EFFECT OF LIGHT AND TEMPERATURE ON STABILITY OF ZEAXANTHIN.

OBJECTIVES

The objectives of this experiment are:-

To identify the stability of carotenoid in storage condition.

To determine effect of light and temperature on carotenoid extract for storage condition.

Identify the degradation kinetics of carotenoid.

Problem Statement

The appropriate storage conditions for zeaxanthin is important to make sure the final product is attractive and can be acceptable for customer.

The degradation of zeaxanthin not only affects the colour of corn but also their nutritive and flavour.

The effect of temperature and light will reduce the composition of zeaxanthin.

INTRODUCTION Zeaxanthin is a naturally nutrient that can

found in human body, fruits, vegetables, corn and marigolds.

Zeaxanthin belongs to the carotenoid family as part of a subgroup called xanthophylls or oxycarotenoids.

Zeaxanthin is a yellow carotenoid that is isomeric with lutein. The yellow pigment in yellow corn is zeaxanthin.

Zeaxanthin play a role in shielding the retina from harmful damage as a result of exposure to light. Zeaxanthin also is one of part in preventing Age Related Macular Degeneration (AMD) disease (Goerge Torrey, 1998).

INTRODUCTION

Figure 1: Structure of zeaxanthin

The chemical formula of Zeaxanthin or also known as 3R, 3'R-β, β-carotene-3,3'-diol is C40H56O2, and its molecular weight is 568.87g/mol.

INTRODUCTION Different temperature and condition of light

exposure could inhibit or slow down the loss of zeaxanthin.

Temperatures not exceeding 20 °C better preserve carotenoids content and are recommended for long-term storage (Alyssa Hidalgo and Andrea Brandolini, 2008).

METHODOLOGYSample preparation

Kinetic DegradationTemperatureLight

Analysis of Zeaxanthin

Extraction

Stability Test

SAMPLE PREPARATION

The corns are clean up and remove the corn’s kernel.

The corn’s kernels need to be dry on oven at 40oC for 5 days (Nurul Husna, 2010).

Grind the kernel for convert it to powder form.

Keep the kernel at the dry place.

Extraction process

Soxhlet extraction is use after drying and grinding process.

Take the weight of corn, flask and thimble. Place the corn into thimbles and take the weight of it.

Fill up ethanol into a flask according the information in Table 1. Based on Table 1, the ratio of the solid solvent is determine by 1 gram of material is equivalent with 20ml of ethanol.

Extraction process

Table 1: The variables and the parameters in the zeaxanthin extraction (Marmy 2005)

Variables Level (Parameters)

Type of solvent Ethanol

Solid/Solvent ratio (w/v) 1:20

Time (hr) 2

Extraction process

o The extraction process begins when the solvent starts to boil and the process are leave to be running for 2 hours.

o The changes colour of a solution must be observed.

o When the process done, stop the heating and cooled down the corn extract.

o After cooling, take the weight of thimble with the corn extract then transfer it into reagent bottle. The differences between the weights of thimble before and after extraction give the approximate weight of the corn extracted.

o Keep the corn extract in the refrigerator with the temperature of 5oC and below.

Stability test

Light

About 40ml of carotenoid extract is store in small bottles.

For the dark condition, the glass bottle is wrapping with several layers of aluminium foil or can put it at amber bottle and store at 25oC.

For the light condition, the sample is exposing to the fluorescent room light during the day and store at room temperature 25oC.

Leave it about one month. Then the absorbance of the sample is checking by using UV-Vis.

STABILITY TEST

Temperature

  About 40ml of carotenoid extract is fill in the

beaker and stored at room temperature 25oC, 30oC and 40oC.

Leave it about one month. Then the absorbance of the sample is checking by using UV-Vis.

STABILITY TEST

Kinetics degradation

About 40ml of carotenoid extract is fill in the cylindrical beaker and placed at 50oC, 60oC and 70oC.

The absorbance of the sample is checking by using UV-Vis at 3min, 5min and 10min.

Analysis of zeaxanthin

The analysis of zeaxanthin is use Ultra Violet Visible Spectrophotometer (UV-Vis).

All the sample is scanned by using UV spectrum in between 400 and 500nm.

The maximum absorption wavelength of zeaxanthin is between 442.6nm and 448.6nm (Zhen Sun and Huiyuan you, 2007).

The absorbance of standard of zeaxanthin is use to compared with the sample.

The yield of zeaxanthin is determined by using the equation below.

Equation the total yield of zeaxanthin (Britton et al., 1995)

X = yield of zeaxanthin (mg) A = absorbance rate y = yield of extracted (ml)A1%

cm=Absorbance coefficient

Statistical analysis

Experiment is run in triplicate. The reported data of mean and standard

deviations are calculated from three replicates.

The results were analyzed by using two way analyses of variance (two - way ANOVA). The differences of mean are (p < 0.05).

REFERENCES George Torrey. (1998). Improved nutrition may

reduce the risk of macular degeneration. American Macular Degeneration Foundation.

Alyssa Hidalgo and Andrea Brandolini. (2008).Kinetics of Carotenoids Degradation during the Storage of Einkorn (Triticum monococcum L. ssp. monococcum) and Bread Wheat (Triticum aestivum L. ssp. aestivum) Flours. American Chemical Society.

Nurul Husna Binti Rosli. Thesis “Optimization of zeaxanthin extraction process by Response Surface Method (RSM)”. November 2010

Marmy Roshaidah Mohd Salleh. Thesis “Penyairan zeaxanthin dari sayur-sayuran tempatan:perbandingan kaedah penyairan dan kesan parameter process terhadap penyairan” .April 2005.

Zhen Sun PhD and Huiyuan Yao MD. (2007). The influence of di-acetylation of the hydroxyl groups on the anti-tumor-proliferation activity of lutein and zeaxanthin. School of Food Science and Technology, Southern Yangtze University, Wuxi, China.

Britton, G., Liaaen-Jensen, S. dan Pfander, H. (1995). “Carotenoids Vol 1A: Isolation and Analysis.” Birkhauser Verlag, Bassel .