EVALUATION OF SUGARCANE JUICE QUALITY AS INFLUENCED BY CANE TREATMENT AND SEPARN CONCENTRATIONS By Ghada A/Rahman A/Razig El Sheikh B.Sc. (Science) Department of Rural Education, Extension and Development University of Ahfad A thesis submitted to University of Khartoum in partial fulfilment for the requirement of the degree of Master of Science in Agriculture Supervisor Prof. Elfadil Elfadl Babiker Department of Food Science and Technology Faculty of Agriculture University of Khartoum January 2009 i DEDICATION To my husband To my parents To my sisters and brothers To Abbass family To those whom I will never forget ii ACKNOWLEDGEMENT First I thank Allah with his wills this work completed. Thank my family, who were ready to render much assistance, I asked for to complete this work. Many people made great efforts and support me during study. My sincere gratitude to: * The study supervisor, Professor Elfadil Elfadl Babiker, Faculty of Agriculture, University of Khartoum, for extending research works and to the final writings of the thesis, that allowed this study to reach conclusion. * Syd/Mohamed Ahmed Fadlased, Kenana Human Resource General Manager. * Dr. Elbashir Ali Hamad, Former Kenana Ex-Training Manager, for invaluable guidance throughout the study which gave confidence to execute it. * Syd/Ibrahim Mustafa, Former Kenana Sugar Factory Manager. * Dr. Makawi Awad A/Rahman, Kenana Sugarcane Researcher, for extending research works to cover essential areas and helping the final writing of the thesis. * Dr.Kamal Sliman, Food engineering and Technology, University of Gezira, for follow-up and thesis revision. * Dr. Ibrahim Doka, Kenana Sugarcane Researcher, for research analysis. * Syd/Dafalla Hashim, Kenana Quality Control Manager, for providing research's requirements. * Kenana Sugarcane Research and Development Department * Kenana Quality Control Department. * My colleagues in Kenana Training Centre. iii LIST OF CONTENTS Page DEDICATION i ACKNOWLEDGEMENT ii LIST OF CONTENTS iii LIST OF TABLES v LIST OF FIGURES vi ABSTRACT vii ARABIC ABSTRACT viii CHAPTER ONE: INTRODUCTION 1 CHAPTER TWO: LIETERATURE REVIEW 3 2.1. Sugarcane and Cane Juice Composition 3 2.1.1 Sugarcane 3 2.1.2 Cane Juice from the Mills 4 2.2 Characteristics of Cane Juice 4 2.3 Chemistry of coloured Non-sugars 4 2.4 Coloured non-sugar originally existing in sugarcane 5 2.4.1 Chlorophyll 6 2.4.2 Anthocyanin 6 2.4.3 Saccharetin 6 2.4.4 Tannins 7 2.5 None coluored in cane which may develop colour 7 2.5.1 Polyphenols 8 2.5.2 Amino compounds 8 2.6 Coloured non-sugars from sugar decomposition products 8 2.6.1 Caramel 9 2.7 Sugar decomposition products 9 2.8 Reaction products between reducing sugars and amino compounds 9 2.9 Physical and chemical properties of coloured non-sugars 10 2.9.1 Inversion 10 2.9.2 Reaction with phenols 10 2.9.3 Reaction with amines 11 2.9.4 Reaction with reducing agents 12 2.9.5 Reactions with oxidizing agents 12 2.9.6 Reaction with aldehydes 12 2.9.7 Effect of pH on colour 12 2.10 Colour developments 13 2.10.1 Raw sugar colour 14 2.10.2 Coluor development in processing raw cane sugar 15 2.10.3 Colour development in white sugar 15 2.11 Removal of colour by precipitate and adsorbents 15 2.11.1 Lime 16 2.11.2 Phosphoric acid 17 2.11.3 Flock conditioners 19 2.12 Definition 19 2.12.1 Primary juice (crushed juice) 19 2.12.2 Secondary juice (mixed juice) 19 iv 2.12.3 Clarified juice 19 2.12.4 Imbibitions 20 2.12.5 pH 20 2.12.6 The sucrose (POL) 20 2,12,7 The dry matter content (brix) 29 2.12.8 Reducing sugar (R.S) 20 2.12.9 Purity 21 2.12.10 Turbidity 21 2.12.11 Colour 21 CHAPTER THREE: MATERIALS AND METHODS 22 3.1 Materials 22 3.2 Methods 22 3.2.1 Determination of pH 22 3.2.2 Determination of the sucrose content (pol) 24 3.2.3 Determination the dry matter content (BRIX) 25 3.2.4 Determination of reducing sugar (RS) 25 3.2.5 Determination of the colour value 26 3.2.6 Turbidity determination 27 3.2.7 Tannin determination 28 3.2.8 Total polyphenols determination 29 3.2.9 Saparan dose experiment 30 3.3 Statistical analysis 32 CHAPTER FOUR: RESULTS AND DICUSSIONS 33 4.1 Effect of milling on the proximate composition (%) of green and burned cane 33 4.2 Effect of processing on quality parameters of burned cane juice 36 4.3 Colouring substances in the raw materials and processed 38 4.4 Effect of different doses of separan on juice quality parameter 41 4.5 Effect of different doses of separan on polyphenols and tannins levels 42 CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS 45 5.1 Conclusion 45 5.2 Recommendations 46 REFERENCES 47 v LIST OF TABLES Table Page 1 Effect of milling on the proximate composition (%) of green and burned cane 34 2 Effect of processing on quality parameter of burned cane juice 37 3 Colouring substances in the raw materials and processed 39 4 Effect of different doses of Separan on juice quality parameters 42 5 Effect of different doses of Separan on polyphenols and tannins levels 45 vi LIST OF FIGURES Figure Page 1 Cane samples 23 2 Sedimentation study apparatus in operation 31 3 Sample of green and burned cane 35 vii EVALUATION OF SUGARCANE JUICE QUALITY AS INFLUENCED BY CANE TREATMENT AND SEPARN CONCENTRATIONS M.Sc. (Thesis) By Ghada A/Rahman A/Razig El Sheikh Abstract: The study is conducted to evaluate juice quality parameters ((percentage of cane )pol, brix, … etc) and the level of colouring materials in crushed cane (green or burned) crushed, mixed and clarified juice and to evaluate the effect of low doses of separan on juice quality and colour. The range of pol (sucrose) for juice treated 10.18 to 15.75%, brix ranged from 12.86 to 20.93%, purity ranged from 82.18 to 95.18%, pH ranged from 5.40 to 7.60, reducing sugar was ranged from 0.58 to 1.10%, turbidity was ranged from 4.96 to 9.60 NTU(nephlo turbidity unit) and colour was ranged from 2600 to 14692 ICUMCA. The study revealed that both the green cane and clarified juices and lime (temperature treatment) had significant (P≤0.05) higher colour readings compared to that of the burned cane, mixed and crushed juice. Likewise, the highest concentrations of colouring materials (polyphenols and tannins) were recorded in green 0.216, crushed 1.189 and final molasses 0.218. Addition of separan at very low concentration (0.015 ppm) was observed to reduce the colouring matter compared to the standard (3 ppm) concentration applied. The results obtained indicated that the juice colouring matter (polyphenols and tannins) levels had been greatly reduced during treatment. viii ﺘﻘﻴﻴﻡ ﺠﻭﺩﺓ ﻋﺼﻴﺭ ﺍﻟﻘﺼﺏ ﺍﻟﻤﻌﺎﻤل ﺒﺘﺭﺍﻜﻴﺯ ﺍﻟﺴﺒﺭﺍﻥ (ﺃﻁﺭﻭﺤﺔ ﻤﺎﺠﺴﺘﻴﺭ) ﻏﺎﺩﺓ ﻋﺒﺩ ﺍﻟﺭﺤﻤﻥ ﻋﺒﺩ ﺍﻟﺭﺍﺯﻕ ﺍﻟﻤﺴﺘﺨﻠﺹ: ﺃﺠﺭﻴﺕ ﻫﺫﻩ ﺍﻟﺩﺭﺍﺴﺔ ﻟﺘﻘﻴﻴﻡ ﺍﻟﻌﺼﻴﺭ ﻤـﻥ ﺤﻴـﺙ ﺍﻟﺒـﻭل (ﻨـﺴﺒﻪ ﺍﻟﺴﻜﺭﻴﺎﺕ) ﻭﺍﻟﺒﺭﻜﺱ (ﻨﺴﺒﻪ ﺍﻟﻤﻭﺍﺩ ﺍﻟﺼﻠﺒﻪ ) ﻭﻏﻴﺭﻫﺎ ﻤﻥ ﺍﻟﺘﺤﺎﻟﻴل ﻭ ﺃ ﻴ ﻀ ﺎﹰ ﺍﻟﻤﻭﺍﺩ ﺍﻟﻠﻭﻨﻴﺔ ﻓﻲ ﻋﺼﻴﺭ ﺍﻟﻘﺼﺏ ﺍﻷﺨﻀﺭ ﻭﺍ ﻟﻤﺤﺭﻭﻕ ﻭﺍﻟﻌﺼﻴﺭ ﺍﻷﻭﻟـﻲ ﻟﻠﻁـﻭﺍﺤﻴﻥ ﻭﺍﻟﻤﺨﻠﻭﻁ ﻭﺍﻟﻨﻘﻲ، ﻭﺘ ﻘﻴﻴﻡ ﺍﺜﺭ ﺍﻗل ﺠﺭﻋﺔ ﻤﻥ ﺍﻟﺴﺒﺭﺍﻥ ﻋﻠـﻲ ﺠـﻭﺩﺓ ﺍﻟﻌـﺼﻴﺭ ﻭﺍﻟﻠﻭﻥ. ﺍﻟﺘﺤﺎﻟﻴل ﻟﻌﺼﻴﺭ ﺍﻟﻘﺼﺏ ﺃﻭﺠﺩ ﺍﻟﺒﻭل ﻓـﻲ ﻤـﺩﻱ ﻤـﻥ 10.18 ﺇﻟـﻲ 15.75%، ﺒﺭﻜﺱ 12.86 ﺇﻟﻲ 20.93%، ﺩﺭﺠﺔ ﺍﻟﻨﻘﺎﺀ 82.18 ﺇﻟﻲ %95.18، ﺍﻟﻬﻴﺩﺭﻭﺠﻴﻥ ﺍﻴﻭﻥ ﻤﻥ 5.40 ﺇﻟﻲ 7.60،ﺍﻟﺴﻜﺭ ﺍﻟﻤﺨﺘﺯل ﻤﻥ 58. ﺇﻟﻲ %1.10 ، ﻭﺍﻟﻠـﻭﻥ ﻤـﻥ 2600 ﺇﻟـﻲ NTD 14692 ﺍﻟﻌﻜﺎﺭﺓ ﻤﻥ 4.94 ﺇﻟـﻲ 9.60 ICUMCA. ﺍﻟﻨﺘﺎﺌﺞ ﺘﻭﻀﺢ ﺍﻟﻌﻼﻗﺔ ﺒﻴﻥ ﺍﻟﻘﺼﺏ ﺍﻷﺨﻀﺭ ﻭﺍﻟﻌﺼﻴﺭ ﺍﻟﻨﻘﻲ ﺤﻴﺙ ﻭﺠﺩ ﺃﻨﻬﻤﺎ ﻴﺤﺘﻭﻴﺎﻥ ﻋﻠﻰ ﻨﺴﺒﺔ ﻋﺎﻟﻴﺔ ﻤﻥ ﻗ ﺭﺍﺀﺓ ﺍﻟﻠﻭﻥ ﻤﻘﺎﺭﻨـﺔ ﺒﺎﻟﻘـﺼﺏ ﺍﻟﻤﺤـﺭﻭﻕ ﻭﺍﻟﻌﺼﻴﺭ ﺍﻟﻤﺨﻠﻭﻁ ﻭﺍﻟﻌﺼﻴﺭ ﺍﻷﻭﻟﻲ. ﻋﻠﻰ ﻨﻔﺱ ﺍﻟﻨﻤﻁ ﻨﺠﺩ ﺃﻋﻠﻰ ﺘﺭﻜﻴﺯ ﻟﻠﻤـﻭﺍﺩ ﺍﻟﻠﻭﻨﻴـﺔ ﺍﻟﺒـﻭﻟﻲ ﻓﻴﻨـﻭﻻﺕ ﻭﺍﻟﺘﺎﻨﻴﻨﻴﺎﺕ ﺴﺠﻠﺕ ﻓﻲ ﺍﻟﻘﺼﺏ ﺍﻷﺨﻀﺭ (0.216) ﻭﺍﻟﻌﺼﻴﺭ ﺍﻷﻭﻟـﻲ (1.189) ﻭﺍﻟﻤﻭﻻﺱ ﺍﻟﻨﻬﺎﺌﻲ (0.218). ﺍﻟﺩﺭﺍﺴﺔ ﺘﺅﻜﺩ ﺃﻥ ﺍﻟﻤﻭﺍﺩ ﺍﻟﻤﻠﻭﻨﺔ ﻟﻠﻌﺼﻴﺭ ﺘﻨﺨﻔﺽ ﺘﺩﺭﻴﺠﻴﺎﹰ ﺍﺜﻨﺎﺀ ﺍﻟﻤﻌﺎﻤﻼﺕ. ﻨﺘﻴﺠﺔ ﺍﻀﺎﻓﺔ ﺍﻟﺴﺒﺭﺍﻥ ﻋﻨﺩ ﺃﺩﻨﻲ ﺘﺭﻜﻴﺯ (ppm 0.015) ﻤﻘﺎﺭﻨﺔ ﺒﺎﻟﻤﻘﻴﺎﺱ ﺍﻟﻤﻌﻴﺎﺭﻱ (ppm 3) ﺍﻟﻤﺴﺘﺨﺩﻡ ﻓﻲ ﺍﻟﻤﺼﻨﻊ ﻗﻠﻠﺕ ﻤﻥ ﻤﺴﺘﻭﻱ ﺍﻟﻤﻭﺍﺩ ﺍﻟﻠﻭﻨﻴﺔ ﻓﻲ ﺍﻟﺒﻭﻟﻲ ﻓﻴﻨﻭﻻﺕ ﻭﺍﻟﺘﺎﻨﻴﻨﺎﺕ ﻭﺼﺎﺤﺏ ﺫﻟﻙ ﺠﻭﺩﺓ ﻋﺎﻟﻴﺔ ﻤﻥ ﻨﻘﺎﺀ ﺍﻟﻌﺼﻴﺭ ﻭﻗـﺭﺍﺀﺓ ﺃﻗل ﻟﻠﻭﻥ. ix x CHAPTER ONE INTRODUCTION Colour of the sugar crystals is an important factor that determines its value in the market and acceptability for various uses. Formation of colour takes place in the juice syrup, and final products because of caramalisation and melunoidius formation. Besides, these juices contain a series of natural colouring compounds and other constituents such as polyphenols, amino acids, etc. All these constituents can not be eliminated during the process of clarification and generate colour during the post-clarification process up to the raw cane. Mathur (1993) reported that polyphenols formed brown iron complexes where as others generate colour by polymerization due to the effect of high temperatures used in the processing operations. Although these colouring factors and constituents can not be eliminated during processing, efforts can be made to reduce the formation of brown iron complexes and polymerization of colouring matters by suitable measures. Colouring matters are found in sugarcane, as in all growing plants. In milling, they are extracted with the cane juice and constitute a portion of the non-sugars to be contended with in subsequent processing of the sugar. Somasekhar (2001) stated that in addition, other colouring materials are formed in the manufacturing and refining operations as a result of chemical reactions between certain non-sugar materials present or developed during the process. The presence of such materials depend on type of cane, soil, and growing 1 conditions, geographical area, and the milling and refining process employed.