Mono and diglycerides are a mixture of fatty substances containing glycerol and one (mono) or two (di) fatty acids. They are manufactured from the breakdown of fats and oils. Commercially available mono and diglycerides may be manufactured from vegetable oils, beef fat, lard or marine oils. Mono and diglycerides from vegetable and marine oils are Halal, whereas from beef fat mashbooh and from lard Haram.
Gelatin is a protein product commercially made from pork skin, cattle bones, calf skin or from fish skin. Usually on one label there is no distinction made as to the source of gelatin present in the Cod. Therefore, any product which contains gelatin is either Haram or at least mashbooh, because the animal source is not identified, unless the label clearly indicates Halal gelatin or fish gelatin. Typical foods which may contain gelatin include frosted cereals, cereals bars, ice cream yogurt, certain dairy drinks, chocolate, candies and so on.
Enzymes are widely used in the food and dairy industry. The sources can be animal, plant or microbial. An animal enzyme commonly used, rennin, is extracted from calf stomachs. Pepsin is another digestive enzymes from the stomachs of pigs. Only the enzyme from plant, calves slaughtered properly) or microbial should be used in Halal foods.
Glycerin is made from fats or oils which could have animal or vegetable origins or even produced from petrochemicals. Product development scientists should avoid glycerin from animal fats in the development of Halal products.
Lard is pork fat and prohibited for Muslims. Fortunately the use of lard in the US has decreased over the last decade due to awareness about cholesterol.
Lecithin is found in the fat portions of all plant and animal systems. It is used in many food products that contain fats as an emulsifier. The most common source of lecithin is soybeans but labels are a rarely descriptive about the source.
Alcohol is an intoxicant and prohibited for Muslims as such. Many liquid flavors (e.g. vanilla) contain alcohol as an ingredient. Foods such as sodas, ice cream. salad dressings, or sauces may contain alcohol in their formulation. Now many flavors are available which are alcohol free. Food flavor may be extracted with alcohol or ingredients precipitated with alcohol but it must be evaporated to minimize the residual level present.