Final thesis - Lecithin

ACKNOWLEDGEMENT Foremost, according to the co-operation between Naresuan University and Nong Lam University, Ho Chi Minh City about internship, I would like to thank Faculty of Agriculture, Natural and Resources and Environment, Naresuan University and Faculty of Food Science and Technology, Nong Lam University, Ho Chi Minh City for giving me a chance to an internship in Thailand for months In addition to that, I would especially like to thank all lecturers in the Faculty of Agriculture, Natural and Resources and Environment, especially, my advisors Assit Prof Dr Riantong Singanusong and Assit Prof Dr Umargar Haruna who guided, advised, encouraged and helped me in my thesis during three months I also would like to thank Asst Prof Dr Orawan Kritsunankul for their invaluable help and suggestion on my experiment and project I could not complete this research without the lots of help I received cheerfully from everybody We experienced great things together and they have shown me their enthusiastic help I also would like to express my gratitude to Dr Nguyen Minh Xuan Hong for suggestion, support, helpful and guidance Furthermore, I would like to thank all my Thai and Vietnamese friends who help and support not only in my thesis, but also in my life during three months become successful, happy, comfortable and cheerful Finally, I am greatly thankful to my family for their inspiration and endless love Nguyen Tan Phat ABSTRACT Nowadays, lecithin is used very widely in food industry because of high benefit that it provides It can be used as emulsifiers, dispersants, wetting agents, viscosity modifiers, surfactants or nutritional supplements In the past, lecithin was extracted from many various sources such as egg yolks, soybean, sunflower or rapeseeds In this study, the extraction of lecithin from rice bran gum sludge was carried out by following the methods of Ceci, Constenla, and Crapiste (2008) with totally treatments which composes ratios of gum/acetone (1:1; 1:1.5; 1:2) and shaking time (30 and 60 minutes) After extraction, the result has shown that at 1:1.5 wet gums to acetone ratio were achieved the highest yield of lecithin (9.99 ± 1.00 %) Then, the obtained lecithin was analyzed acid value and moisture content The acid value was decreased when increasing the shaking time and the acid value has reached the highest value at the sample which has 1:1 gum to acetone ratio and 30 minutes shaking (25.75 ± 0.11) The moisture content was determined by Moisture analyzer and there is no significant difference between the means of the result Rice bran gum sludge contains much of phospholipid; therefore, the obtained lecithin has highest antioxidant activity (25.57 - 39.52%) Normally, lecithin has high solubility in oil However, in this study, the solubility in oil of obtained lecithin is very low The reason maybe is the temperature of oil is 240C TABLE OF CONTENT ACKNOWLEDGEMENT i ABSTRACT ii TABLE OF CONTENT iii LIST OF TABLES iv LIST OF FIGURES vi LIST OF ABBREVIATIONS vii CHAPTER 1: INTRODUCTION .1 1.1 Introduction .1 1.2 Research Aim 1.3 Research Scope CHAPTER 2: LITERATURE REVIEW 2.1 Introduction about rice bran 2.2 Rice bran oil (RBO) 2.3 Lecithin 2.4 Extraction of lecithin .8 2.5 Application of lecithin 11 CHAPTER MATERIALS AND METHODS .13 3.1 Materials .13 3.2 Chemicals 13 3.3 Apparatus 13 3.4 Methodology 13 3.4.1 Method for lecithin extraction from degumming by-product 13 3.4.2 Analysis 15 3.4.2.1 Yield 15 3.4.2.2 Acid value .15 3.4.2.3 Moisture content .15 3.4.2.4 Antioxidant activity (DPPH) 15 3.4.2.5 Solubility in oil .17 3.4.3 Statistical analysis 17 CHAPTER RESULTS AND DISCUSSIONS 18 4.1 Composition of weight gum sample .18 4.2 Effect of shaking time and acetone to gum ratio and on the extraction of lecithin 18 4.3.1 Acid value 20 4.3.2 Moisture content 21 4.3.3 Antioxidant activity (DPPH) 22 4.3.4 Solubility in oil 23 CHAPTER CONCLUSIONS AND RECOMMENDATIONS 24 5.1 Conclusions 24 5.2 Recommendations 24 REFERENCES 25 APPENDIX 28 LIST OF TABLES Table 2.1 Composition of crude lecithin obtained from various sources Table 4.1 Composition of rice bran oil gum sludge .18 Table 4.2 Effect of shaking time and acetone to gum ratio on the extraction of dried gum 19 Table 4.3 Effect of the shaking time and acetone to gum ratio on the Acid value of the lecithin .20 Table 4.4 Effect of shaking time and acetone concentration on the acid moisture content of lecithin 21 Table 4.5 Effect of shaking time and acetone concentration on the antioxidant activity of lecithin 22 Table 4.6 Effect of shaking time and acetone concentration on the solubility in oil of lecithin .23 LIST OF FIGURES Figure 2.1 Structure of rice kernel Figure 2.2 Process of chemical refining RBO Figure 2.3 Structure of soybean lecithin Figure 2.4 Some phosphatides in soybean lecithin Figure 2.5 Flowchart for the lecithin processing 10 Figure 2.6 Some products containing lecithin 11 Figure 3.1 Flowchart of lecithin production 14 Figure 4.1 Appearance of lecithin after extraction with acetone 19 LIST OF ABBREVIATIONS CSL Crude soybean lecithin HDL High-density lipoprotein LDL Low-density lipoprotein RBO Rice bran oil RBL Rice bran lecithin SL Soybean lecithin CHAPTER 1: INTRODUCTION 1.1 Introduction Rice is the top of food crop in the world, and rice bran is a by-product which is obtained after rice processing Rice bran is the cuticle between the paddy husk and the rice grain (Amarasinghe, Kumarasiri, & Gangodavilage, 2009) Long time ago, rice bran was mainly used for animal feed without any extraction methods Thus, in recent year food industry has been developing in rice bran extraction to obtain wishful oil, protein, lecithin or other substances (Orthoefer, 1996) Nowadays, lecithin is very commonly used in food, pharmaceutical and cosmetic industries About 25-30% used in margarine, 25-30% used in baking chocolate and ice cream, 10-20% for technical products, 3-5% in cosmetic and approximately 3% for pharmaceutical (Wu & Wang, 2004) In food, lecithin provides about a dozen functions, including as an emulsifier, as a wetting agent, for viscosity reduction, as a release agent and for crystallization control Lecithin also provides functions in numerous industrial applications as well (List, 2015) In addition, native and modified lecithin is widely employed as multifunctional ingredients in food industries (Cabezas, et al , 2009) Besides, soybean phospholipids are also widely used as emulsifiers, wetting agents and baking improvers (Patil, Galge, & Thorat, 2010) Lecithin contains mainly of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and other minor compounds such as phosphatidic acid (PA), triglycerides, carbohydrates, etc (Cabezas et al., 2009) Lecithin usually comes from sources such as soybean, egg, milk, rapeseed, cottonseed, and sunflower Crude soybean lecithin typically contains 18% PC, 14% PE, 9% PI, % minor phospholipids (PL), 11% glycolipids, 5% complex sugars and 37% neutral oil (Wu and Wang, 2004) Alternatively, according to Van Nieuwenhuizen (2014) & Prasad (2015), rice bran has a highest content of lecithin (PL 53.4%) Therefore, extraction of lecithin from rice bran oil would be necessary due to its high potential in food industry for use as emulsifier Moreover, lecithin is mostly nontoxic in acute oral studies, short-term oral studies and sub-chronic dermal studies in animal It is also neither a reproductive toxicant, nor is it mutagenic (Lecithin, 2001) Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, which are amphiphilic - they attract both water and fatty substances (and so are both hydrophilic and lipophilic) and used for smoothing food textures, dissolving powders (emulsifying), homogenizing liquid mixtures, and repelling sticking materials It is also a mixture of glycerophospholipids which includes phosphatidylcholine, phosphatidylinositol and phosphatidic acid 1.2 Research Aim The aims of this research were as follows: To extract lecithin from the degumming by-product of rice bran oil refining To determine the yield and analyze moisture content, acid value, antioxidant activity and solubility in oil of extracted lecithin To compare the antioxidant activity between extracted lecithin and commercial lecithin 1.3 Research Scope This research was limited to the laboratory extraction of lecithin from the degumming sludge obtained during the refining process of RBO It was also concern with the determination of acid value, antioxidant activity, solubility in oil and moisture content of extracted lecithin Gum sludge was kindly supplied at Surin Bran Oil Company Limited, Thailand CHAPTER 2: LITERATURE REVIEW 2.1 Introduction about rice bran Rice is one of the most importance food grains in the world It is a main staple food in Thailand, Viet Nam and almost Asian countries Rice is also the main export produce of Thailand and Vietnam Following by USDA and Foreign Agricultural Services (2010) there are approximately 20 million tons of rice are produced in Thailand every year, which produces about 1.3 million tons of rice bran (Thanonkaew et al., 2012) Rice bran is a byproduct (8%) of the rice milling industry which consists of pericarp, the seed coat, the nucleus and the aleuronic layer Rice bran was chosen due to its granular structure, insolubility in water, chemical stability and local availability (Montanher, Oliveira, & Rollemberg, 2005) Figure 2.1 Structure of rice kernel (Sources: Orthoefer ,1996) The composition of rice bran depends on the rice type, climatic conditions, and rice processing methods The oil content in rice bran varies from 12-25 wt % and approximately 95-98% of the oil is extractable (Amarasinghe and Gangodavilage, 2004) Rice bran is rich in protein, lipids, dietary fiber, vitamins and minerals (Luh, Barber, and de Barber, 1991) However, in the past those nutrients have been mainly used for animal feed, not for human consumption Therefore, many recent researches which give the way to ... water-loving (polar) and fat-loving (non-polar) elements of an emulsifier such as lecithin Typically, lecithin products are added to the oil phase for oil-in- water emulsions In water-in-oil... Chemicals - KOH O.1N Diethyl ether Ethanol 95% Hexane Distilled water DPPH (2,2-diphenyl-1-picrylhydrazyl) Methanol 3.3 Apparatus - BUCHI rotary vacuum evaporator R-124 Orbital Shaker N-Biotek... about 21. 9-2 3% of the bran dry weight and contained 88. 1-8 9.2% neutral lipids, 6. 3-7 % glycolipids, and 4. 5-4 .9% phospholipids Neutral lipids included 8 3-8 5.5% triacylglycerols, 5. 9-6 .8% monoacylglycerols