Istanbul Technical University Graduate School Of
Total Page：16
File Type：pdf, Size：1020Kb
ISTANBUL TECHNICAL UNIVERSITY GRADUATE SCHOOL OF SCIENCE ENGINEERING AND TECHNOLOGY THE EFFECTS OF NECTAR PROCESSING ON SOUR CHERRY ANTIOXIDANT COMPOUNDS: CHANGES IN METABOLITE PROFILE AND BIOAVAILABILITY Ph.D. THESIS Gamze TOYDEMİR (506062502) Department of Food Engineering Food Engineering Programme Thesis Advisor: Prof. Dr. Dilek BOYACIOĞLU Anabilim Dalı : Herhangi Mühendislik, Bilim Programı : Herhangi Program MAY 2013 İSTANBUL TEKNİK ÜNİVERSİTESİ FEN BİLİMLERİ ENSTİTÜSÜ NEKTAR İŞLEME PROSESİNİN VİŞNEDEKİ ANTİOKSİDAN BİLEŞİKLER ÜZERİNDEKİ ETKİSİ: METABOLİT PROFİLİ ve BİYOYARARLILIKTAKİ DEĞİŞİMLERİN İNCELENMESİ DOKTORA TEZİ Gamze TOYDEMİR (506062502) Gıda Mühendisliği Anabilim Dalı Gıda Mühendisliği Programı Tez Danışmanı: Prof. Dr. Dilek BOYACIOĞLU Anabilim Dalı : Herhangi Mühendislik, Bilim Programı : Herhangi Program MAYIS 2013 vi Annem, babam ve ağabeyime, vii viii FOREWORD Sour cherry is an important fruit in Turkey, which is the world’s leading producer. Turkish sour cherries are highly esteemed for their high quality juice (called “nectar”). The objective of this thesis was to investigate the effects of industrial-scale processing of sour cherry fruit into nectar on the composition of the end product and bioavailability, paying specific attention to the phenolic antioxidant, particularly anthocyanins. I hope this research will contribute to the limited literature on sour cherry and its health promoting bioactive components. First of all, I would like to express my special thanks and gratitude to my supervisor and mentor, Prof. Dr. Dilek BOYACIOĞLU who taught me the academic life, constituted and shaped my scientific vision, encouraged me in several ways to further improve myself, and supervised me to carry out this study. I also would like to thank Prof. Dr. Beraat ÖZÇELİK and Prof. Dr. Reşat APAK with whom it was a pleasure to work with and I do appreciate for their valuable contributions. This thesis is a product of an intensive multi-disciplinary study which was carried out in PRI (Plant Research International), The Netherlands and FBR (Food and Biobased Research), The Netherlands. This study was included in and supported by EU 7th Frame ATHENA Project (12 months) and was also sponsored by Istanbul Technical University (3 months). I would also like to thank TUBITAK (The Scientific and Technological Research Council of Turkey) which provided a financial support with a PhD scholarship (5 years). It is my privilege to express my special thanks and sincere appreciations to Dr. Jules BEEKWILDER, Dr. Ric DE VOS, Dr. Robert HALL, Dr. Victoria GOMEZ ROLDAN, Dr. Ingrid VAN DER MEER, Mr. Harry JONKER, and Mr. Bert SCHIPPER from PRI who had a great participation and contribution to my dissertation. I also would like to thank Dr. Jurriaan MES and Mrs. Monic Tomassen with whom I had the chance to work with Caco-2 cells and learn this technique in detail. I also would like to express my gratitude to Aroma Bursa Fruit Juice and Food Industry Inc. and specifically to Mr. Birol GÖÇTÜ for providing the samples from sour cherry nectar processing. I express my gratitude and acknowledge to Assis. Prof. Esra ÇAPANOĞLU GÜVEN who not only helped to shape my dissertation, bu also contributed to it in various ways. I also would like to express my special thanks and acknowledge to Senem KAMİLOĞLU who contributed to my work in various ways. I would like to thank Zeynep TACER CABA, Sezen SÜZME, Nalan DEMİR, Yusuf ŞEN, and all my friends who helped and encouraged me during this long time of study. Finally, a very special note of appreciation and thanks to my mother Nejla, my father Hasan, and my brother Murat for their love, patience, help and support throughout my life and education. I would like to give this thesis as a gift to my family. March, 2013 Gamze TOYDEMİR (Food Engineer) ix x TABLE OF CONTENTS Number FOREWORD ............................................................................................................. ix TABLE OF CONTENTS .......................................................................................... xi ABBREVIATIONS ................................................................................................. xiii LIST OF TABLES ................................................................................................... xv LIST OF FIGURES ............................................................................................... xvii SUMMARY ............................................................................................................. xix ÖZET ....................................................................................................................... xxv 1. INTRODUCTION .................................................................................................. 1 2. LITERATURE ....................................................................................................... 7 2.1 Sour Cherry ........................................................................................................ 7 2.2 Nutritional Properties of Sour Cherries .............................................................. 9 2.2.1 Anthocyanins ............................................................................................ 14 2.2.2 Other flavanoids ........................................................................................ 16 2.2.3 Phenolic acids ........................................................................................... 19 2.3 Effects of Processing on Sour Cherry Antioxidants ......................................... 20 2.4 Bioavailability of Sour Cherry Phenolics ......................................................... 24 2.4.1 Dietary intake of flavonoids ...................................................................... 24 2.4.2 Health-promoting effects of sour cherries ................................................ 26 2.4.3 Absorption mechanisms and metabolism of anthocyanins ....................... 28 2.4.3.1 In vitro gastrointestinal (GIT) digestion model ................................. 31 2.4.3.2 In vitro Caco-2 cell model.................................................................. 33 2.4.4 Food Matrix and Bioavailability ............................................................... 36 3. MATERIALS AND METHODS ........................................................................ 39 3.1 Materials ........................................................................................................... 39 3.1.1 Chemicals .................................................................................................. 39 3.1.2 Nectar processing samples ...................................................................... 40 3.2.1 Moisture content analysis .......................................................................... 44 3.2.2 Spectrophotometric assays ........................................................................ 44 3.2.2.1 Extract preparation ............................................................................. 44 3.2.2.2 Analysis of total phenolics ................................................................. 44 3.2.2.3 Analysis of total flavonoids ............................................................... 45 3.2.2.4 Analysis of total anthocyanins ........................................................... 45 3.2.2.5 Analysis of total antioxidant capacity ................................................ 45 3.2.3 Targeted HPLC analysis of anthocyanins, flavonols, and phenolic acids 46 3.2.4 Targeted HPLC analysis of procyanidins. ................................................ 47 3.2.5 HPLC analysis of reduced and non-reduced forms of vitamin C ............. 48 3.2.6 On-line antioxidant analysis ...................................................................... 49 3.2.7 Untargeted metabolomics analysis using LC-QTOF-MS ......................... 49 3.2.8 Processing of LC-MS data ........................................................................ 50 3.2.9 Bioavailability analysis to determine the effect of nectar processing on .. 51 bioavailability of sour cherry anthocyanins ....................................................... 51 xi 3.2.9.1 Sour cherry samples ........................................................................... 51 3.2.9.2 Bioavailability analysis using simulated in vitro gastrointestinal (GI) ........................................................................................................................ 52 digestion model .............................................................................................. 52 3.2.9.3 Bioavailability analysis using in vitro Caco-2 cell model.................. 53 3.2.10 Statistical analysis ................................................................................... 57 4. RESULTS AND DISCUSSION........................................................................... 59 4.1 Moisture Contents of Sour Cherry Samples ..................................................... 59 4.2 Spectrophotometric Assays............................................................................ 60 4.2.1 Total phenolics, total flavonoids, and total anthocyanins ................... 60 4.2.2 Total antioxidant capacity ...................................................................... 66 4.3 Targeted HPLC Analysis for Phenolic Identification and Quantification 71 4.3.1 Anthocyanins ............................................................................................. 73 4.3.2 Procyanidins