The following items may or may not contain gluten depending on where and how they are made, and it is sometimes necessary to check with the manufacturer to find out:

Artificial Colors4
Baking powder
4
Caramel Color
1, 3
Caramel Flavoring
1, 3
Clarifying Agents
4
Coloring
4
Dextrins
1,7
Dextrimaltose
1,7
Dry Roasted Nuts
4
Emulsifiers
4
Enzymes
4
Fat Replacer
4
Flavoring
6
Food Starch1, 4
Food Starch Modified
1, 4
Glucose Syrup
4
Gravy Cubes
4
Ground Spices4
Seafood Analogs4
Seasonings4
Sirimi4
Smoke Flavoring
4
Soba Noodles
4
Soy Sauce
4
Soy Sauce Solids
4
Sphingolipids
4
Stabilizers
4
Starch
1, 4
Stock Cubes
4
Suet
4
Tocopherols
4
Vegetable Broth
4
Vegetable Gum
4
Vegetable Protein
4
Vegetable Starch
4
Vitamins
4
Wheat Starch5
HPP4 (Hydrolyzed Plant Protein4 )
Hydrolyzed Protein
4
HVP4 (Hydrolyzed Vegetable Protein4 )
Hydrogenated Starch Hydrolysate
4
Hydroxypropylated Starch
4
Maltose
4
Miso
4
Mixed Tocopherols
4
Modified Food Starch
1, 4
Modified Starch
1, 4
Natural Flavoring
6
Natural Flavors
6
Natural Juices
4
Non-dairy Creamer
4
Pregelatinized Starch
4
Protein Hydrolysates
4

1) If this ingredient is made in North America it is likely to be gluten-free.
3) The problem with caramel color is it may or may not contain gluten depending on how it is manufactured. In the USA caramel color must conform with the FDA standard of identity from 21CFR CH.1. This statute says: the color additive caramel is the dark-brown liquid or solid material resulting from the carefully controlled heat treatment of the following food-grade carbohydrates: Dextrose (corn sugar), invert sugar, lactose (milk sugar), malt syrup (usually from barley malt), molasses (from cane), starch hydrolysates and fractions thereof (can include wheat), sucrose (cane or beet). Also, acids, alkalis and salts are listed as additives which may be employed to assist the caramelization process.
4) Can utilize a gluten-containing grain or by-product in the manufacturing process, or as an ingredient.
5) Most celiac organizations in the USA and Canada do not believe that wheat starch is safe for celiacs. In Europe, however, Codex Alimentarius Quality wheat starch is considered acceptable in the celiac diet by most doctors and celiac organizations. This is a higher quality of wheat starch than is generally available in the USA or Canada.
6) According to 21 C.F.R. S 101,22(a)(3): [t]he terns natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof. Whose significant function in food is flavoring rather than nutritional.
7) Dextrin is an incompletely hydrolyzed starch. It is prepared by dry heating corn, waxy maize, waxy milo, potato, arrowroot, WHEAT, rice, tapioca, or sago starches, or by dry heating the starches after: (1) Treatment with safe and suitable alkalis, acids, or pH control agents and (2) drying the acid or alkali treated starch. (1) Therefore, unless you know the source, you must avoid dextrin.
May 1997 Sprue-Nik News. (1) Federal Register (4-1-96 Edition) 21CFR Ch.1, Section 184.12277. (2) Federal Register (4-1-96) 21 CFR. Ch.1, Section 184.1444