It is naïve to suggest that customers only need to avoid pork, gelatine and alcohol, or sherry trifles etc.
From the Islamic bulletin
Pork products are sometimes used to make snack foods such as puddings, jello, chips, crackers, cookies, donuts and marshmallows including marshmallow bits in cereal and hot cocoa. Pork products are also found in some brands of cake frosting, cheese spreads, yogurt, margarine, and ice cream. Look for words like lard, animal fats, animal glyceride, hydrolyzed animal protein, enzymes, emulsifiers, monostearates, mono and di-glyceride and gelatin on the label when you buy these products. Dairy products such as whipped cream, sour cream and cheese may also contain gelatin or rennet. Rennet is an enzyme which turns milk solids into cheese. Animal rennet is most often used. Look for mono and di-glyceride (forms of glycerine), or enzymes on the label. They may not all be made with pork but the only way to know for sure is to contact the company or look for the Kosher marking (K or U) on the label. Pork in the form of glycerine, keratin, collagen and tallow are used in cosmetics and toiletries. Some common ones that contain pork or pork by-products are lipstick, shaving cream, toothpaste, had lotion, bath soap and shampoos. Pork is also hidden in detergents, cleansers, dish liquids, and soaps.
Some medications may also contain pork products; the most common is the gelatin coated tablet of the gelatin capsule (gelcaps). The Physicians Desk Reference is a reliable source that we can refer to for the names, ingredients, indications, reactions and brands of every prescription and non-prescription drug or medication on the market.
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Let's also remember that all Kroger products contain gelatine, then there's marshmallows, some sauces, some gravy, some bagged seasoning mixes, cream soda, Kelloggs Rice Krispie Treat squares, Special K Protein Snack bars, Kelloggs Fruit Snacks, Sara lee Classic Cheesecake, Sara Lee Strawberry French cheesecake, Sara Lee Tangy Lemon Meringue pie, Trident Layers gum, Trident Splash Gum, Krafters Dry Roasted Peanuts, Mentos sweets and chewing gum, Clorets Gum and the list goes on and on.
If there were to be a muslim who refuses any product with pork in, it is foolish to think that the average customer will know which products these are.
I haven't even started on the alcohol list.