Snail mucous has many advantages, what is the best way to extract it without changing its composition?

You can use noninvasive mechanical stimulation, such as placing the Eremina desertorum snail on a sterile, rough surface (such as gauze) in a moist environment. This induces mucus secretion without causing stress or injury.

Collect the mucous from a sheet of paper and dissove it with ethanol of various pecentages.
Best

Let it walk on the absorbent paper, such as filter paper used in the chemistry lab, then cut out the snail tracks and dissolve them in PBS. 

Put the snails in a humid chamber let them do the trails, use a soft silicone brush across the footplate and put the secretion in pipette or sterile plates, store in cold conditions

Physically, an uncomfortable (threatening) environment stimulates snail mucus.
Chemically, citric acid may stimulate snail mucus
It should be collected in a piece of glassy sheet, and it may be dissolved in PBS. 

Through a mild, non-stress mechanical stimulation process without altering its composition, which mimics the snail's natural mucous processes. 

Extracting snail mucous without altering its composition requires a gentle, non-invasive method that avoids stressing the snails or introducing contaminants. Based on my take and after searching in literature, Here are the best methods to achieve high-quality, unaltered snail mucin:

1. Natural Secretion Method (Most Ethical & Purest Form)
Process:

Advantages:

2. Osmotic Stimulation (Mild & Effective)
Process:

Advantages:

In case carbohydrates extraction is the main objective, then use ethanol or dichloromethanol.
But, if the objective is to extract active protein constituents, then use Sigma Aldrich ‘s bugbuster lytic solution 

The following steps may be followed to safely collect the Snail mucus:
 
 1. Creating a Eco-friendly Environment for Snail:
 The produce a natural habitat of Snails,  it is useful to sustain a humid and somewhat warm setting, which adopts a sense of security and encourage mucus production.
 
 2. A mild Stimulation:
 Some approaches may be adopted, may be  applying a crawling structure or a natural vibration to naturally encourage mucus production.
 
 3. Natural way of Collection:
 After the mucus is gathered, a suitable collection system can be arranged with crawling structure, so that most of the mucus can be collected without harming the Snail  

 4. Separation and Deep freeze Storage:
 The collected mucus can be filtered to remove any impurities and then stored in a deep freezer in order to not allowing degradation of the mucus. 

 5. Well Being and Sustainable Practices:
 The importance is given on wellbeing and sustainable collection techniques, stressing the well-being of the snails and reducing any possible damage during the extraction process.

Snail mucus might contain some crucial polysaccharides (i.e hyaluronic acid), Collagen or elastin protein, some peptides, Metal chelating peptides that have numerous applications in pharmaceuticals and the research field. Special consideration for the extraction of mucus from snails without altering their natural composition involves maintaining a sterile environment and a lower temperature during the extraction process. Firstly, gently wash the snail with DDW and place it on an acrylic sheet. Secondly, select a suitable stimulation method for the movement and secretion of mucus. Stimulation by mild seawater mist or rhythmic vibration might not affect the mucous composition. Thirdly, the secreted mucus on the acrylic sheet collection is challenging and requires careful consideration. Rinsing the surface with PBS dissolves the mucus, making it easier to collect. Finally, sterilise it by filtration (using a 0.22 µm filter) and lyophilise to store at a lower temperature.  

To extract snail mucous without changing its natural composition, the most effective method is gentle and non-invasive. This usually involves creating a calm environment where the snails are encouraged to secrete mucus often using mild techniques like soft misting or slight vibration. The mucus is then carefully collected, filtered, and stored at low temperatures to preserve its original properties. This way, the bioactive components remain stable and effective, without the use of heat or harsh chemicals.

U may also want to gently try and increase the mucus production and secretion prior to collection.

Cold filtrations with gentle treatment yield the mucin. Freeze-drying can be conducted on this obtained extract to ensure maximum cell integrity. Since lyophilization is done at low temperature without solvents, this prevents further denaturation of active components.

Allow the snail on a paper and dissolve the paper in phosphate buffer. Remove the paper using chromatography..

Snail mucus is possible to extract. Allow snails to move about and it releases its mucus and which can be dried and collect thereafter.

Similar to collecting mucus on the paper, collect it on a moving surface, so that the concentration of mucus can be increased at a particular place.

Secondly, the silica or some other inert material powder can be spread over which snails will crawl. The powder can be collected later and used for mucus extraction.