Final answer:
In the β-oxidation pathway, the reaction catalyzed by beta-hydroxyacyl CoA dehydrogenase produces NADH as the reduced coenzyme.
Step-by-step explanation:
The coenzyme that is produced in the reaction catalyzed by beta-hydroxyacyl CoA dehydrogenase is NADH. This reaction is a step in the β-oxidation pathway of fatty acids where the β-hydroxyacyl CoA undergoes dehydrogenation to form β-keto acyl-CoA. During this process, the coenzyme NAD+ is reduced to NADH + H+, which can later produce ATP when oxidized through the electron transport chain.