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Chicoric acid (ChA) and caftaric acid (CafA) were identified as bioactive components of chicory and have been ascribed a number of health benefits. This study investigated the hydrolysis of ChA and CafA with enzymes and a probiotic bacterium Lactobacillus johnsonii (La1). Esterase from Aspergillus japonicus (24 U/mg) hydrolyzed 100% of ChA (5 mM) and CafA (5 mM) after 3 h, at pH 7.0 and 37 °C. Under the same reaction conditions, 100% hydrolysis of ChA and CafA was achieved with a spray-dried preparation of La1. The addition of La1 (100 mg/mL, 3.3 E9 cfu/g) to CafA solution in a gastrointestinal model (GI model) resulted in 65% hydrolysis of CafA. This model simulates the physicochemical conditions of the human gastrointestinal tract. No hydrolysis of CafA was observed after passage through the GI model in the absence of La1. The results of this study support the hypothesis that ChA and CafA are degraded by gut microflora before absorption and metabolization.

Rosmarinic acid (RA) was identified as one of the main components of rosemary extracts and has been ascribed to a number of health benefits. Several studies suggested that after ingestion, RA is metabolized by gut microflora into caffeic acid and derivatives. However, only limited information on the microorganisms and enzymes involved in this biotransformation is available. In this study, we investigated the hydrolysis of RA from rosemary extract with enzymes and a probiotic bacterium Lactobacillus johnsonii NCC 533. Chlorogenate esterase from Aspergillus japonicus (0.02 U/mg) hydrolyzed 90% of RA (5 mg/mL) after 2 h at pH 7.0 and 40 degrees C. Complete hydrolysis of RA (5 mg/mL) was achieved with a preparation of L. johnsonii (25 mg/mL, 3.3 E9 cfu/g) after 2 h of incubation at pH 7.0 and 37 degrees C. No hydrolysis of RA was observed after the passage of rosemary extract through the gastrointestinal tract model (GI model). Thus, RA is hydrolyzed neither chemically under the conditions of the GI model (temperature, pH, and bile salts) nor by secreted enzymatic activity (lipase and pancreatic enzymes). The addition of L. johnsonii cells to rosemary extract in the GI model resulted in substantial hydrolysis of RA (up to 99%).