In the food industry, the primary catalysis is coupled to conversion of NADH and H+ to NAD+ with diaphorase coupled with converting the non-fluorescent resazurin to the highly fluorescent substance resorufin to measure the content of D-lactate in food products.
D-lactic dehydrogenase catalyzes the conversion of pyruvate into D-lactate, with oxidation of NADH to NAD+. D-lactic dehydrogenase can also catalyze the reverse reaction, conversion of D-lactate into pyruvate with reduction of NAD+ to NADH.