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CHAPTER I THE PROBLEM

Introduction

In the Philippines, soy beans are enjoyed most in the form of

popular street snack called taho. This yogurt-like concoction is similar to fresh

tofu as both are eaten with spoons. Taho is served by street vendors who carry

shiny tin containers that are balanced on both ends of a wooden plank. One can

hold the hot taho, which is scooped into a cup. The other can hold the caramel

sauce and tapioca which is mixed in the cup. These vendors travel the residential

streets and main thoroughfares in the early morning to serve this instant and

affordable breakfast to the hungry populace. If you are wary of the hygiene of

these taho vendors, you can try the taho served in the supermarkets of Manila,

which comes in various flavors.

This sweet treat is soy milk either jelled with agar or thickened with the

same coagulant used for tofu. The texture varies from sippable to spoonable.

In the recent visit to a taho factory, Benith‟s Taho in Malvar Batangas, the

researchers found out that taho takes amount of time to make and needs stirring

regularly due to long production of soy milk, the major ingredient in making taho.

In addition, soy milk is being popularized as the best substitute to cow‟s milk

especially for lactose intolerants.

With the problem presented above, the researchers have thought of

making a soy milk making machine. This could shorten time and work force

http://www.asiahotels.com/hl/Philippines.asp

http://www.asiahotels.com/hl/Philippines.asp



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needed in making soy milk. The project would open up many opportunities for

young entrepreneurs in entering the soy milk industry.

Objectives of the Study

The main objective of the study is to provide an automated soy milk

making machine.

Specifically, the study aims to;

1. Design and create a soy milk making machine considering the following

parameters:

1.1. Machine Component

1.2. Material Requirements

2. Conduct preliminary testing to establish the following parameters:

2.1. Temperature Setting

2.2. Operating time

3. Test performance of soy milk making machine to be able to determine the

following parameters:

3.1. Production rate

3.2. Percent yield

3.3. Properties of soy milk produced

a. pH

b. Specific Gravity

c. Viscosity



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4. Provide operational and maintenance safety manual for soy milk making

machine

Significance of the Study

The primary significance of the study is to obtain an economical design of

a soy milk making machine.

A soy milk making machine will be a great start for small entrepreneurs,

who utilizes soy milk as a raw material who would like to minimize the time and

space capacity of making soy milk.

The study would open a new window for the growing number of soy milk

users as an alternative for dairy products as a good source of protein.

For the future researchers, this study will serve as a reference material. It

will also serve as an important part for the related literature of other studies and

as a based study for future innovations.

For the university, this study will serve as another contribution to

achievements in the field of engineering. It will be valuable for it may serve as a

supplement to instruction materials for various electronics and mechanical

subject.

Scope and Delimitations of the Study

This study focused in the design and development of a soy milk making

machine. The design consisted of motor, blades and shaft, canister, feed hopper,

gate valve, frame and footing, heating element and control box. The prototype



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was made compact by joining the blades and the heating element in casing with

the same space.

The compact grinder and heater designed in this study were made for

home and small commercial purposes. It was constructed from materials

availably bulk in the market which are low cost but showed significantly high

quality and can withstand the environment given by the processes it would

undergo.

The soybean that would be fed into the machine must be soaked for at

least 6 hours for better processing of this raw material. Hot blanching of soaked

soybeans must be done to eliminate the beany-off flavour. (Rumbley, 2005)

Conceptual Framework

The soy milk making machine was designed to grind and heat soybean for

the extraction of soy milk. The methods for achieving the design were presented

in Figure 1, the research paradigm. It showed and illustrated clearly the process

undergone in order to design and fabricate the prototype of the machine

mentioned.

The first step was gathering of data and information about soybean and

how grinding works. The next step was designing the machine itself, and this

required materials and equipment components together with their proper costing;

Development of the project was next after designing the prototype. This

included method of construction and mechanical assembly. Preliminary and



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secondary testing of the prototype were done together with some adjustments for

more efficient use of the machine.

Lastly, an operational manual of the soy milk making machine was

produced.



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Definition of Terms

The following terms are defined conceptually and operationally for the

better understanding of the study.

Blade. In this study, it is the material to be used to grind the soybean.

Body Frame. It is built to handle weight of components especially the

casing and grinding machine.

Electrical Heating Tube. In this study, this is responsible in heating and

cooking of the ground soybean.

Feed Hopper. This collects the soybeans to be grinded in the machine.

Motor. It transmits a rotational motion to shafts to turn the other members

of the linkage (blade) into a rotary motion.

Motor Shaft. This is the one responsible for transmitting the rotating

motion from the motor to other linkages (blade).

Grinder. In this study, this refers to the machine used to grind soy beans

for the extraction of soy milk.

Soybean. In this study, this is where soymilk is extracted .

Soymilk. In this study, this refers to mixture of ground soybean and water

after heated.

Temperature Gauge. In this study, this refers to the apparatus used in

checking for the proper temperature of the soy milk to be produced.



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CHAPTER II

REVIEW OF RELATED LITERATURE

This chapter presents theories and concepts used to pursue this study.

The purpose of this section is to discuss in details the theories of the parameters

in determining the said objectives.

CONCEPTUAL LITERATURE

This section presents the related topics that contain information for

thorough understanding of the design.

I. Soybean

The soybean is the most widely grown and utilized legume in the world

and one of the most well researched, health-promoting foods available today.

Like other beans, soybeans grow in pods, featuring edible seeds. While we

most often think of them as being green, the seeds can also be yellow, brown

or black.

Figure 2 Soybean

(Source: antioxidantsbiotech.yolasite.com)



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It has high nutritional qualities. Soybean has a high protein content of 40%

by weight, 32% carbohydrate, 20% fat, 5% minerals and 3% fiber, and other

trace substances. It is used as sources of protein in human food, animal feed

and in industries. It is also used in industries as a source of edible oil and the

by-product of the oil extraction is the soybean cake used as animal feed.

A. Health Benefits from Soybean

1. Soybean improves bone health

Soy products, such as soy milk, do not contain a lot of

calcium but the soy isoflavones may help to reduce the

osteoporosis risk. Several studies have suggested that soy

isoflavones may be a factor in helping to prevent bone loss.

The isoflavone genistein seems to inhibit bone breakdown and

may have similar effects than estrogens in maintaining bone

tissue. Soy can also indirectly improve bone health. Diets

which are high in animal protein cause more calcium to be

excreted in the urine. Replacing animal protein with soy

protein may help to prevent calcium loss from the bones.

2. Soybean relieves menopausal symptoms

Epidemiological data show that Asian women suffer

less from hot flashes and night sweats compared to Western

women. These symptoms of menopause are caused by low

estrogen levels. Estrogens play a role in the body temperature

http://www.isoflavones.info/menopause-symptoms.php

http://www.isoflavones.info/menopause-symptoms.php



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control. Soy isoflavones can through their estrogen-like effect

control these menopausal symptoms.

3. Soybean reduces risk of heart diseases

In countries were soy products are ingested regularly,

the rates of cardiovascular diseases is low. Research

suggests that soy may help to prevent heart disease by

reducing total cholesterol, low density lipoprotein cholesterol

and preventing plaque buildup in the arteries, which could lead

to stroke or heart attack. These health benefits are also mainly

attributes to the soy isoflavones. The soy isoflavone genistein

may also increase the flexibility of blood vessels.

4. Soybean helps to prevent certain cancers

Several studies have indicated that a regular intake of

soy foods may help to prevent hormone related cancers such

as breast cancer, prostate cancer and colon cancer.

II. Soy Milk

Soy milk is a high protein, iron-rich milky liquid produced from pressing

ground, cooked soybeans. Creamy white soy milk resembles cow's milk

but in fact differs from its dairy counterpart in a number of ways. Not only

is it higher in protein and iron content, but it is cholesterol-free, low fat, and

low sodium. It is, however, lower in calcium and must be fortified with

calcium when given to growing children. Those who are allergic to cow's

http://www.soya.be/soy-cholesterol.php

http://www.soya.be/soy-cholesterol.php



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milk or are unable to digest lactose, the natural sugar found in cow's milk,

find soy milk easy to digest since it is lactose-free. Those who are calorie-

conscious can purchase reduced fat soy milk (called lite soy milk) but this

is often lower in protein as well. Some do not enjoy the taste of original

soy milk, so manufacturers now offer flavored soy milk. Soy milk can be

substituted for milk in nearly any recipe. Those who merely want to boost

protein intake often add powdered soy milk to other beverages; others find

it economical to purchase it in powder form and then make soy milk when

they add water to the powder. Children under one year of age should be

given a formula of soy milk specifically developed with their nutritional

needs in mind. Soy milk that is intentionally curdled is known as tofu.

(How soy milk is made, n.d.)

A. Properties of Soy Milk

An evaluation was done by Namrata Harjai and Gurmukh

Singh entitled “Evaluation of Different Soybean Varieties for

Manufacture of Soymilk”, which yield with different properties.

a. pH

The pH, which is an abbreviation for „power of hydrogen‟, is

a measuring unit of acidity and alkalinity of a solution. It is

numerically equal to 7 for neutral solutions, increasing with

increasing alkalinity (14 = maximum alkalinity) and decreasing with

increasing acidity (0 = maximum acidity). The Ideal range for the

human BODY is suggested, by some sources, as between 6.1 and



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7.0. Others indicate a preference for 6.5 to 7.5, taking into account

variances during the day in accord with metabolic cycles. After the

evaluation, Harjai and Singh found out that soy milk exhibited

value of pH ranging from 6.7-6.77 Standard value is from 4 to 9.

(Acid-Alkaline and pH Quick Reference Food Charts, n.d.)

b. Viscosity

Viscosity is an internal property of a fluid that offers

resistance to flow. After the evaluation, Harjai and Singh found out

that soybeans exhibited values of viscosity ranged from 4.37 to

5.77 Poise. In order to calculate the viscosity of the soymilk, falling

sphere can be used. Weigh each sphere on an electronic scientific

scale and record on a sheet of paper the mass of each sphere (in

kilograms). Measure each sphere for diameter then divide that by

two to equal the radius. Record each radius value on the paper.

Calculate the volume of each sphere using the formula v=

(4πr^3)/3, where "v" represents volume and "r" represents the

sphere's radius. π equals 3.14

Determine the density of each sphere by dividing the mass

found in Step 1 by the volume found in Step 2. Record the density

of each sphere.

Place an empty beaker on the scale and record its weight.

Remove the beaker and fill it with 10 ml of the liquid. Subtract the

weight of the empty beaker from the weight of the full beaker and



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divide the answer by 10 to calculate the density of 1 ml of that

liquid. In determining the viscosity, prepare the workstation with a

graduated cylinder, the spheres, liquids, paper, stopwatch and

tape. Carefully pour liquid into a graduated cylinder until it is nearly

full. Leave about a half inch of space between the liquid and the top

of the cylinder.

Mark off a spot, using the tape, about 2 cm below the liquid's

surface and another about half an inch from the bottom of the

cylinder. These marks will help determine the distance of the

sphere's fall. Use either the top or the bottom of the tape as a

guide, but remain consistent. Measure the exact distance between

the tape marks and record it.

Hold the sphere on the surface of the liquid. Simultaneously

start the stopwatch and drop the sphere. Stop the watch when the

sphere reaches the second tape mark. Record the data. Repeat the

drop using the other spheres and record their data. Repeat Steps 1

through 4 with the other liquid.

Calculate the velocity of the spheres by dividing the distance

between the tape marks by the time it took for the sphere to reach

the second mark.

Calculate the viscosity using the equation η= (2("p)ga^2)/ 9v

where "η" represents viscocity, ""p" represents density difference of

sphere and liquid, "g" represents acceleration of gravity (which



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equals 9.8 m/s/s), "a" represents sphere radius, and "v" represents

velocity. Remember, viscosity is marked with the unit of pascal-

second (Pa*s).

c. Specific Gravity

Specific gravity is the ratio of density of a substance to the

density of a reference substance, in this project is water. It has

been researched that milk has a specific gravity (SG) of 1.01-1.05.

After evaluation of Harjai and Singh, they had found out that the

soy milk has a specific gravity of 1.04-1.05.

B. Processing of Soybean to Soy milk

Modern processing methods have evolved for a number of

reasons; the main one being to eliminate or reduce the "beany" off-

flavor, present with traditional processing. Competing methods are

available for modern processing. Most modern technology is

designed to eliminate or reduce the problem "beany" off-flavor and

optimize yield and functionality. These competing technologies

employ various methods and principles including hot grinding of

soaked soybeans, cold grinding of soaked soybeans, hot blanching,

dry bean grinding and others. (Soymilk Production, n.d.)

There is technology available to simplify things. Automatic

soy milk maker with a microprocessor that controls and monitors

the whole messy process makes a batch of soy milk in just 15 to 20

minutes (see fig. 3). All that is needed to do is add water and



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soybeans and start the machine. The proportion will be 80 grams

per 5 and ½ cups of water, each cup having 177 mL of water.

Soybeans can be pre-soaked for six hours or so to reduce

phytates, which are salt from phytic acid which can be harmful to

humans to improve the flavor and digestibility of the soymilk. The

machine does the rest. It heats the beans and water to 80°C before

grinding to eliminate the overly beany flavor commonly associated

with homemade soy milk. Then the machine finely grinds the

soybeans, producing soy milk. The process is finished after

thoroughly boiling the soy milk and upon pouring of the cooked

mixture it passes a built in strainer in order to separate the soy milk

from residue which is called okara. (Rumbley, 2005)

Fig. 3 Automatic soy milk making machine

(Source: http://www.veg-world.com)

C. Benefits of Soymilk.

Soya milk has nutritional and ecological benefits.



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1. Nutritional

Nutritionally, soya milk is quite similar to dairy milk.

Following are some of the reasons why it is endorsed as

a substitute to dairy milk.

a. The protein content of soya milk is quite similar to

that of dairy milk.

b. The protein found in soya milk is vegetable in

nature. Unlike animal protein found in dairy milk,

vegetable protein prevents loss of calcium through

the kidneys. (Much of the calcium in soya beans is

lost during the process of extracting the milk

through the residual pulp which is discarded.

However, commercial soya milk is adequately

fortified with calcium.)

c. Dairy milk has saturated fats, which can lead to

high cholesterol. Soya milk, on the other hand,

contains very little saturated fat.

d. Commercial soya milk is also fortified with vitamins

such as B12. This makes soya milk a substitute for

dairy milk for vegans. Vegans are people who

prefer not to consume or use any products of

animal origin. Soya milk has no lactose and can



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be easily digested by people who arelactose

intolerant.

e. Allergies due to dairy milk are quite common

among children. Compared to this, very few

children are allergic to soya milk. Before switching

children to soya milk, however, consult their

doctor.

f. Soya milk contains prebiotic sugars such as

stachyose and raffinose. These play a role in

improving immunity and removing toxins in the

body.

g. Dairy milk may contain harmful synthetic

hormones such as RBGH (recombinant bovine

growth hormone) that are used to increase milk

production in cattle.

h. Certain studies have linked dairy milk in childhood

to the development of insulin-dependent diabetes

in later life, though this has not been conclusively

proved. With soya milk there is no such risk.

i. Soya milk is exceptionally rich in isoflavones such

as genistein and daidzein. These confer certain

health benefits such as reducing cholesterol

levels, controlling osteoporosis, and reducing



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cancers of the prostrate and breast. Isoflavones

also protect body cells from oxidation.

2. Ecological

Apart from its nutritional benefits, widespread use

of soya milk may have ecological advantages. This is

because soya beans grown on an area of land can produce

more soya milk than if the same amount of land is used to

grow fodder for cattle. However, as the quality of land

required for cultivating soya beans differs from that used to

grow fodder, this is a debated issue.

III. Grinding Equipment

Grinding equipment can be divided into two classes - crushers and

grinders. In the first class the major action is compressive, whereas grinders

combine shear and impact with compressive forces.

A. Crushers

Jaw and gyratory crushers are heavy equipment and are not used

extensively in the food industry. In a jaw crusher, the material is fed in

between two heavy jaws, one fixed and the other reciprocating, so as to

work the material down into a narrower and narrower space, crushing it as

it goes. The gyrator crusher consists of a truncated conical casing, inside

which a crushing head rotates eccentrically. The crushing head is shaped



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as an inverted cone and the material being crushed is trapped between

the outer fixed, and the inner gyrating, cones, and it is again forced into a

narrower and narrower space during which time it is crushed. Jaw and

gyratory crusher actions are illustrated in Fig. 4(a) and (b).

Figure 4 Crushers: (a) jaw, (b) gyratory

(Source: http://the-vms.com)

Crushing rolls consist of two horizontal heavy cylinders, mounted

parallel to each other and close together. They rotate in opposite

directions and the material to be crushed is trapped and nipped between

them being crushed as it passes through. In some case, the rolls are both

driven at the same speed. In other cases, they may be driven at

differential speeds, or only one roll is driven. A major application is in the

cane sugar industry, where several stages of rolls are used to crush the

cane.



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B. Hammer mills

In a hammer mill, swinging hammerheads are attached to a rotor

that rotates at high speed inside a hardened casing. The principle is

illustrated in Fig. 5(a).

Figure 5 Grinders: (a) hammer mill, (b) plate mill

(Source: http://the-vms.com)

The material is crushed and pulverized between the hammers and

the casing and remains in the mill until it is fine enough to pass through a

screen which forms the bottom of the casing. Both brittle and fibrous

materials can be handled in hammer mills, though with fibrous material,

projecting sections on the casing may be used to give a cutting action.

C. Fixed head mills

Various forms of mills are used in which the material is sheared

between a fixed casing and a rotating head, often with only fine

clearances between them. One type is a pin mill in which both the static



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and the moving plates have pins attached on the surface and the powder

is sheared between the pins.

D. Plate mills

In plate mills the material is fed between two circular plates, one of

them fixed and the other rotating. The feed comes in near the axis of

rotation and is sheared and crushed as it makes its way to the edge of the

plates, see Fig. 11.2(b). The plates can be mounted horizontally as in the

traditional Buhr stone used for grinding corn, which has a fluted surface on

the plates. The plates can be mounted vertically also. Developments of

the plate mill have led to the colloid mill, which uses very fine clearances

and very high speeds to produce particles of colloidal dimensions.

D. Roller mills

Roller mills are similar to roller crushers, but they have smooth or

finely fluted rolls, and rotate at differential speeds. They are used very

widely to grind flour. Because of their simple geometry, the maximum size

of the particle that can pass between the rolls can be regulated.

F. Miscellaneous milling equipment

The range of milling equipment is very wide. It includes ball mills, in

which the material to be ground is enclosed in a horizontal cylinder or a

cone and tumbled with a large number of steel balls, natural pebbles or

artificial stones, which crush and break the material. Ball mills have limited

applications in the food industry, but they are used for grinding food

colouring materials. The edge runner mill, which is basically a heavy broad



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wheel running round a circular trough, is used for grinding chocolate and

confectionery.

Many types of milling equipment have come to be traditional in

various industries and it is often claimed that they provide characteristic

actions that are peculiarly suited to, and necessary for, the product.

G. Cutters

Cutting machinery is generally simple, consisting of rotating knives

in various arrangements. A major problem often is to keep the knives

sharp so that they cut rather than tear. An example is the bowl chopper in

which a flat bowl containing the material revolves beneath a vertical

rotating cutting knife.

Synthesis

The literature cited helped and guide the researchers while developing a

soy milk making machine. Important data include, some facts regarding soybean,

process in making soy milk, machines used in making soymilk and other

parameters used in making soy milk.

In the process of making soy milk, the bean is heated together with water

until a temperature of 80 ºC is attained. After heating, soybeans are grounded

and boiled thoroughly, then strained to separate residue from milk. In

consideration, a grinder will be built together with a heating element in order to

lessen time and work force in providing an optimal output.



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CHAPTER III

DEVELOPMENT METHODS AND PROCEDURES

This chapter provides the summary of the project study development and

fabrication. It focuses on the understanding of the objectives that leads to the

completion of the prototype.

I. Research Design

This study employed an engineering design, planning and analysis. To

achieve the objectives of the study, the totality of the design of the soymilk

included the development stage, design and fabrication stage, preliminary testing

and actual gathering of data.

II. Development Stage

The procedure that was used for the attainment of the objectives of the

study was the following:

The first stage of the study focused on the gathering of data, fabrication

and assembly of the soymilk making machine.

The second stage devoted to preliminary testing in order to identify some

problems regarding the performance of the machine. Further modification were

included in this stage.

The last stage was concerned on the actual gathering of data to determine

the performance of the soymilk making machine.



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III. Design and Fabrication Stage

In the fabrication and assembly of the prototype, important procedures

were followed such as the construction of the structural frame of the unit that

included the cutting of material in accordance with the design of the prototype

and welding and joining of all the structural parts. The next step was the system

construction where all the specified components and the housing assembly were

properly installed and interconnected as designated. The final step conducted

was the finishing touches and paint application to acquire a presentable display

of the prototype.

IV. Preliminary Testing and Modification Stage

After the fabrication of the prototype, a preliminary testing was conducted.

This was done in order to evaluate the performance of the soymilk making

machine in terms of the mass of soybean required and time of production at the

entire process.

A. Method of Determining the Capacity per Batch

The capacity per batch of operation was considered in order to

determine the proper amount of soybeans and water that was fed in the

container. The ratio of soybeans to water is 80 grams to 973.5 mL.



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B. Methods of Determining the Operating Temperature

The machine was equipped with temperature gauge to record the

working temperature.

C. Methods of Determining the Operating Time

Operating time ranged from 15 to 20 minutes upon feeding of mixture

to the machine.

V. Actual Gathering of Data

After gathering the data needed, the performance of this soymilk making

machine was determined. The test was done in three trials in order to evaluate

the parameters of the machine.

When the preliminary testing was done, the operational manual was

produced. The data collected were used to validate the soymilk making machine.

It included the determination of production rate, amount of wasted raw material

and the percent yield.

While the soymilk making machine was operating, the important data that

were gathered in the testing process and were listed down. These data were

tabulated and analyzed accordingly and were stated in the manual that had

arrived at the right conclusions and good recommendations for better

modifications.



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VI. Methods of Determining the Performance Parameter

To test the performance of soymilk making machine, different parameters

were considered.

A. Methods of Determining the Production Rate

The production rate of the soymilk machine was determined by the

equation:

total weight of soymilk produced, (kg)Production Rate

time to produce soymilk, (hr)

B. Method of Determining Percent Yield

Percent yield was determined using the formula:

weight of soymilk produced, (kg)Percent Yield x100%

weight of feed mixture, (kg)

C. Method of Determining Power of Hydrogen

Power of Hydrogen was determined through the use of pH test papers

or litmus papers. The pH level will be determined by the color given in the

manual on the said test papers.

D. Method of Determining Viscosity

Viscosity can be obtained from the equation presented here as

demonstrated in chapter 2



2

sphere liquid

3

sphere

3

liquid

2

( )

where :

viscosity, Pa-s

density of ball, kg/m

density of soymilk, kg/m

g = 9.81 m/s

r = radius of the

g2 r9 v

ball, m

v = velocity of the ball, m/s

E. Method of Determining Specific Gravity

Specific Gravity was determined through ratio of densities of soy

milk and water.

soymilk

soymilk

soymilk

soymilk

water

MassDensity

Volume

Specific Gravity (SG)

DensitySG=Density

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