[6-1130-P] Functional/Wellness Foods & Nutrition (6th)

[6-1130-P-08] Effect of Extracting Conditions on Plant Extract Colors and Stability of Antioxidant Properties during in vitro Gastrointestinal Digestion

*Rattika Aeka¹, Titikan Liangpanth¹, Rungarun Sasanatayart¹ (1. School of Agro-Industry, Mae Fah Luang University(Thailand))

Keywords:Anthocyanins , Carotenoids , Betalains, Chlorophylls, in vitro gastrointestinal digestion, Antioxidant

Natural pigments extracted from plants provide distinctive color and exert antioxidant effects that are far more superior than synthetic colorants. Synthetic colorants tend to be undesirable by consumers, due to the harmful effects on human health, including allergic reactions, mutagenicity and potential carcinogenicity. As a result, there is a worldwide trend toward the natural colorants, in particular in food applications. In this study, four major types of plant pigment including anthocyanins from butterfly pea flower (Clitoria ternatea L.), betalains from dragon fruit peel (Hylocereus undatus), carotenoids from turmeric rhizome (Curcuma longa) and chlorophylls from pandan leaf (Pandanus amaryllifolius) were extracted under different conditions. Three types of solvent (water, 70% w/w acedic acetone and 50% w/w aqueous ethanol) and three mechanical extraction methods (shaking 25°C for 24 h, sonication at 25°C for 1 h and sonication at 65°C for 1 h) were compared. Results showed that 50% w/w aqueous ethanol was the most effective solvent for extraction of carotenoid form turmeric and chlorophyll from pandan leaf whereas, water was the most effective solvent for extraction of betalain form dragon fruits peel and anthocyanin form butterfly pea flower. Between mechanical extractions, sonication was better than shaking in extracting the require pigments (carotenoids, betalains, anthocyanins and chlorophylls), total phenolics and total flavonoid from selected plants. Overall, sonication at 25°C was better than sonication at 65°C in obtaining plant extract with high antioxidant activities based on FRAP and DPPH with the reduced energy consumption. Therefore, color extracted with sonication at 25°C was used for testing the stability upon in vitro gastrointestinal digestion. Results showed that pigment compounds and related antioxidant activities of all four color extracts become less stable along digestion. Results revealed that the stability of each pigments and their related antioxidant during in vitro digestion from high to low were anthocyanins, carotenoids, chlorophylls and betalains, respectively. Data of this study supports the extension use of natural colorants as substitutes for synthetic dyes in food applications. However, the effect of food processing parameters including pH, heat and ingredients must be taken into accounted.