There is a series of products that are produced in intensive Sericulture:
- Raw Silk
- Organic Fertilizers – Compost
- Animal Feeds
- Silk Proteins – Sericin
Raw Silk is the main Sericulture product that derives from the cocoon reeling process. Prior to this process the cocoons are inserted in hot water where Sericin – the main Silk protein – expands and softens. Special brushes pick up the edges of the fibers and the reeling process begins.
Raw Silk’s classification depends upon several qualities and characteristics like size deviation (denier), evenness, cleanliness, tenacity, elongation etc. It should be noted that the silk diameter is not uniform throughout the length of the silk fiber, hence the “denier” index, a weight to length ratio. Silk fibers with different denier indices (20/22 Good quality grades are identified by the letter A.
The good quality grades commonly used are A, 2A, 3A, 4A, 5A and 6A. The finest quality Silk is the 6A grade that is rare and the most expensive to produce and buy.
Silkworms feed exclusively on mulberry leaves. The unconsumed leaves along with Silkworm litter and faecal matter make first grade compost – organic fertilizer that can be used on the Mulberry plantation.
Moreover, the cultivation of broad beans and/or chickpeas for animal feed during the cold months provides ample supply of the nitrogen required for the Mulberry trees.
Finally, the waste from the parallel animal feeds makes excellent organic fertilizer.
Silkworms consume large amounts of Mulberry leaves that are supplied by the Mulberry plantation. Mulberry trees are pruned, the leaves are fed to the Silkworms and the branches that remain are processed into pellets.
Mulberry pellets are produced without the addition of chemicals, have excellent properties and are considered to be environmental friendly solid bio-fuel.
One hectare of Mulberry trees produces 4 metric tons of branches equal to 28.000 Kcal on an annual basis. The biomass produced can cover the energy requirements of the Sericulture Unit and/or can be exploited commercially.
During the reeling process the Silk fiber is unreeled from the cocoon and the pupa that was inside the cocoon emerges. The pupa accounts for 80% of the fresh cocoon’s weight and about 50% of the dried one.
The pupa is full of nutritious ingredients that make it excellent food for poultry, fish and mammals.
The amount of pupae produced along with the broad beans and chickpeas produced during the winter time can support a modest animal feed activity.
Silk consists of two proteins: Fibroin and Sericin. These proteins come out of the Silkworm’s glands during the weaving of the cocoon.
Fibroin is in the center of the Silk fiber. It is insoluble to water, consists of two smaller fibers and their cross section is triangular.
Sericin is water soluble and embraces, covers, protects, moisturizes and bio-connects the Fibroin. Sericin consists of 18 aminoacids that make its properties similar to Keratin – the natural protein of human skin and hair- hence its use in cosmetics and in medicine (wound healing, joints, cardiac valves, arteries etc).
Silk proteins are natural biopolymers that can be used in diagnostics as biosensors and also in information technology as memory devices.