PREPARATION AND QUALITY ANALYSIS OF YACON (Smallanthus sonchifolius) BASED HERBAL WINE by Samit Karki Department of Food Technology Central Campus of Technology Institute of Science and Technology Tribhuvan University, Nepal 2019 Preparation and Quality Analysis of Yacon (Smallanthus sonchifolius) Based Herbal Wine A dissertation submitted to the Department of Food Technology, Central Campus of Technology, Tribhuvan University, in partial fulfillment of the requirements for the degree of B. Tech. in Food Technology by Samit Karki Department of Food Technology Central Campus of Technology, Dharan Institute of Science and Technology Tribhuvan University, Nepal May, 2019 ii Tribhuvan University Institute of Science and Technology Department of Food Technology Central Campus of Technology, Dharan Approval Letter This dissertation entitled Preparation and Quality Analysis of Yacon based Herbal Wine presented by Samit Karki has been accepted as the partial fulfillment of the requirement for the B. Tech. degree in Food Technology Dissertation Committee 1. Head of the department (Mr. Basanta Kumar Rai, Assoc. Prof.) 2. External Examiner (Birendra Kumar Yadav, Asst. Prof.) 3. Supervisor (Mr. Dev Raj Acharya, Lecturer.) 4. Internal Examiner (Geeta Bhattarai, Assoc. Prof.) May 28, 2019 iii Acknowledgements I have realized that the task of preparing a dissertation is not as easy as I thought it to be. I am grateful to those who have directly and indirectly helped me to bring this dissertation to this form. I would like to express my heartily gratitude to my respected guide Dev Raj Acharya, Lecturer, Central Department of Food Technology, Dharan for his encouragement and constructive recommendations on doing this research. I wish to express my deep sense of gratitude to Prof. Dr. Dhan Bahadur Karki (Campus chief, CCT) for providing valuable suggestions and necessary facilities during the work. I am also grateful to Assoc. Prof. Mr. Basanta Kumar Rai (Chairperson, Food Technology Department) for his kind support. Pleasant thanks go to my friends and seniors for their direct and indirect co-operations and suggestions during my research. I am also grateful to Mr. Lila Mani Pokhrel, Mr. Sachin Basnet, Mr. Mahesh Shrestha, Mr. Ashok Parajuli, Mr. Pradip Katwal, Miss Avisika Regmi, Mr. Navin khadka and Mr. Gaurav Gurung for their helping hands. I also express my sincere thanks to my teachers and staffs of library and laboratory for their co-operations. I express my affectionate thanks to Mr. Wangdi Sherpa and his family, Jorpati, Hiley for their support and other helps needed. Finally I owe my deepest gratitude to my respected parents and my family for making me able to stand in this position where I am now. Date of submission: May 28, 2019 Samit Karki iv Abstract Wines were prepared by fermenting yacon juice, yacon pulp and yacon syrup musts maintained at 24°Bx TSS, 3.8 ± 0.1 pH and 100 ppm SO2 for 20 days at 26 ± 2°C temperature. The wines were analyzed for their chemical and sensory characteristics and the best wine was selected. Sarpaganda (R. serpentina) and Pakhanbed (B. ciliata) root powders were separately added to the yacon juice must at the rate of 10 g/L, and effects of herbs addition on the chemical and sensory properties of yacon juice wine were studied. Results showed that the total and fixed acidities were maximum in yacon syrup wine (0.86 and 0.72%, m/v as lactic acid) compared to yacon juice and pulp wines. No significant difference in TSS was found among yacoon wines. Antioxidant activity was highest in yaon syrup wine (89.83%), while it was lowest in yacon pulp wine (42.44%). Total phenolics content was more than 2-fold in yacon syrup wine (86.5 mg GAE/100 ml) compared to yacon juice and pulp wines. Yacon juice wine had significantly higher alcohol content (12.5%, v/v) than those of others. Total esters, total aldehydes and higher alcohol contents of the three wines ranged from 46.36 to 55.05 g ethyl acetate/100 L alc, 0.21 to 0.29 g acetaldehyde/100 L alc) and 17.0 to 22 mg/100 ml wine respectively. Methanol contents did differ among the wines (0.00155 ± 0.00015%, m/v). Sensory evaluation showed that wine made from yacon juice had relatively better sensory quality of all the wines. Chemical analysis showed that herbs addition had no significant effect on pH, TSS, fructose and volatile acidity of yacon juice wines. Pakhanbed added wine had significantly higher total phenolic content (103.5 mg GAE/100 ml) compared to control wine (42.7) and Sarpaganda added wine (47.1). Total reducing sugars (mg% as glucose) was lowest in yacon juice wine (115.7) compared to Pakhanbed (243.9) and Sarpaganda (251.4) added yacon juice wines. Addition of herbs had no significant effect (p<0.05) on alcohol, total esters, total aldehydes, fusel oil and methanol contents of yacon juice wine. Addition of Pakhanbed significantly enhanced the antioxidant activity of wine. Sensory evaluation indicated that Pakhanbed added yacon juice wine had higher sensory preference scores of all the wines evaluated. Therefore, addition of Pakhanbed at the rate of 5 g/L of yacon juice must could significantly enhance the medicinal value of wine without significantly affecting its chemical and sensory properties. v Contents Approval Letter .................................................................................................................. iii Acknowledgements ............................................................................................................. iv Abstract ............................................................................................................................... v Contents .............................................................................................................................. vi List of tables ....................................................................................................................... xi List of figures .................................................................................................................... xiii List of abbreviations ........................................................................................................ xiv 1. Introduction ........................................................................................................... 1-4 1.1 General introduction ............................................................................................ 1 1.2 Statement of the problem ................................................................................... 2 1.3 Objectives ......................................................................................................... 3 1.3.1 General objective ................................................................................ 3 1.3.2 Specific objectives .............................................................................. 3 1.4 Significance of the study ................................................................................... 3 1.5 Research hypotheses .......................................................................................... 4 1.6 Limitations of the study ..................................................................................... 4 2. Literature review .................................................................................................. 5-84 2.1 Historical background of alcoholic beverage ..................................................... 5 2.2 History of wine making ..................................................................................... 6 2.3 Wine industry and market in Nepal .................................................................... 7 2.4 Classification of wine ........................................................................................ 9 2.5 Chemical composition of wine ........................................................................ 10 2.5.1 Alcohol ............................................................................................. 10 2.5.2 Esters ................................................................................................ 12 2.5.3 Aldehydes ......................................................................................... 12 2.6 Some research works conducted in wine .......................................................... 14 vi 2.7 Wine yeast ....................................................................................................... 16 2.8 Alcoholic fermentation .................................................................................... 18 2.8.1 Biochemistry of alcohol fermentation by yeast .................................. 19 2.8.2 Stoichiometry.................................................................................... 20 2.8.3 Malo-lactic fermentation ................................................................... 20 2.9 General cultural condition for alcoholic fermentation ...................................... 21 2.9.1 pH ..................................................................................................... 22 2.9.2 Temperature ....................................................................................... 22 2.9.3 Sugar concentration .......................................................................... 23 2.10 General method of wine preparation .............................................................. 23 2.10.1 Selection of raw material ................................................................. 25 2.10.2 Crushing and blending ...................................................................