SHEFFIELD HALLAM UNIVERSITY
SHEFFIELD HALLAM UNIVERSITY
School of Business Technology and Engineering
Department of Food and Nutrition Sciences
MODULE 44-704463
DISSERTATION
OPTIMISE PARAMETERS FOR THE GRINDING ELEMENT OF THE SOY MILK MAKING PROCESS THE TOFOO COMPANY LIMITED
Submitted by
SALAAM, HAFEEZ ADEYEMI
31001355
Supervisor:
SOEREN VONSILD
In partial fulfilment of the requirements for the degree of
Master of Science in Food and Nutrition Sciences
AUGUST, 2022
ABSTRACT
ACKNOWLEDGEMENTS
First of all, I would like to thank Almighty Allah from the bottom of my heart for granting me sound health, strength and determination to carry out this important program successfully. This dissertation is the result of the combined efforts of many individuals and Sheffield Hallam University. So it's wise to give credit to some of the key contributors. First of all, I would like to thank my supervisors, Mr. Soeren Vonsild and Dr. Caroline Millman of Sheffield Hallam University, sincerely for her patient, kind and thoughtful guidance, supervision and ongoing support throughout the course of this study, without them this research would not have been completed. Their useful suggestions, comments and timely corrections of the dissertation culminated in the creation of this work. Many thanks go to the technical staff at the National Center of Excellence for Food Engineering (NCEFE), Sheffield Hallam University for their great support. In this regard, I thank Mr Jonathan Shepherd and Dr. Bipronath Dubey for their valued assistance. I am grateful to Sheffield Hallam University for providing me with the best study environment and providing me with all the resources I needed for my studies. In addition, I am grateful to the Department of Food and Nutrition Sciences for giving me the opportunity to pursue my studies. I would also like to thank my faculty members in the Food and Nutrition Sciences department at Sheffield Hallam University. I would like to say a big thank you to Mrs Lucy, Director of Technical of The Tofoo Company Limited and all the staff. I would also like to express my gratitude to my colleagues at the university namely Adeshina, Busayo and all my classmates for their encouragement and support during the research and production of the dissertation. My special thanks to my wife Salaam, Nofisat Omobola, my daughter Salaam, Mazeedat Fikayo, my son Salaam, Mazeed Ayodeji, my family members and relatives for their prayers, encouragement and support throughout the study program. Finally, I am very grateful to my parents for their moral and spiritual prayers.
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF TABLES
CHAPTER ONE
INTRODUCTION
1.1 Background information of the study
Tofu is a super healthy plant-based protein. Its made from soya bean curd, which sounds a bit weird but is actually amazing. Its one of the most complete and versatile protein foods in the world. Tofu has a subtle flavour, allowing it to be a taste chameleon taking on the flavour of any dish it goes in. Tofoo Company Limited is a functional company that merged on May 24, 1999 with a registered office in Malton, North Yorkshire. Tofoo Company Limited has been operating for 23 years. There are currently 4 directors in operation according to the latest confirmation statement submitted by 24 May 2022. In 2015, husband and wife David Knibbs and Lydia Smith bought a small artisan tofu business in Malton, North Yorkshire which had been run by Ron, a Vegan and absolute student of making the best tofu from a traditional Japanese recipe. Their vision was to launch an exciting new, tofu brand using this fantastic product to show that the world should love tofu. They wanted to create a fun and exciting brand that could be stocked within UK supermarkets and that made high quality handmade tofu accessible to all. In September 2016, The Tofoo Co. was born. At Tofoo Co. Tofoo is made to a traditional Japanese recipe using only 3 ingredients: water, soya beans and nigari as a binder which is only available within the UK. We source all our beans from Canada & Italy from reputable growers who do not incorporate pesticides and chemical fertilizers and who do not use genetically modified organisms. We are always on the lookout for sources closer to home, but we will only ever buy great tasting, salute worthy, sustainable beans (https://tofoo.co.uk).
Soymilk was first established in China. Soy milk is made up of 1.5% carbohydrates, 3.0% protein, 94% moisture, 1.5%, ash, fat, minerals and vitamins (Dipika, 2015). It is because of these nutritious foods and the relatively low cost, that soy milk plays an important role in the diet of people in many developing countries. Nutrients contained in eight ounces of plain soy milk 140gm, 10g protein, 4gm fat, 14gm carbohydrates, 120mg carbohydrates, iron 1.8mg, 0.1mg riboflavin and 80mg of calcium. It has about the same amount of protein as cow's milk, although its amino acid profile varies (Deepika et al., 2017).
Soy milk is a plant-based method instead of milk; it is made by immersion in water and grinding soybeans and can be made at home or bought for sale. Commercial soy milk may include the inclusion of ingredients such as sweeteners and salts, and the product may also be fortified with nutrients including vitamins B2, B12, D, calcium and iodine (www.bbcgoodfood.com).
The growing popularity of soy milk as a global beverage is attributed to health benefits e.g. low cholesterol and lactose, its ability to reduce bone loss and menopause, prevent and reduce heart disease and certain cancers. As this beverage is low in cholesterol and low in energy, it can enhance the health benefits of reducing body weight and blood lipids. With a unique nutty flavor and rich diet, soy milk can be used as a supplement to dairy milk. It is available as a light, palatable beverage or in a variety of flavors that include chocolate, vanilla and almonds (Deepika et al., 2017).
Soymilk tofu food is gaining popularity in western countries; it is still the most important and popular plant based product in eastern and south eastern Asia, United kingdom and Nigeria. Tofu, also known as soy curd, is a soft, cheese-like meal made from the coagulating of hot milk with a coagulant. It is traditionally produced by wrapping fresh hot soy milk with salt (CaCl2 or CaSO4) or acid (glucuno-d-lactone) (Obatolu, 2008).
Grinding is an energy hungry process and it is important to use energy as efficiently as possible. Electrical power is required to separate objects and to overcome friction between moving parts of a machine. Almost all the energy in the grinding system is dissipated as heat and only 0.06 - 1% of the input energy is used to reduce the size of the object (Ghorbani et al., 2010).
Grinding or size reduction is an important unit function that changes particle size and shape, increases compact mass, improves flow structures, increases porosity and produces new space. However the physical properties and flow of organisms depend largely on particle size and distribution (Thirupathihalli and Balaraman, 2013).
Wet digestion of soybeans is an important step, not getting enough attention. Wet grinding is usually done after complete filling of the grain which softens the grain. During the blanching process seed coat of soybean is plasticized. Therefore pre-immersion in water can be beneficial especially at low temperatures (<50 C) by reducing the required immersion time without reducing the number of initial germs. The absorption of water during immersion is directly related to changes in the text elements and the grinding properties of soybeans for processing. Pre-immersion of soybeans seems to be beneficial in reducing its size and separating fiber from other parts of the digestive process without reducing digestion time and energy (Vishwanathan et al., 2011).
Particle size and particle size distribution (PSD) of dispersed systems affect important structures such as surface area, recycling, lighting, packing congestion, and rheological structures. Measurable changes in particle size or PSD provide important indicators of fusion or fragmentation, which can help predict the stability and range of major colloidal system structures (HYPERLINK "https://www.sciencedirect.com/science/article/pii/S0022030209704977" l "!"Beliciu and Moraru, 2009).
The distribution of soy protein particles is equally important, the distribution of particle size and the similarity of the particles is a major factor contributing to the structural and behavioural structure of food and beverages. Particle size affects the melting and texture of the final food preparation (Hima et al., 2018).
Measurement of powdered food particles is widely used to control product volume. By measuring the particle size of food products, it is possible to examine the relationship between particle size and mass density or the relationship between particle size and product melting. Recently, particle size testing has been considered an important factor in the development of micron microscopic particles or nano-particles. Traditionally, the filter filter method is the simplest method used for particle measurement, which has been developed internationally (Byung-Man et al., 2009).
Despite the fact that the above reports have improved the understanding of the benefits of pre-immersion and the regulation of grinding temperatures in processing soybeans, there are no studies on the parameters of grinding soybeans. The current study therefore aims to investigate the impact of varying key parameters of the grinding process in manufacturing of soymilk, such as the ratio of water addition and understanding the influence of the output of particle size on the protein extractability and the yield. The processing area and laboratory spaces at National Centre of Excellence for Food Engineering (NCEFE) and City campus will be utilized in this project after the process and parameters have been defined through a visit to The Tofoo Co factory.
Aim of the study
Investigate the impact in yield varying key parameters of the grinding element of the manufacture of soy milk at The Tofoo Co factory.
1.3 Objectives of the study
To evaluate possibilities for improving yield by altering the current process parameters at The Tofoo Company limited.
1.3.1 Specific Objective:
To determined the effects of grinding time (40, 60, 120, 180, 240 and 300 seconds) on the particle sizes of soybean flour.
To determine the influences the yield of soy milk extracted based on the grinding time.
CHAPTER TWO
2.0 LITERATURE REVIEW
2.1 Grinding Process
The grinding process, a unit operation to reduce the size of material, plays a major role in many aspects in the food industry. Many food processes frequently require size reduction, which is accomplished by applying diverse forces to create particles with certain sizes and shapes. Size reduction, directly linked to chemical and microbiological stability and convenience, is one of the most cardinal and energy consuming processes in the food industry. In the food industry, powders are considered as both end products and intermediate products between unit operations (Murrieta-Pazos et al., 2012). The grinding process involves a variety of operations using equipment such as mincer, crushers, cutters, mills, grinders, shredders, disintegrators and homogenizers (Djantou et al., 2007). Grinding requires the breaking or tearing of the materials by such mechanisms as compression, impact, attrition or shear and cutting (Barbosa-Cnovas et al., 2005). Solid food materials are broken down into a large number of ne particles by size-reduction mechanisms. Powders, then, are produced by grinding. Many parameters involved in the grinding process and related to the material, such as the grinding method and machinery, grinding time, and the strength and moisture content of the material, affect the powder characteristics. The amount of moisture in food materials before grinding is a particularly important factor because it helps determine the materials physical properties and the powder properties (Ngamnikom and Songsermpong, 2011). Many researchers have investigated the efciency of the grinding process as applied to grains and other food materials with various moisture contents (Lee et al., 2013). Several studies have shown that the particle properties depend on the structure of food materials, which might be different at various levels of moisture content (Lee and Yoon, 2015) In addition, them as fraction of coarse particles is smaller for those with a lower moisture content than for those with high moisture levels, and vice versa (Moon and Yoon, 2017). The fact that the coarser particles generally have less sphericity is closely related to the internal friction between particles. Especially, the powder ow properties are signicantly inuenced by the irregular shapes in coarse particles (Lee and Yoon, 2015). Thus, the powders from the food materials with different levels of moisture content could show different powder properties with regard to such issues as shapes of particles, particle size distribution, and owabilitywhich is the ability of a powder to ow. Grinding is an energy intensive process in which a hard matter is brokendown. The consumption of energy for reducing the size of numerous types of agricultural and food materials increases when the size of the screen opening changes from coarser to ner and when an increase is present in the moisture content or material hardness (Rozalli et al., 2015). The requirement in energy consumption in grinding increases as the moisture level in the material becomes higher. This is due to higher moisture contents that make the process of deforming and cutting the material more intensive (Lee and Yoo, 2014). Therefore, the grinding energy has to be analyzed to reduce inefcient energy consumption. Several models, such as Fitzpatrick et al., (2004) have explained the consumption of energy during the process of grinding food and agricultural material. The properties of powders play a cardinal role in processing or handling operations, such as formulation and mixing, storage in hoppers and silos, compression and packaging, and transportation (Opalinski et al., 2012). The cohesiveness of powders is associated with the moisture content due to the inter-particle liquid bridges, which cause the spontaneous agglomeration of particles. It is important for the powder to exhibit properties that allow it to ow easily, in a uid-like manner, so that the materials can be handled without serious limitations, such as cohesiveness, friction, and the interlocking of particles. The design of efcient powder handling processes requires the measurement of powder ow properties. Flow ability comprises the particle properties (i.e., size and shape) by grinding, grinding energy consumption and models, as well as powder ow ability depending on the moisture content. Generally, ow properties of powders are determined by a shearing test based on the Jenike shear cell test (Fitzpatrick et al., 2004) Recently, many novel methods to optimize the ow patterns of powders in the handling processes have been reported, such as simulations with a discrete element method (DEM), rheological measurements, and image analysis using a computer (Fu et al., 2012).
2.2 Inuence of Moisture Content on the Grinding Process
Grinding is accomplished by exerting mechanical stress on a material followed by its rupture, and the energy this process requires depends upon the friability of the material. In the grinding process, the initial moisture content affects the materials mechanical properties, such as strength, stiffness, elasticity and plasticity (Djantou et al., 2011). The grinding time and energy consumption are determined by these mechanical properties of the food materials, as are the appearance and characteristics of the nal ground product (Balasubramanian et al., 2013). Generally, the efciency of the food grinding process increases as the moisture content of the material decreases because material with less moisture is more brittle (Dabbour et al., 2015). The increasing plasticity or ductility of the materials containing a high amount of moisture is responsible for the increase in the energy consumption during grinding. Therefore, dry or wet grinding methods, in which the initial moisture content is adjusted before grinding, have been employed in commercial grinding processes to investigate the effect of moisture content on the grinding efficiency (Lee et al., 2013). These grinding processes with various grinding machines affect the compositions, the distribution of particle size, and quality of the end product of the food materials. In addition, modeling of the grinding process has been studied and reported in the literature. This modeling studies addressed what is known as the dynamic principle which utilizes the rst-order reaction kinetics based on the kinetic behavior of particle size reduction, as well as grinding characteristics, with the aim of prediction, optimization, and analysis of the grinding process.
2.3 Grinding Methods for Food Materials
Grinding methods and grinding machinery are major operational factors that control the powder properties with certain initial moisture content of food materials. There are three methods used to prepare food powder by adjusting moisture content: dry grinding, semi-dry/wet grinding and wet grinding (Chiang and Yeh, 2002). Dry grinding is conducted without water and with a low consumption of grinding energy. On the other hand, wet grinding uses excess water, which is directly linked to loss of powder, high water consumption, high energy consumption and treatment of wastewater. The powder properties, such as structures, viscosity and particle size, could be controlled by implementing the semi-dry/wet grinding process because the intermediate properties can be found (Lee et al., 2013). Grinding operations using the three grinding methods and various grinding machines lead to different grinding result, i.e., particle size, composition, functional properties, and product quality using the powder. On the other hand, the inherent structure of food materials, applied grinding power, and grinding technology also contribute to the grinding properties, but this will not bead dressed in this bibliographical study which concerns the moisture content.
2.3.1 Dry and Semi-Dry/Wet Grinding
Dry and semi-dry/wet grinding are common methods that do not add excess water during grinding, do not produce waste water, and thus, consume lesser amounts of energy during grinding. The sample for dry grinding is usually used as is or dried, and for semi-dry/wet grinding includes previous soaking and draining process. Generally, these are the three methods used in most grinding processes of food materials. Grinding machines used in the dry grinding method include a pin mill, hammer mill, disc mill, roller mill, etc. The semi-dry/wet grinding process also uses dry grinding machinery. Dry and semi-dry/wet grinding methods have been carried out to investigate the effect of moisture content on grinding cereals, legumes, fruit and spices (Dabbour et al., 2015). However, the dry grinding method has some draw backs due to the generation of heat, which causes damage to physical and functional qualities of resulting powders, such as nutrient components and aroma (Murthy et al., 2007). The dry grinding of rice using a roller mill, hammer mill and pin mill has been investigated in the study of Ngamnikom and Songsermpong, (2011). The maximum temperature of samples after dry grinding increased up to 46.5 C, whereas wet and freeze grinding increased up to 39.5 C and 25.2 C, respectively. Both the pin mill and hammer mill generated more heat than the roller mill; however, damage to the starch content was the highest in the dry grinding processes, and there were no signicant differences in damaged starch content among the grinding machines. In the semi-dry/wet grinding process, the powder properties were intermediate to dry and wet ground powder with regard to damaged starch amount, viscosity, particle size, etc. The higher initial moisture content of the sample of the semi-dry/wet grinding method produced powder of better physical and functional quality. The rice powder resulting from the semi-dry/wet grinding method had quality attributes in whiteness and damaged starch content that improved as the moisture content increased (Tong et al., 2015). However, it had a lower grinding efciency than the dry grinding method (Tong et., al., 2016).
2.3.2 Wet Grinding
Wet grinding is a conventional process to prepare food powder, and it includes ve successive processes: hydration (also known as soaking), adding additional water during grinding, ltering, drying and sieving. Wet grinding is generally conducted after complete hydration that enables the food materials to soften. Generally, the moisture content of the soaking curve reaches equilibrium Ngamnikom and Songsermpong, (2011). Wet grinding is advantageous for the quality attributes of the end product. Rice powder showed the highest whiteness and the lowest damaged starch content in the study of (Tong et al., 2015). The better starch quality of rice after wet grinding was also observed in the studies of Leewatchararongjaroen and Anuntagool, (2016). It was observed that the pre-soaking of soybean is useful in the size reduction and the separation of the ber from other constituents generated during the grinding process, besides reducing the grinding time and energy (Djantou et al., 2011). The drawbacks of this process are that it requires the use of many equipment and human resources. In light of the costs associated with product loss, an alternative method is needed for the high water consumption, high energy consumption and treatment of wastewater Ngamnikom and Songsermpong, (2011). In addition, this method induces changes in both the chemical and the physical property Ngamnikom and Songsermpong, (2011). For instance, off-avors are produced during wet grinding of soybean, a pretreatment process for soymilk. The wet grinding provides favorable circumstances to accelerate the chemical reactions, such as lipid oxidation presented in water and air catalyzed by lipoxygenase. Therefore, the costs of operation, soaking time and the materials characteristics have to be considered for this method.
2.4 Particle Shape and Size Distribution
After grinding, the particles of food powder have various sizes and shapes. In food processing, mixing and ow operations can be affected by the sizes and shapes of the particles (Bayram and ner, 2007). Therefore, in food processing-related tasks, such as the manufacturing and transportation of products, it is necessary to determine and to understand the characteristics of particles (Tong et al., 2015). Especially, the particle size determines the quality of food products. For example, uniform dispersion of particles in food products showed an acceptable and desirable consistency. The grinding process utilizing shear forces or attrition plays a major role in producing ne food particles. According to Barbosa-Cnovas et al., (2005). Three main particle attrition mechanisms have been studied: shattering, chipping and erosion. These mechanisms are governed by the failure modes respectively, brittle, semi-brittle and ductile. Medium-sized particles are produced by shattering, whereas the smaller particles are produced by erosion. Usually soft materials are subjected to ductile failure. The initial moisture content of food materials might be closely related to these attrition mechanisms.
Particle shape and size distribution are closely related to a materials hardness. After grinding, the particle shape is more irregular for the food materials with high moisture content due to the brittle breakdown characteristics. For the dry and wet grinding of rice, the particle shape showed sharp breakage angles after dry grinding, and round and smooth surfaces were observed in the particles subjected to wet grinding (Ngamnikom and Songsermpong, 2011). For the powder resulting from dry and semi-dry/wet grindings, the increase of initial moisture content increased the average particle size and the large particle fraction (Chiang and Yeh, 2002). When the moisture content is low, the food material is brittle, and breakdown by force is applied. However, an increase in a materials plasticity is observed when moisture content increases. In the study by Djantou et al., (2011) wheat kernels hewed many cracks when the moisture amount was lesser than 16%, whereas the cracks were not observed when the moisture content was above 16%. Similar results have been observed in the grinding of black soybean and pea. Alternatively, opposite results are found by the wet grinding process. On the materials with the equilibrium moisture, the softening effect by soaking in water resulted in as maller mean particle size and ne particle fractions. The nest mean particle size after wet grinding was observed in grinding of rice compared to the particles resulting from dry and semi-dry/wet grinding (Bayram and ner, 2007).
2.5 Recent Grinding Methods and Powder Flowability Measurement Methods
In a number of recent studies, the grinding methods used to make food powders with improved quality have been examined. Especially, it was found that cryogenic grinding performs better than any other method because this technology can maintain a low temperature, using liquid nitrogen at 196C, and the heat generated during grinding is absorbed. Cryogenic grinding of food materials has been used mainly for the process of grinding spices (Sharma et al., 2014). Singh and Goswami, (2000) as early as 2000, designed and developed a cryogenic grinding system that has been used for various spices, such as cumin seed. Grinding characteristics of fenugreek resulted in an energy requirement that did not alter with moisture in cryogenic grinding compared with ambient grinding conditions (Sharma et al., 2014). In the research of Ghodki and Goswami, (2017) cryogenically ground black pepper powder with different levels of moisture content was studied. Through conventional grinding methods, black pepper powder with high moisture content was stickier than when the cryogenic grinding method was used, because in the latter method, the material had become brittle. Another of the new approaches to studying the grinding process and powder owability is a numerical method, such as the discrete element method (DEM), which is applied to design mechanical behavior and simulate particle ow. The DEM has been used by many researchers to simulate milling processes of food materials such as black pepper seeds (Ghodki and Goswami, 2017;Ghodki et al., 2018).
In addition, the ring shear cell test for measuring owability of powder is also simulate dusing DEM. This approach can be applied to predict and analyze the owability and the ow properties using various particle properties, which are inuenced by the moisture content of the food materials (Djantou et al., 2011).
2.6 History of the Tofoo Company Limited
THE TOFOO COMPANY LIMITED is a limited private company (Ltd.) based in 4 RYE CLOSE YORK ROAD BUSINESS PARK, United Kingdom, employing 101 people. The company started trading on 24 May 1999. The company's registration number is 03775780, the main business line producing other food products n.e.c, and the company is listed as active. In 2015, husband and wife team David and Lydia decided to rip up the rulebook and stick their tongue out at the tofu establishment. Heres how it all went down (https://tofoo.co.uk):
2015
David and Lydia saw a gap in the tofu game no one was giving that block of white stuff much love. So, they hatched a plan to take over the (tofu) world.
First job was designing the brand.
2016
David and Lydia begged, borrowed and blagged enough cash to buy a small artisan tofu business in Malton, which was already making the best organic tofu, to a traditional Japanese recipe. Handy!
After a years extensive research, brand building and schmoozing buyers, Naked and Smoked Tofoo hits the supermarkets. First major listings Tesco in 2000 outlets & Ocado!
2017
Sainsbury, Waitrose and Co-op fall in love with Tofoo theyre only human.
We join forces with Mob Kitchen to make some ridiculously tasty recipes including tofu coated in crispy cornflour. Did somebody say game changer?
2018 EXPANSION
Sainsbury, Waitrose and Co-op fall in love with Tofoo theyre only human.
We join forces with Mob Kitchen to make some ridiculously tasty recipes including tofu coated in crispy cornflour. Did somebody say game changer?
2019
10K followers on Instagram hello Tofooniacs.
New ranges: Crispy Tofoo Southern Fried Tofoo Bites and Wholemeal Tofoo Chunkies.
Say hello to Tempeh tofus chunkier brother.
2020
Veganuary helps us smash the 1million mark in January. Tofu is here to stay.
The Tofoo Sizzler range launches with a bang! All sizzle, no shizzle.
Tofoo becomes the UKs number 1 tofu brand.
Our Cubed range of Tofoo and Tempeh launches.
Tofoo gets its first listings in Morrisons!
2021
Veganuary helps us smash the 1million mark in January. Tofu is here to stay.
The Tofoo Sizzler range launches with a bang! All sizzle, no shizzle.
Tofoo becomes the UKs number 1 tofu brand.
Our Cubed range of Tofoo and Tempeh launches.
Tofoo gets its first listings in Morrisons
2.1.1 Tofoo company limited Financial Statements
According to a recent financial report from TOFOO COMPANY LIMITED submitted for 2020-12-31, the company has a net worth of 708,227.00, a total assets of 7M while Working-Capital is 402,196.00. Compared to last year, the company reported a 99.98% increase in revenue, equivalent to -708093. At the same time, Total Assets increased by 37.95%, or -2690615 beans (https://tofoo.co.uk).
Figure 2.1: Pictorial representation of stages of processing of soy milk at The Tofoo Company Limited
2.7 History of Soy Bean
Soy bean is widely cultivated as a species of legume of East Asia. Origin of soy bean happened in south-eastern part of Asia and China was the first country to domesticate the soy bean cultivation. From China, soy bean was introduced to India. Traditional small scale soybean cultivation practices may be found in Himachal Pradesh, Utaranchal, eastern part of West Bengal, Manipur etc. regions of India including Central India since long time back. Beneficial effects of soybean on human health and positive effects of its cultivation on soil fertility are well known, for which soy bean cultivation was promoted in India. Promoting soy bean cultivation was not that much successful because of farmers ignorance about soy bean cultivation practices, unavailability of high-yield seeds, unorganized market and unpopularity about the utilization of soybean (Banerjee et al., 2019).
Soy Milk
Soy milk is a beverage made from soybeans. Soy milk is a stable emulsion, which is considered as staple Asian cuisine. Overnight soaked soy beans are crushed with water and filtered to get the soy milk. Composition of soy milk and cows milk are quite similar (Anonymous, 2018). Similar to milk, soy milk or plain soybean beverage is the pale liquid, which, is rich in protein and other nutrients with or without adding optional additives or ingredients. One advantage of soy milk over cow/buffalo milk is, this milk doesnt contain lactose or cholesterol and the fibres present can be removed from the final product (FAO, 2018).
Nutritional Importance of Soy Milk
Soy milk has the same amount of protein as cow's milk, though the amino acid profile differs. Unlike cow's milk, it has little saturated fat and no cholesterol (Anonymous, 2018). Soy is naturally high in essential fatty acids, proteins, fiber, vitamins and minerals. These nutrients provide energy and keep the body functioning at its optimum level. Below are the six most important health benefits of drinking soy milk (Anonymous, 2014).
Improve lipid profile
Strengthen blood vessel integrity
Promote weight loss
Prevent prostate cancer
Prevent postmenopausal syndromes
Prevent osteoporosis
Soy Milk Production
Soy Milk Production is demonstrated in a flow chart shown in Fig. 1. Soy beans were soaked overnight for 18 h in warm potable water to give a bean: water ratio of 1:3. During soaking of soy beans at room temperature, 0.5-1% sodium bicarbonate solution is also used. The beans are then drained, rinsed with potable water and blanched for 5 min in boiling water. The blanched beans are drained, de-hulled and ground with potable water in a blender. The resulting slurry is filtered through a muslin cloth and the extract (milk) obtained is boiled for 15 min (Banerjee et al., 2019).
Soybeans
Sorting and Washing
Soaking (18 h)
Blanching (for 5min)
Draining
DehullingGrinding Milling
Diluting with water (1:3)
Sieving/Filtering
Boiling (for 15min)
Cooling
Soymilk
Figure 2.2: Flow Chart for Soymilk Production (Banerjee et al., 2019).
CHAPTER THREE
3.0 METHODOLOGY
3.1 Materials
Organic soybeans (Canadian origin) were gotten from The Tofoo Company Limited 4, Rye Close, Malton, North Yorkshaire YO17 6YD and transported to National Centre of Excellence for Food Engineering (NCEFE), Sheffield Hallam University, Sheffield, UK. The equipment and chemicals used were of analytical grade gotten from National Centre of Excellence for Food Engineering (NCEFE), Sheffield Hallam University, Sheffield, UK.
3.2 Methods
3.2.1 Hydration of Soybean
Whole (250g) of Soy bean (SB) were soaked separately in water (1:5) for 16 hours in water at room temperature (162C). Excess water was drained off before grinding.
Figure 3.1: Pictorial representation of hydrated (soaked) Soybeans
3.2.2 Grinding Techniques
A wet grinding method was adopted in this study. Batch grinding was carried out on the hydrated soybeans for 40, 60, 120, 180, 240 and 300 seconds using a 220W Laboratory blender (Warning commercial, Model: WSG60K made in China) with 430mL of added water. The wet samples were kept for further analysis.
C
B
A
(a.) Grinded Slurry (b.) Extraction process of the sample using moslen cloth (c.) Wet grinded sample
Figure 3.2: Pictorial representation of Grinded sample
3.2.3 Particle size analysis by wet method
Distribution of the size of soybean particles for wet analysis is measured by laser diffraction (Malvern Mastersizer Hydro 3000S, Malvern Instruments Ltd., UK). In the wet analysis method, pure water is used to disperse the sample particles from the inlet to the cell sample. About 1 g of the sample was dissolved in 10 ml of water. The sample was added by dropping into the sample area containing approximately 400 ml. Ratings were repeated at least three times to ensure recurrence.
3.2.4 Determining Extract yield
Extract yield was determined according to Zhanrui et al., (2021) with slight modification. Extract of each samples sample of was weighed, and recorded as W1. Initial weight of the dried Soybean samples was also weighed and recorded as W0. Extract yield was calculated using the following equation:
Y = W1 X 100
W0
Where Y represents Extract yield (g / 100g), W1 Extract quality (g), and W0 Initial dried soybean quality (g).
3.2.5 Statistical analysis
Data obtained would be analyzed using the analysis of variance (ANOVA) to determine difference sample means and Duncans Multiple Test (DMRT) would be used to separate the means at P0.05 with Statistical Package for Social Sciences version 16.0 for window (SPSS Inc. Llinois, USA).
CHAPTER FOUR
RESULTS
Figure 4.1 Average yield soy milk extract of soy beans by grinding time
KEY:
A = Soaked sample grinded at 40 seconds
B = Soaked sample grinded at 60 seconds
C = Soaked sample grinded at 120 seconds
D = Soaked sample grinded at 180 seconds
E = Soaked sample grinded at 240 seconds
F = Soaked sample grinded at 300 seconds
G = Sample gotten from Tofoo company
Figure 4.2: Average particle size of soy beans by grinding time
KEY:
A = Soaked sample grinded at 40 seconds
B = Soaked sample grinded at 60 seconds
C = Soaked sample grinded at 120 seconds
D = Soaked sample grinded at 180 seconds
E = Soaked sample grinded at 240 seconds
F = Soaked sample grinded at 300 seconds
G = Sample gotten from Tofoo company
Table 1: Average yield soy milk extract and particle size of soy beans by grinding time
Grinding Time Parameters
Soy milk extract (%) Particle size (m)
A 48.73 0.09 288 11.76
B 53.40 0.16 250.3 6.94
C 56.20 0.16 201.3 7.41
D 60.70 0.14 179.6 4.92
E 72.20 0.16 151.3 1.25
F 74.53 0.16 136.6 3.68
G 40.00 0.00 907.6 34.72
Values were triplicate determination
KEY:
A = Soaked sample grinded at 40 seconds
B = Soaked sample grinded at 60 seconds
C = Soaked sample grinded at 120 seconds
D = Soaked sample grinded at 180 seconds
E = Soaked sample grinded at 240 seconds
F = Soaked sample grinded at 300 seconds
G = Sample gotten from Tofoo company
Figure 4.3: Graphical representation of particle size of sample A
Figure 4.4: Graphical representation of particle size of sample B
Figure 4.5: Graphical representation of particle size of sample C
Figure 4.6: Graphical representation of particle size of sample D
Figure 4.7: Graphical representation of particle size of sample E
Figure 4.8: Graphical representation of particle size of sample F
CHAPTER FIVE
DISCUSSION
CHAPTER SIX
CONCLUSION AND RECOMMENDATIONS
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APPENDIX
Table 1: Average yield soy milk extract of soy beans by grinding time
Grinding Time Value (%)
1 2 3 Mean STD
A 48.80 48.60 48.80 48.73 0.09
B 53.60 53.20 53.40 53.40 0.16
C 56.00 56.20 56.40 56.20 0.16
D 60.80 60.80 60.50 60.70 0.14
E 72.00 72.20 72.40 72.20 0.16
F 74.40 74.40 74.80 74.53 0.19
G 40.00 KEY:
A = Soaked sample grinded at 40 seconds
B = Soaked sample grinded at 60 seconds
C = Soaked sample grinded at 120 seconds
D = Soaked sample grinded at 180 seconds
E = Soaked sample grinded at 240 seconds
F = Soaked sample grinded at 300 seconds
G = Sample gotten from Tofoo company
Table 2: Average particle size of soy beans by grinding time
Grinding Time Value (m)
1 2 3 Mean STD
A 304 276 284 288 11.76
B 260 247 244 250.3 6.94
C 208 205 191 201.3 7.41
D 186 179 174 179.6 4.92
E 153 150 151 151.3 1.25
F 141 137 132 136.6 3.68
G 956 891 876 907.6 34.72
KEY:
A = Soaked sample grinded at 40 seconds
B = Soaked sample grinded at 60 seconds
C = Soaked sample grinded at 120 seconds
D = Soaked sample grinded at 180 seconds
E = Soaked sample grinded at 240 seconds
F = Soaked sample grinded at 300 seconds
G = Sample gotten from Tofoo company
ASSESSMENT CRITERIA
Dissertation (12,500 words).Deadline: JULY 29th 2022, 3pm.
Introduction and abstract
Situates the research question within the, theory, and concepts
Explains the value of the study.
Relevance of the research question, to the field of study is fully justified.
Leads logically into the Literature Review.
Abstract of professional academic standard.
Literature Review
Demonstrates up to date knowledge of the literature in the field of study.
Critically assesses previous research in the chosen field of study.
Should provide a thematic and conceptual basis for the student's study.
A wide range of relevant sources aggregated, evaluated and sorted for logical connections.
Rigorously and critically interpreted within the context of the research identifying clear gaps within the literature that the study will address.
Demonstrates a thorough awareness of the subject area.
Methodology Results
Explanation and justification of methodology.
Research method and research techniques.
Comprehensive explanation with thorough justification of a most appropriate method.
Alternative methods and techniques (& own approach) are considered and evaluated.
Results
Presentation of results.
Clear, effective presentation of data that shows the validity and reliability of data collected.
Conclusion
Clear conclusions drawn from research study.
Clear and relevant conclusions drawn from the research project.
Recommendations and Limitations
Valid recommendation following from the work (if appropriate).
Contribution to knowledge.
Limitations of the research and suggestions for further work.
Actionable recommendations following from the project.
Clearly demonstrates a contribution to knowledge.
Limitations of the research are explored and suggestions for further work discussed.
