research group Cultivation and Product Development of Wild Silkworm and Economic insects for Value Added Creation which is used in research directions that are interdisciplinary, such as poverty alleviation, improved standard of living, and competition enhancement at the international level. Research output leads to various commercial products such as processed foods, silk, and textile products: these include Eri silk yarn production and furnishing/machines, cosmetic products (petty patent Nos.7590, 7591, 7592 and 7593), large cocoon (Jumbo), and development of highly productive and high temperature tolerant variety for best survival against global climate change. Additionally, new food plants, i.e. Kesseru (Heteropanax fragrans) (Sirimungkararat et al., 2013) have been found useful for Eri culture all year round and for cassava leaf substitution during hot season with equivalent Eri silkworm nutritional value. The model village of Eri silkworm rearing has been developed for value-added creation and sustenance. The research programmes also cover Eri protein source for schools and communities, food supplements for human and animals, UV protection products, ecorace selection, and varietal improvement using biotechnological methods and also medical materials by co-operation and exchange research at the international level.
Eri silkworm, a wild silk, produces a natural fiber like cotton but still contains lustrous quality. The rearing is similar to mulberry silkworm, but easier. Since 1991, the Eri silkworm has been fully researched in many aspects in the Northeast of Thailand by Associate Professor Dr. Sivilas Sirimungkararat and her colleagues of the Faculty of Agriculture, Khon Kaen University. Their research findings reported that this can be produced without waste (Zero Waste). With the appropriate sources in terms of rearing by using the local wisdom and the largest food source (cassava) of the country, currently Eri silkworm has become a new kind of commercial insect with great economic value in Thailand. The core factor of the Eri silkworm planting is based on food plant and environment, especially temperature and humidity. The culturing of Eri silkworm with cassava leaves in the Northeast has a life cycle of about 47 – 59 days.
Outstanding Features of the Eri Silkworm
Friendly Environmental Product
The Eri silkworm is easily grown like the mulberry silkworm but simpler, less labor-intensive, and can be raised throughout the year. Regarding disease and pest resistance, it does not need any chemicals (carcinogen) in rearing process. Hence, it is an environmentally-friendly product (eco-product). Moreover, the Eri’s feces and waste water derived from yarn producing could be used in controlling both causal agent of plant and human bacteria including insect pests (Sirimungkararat et al., 2009).
Fiber and Cosmetic
Eri silk yarn is similar to cotton mixed with silk that has lightened. The silk’s fiber contains microscopic holes imparting a quality of thermal property, well ventilated, feeling cool in hot weather and warm in cold weather. Furthermore, it can filter out ultraviolet light. The final product is beautiful and unique. Some fabric designed like mixing with wool or pattern in based on the technique of the silk yarn production. However, the fabric is easy to launder, care for, and is very durable.
The 1st world finding and academic reporting of the prototype reeling machine (petty patent No 2075) by KKU researcher leading to produce the series of Eri silk reeling and spinning machines, collectively petty patents (Nos. 2821, 3820, 3982, 4149, 6288, 6408, 6698, 6608 and 7759).
Food and Health
Currently, it is less used for food and protein source. Whereas Eri silkworms have high protein (66%), which is among the highest of the world’s edible insects, as compared to mulberry silk (53-54%). Therefore, Eri processed foods could be diversified and have been favorable to consumers and livestock with good nutrition, good taste, and high in protein. In addition, it provides sustainability to the community.
Free of Waste (Zero-Waste)
All parts of its life cycle and rearing process are useful and exploitable in terms of “Zero-Waste”. Even the Waste-Water, containing sericin protein, derived from yarn production, can be used in various aspects e.g.:-1. Inhibition of bacterial pathogens that cause disease in humans. 2 Utilization as components in cosmetics such as lotions and soaps, which are well-accepted by users (petty patents Nos. 7590, 7591, 7592 and 7593). By-product from yarn producing is pupa, which is suitable as substrate for Cordyceps militaris and lsaria tuiriepes (C. takaomontana)(KKU-1: local isolate) and first reported in Thailand (Sinmungkararat et al., 2014). Also Eri silkworms are good for culturing Cordyceps.
Based on good property in protein, rearing, food plant, and safety, eri silk (larva, pupa) is suitable for feeding the aquarium fish (Silver arowana : Osteoglossum bicirrhosum), an animal of high value (Sirimungkararat et al., 2001). In the case of mass rearing of natural enemies (parasites, predators) for use in organic farming, this insect is also available.
Insect is one of the best food sources of the world in the present. Now the FAO and EU have well accepted this source. Most recently, it has also been considered for application in space. Also to adapt in global warming situation, the research group has succeeded in breeding and selecting a heat-tolerant variety and jumbo quality (Sirimungkararat et a/., 2014), which are ongoing for research and extension in the near future.
The Eri silk products have been studied and developed for a long time, particularly in India. However, the production capacity still has not reached its full potential. Meanwhile, business groups in India are focused on other kinds of silk such as mulberry, Tasar and Muga. We have a great opportunity to research and develop a unique Thai Eri silk. Therefore, the research team has been producing innovative products such as textiles, fabrics, foods, cosmetics, and studying waste application as pesticides to control disease causal agents of humans, including improvement of heat-resistant variety and large size of silk cocoon (Jumbo).
Machinery and Textile of Thai Community Product Standard
The research team of Khon Kaen University discovered and first reported on the academic world on prototype production of the Eri silk reeling machine (Patent No. 2075). It has further developed a series of various innovative creations and models of textile production from the Thai Eri silk reeling machine and spinning machine up to eight (8) patients, namely the patent Nos. 2821, 3820, 3982, 4149, 6288, 6698, 6408 and 7759. respectively. These give rise to products that can be woven with other natural fibers, wool and natural dyed fabric together with designing and pattern design, etc. The final production has resulted in the Community Product Standard of more than10 products such as fabric, suit, purse, traditional flag, scarf, neck-scarf, dish cover, knitted hat, stationary bag, pillow cover, shoe and houseware textiles.
The Eri silk is one of the edible insects in the world. It is a safe food and is high in protein, about 66% compared with mulberry silkworm which it is 53-54%.The process of silkworm rearing does not use toxic chemicals or carcinogens, unlike the other types of insect cultivation, particularly mulberry silkworm. The pupa, larva and Eri silk have been processed as foods. They are safe, and have delicious taste, and are therefore favorable and acceptable to consumers Both larva “Duan Mor Khor”(KKU-Express Train) and pupa “Sab MorKhor” (KKU-Delicious) were registered as part of cooked foods, which are leading to more than 12 patients.
What’s Next for Eri and Myself?
From rearing silk, to quality cosmetics, to medical treatments, to a healthy food source, I’m fascinated by the opportunities of the Eri Silkworm and believe we will see an increased use of this animal in surprisingly creative ways. Regarding continuing studies on the insect, I was invited back to Khon Kaen University at the end of January, when the new semester starts, to visit some local Eri farms. Looking forward to seeing first-hand how villages are cultivating Eri as a staple resource for their survival.