1 complexation of curcumin with soy protein isolate and its implications on solubility and stability...

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Complexation of curcumin with soy protein isolate and its implications

on solubility and stability of curcumin

SourceSource：： Food Chemistry 130 (2012) 960–965

SpeakerSpeaker：： Syu,Yu-LianSyu,Yu-LianStudent ID No.Student ID No.：： 100751106100751106

DateDate：： 101101年年 0303月月 2222日日

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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.

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IntroductionIntroduction

• 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.

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Introduction(Cont.)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.

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Introduction(Cont.)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.

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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.

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Materials and methods

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Materials• Curcumin was purchased from ICN biomedicals, Inc.

(Aurora,Ohio). • 2, 2-diphenyl-1-picrylhydrazyl (DPPH) was from Sig

ma 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.

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Preparation of soy protein isolateSoy protein isolate (SPI)

10-fold distilled water adjusted to pH 8 with 2 M NaOH

stirred for 1hr

supernatantadjusted to pH 4.5

with 2 M HCl

soy protein curdcollected by centrifugation(8000 rpm, 20 min)

4-fold distilled wateradjusted to pH 7 with 2 M NaOH

freeze-drying

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Complexation of curcumin with SPI

curcumin was added to 5% (w/v) SPI solution

homogenizer for 10 min

magnetic stirrer overnight

centrifugation (8000 rpm, 20 min)

supernatant

spray-dried

SPI–curcumin complex powder.

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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).

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Fluorescence measurement

curcumin 5 μM in a Tris–HCl buffer pH 7.4 SPI from 0 to 5 mg/ml

Fluorescence spectrophotometry

SPI solutions 5 μM in a Tris–HCl buffer pH 7.4

Fluorescence spectrophotometry

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Foaming capacity• Foaming capacity of samples was determined ac

cording to the method of Sathe and Salunkhe (1981).

Samples

measuring cylinder

Homogenizer for 1 min

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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).

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The antioxidant activity of the samples were measured by the

following methods

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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)

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

DPPH radical scavenging activity(cont.)

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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)

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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.)

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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.

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Results and discussion

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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.

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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.

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Thank you for listening