Steps of Sericulture and Chemistry in Silk Extraction
Sericulture is essential in chemistry and helps students understand both biological and chemical processes for producing natural fibres, especially silk. This topic connects science with everyday life, agriculture, and industry, and is often asked in school exams and project work.
What is Sericulture in Chemistry?
Sericulture refers to the scientific process of rearing silkworms, mainly Bombyx mori, for the commercial production of silk fibres. This concept appears in chapters related to animal fibres, polymers, and everyday chemistry, making it a foundational part of your chemistry syllabus.
Molecular Formula and Composition
Natural silk fibre mainly contains the protein fibroin, with the empirical formula (C15H23N5O6)n. Silk is produced by silkworms feeding on mulberry leaves and is categorized under natural animal fibres and biopolymers.
Preparation and Synthesis Methods
Sericulture involves both traditional bio-farming and chemical processing. The key steps are:
- Rearing silkworms from eggs on mulberry leaves.
- Harvesting silk cocoons formed by the larvae.
- Extracting silk by treating cocoons in hot water to dissolve sericin (gum protein).
- Reeling out silk threads, dyeing, spinning, and weaving into fabrics.
Physical Properties of Silk Fibre
Silk is a natural, lustrous, soft fibre. It is lightweight, strong, slightly elastic, and has a smooth texture. Melting point is around 170–180°C; it is insoluble in water and most organic solvents, but soluble in concentrated acids.
Chemical Properties and Reactions
Silk is mostly protein (fibroin and sericin). It is amphoteric, reacts with both acids and bases, and gets hydrolyzed by concentrated acids. The main chemical process is degumming, which uses hot water or mild alkali to remove sericin, leaving pure fibroin for fabric production.
Process of Sericulture
- Female silkworms lay eggs on mulberry leaves.
- Eggs hatch into larvae (caterpillars), which feed on mulberry leaves for about 25 days.
- Larvae spin cocoons by secreting liquid silk protein around themselves.
- Harvesting cocoons carefully without breaking the fibre.
- Boiling cocoons in water to soften sericin and kill the pupae.
- Reeling: Unwinding the silk fibre, usually 600–900 meters per cocoon.
- Degumming and dyeing to remove sericin and prepare threads for spinning.
- Spinning and weaving to make silk cloth.
Types of Sericulture
| Type | Silkworm Species | Main Host Plant | Silk Produced |
|---|---|---|---|
| Mulberry Sericulture | Bombyx mori | Mulberry (Morus alba) | Mulberry silk (most common) |
| Tasar Sericulture | Antheraea mylitta | Arjun, Asan trees | Tasar silk (wild silk) |
| Eri Sericulture | Philosamia ricini | Castor plant | Eri silk (Ahimsa/Peace silk) |
| Muga Sericulture | Antheraea assamensis | Som, Soalu plants | Muga silk (golden yellow) |
Frequent Related Errors
- Confusing sericulture (silk farming) with apiculture (bee farming).
- Thinking all silk worms use the same plant; only mulberry worms eat mulberry leaves.
- Assuming degumming is optional – it's essential in commercial silk production.
- Believing silk is fully plant-derived (actually animal-derived protein).
Uses of Sericulture in Real Life
Silk from sericulture is used to make sarees, dresses, scarves, and high-fashion garments. It is also used in medical sutures (stitching material), parachutes, and carpeting due to its strength and fineness. Sericulture provides jobs in rural areas and supports artisan communities.
Relation with Other Chemistry Concepts
Sericulture connects with proteins (since silk is a protein fibre), natural polymers (silk is a biopolymer), and environmental chemistry (eco-friendly and biodegradable production). It also contrasts with synthetic polymers and animal fibres.
Step-by-Step Reaction Example
1. Silkworms release fibroin protein and sericin while spinning the cocoon.2. Boiling the cocoon in water loosens sericin (degumming process).
3. Silk fibroin fibre is unwound and treated with dyes or mordants to add colour.
4. Final product is woven into fabric.
Lab or Experimental Tips
Remember: Silk is a protein, not a carbohydrate. When testing, silk fibre gives a positive result in the Biuret test (for proteins). Vedantu educators recommend drawing labelled diagrams of the sericulture process for better exam scores and understanding.
Try This Yourself
- Draw and label the lifecycle of a silkworm.
- Name the main protein found in silk fibre.
- List two advantages of silk over synthetic fibres.
- Compare sericulture with apiculture in one sentence.
Final Wrap-Up
We explored sericulture—its process, chemical composition, and uses in real life. Understanding the links between biology and chemistry in sericulture helps you answer exam questions and appreciate natural fibres. For more details, diagrams, and live lessons, check out resources on Vedantu.
FAQs on Sericulture: Definition, Process, and Chemistry
1. What is sericulture?
Sericulture is the scientific process of rearing silkworms to produce natural silk fibres used in textiles. It involves:
- Cultivation of mulberry plants
- Rearing and caring for silkworms
- Harvesting and processing silk cocoons
2. What are the main steps in the sericulture process?
The sericulture process involves several key steps:
- Silkworm egg laying: Collection of fertilized eggs
- Hatching: Silkworm larvae emerge from eggs
- Feeding: Larvae fed mainly on mulberry leaves
- Cocoon formation: Larvae spin silk cocoons
- Harvesting: Cocoons are collected and boiled
- Silk extraction (Reeling): Silk threads are unwound from cocoons
3. Are silkworms killed in sericulture?
In most commercial sericulture, silkworms are killed during the boiling of cocoons to prevent them from breaking the silk thread while emerging. This process maintains the silk's continuous filament.
4. What is the chemical composition of silk?
Silk mainly contains two proteins:
• Fibroin: Makes up 70–80%, provides strength and shine
• Sericin: About 20–30%, acts as a gummy coating
Raw silk is a natural polymer, rich in amino acids like glycine, alanine, and serine.
5. Which trees or plants are used in sericulture?
The mulberry tree (Morus alba) is the primary plant for sericulture, as its leaves serve as the main food source for Bombyx mori silkworms. Other host plants are used in different types (Tasar, Eri, Muga).
6. What are the main types of sericulture practiced in India?
The four main types of sericulture are:
• Mulberry sericulture (Bombyx mori)
• Tasar sericulture (Antheraea mylitta)
• Eri sericulture (Philosamia ricini)
• Muga sericulture (Antheraea assamensis)
7. What is the importance of sericulture?
Sericulture is important because it:
- Provides employment and rural income
- Supplies raw silk for textile industry
- Contributes to sustainable agriculture
- Adds economic value through export and crafts
8. What is the degumming process in sericulture?
Degumming is the chemical process of removing sericin (gum protein) from silk threads after cocoon boiling. This process uses hot water, soap, or mild alkali to produce smooth, lustrous silk fibres.
9. Can silk be dyed directly after extraction?
Silk fibres are usually bleached and mordanted before dyeing. This treatment enhances dye absorption, resulting in bright and long-lasting colors.
10. How is sericulture eco-friendly compared to synthetic fibre production?
Sericulture is more eco-friendly because:
- It uses renewable, biodegradable materials
- Produces lower chemical waste
- Reduces environmental pollution compared to synthetic fibres
11. What is the role of chemistry in sericulture?
Chemistry in sericulture involves:
- Understanding protein structure (fibroin, sericin)
- Processes like degumming and dyeing
- Analyzing the quality and molecular properties of silk fibres
- Innovating safer and eco-friendly extraction methods
12. What are some key differences between sericulture and apiculture?
Sericulture involves rearing silkworms for silk, while apiculture deals with rearing bees for honey. Both are agro-based, but their products, organisms, and processes differ.
