Carotenoids retention in leafy vegetables based on cooking methods

1. WELCOME

2. Presented By
Sultana Jahan
Examination Roll: 116
Registration No. 6298
M.S. Examination- 2011
Course No. FN-508
Session: 2010-11
Department of Food and Nutrition Science
Bangladesh Home Economics college, Dhaka

3. Title of Seminar Presentation
Carotenoids retention in leafy vegetables
based on cooking methods
Chang, S.K., Nagendra Prasad, K. and Amin, I.
 Department of Nutrition and Dietetics, Faculty of
Medicine and Health Sciences, Universiti Putra
Malaysia, Selangor, Malaysia
 Chemical Engineering Discipline, School of
Engineering, Monash University, Selangor, Malaysia
 Laboratory of Halal Science Research, Halal Products
Research Institute, Universiti Putra Malaysia,

4. Contents
 Introduction
 Rationale of The Topic
 Objectives
 Materials and Methods
 Results
 Discussion
 Limitation of The Study
 Conclusion
 References

5. Introduction
 Many vegetables and fruits contain significant amounts
of β-carotene and other provitamin A that can be absorbed
and converted to vitamin A in the human body.
 About 5 to 78 % of the β-carotene degraded when
vegetables are prepared using different cooking methods.
 Several reports have documented the losses of β-
carotene of vegetables after boiling, stewing, frying,
blanching and pressure cooking.
 Among these conventional methods boiling and stir-frying
are selected for this study.

6. Rationale of the Topic
 It is mostly important to determine the percentage of
labile nutrients and other health-promoting food
components of vegetables that is retained or lost during
cooking practices.
 The factors that enhance or reduce degradation can be
recommended to minimize losses of nutrients in foods.
 This study will provide guidance in healthy food
preparation methods that did not deplete nutrient content
in vegetables.
 Indirectly, this also contribute in recommending healthy
cooking methods to the general public.

7. Objectives of the study
General Objective
 To study the Carotenoids retention in leafy
vegetables based on various cooking methods.

8. Specific Objectives
 To determine the effects of different domestic
cooking methods on carotenoids retention in
commonly consumed leafy vegetables.
 The study is aimed to evaluate the extent of loss of
lutein and β-carotene form the main carotenoids
contributing to the health benefits in human.
 To compare the effect of boiling and stir-frying at
different cooking durations on raw and cooked leafy
vegetables.

9. Materials and Methods
 Seven types of green leafy vegetables were selected based
on popular consumption by Malaysian people.
 These vegetables were Chinese cabbage, swamp cabbage,
spinach, Ceylon spinach, red spinach, white spinach and
tapioca shoots.
 One kilogram was taken and divided into three portions with
300 g for each application.
 One portion was retained raw and others were cooked in
different methods which were boiled and stir fried.

10. Images of Sample

11. Methods
 The β-carotene and lutein were extracted according to
the method AOAC.
 The sample (10 g) was added with 40 ml of ethanol and
10 ml of potassium hydroxide, with 0.1% BHT and
homogenized for 3 min.
 The carotenoids of homogenized sample were
analysised by HPLC technique at 21°C.
 Data were expressed as mean value ± standard
deviation of which all experiments were repeated three
times.

12. Results
Table 1: Lutein content of vegetables and its retention after
cooking
Vegetables (100g) Treatment Lutein (μg/ 100gedible Concentration True Retention
portion) change (%CC) of lutein (%)
Swamp Cabbage Raw 53 ±0.5
(Ipomoea aquatica) SF4 61 ±0.2 15.7 94.5
SF8 26 ±0.0 -51.8 34.5
B4 31 ±1.5 - 40.7 78.8
B8 90 ±1.3 68.9 241.5
Spinach (Spinacia Raw 495±1.4
oleracea) SF4 15 ±2.8 -68.9 28
SF8 124±1.9 -74.9 20
B4 428±0.5 -13.5 99.4
B8 140±2.4 -71.8 35.3
Tapioca Shoots Raw 134±1.9
(Manihot utilissima) SF4 26 ±0.1 -80.8 34.9
SF8 99 ±0.0 -26.4 44.2
B4 230±0.7 71 213.8
B8 388±0.4 188.8 418.8
White Spinach Raw 59 ±1.3
(Amaranthus viridis) SF4 125±19.4 111.4 153.5
SF8 28 ±0.5 -52.8 18.8
B4 110±0.0 86.8 242.8
B8 235±21.5 297.9 417.9

13. Table 2: β-carotene content of vegetables and its retention after cooking
Vegetables
(100g) Treatment
β-carotene
(μg/100gedible portion)
Concentration
change (%CC)
True Retention
(%TR} of β-
carotene
Swamp Cabbage Raw 138.4 ±5.8
(Ipomoea aquatica) SF4
309.
3 ±2.3 123.5 178.8
SF8 619 ±1.4 347.2 313
B4 336.35 ±6.2 143 315.9
B8
376.3
5 ±12.9 171.9 380.7
Spinach (Spinacia Raw 6176.5 ±65.8
oleracea) SF4
2206.
5 ±28.9 -64.3 32
SF8 1448 ±1.4 -76.5 18.8
B4 3123 ±1.4 -49.4 58.2
B8 6193 ±349.3 0.27 125.3
Tapioca Shoots Raw 3265.5 ±0.7
(Manihot SF4 602.8 ±20.9 -81.54 14.8
utilissima) SF8 10521 ±2.8 222.2 193.3
B4 1386.8 ±8.1 -57.53 53
B8 2705 ±21.9 -17.2 120
White Spinach Raw 4994 ±14.7
(Amaranthus SF4
1260.
2 ±12.9 152.3 176.6
viridis) SF8 583.9 ±1.6 16.92 46.8

14. Discussion
 Table 1 and 2 show, the lutein and β-carotene contents
of the selected vegetables after boiling and stir-
frying for 4 and 8 minutes respectively.
 Results obtained show that the stir-frying had reduced
lutein content for all vegetables ranging from 8-89%.
 The effect of boiling for lutein varied (0-428%) with
different vegetables at both cooking durations of 4 and 8
minutes.
 Boiling for 8 minutes increased retention of β-carotene in
all vegetables ranging from 18-380%.

15.  While stir-frying generally increased the retention of β-
carotene for all vegetables 2-3 times except for spinach.
 β-carotene was in the order of spinach > tapioca shoots >
Ceylon spinach > red spinach > Chinese cabbage > white
spinach > swamp cabbage.
 So, the lutein content was in the order of spinach > Ceylon
spinach > red spinach > Chinese cabbage > swamp
cabbage > white spinach > tapioca shoots.
 Both lutein and β-carotene were negatively affected by
frying while boiling resulted increase of β-carotene but
11% losses of lutein.

16. Limitation of The Study
 Vegetables from different places may have different
composition of minerals and vitamins affected by the
usage of fertilizers and herbicides.
 Difficulties in analysis are due to qualitative and
quantitative variations in composition and wide
concentration range of the carotenoids in a given food.
 It would be necessary to carry out a greater number of
analysis for each vegetable from different geographical
sources at different times.

17. Conclusion
The present study exhibits β-carotene retention
in the vegetables studied with cooking methods
and type of vegetables. Cooked vegetables have
variations in carotenoids composition brought by
varying cooking conditions (time and
temperature), types of vegetables and the
interaction between cooking methods and types
of vegetables.

18. References
 Aman, R., Schieber, A. and Carle, R. 2005. Effects of Heating and Illumination
on Trans-Cis Isomerization and Degradation of β-Carotene and Lutein in Isolated
Spinach Chloroplasts. Journal of Agricultural and Food Chemistry 53: 9512-9518.
 Aman, R., Biehl, J., Carle, R., Conrad, J., Beifuss, U., Schieber, A. 2005.
Application of HPLC coupled with DAD, APcI-MS and NMR to the analysis of
lutein and zeaxanthin stereoisomers in thermally processed vegetables. Food
Chemistry 92: 753-763.
 Amin, I. and Cheah, S.F. 2003. Determination of Vitamin C, β-carotene and
Riboflavin contents in Five Green Vegetables Organically and Conventionally
Grown. Malaysian Journal of Nutrition 9(1): 31-39.
 AOAC. 1984. Official Methods of Analysis, 18th edition.
 Bernhardt, S. and Schlich, E. 2006. Impact of different cooking methods on food
quality: Retention of lipophilic vitamins in fresh and frozen vegetables. Journal of
Food Engineering 77: 327-333.
 Chen, B.H. and Tang, Y.C. 1998. Processing and stability of carotenoid powder
from carrot pulp waste. Journal of Agricultural and Food Chemistry 46: 2312-
2318.
 Wen, T. N., Prasad, K.N., Bao, Y. and Amin, I. 2010. Bioactive substance