THE EFFECT OF BOILING, STIR-FRYING, AND STEAMING ON THE GLUCOSINOLATE CONTENT IN CHINESE CABBAGE (Brassica rapa covar
Pekinensis) AND CHOY SUM (Brassica rapa var. Parachinensis L.)
PENGARUH PEREBUSAN, PENUMISAN, DAN PENGUKUSAN TERHADAP KANDUNGAN GLUKOSINOLAT PADA SAWI PUTIH (Brassica rapa covar
Pekinensis) DAN SAWI HIJAU (Brassica rapa var. Parachinensis L.)
BACHELOR THESIS
Submitted to the Faculty of Agricultural Technology in partial fulfillment of the requirements for obtaining the Bachelor Degree
By:
NOVITA IKA PUTRI 08.70.0049
DEPARTMENT OF FOOD TECHNOLOGY FACULTY OF AGRICULTURAL TECHNOLOGY
SOEGIJAPRANATA CATHOLIC UNIVERSITY SEMARANG
2012
THE EFFECT OF BOILING, STIR-FRYING, AND STEAMING ON THE GLUCOSINOLATE CONTENT IN CHINESE CABBAGE (Brassica rapa subs.
Pekinensis) AND CHOY SUM (Brassica rapa subs. Parachinensis L.)
PENGARUH PEREBUSAN, PENUMISAN, DAN PENGUKUSAN TERHADAP KANDUNGAN GLUKOSINOLAT PADA SAWI PUTIH (Brassica rapa subs.
Pekinensis) DAN SAWI HIJAU (Brassica rapa subs. Parachinensis L.)
By :
NOVITA IKA PUTRI NIM : 08.70.0049
Department : Food Technology
This bachelor thesis has been approved and defended in front of examiners in : July 16,2012
Semarang, July 24, 2012
Agricultural Technology Faculty Soegijapranata Catholic University
Supervisor I Dean
Prof. Dr. Ir. Y. Budi Widianarko, M.Sc Ita Sulistyawati, S.TP, M.Sc
Supervisor II
R. Probo Yulianto, S.TP, M.Sc
i SUMMARY
Brassica vegetables contain glucosinolates whose some of the hydrolysis products can function as anticancer substances. However, the content of glucosinolates is highly influenced by processing of the vegetables. This research aims to study the effect of processing towards the content of glucosinolates in Brassica vegetables, namely Chinese cabbage and choy sum. Thus, the best processing can be identified based on the least glucosinolates loss. The processing applied to the vegetables were steaming, stir-frying without water, stir-frying with water, boiling hot start lid on, boiling hot start lid off and boiling cold start. The analyzed parameter was glucosinolate concentration. Glucosinolate contents were measured with High Performance Liquid Chromatography (HPLC) after the samples were extracted and desulphated. The result shows that steaming increased glucosinolate content up to 56,75% in Chinese cabbage and up to 62,89% in choy sum. This research, however, shows an inconsistent increase of glucosinolate content after stir-frying and various results after boiling. Generally, boiling caused the glucosinolate content to decrease. Therefore, it can be concluded that the best processing for Brassica vegetables, in terms of glucosinolate retention, is steaming.
ii RINGKASAN
Sayuran Brassica mengandung senyawa glukosinolat dengan produk turunannya yang mampu menghambat senyawa karsinogen. Meskipun demikian, kandungan senyawa glukosinolat dalam sayuran Brassica sangat dipengaruhi oleh proses pengolahan. Penelitian ini bertujuan untuk mengidentifikasi pengaruh proses pengolahan terhadap kandungan glukosinolat dalam sayuran Brassica, yakni sawi putih dan sawi hijau. Dengan demikian dapat diketahui proses pengolahan yang paling baik berdasarkan hilangnya kandungan glukosinolat yang paling minimal. Proses pengolahan yang diaplikasikan ke sayur tersebut adalah pengukusan, penumisan tanpa air, penumisan dengan air, serta perebusan, dengan perlakuan sayur dimasukkan setelah air mendidih dan sebelum air mendidih. Parameter yang diukur adalah kandungan glukosinolat. Kadungan glukosinolat diukur dengan High Performance Liquid Chromatography (HPLC) setelah bahan melalui proses ekstraksi dan desulfatasi. Hasil analisa menunjukkan bahwa pengukusan dapat meningkatkan kandungan glukosinolat pada sawi putih sebanyak 56,75% dan sawi hijau sebanyak 62,89%. Meskipun demikian, hasil analisa penelitian ini menunjukkan adanya peningkatan yang tidak konsisten pada sawi putih dan sawi hijau setelah penumisan sedangkan perebusan memberikan hasil yang bervariasi. Namun pada umumnya perebusan akan menyebabkan kandungan glukosinolat berkurang. Dengan demikian dapat disimpulkan bahwa proses pengolahan yang terbaik untuk sayuran Brassica, dalam hal retensi glukosinolat, adalah pengukusan.
iii FOREWORD
Author would like to thank the only one God for His blessing so author can finish this thesis entitled THE EFFECT OF BOILING, STIR-FRYING, AND STEAMING ON THE GLUCOSINOLATE CONTENT IN CHINESE CABBAGE (Brassica rapa subs. Pekinensis) AND CHOY SUM (Brassica rapa subs. Parachinensis L.) as one of the requirement for obtaining bachelor degree in Agricultural Technology Faculty.
Author realize that many parties were involved in the completion of this thesis. Thus, author would like to say thank you to :
1. Ita Sulistyawati, S.TP., MSc, as the Dean of Agricultural Technology Faculty, Soegijapranata Catholic University.
2. Prof. Dr. Ir. Y. Budi Widianarko, MSc. as the supervisor who has given his time to help and continually encourage the author to finish this thesis. Thank you for the patience and the support for the author.
3. Robertus Probo Yulianto Nugrahedi, S.TP., MSc as the co-supervisor who has helped the author, especially as the sponsor for this thesis. Thank you for inviting the author into the team of this research project.
4. All lecturers and staffs of Agricultural Technology Faculty for the support and guidance during my college time.
5. Mas Soleh, Mas Pri and Mba Endah, the laboratory assistant, thank you for the willingness to help all the senior year student with all our laboratory works.
6. All of my family who have waited for me patiently to graduate and always support me in order to finish my thesis.
7. My partner in this project, Caesariana Ariyani, S.TP and Jurita Permata Sari, thank you for the support for this thesis. Also thank you for all the jokes and the abnormalities which made my day in the laboratory.
8. For the author’s aunt, Ko In, who specially provide all the vegetables needed in this research.
9. All of my friend in FTP, Probioters, Acih, Tabita, Awei, Ria, Citra and the rest of the Big Famz, Dea, Heny, Vincent, Mona, Fifi, Gladys, Jeffry, BJ and FTP family,
iv
Melita, Donny, Intan, Juju, Tommy, Elke, JC, Vaut, Fefe and many others that the author can not mention one by one.
10. All of my friends from other Faculties in Unika, Co-trainer, GLORY, and other friend I met in so many occasions, thank you for enliven my days in Unika.
11. Poppy, Lolly, Hippo, and the babies, thank you for cheering the author in the process of completing this thesis.
12. All related parties who helped the author finishing this thesis.
The author realizes that there are still so many mistakes and flaws in this thesis. The author would like to apologize for the entire mistakes and will welcome any criticism and suggestion for the betterment of this thesis and the author herself. The author hopes that this thesis can be useful for the future generations and for the society.
Semarang, June 2012 Author,
Novita Ika Putri
v TABLE OF CONTENT SUMMARY... i RINGKASAN ... ii FOREWORD ... iii TABLE OF CONTENT... v INDEX OF TABLES... vi
INDEX OF FIGURES ... vii
INDEX OF APPENDICES ... viii
1. INTRODUCTION ... 1
1.1. Background ... 1
1.2. Literature Review ... 2
1.3. Purpose ... 7
2. MATERIALS AND METHOD... 8
2.1. Materials ... 8
2.2. Method ... 8
3. RESULT ... 14
3.1. Chinese Cabbage ... 14
3.2. Choy Sum ... 19
3.3. Correlation between Glucosinolates ... 23
4. DISCUSSION ... 25
4.1. Glucosinolates in Chinese Cabbage ... 25
4.2. Glucosinolates in Choy Sum ... 26
4.3. Effect of Processing to Glucosinolates ... 27
5. CONCLUSION ... 31 5.1. Conclusion ... 31 5.2. Suggestion ... 31 6. REFERENCES ... 32 7. APPENDICES ... 35 Perpustakaan Unika
vi
INDEX OF TABLES
Table 1. Glucosinolates Commonly Found in Brassica Vegetables ... 5
Table 2. Gradient System of Eluent A & B during HPLC Run... 12
Table 3. Glucosinolates Content after Various Processing in Chinese Cabbage ... 15
Table 4. Glucosinolates Content after Various Processing in Choy Sum ... 19
Table 5. Correlation Between Glucosinolates in Chinese Cabbage ... 24
Table 6. Correlation Between Glucosinolates in Choy Sum ... 24
vii
INDEX OF FIGURES
Figure 1. Chinese Cabbage ... 3
Figure 2. Choy Sum ... 3
Figure 3. General Structure of a Glucosinolate ... 5
Figure 4. Myrosinase-catalyzed Hydrolysis of Glucosinolate... 6
Figure 5. Vegetables are Chopped into Bite-size ... 9
Figure 6. The Flame Used for Cooking ... 9
Figure 7. Boiling Lid On ... 10
Figure 8. Boiling Lid Off ... 10
Figure 9. Analytical Scheme ... 10
Figure 10. Desulphation Column Used in This Research ... 12
Figure 11. Chromatogram of Glucosinolates in Chinese Cabbage ... 14
Figure 12. Progoitrin in Chinese Cabbage after Various Processing ... 16
Figure 13. Sinigrin in Chinese Cabbage after Various Processing... 16
Figure 14. Glucoraphanin in Chinese Cabbage after Various Processing ... 17
Figure 15. Glucobrassicin in Chinese Cabbage after Various Processing ... 18
Figure 16. Glucosinolates in Chinese Cabbage after Processing ... 18
Figure 17. Chromatogram of Glucosinolates in Chinese Cabbage ... 19
Figure 18. Progoitrin in Choy Sum after Various Processing ... 20
Figure 19. Gluconapin in Choy Sum after Various Processing ... 21
Figure 20. Glucobrassicanapin in Choy Sum after Various Processing ... 22
Figure 21. Glucobrassicin in Choy Sum after Various Processing ... 22
Figure 22. Glucosinolates in Choy Sum after Processing ... 23
viii
INDEX OF APPENDICES
Appendix 1. Statistical Analysis of Glucosinolate Content in Chinese Cabbage ... 35 Appendix 2. Statistical Analysis of Glucosinolate Content in Choy Sum ... 38
