1. 1 Complexation of curcumin with soy protein isolate and its implications on solubility and stability of curcumin Source ： Source ： Food Chemistry 130 (2012) 960–965 Speaker ： Syu,Yu-Lian Student ID No. ： 100751106 Date ： 101 年 03 月 22 日

2. 2 Background Curcumin (bis-a,b-unsaturated b-diketone), commonly called as diferuloylmethane, is a low- molecular-weight, natural polyphenolic compound found in the rhizome of turmeric (Curcuma longa). It has a wide range of pharmacological activities including anti-inflammatory, antioxidant, antiproliferative and antiangiogenic (Anand, Kunnumakkara, Newman, &Aggarwal, 2007) properties.

3. 3 Introduction The effectiveness of a functional food depends on preserving the activity of the bioactive molecule. Moreover, the activity depends on its solubility, stability, absorptionand bioavailability. The effectiveness of nutraceutical products in preventing diseasesdepends on preserving the bioavailability of the active ingredients.

4. 4 Introduction(Cont.) Protection of the bioactive compounds against conditions encountered in food processing and in the gastrointestinal tract (pH, presence of enzymes and other nutrients) is of paramount importance (Bell, 2001). By encapsulation, a bioactive compound can be protected from environmental destructive factors, solubilised and delivered in a controlled manner.

5. 5 Introduction(Cont.) In searching food-grade materials to form complexes with curcumin, we focused on soy protein isolate (SPI). Soy proteins are used extensively in food manufacturing, because of their functional properties, low cost, availability and high nutritional value.

6. 6 Aim The aim of this study was to investigate the potential of SPI as a carrier for curcumin. An approach was made to enhance the water solubility and stability of curcumin by complexing it with SPI.

7. 7 Materials and methods

8. 8 Materials Curcumin was purchased from ICN biomedicals, Inc. (Aurora,Ohio). 2, 2-diphenyl-1-picrylhydrazyl (DPPH) was from Sigma Aldrich Chemicals Co. (St. Louis, MO). Curcumin stock solution was prepared in methanol. Absorbance measurements were made on a Shimadzu 1601 double beam spectrophotometer,using a 10 mm path length quartz cell.

9. 9 Preparation of soy protein isolate Soy protein isolate (SPI) 10-fold distilled water adjusted to pH 8 with 2 M NaOH stirred for 1hr supernatant adjusted to pH 4.5 with 2 M HCl soy protein curd collected by centrifugation (8000 rpm, 20 min) 4-fold distilled water adjusted to pH 7 with 2 M NaOH freeze-drying

10. 10 Complexation of curcumin with SPI curcumin was added to 5% (w/v) SPI solution homogenizer for 10 min magnetic stirrerovernight centrifugation (8000 rpm, 20 min) supernatant spray-dried SPI–curcumin complex powder.

11. 11 Stability measurements To study the stability, SPI–curcumin complex was dissolved in water, simulated gastric and intestinal fluids. The stability of curcumin was calculated by measuring the absorbance at 425 nm at different time intervals. Simulated gastric and intestinal fluid was prepared without enzyme as followed by Maltais et al. (2009).

12. 12 Fluorescence measurement curcumin 5 μM in a Tris–HCl buffer pH 7.4SPI from 0 to 5 mg/ml Fluorescence spectrophotometry SPI solutions5 μM in a Tris–HCl buffer pH 7.4 Fluorescence spectrophotometry

13. 13 Foaming capacity Foaming capacity of samples was determined according to the method of Sathe and Salunkhe (1981). Samples measuring cylinder Homogenizer for 1 min

14. 14 Emulsion capacity 3 ml proteinsolutions (1% w/v)1 ml of refined groundnut oil 50 mM Tris–HCl buffer (pH 8) vortexed for 1min 50 μl dissolved in 5 ml of 0.1% (w/v) SDS. Absorbance 500nm The emulsion capacity of samples was determined according to the method of Pearce and Kinsella (1978).

15. 15 The antioxidant activity of the samples were measured by the following methods

16. 16 DPPH radical scavenging activity Samples dissolved in water( 0–10 mg/ml) 0.5 ml of the sample added to 1 ml 0.2 mM DPPH then mixed vigorously After incubation for 30 min centrifuged (8000 rpm 10 min) UV-spectrophometer (517nm) dissolved in water( 0–10 mg/ml) 0.5 ml of the sample added to 1 ml 0.2 mM DPPH After incubation for 30 min centrifuged (8000 rpm 10 min) UV-spectrophometer (517nm) Samples dissolved in water( 0–10 mg/ml) 0.5 ml of the sample added to 1 ml 0.2 mM DPPH After incubation for 30 min centrifuged (8000 rpm 10 min) UV-spectrophometer (517nm) then mixed vigorously Samples dissolved in water( 0–10 mg/ml) 0.5 ml of the sample added to 1 ml 0.2 mM DPPH After incubation for 30 min centrifuged (8000 rpm 10 min) UV-spectrophometer (517nm) then mixed vigorously Samples dissolved in water( 0–10 mg/ml) 0.5 ml of the sample added to 1 ml 0.2 mM DPPH After incubation for 30 min centrifuged (8000 rpm 10 min) UV-spectrophometer (517nm)

17. 17 DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was measured using the method of Yen and Wu (1999). DPPH radical scavenging activity(cont.)

18. 18 Reducing power Reducing power was determined by the method of Oyaizu(1986). The sample solution (0.1 ml, 0–10 mg/ml) 0.4 ml 0.2 M phosphate buffer (pH 6.6) and 0.5 ml 1% (w/v) potassium ferricyanide mixed Heating (50 ℃ 20min) added to (0.5 ml) of 10% (w/v) TCA centrifuged (3000 rpm 10 min)

19. 19 Supernatant(0.5ml) mixed with 0.5 ml of distilled water and 0.1 ml 0.1% (w/v) ferric chloride absorbance was read at 700 nm. Reducing power(Cont.)

20. 20 Statistical analysis For all the measurements, a minimum of triplicates were taken for data analysis. Using the Origin 6.1 software, all of the values were plotted. Data were expressed as means ± standard deviations. One way analysis of variance (ANOVA) was employed to identify significant differences (p < 0.05) between data sets using software Origin 6.1.

21. 21 Results and discussion

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32. 32 Conclusion In the present study, it was shown that SPI can form complexes with curcumin. The antioxidant activity of SPI increases after complexation with curcumin.

33. 33 References Vivek, R. Y., Sahdeo, P., Ramaswamy, K., Jayaraj, R., Madan, M. C., Lauri, V., et al.(2010). Cyclodextrin-complexed curcumin exhibits anti- inflammatory and antiproliferative activities superior to those of curcumin through higher cellular uptake. Biochemical Pharmacology, 80, 1021–032. Maltais, A., Remondetto, G. E., & Subirade, M. (2010). Tabletted soy protein cold-set hydrogels as carriers of utraceutical substances. Food ydrocolloids, 24(5),518–524. Efstathia, I. P., Spyros, J. K., & Vaios, T. K.(2011). Stability and release properties of curcumin encapsulated in Saccharomyces cerevisiae, b- cyclodextrin and modified starch. Food Chemistry, 125, 913–922. Leung, M. H. M., & Kee, T. W. (2009). Effective stabilization of curcumin by association to plasma proteins: Human serum albumin and fibrinogen.Langmuir, 25(10), 5773–5777.

34. 34 Thank you for listening