I am Kushani, engaged in selling Pepsin in Russia, thus, it is extremely important for me to select a reliable supplier of Pepsin.
Certificate
A formal operation supplier of food additives normally passes ISO certificate as well as other well-known certificate like halal, kosher, ect.
Supply of Products
Compared with Manufacturers, other than service advantage, main advantage of trading companies lies in being able to provide various kinds of products. For example, when we would like to order Pepsin as well as several other food ingredients, trading companies becomes the best choice, since unlike factories, traders can provide one-stop service and have greater bargaining powder which permits a lower price.
Of course , we can purchase Pepsin directly from manufacturers if the volume is large enough, but it won’t be a bad choice if we keep in touch with some large-scaled traders. Because once your long-term-cooperate factory is in short of Pepsin , we can turn to trading companies, who can help to find other suppliers shortly or even direct supply Pepsin in no time.
As far as we know, big suppliers of food additives and ingredients can basically provide more than 100 kinds of products, among which, Foodchem International Corporation are able to supply overseas customers more than 300 kinds of food additives and ingredients, plant extracts, nutritional supplements, apis, etc.
Google “Company Name”
A renowned company name usually shows a great deal results on Goolge Search, because its company name is frequently searched by their customers or cited by other web sites.
Take “Foodchem International Corporation” as an example, as has been showed in the below picture, there comes out more than 298,000 searching results on Google. 
Company Name
As a professional trader or manufacturer of food additives, normally its company name has food, chemical, additives or other key words in it. Other trading companies who have affairs in all fields, usually performs unprofessionally.
Sales of Supplier
There are tons of suppliers of Pepsin in China, thus, supply scale should be important, Pepsin suppliers with a certain size suppliers tend to have more bargaining power, in some country, we can even find their Pepsin supply volumes through customs data.
Warehouse
Warehouse is also important for Pepsin suppliers, Pepsin traders make judgments through Pepsin market situation. On one hand, while Pepsin is in the upside, traders purchase bulk Pepsin for storage, and sell with the price advantage; On the other, vendors need to keep cargo in warehouse in case customers need LCL loaded.
Foodchem International Corporation owns an EDC warehouse in Shanghai, an advanced warehouse system which only few trading companies in Shanghai can provide, it avails fast delivery within 1 week.
Shipping and Payment
In order to meets different needs of buyers, according to intercoms, Pepsin suppliers often provides several payment ways, such as FOB, L/C, D/P, T/T and so on.
Exquisite Website
Qualified Pepsin suppliers tend to have more elaborate and professional web site, with better user experiences and less bugs or faults.