Is there a way to inhibit the effect of amylase enzyme on glucomannan?
Potential solutions will vary with the target animal, target site within the digestive tract and dosing duration desired. Is this for ruminants, nonruminants or humans? Where do you want it released? Is this a single dose or is the goal to feed the material continuously and continually inhibit amylase? Suggestions below are an attempt to relate to all scenarios.
First, nonruminants (except horses) produce saliva containing beta amylase. So some type of physical coating to reduce digestion during residence in the stomach may be needed.
Protecting the material from amylases in the intestine is more difficult. If this is a single dose, one could inhibit intestinal amylases for an hour or two by dosing with various amylase inhibitors (“Starch Blockers”) or amylose analogs. If the goal is continuous administration, one might package the material with one of several commercially available amylase inhibitors isolated from legumes or wheat as described here. Relative effectiveness of inhibitors in human diabetics has been variable with wheat amylase inhibitors often being more effective than legume derived amylase inhibitors as discussed here. One also could dose or encapsulate the material with the chemically derived amylase inhibitor, acarbose, a compound used with human diabetics. Being similar in structure to a hexaglucan, acarbose will competitively inhibit amylase.
If the product is for ruminants, coating the product with resistant protein or complex (e.g., mixed and dried with blood) or a saturated fat (e.g., palm oil) would protect it from ruminal destruction while liberating it under acid conditions in the abomasum or gradually with lipase in the small intestine. A sterol coating might work if one wants to deliver the material to the large intestine and avoid both ruminal and small intestinal digestion of ruminants or avoid digestion in the stomach and small intestine of nonruminants. Polysaccharide gels also could protect the compound from small intestinal enzymes, but release in the large intestine would be limited. Alternatively, one could form a capsule with commercially available resistant starch (retrograde starch usually derived from amylose) to deliver material to the large intestine where certain microbes (e.g., bifida) not found elsewhere in the gut would partially degrade the resistant starch and release a portion of the desired compound.
One also could consider linking ions (e.g., copper), calcium-binding compounds (e.g., citrate, oxalate, phytate) to reduce calcium (that is an essential cofactor for amylase) or chemically bind fatty acids to free hydroxyls of the glucomannan hoping that these would not inhibit the desired action of the compound. Finally, one could encapsulate the material with an organic or inorganic acid to lower the local pH below the optimum for amylase activity (7.4). One also could include a protein-binding (and amylase binding) agent (e.g., tannin; formaldehyde) and thereby inhibit degradation immediately around a capsule.