All right, for you guys who like spit but dont produce enough of your own, here is the recipe for the real thing. Human saliva is 98% water but it contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. To get a true replacement you need:
Water
Electrolytes:
o 2-21 mmol/L sodium
o 10-36 mmol/L potassium
o 1.2-2.8 mmol/L calcium
o 0.08-0.5 mmol/L magnesium
o 5-40 mmol/L chloride
o 25 mmol/L bicarbonate
o 1.4-39 mmol/L phosphate
o Iodine mmol/L
Mucus. Mucus in saliva mainly consists of mucopolysaccharides and glycoproteins;
Antibacterial compounds (thiocyanate, hydrogen peroxide, and secretory immunoglobulin A)
Epidermal growth factor or EGF
Various enzymes. There are three major enzymes found in saliva.
o α-amylase (EC3.2.1.1). Amylase starts the digestion of starch and lipase fat before the food is even swallowed. It has a pH optima of 7.4.
o lingual lipase. Lingual lipase has a pH optimum ~4.0 so it is not activated until entering the acidic environment of the stomach.
o Antimicrobial enzymes that kill bacteria.
Lysozyme
Salivary lactoperoxidase
Lactoferrin[8]
Immunoglobulin A[8]
o Proline-rich proteins (function in enamel formation, Ca2+-binding, microbe killing and lubrication)[8]
o Minor enzymes include salivary acid phosphatases A+B, N-acetylmuramoyl-L-alanine amidase, NAD(P)H dehydrogenase (quinone), superoxide dismutase, glutathione transferase, class 3 aldehyde dehydrogenase, glucose-6-phosphate isomerase, and tissue kallikrein (function unknown).[8]
Cells: Possibly as much as 8 million human and 500 million bacterial cells per mL. The presence of bacterial products (small organic acids, amines, and thiols) causes saliva to sometimes exhibit foul odor.
Opiorphin, a newly researched pain-killing substance found in human saliva.
You wont be historically correct unless you get them all in there.