Original article Study on enhanced absorption of phenolic compounds of Lactobacillus-fermented turmeric (Curcuma longa Linn.) beverages in rats Plangpin Pianpumepong, 1,2 Anil Kumar Anal, 1* Galayanee Doungchawee 3 & Athapol Noomhorm 1 1 Food Engineering and Bioprocess Technology, School of Environment, Resources and Development, Asian Institute of Technology, PO Box 4, Klongluang, 12120, Thailand 2 Department of Postharvest and Processing Engineering, Rajamangala University of Technology, Isan Nakhon Ratchasima, 30000, Thailand 3 Department of Pathobiology, Mahidol University, Bangkok, 10400,Thailand (Received 9 February 2012; Accepted in revised form 11 May 2012) Summary Lactobacillus plantarum, used as starter culture to produce turmeric beverages, was isolated and screened from the turmeric rhizomes. Fermented turmeric beverages were evaluated for its antioxidant activity using 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and ferric-reducing antioxidant power (FRAP) assay. The fermentative process resulted in an increase in antioxidant activity. The absorp- tion of turmeric powder, turmeric powder-mixed encapsulated probiotic (TP) and encapsulated fermented turmeric beverage (TB) in rats was measured in terms of antioxidant activity in the plasma. Plasma anti- oxidant concentration was higher in rats administrated fermented turmeric beverage than other turmeric products, at all the time points. The maximum concentration (C max ) value and area under the plasma concentration versus time curve (AUC) were higher in the rat administered with TB. The value was lower in the plasma of rats administered with turmeric powder and TP. The results indicated that the fermenta- tive turmeric possesses better bioavailability and in accordance with the concentrations of polyphenolic compounds in the rat plasma. Keywords Antioxidant absorption, encapsulation, in vivo studies, lactic acid bacteria, polyphenols, turmeric rhizome. Introduction Phenolic compounds occur naturally in fruit, vegeta- bles, nuts, seeds, rhizomes, flowers and barks of the plants. Phenolic compounds have long been considered inert and nonessential for human health; however, in the last few years, it has been shown that these com- pounds affect a wide variety of biological systems in mammals, exhibiting antioxidant, anti-inflammatory, antibacterial, antiviral and anticarcinogenic effects. Phenolic compounds are recently investigated for their possible health benefits for some disorders such as Alz- heimer’s disease and liver disorders. These compounds have been known to act as antioxidants because of their ability to donate electrons and their stable radical intermediates, which can effectively prevent the oxida- tion at cellular and physiological level (Cuvrelier et al., 1992). Turmeric (Curcuma longa Linn.) is extensively used as a spice, food preservative and colouring material in most of the Asian countries (Chattopadhyay et al., 2004; Goel et al., 2008). Curcumin, widely attended as antioxidant, is a phenolic nontoxic compound derived from the turmeric rhizomes (Ganiger et al., 2007). However, because of its poor water solubility, poor permeability and/or poor stability, there is minimal absorption from the gut and hence avid metabolism in the body, causing the lack of systemic availability (Christopher et al., 2002). The ability to absorb the amount of dietary antioxidants is a prerequisite for their bioavailability. Very limited studies have been conducted on the absorption and bioavailability of selected dietary antioxidants. Because of its increasing demand, the nondairy- based probiotics have recently been incorporated into healthy fruit, vegetables and herb-based beverages (Bisakowski et al., 2007; Panda et al., 2009). Probiot- ic-based functional foods have been found rich in bio- active components such as minerals, vitamins, dietary * Correspondent: Fax: +66 25246200; e-mails: anilkumar@ait.ac.th; anil.anal@gmail.com International Journal of Food Science and Technology 2012 47, 2380–2387 doi:10.1111/j.1365-2621.2012.03113.x © 2012 The Authors. International Journal of Food Science and Technology © 2012 Institute of Food Science and Technology 2380