1

UNIVERSITY OF NAIROBI

FACULTY OF AGRICULTURE

DEPARTMENT OF FOOD SCIENCE, NUTRITION AND TECHNOLOGY

COURSE: PRACTICAL FOOD PROCESSING

TITLE: EFFECT OF GUAR GUM AND STARCH ON THE STABILITY OF

PASSION NECTAR

YEAR: FIRST YEAR M.Sc. FOOD SCIENCE AND TECHNOLOGY

NAME OF STUDENT: BEATRICE ALEYO AKWEY A

A5617123212007

SUPERVISOR: PROF. JASPER K. IMUNGI

DATE: SECOND SEMESTER2007/2008

EFFECT OF GUAR GUM AND STARCH ON THE STABILITY OF PASSION

NECTAR

BEATRICE ALEYO AKWEY A

A56171232/2007

THIS PROJECT IS SUBMITTED IN PARTIAL FULFILMENT OF THE

REQUIREMENTS FOR THE AWARD OF MASTER OF SCIENCE DEGREE IN

FOOD SCIENCE AND TECHNOLOGY

2

DECLARATIONThis is my original work and to the best of my knowledge has not been presented for a

degree or diploma in any other university.

Sign . 5\1 \Date .

BEATRICE ALEYO AKWEY A

This project has been submitted with approval of University Supervisor

Sign . Date .

PROF. JASPER K. IMUNGI

3

ABSTRACT

Stability is a critical parameter for compositions that comprise one or more materials in

which passion juice and nectar are examples. In such unstable compositions changes may

occur over time which result in separation of layers (phase separation), where the layers

have different colors and/or densities.

This project aimed at treating passion nectar with guar gum and starch at various

concentrations to determine the most effective stabilizer and at which concentration at

room temperature.

The nectar was produced in the normal way, and then given different doses of each

stabilizer, and left to stand for a period of one and a half months. Physical stability of

each nectar with specific concentration was recorded on each day.

Data obtained is presented in form of tables and line graphs. Guar gum at 1% and starch

at 1.5% stabilized passion as a result increase in viscosity. Starch had detectable off

flavour.

4

ACKNOWLEDGEMENT

I wish to sincerely thank my supervisor Prof. Jasper Imungi for professional guidance,

Laboratory Technicians in the department of Food Science for technical help and fellow

Postgraduate Students in the department for their positive criticism and assistance when I

was working on this project.

5

TABLE OF CONTENTSDECLARATION 3

ABSTRACT 4

ACKNOWLEDGEMENT 5

TABLE OF CONTENTS 6

CHAPTER ONE 7

1.0 INTRODUCTION 7

1.1 LITERATURE REVIEW 7

1.1.1 Passion Fruit. 7

1.1.2 Passion fruit utilization 8

1.1.3 Heat Processed Juice 10

1.2 PROBLEM DESCRIPTION 10

1.3 OBJECTIVES: 12

1.4 JUSTIFICATION 13

1.5 HYPOTHESIS 14

CHAPTER TWO 15

2.0 METHODOLOGY 15

2.1 PRODUCTION OF PASSION NECTAR 15

2.2 Sensory evaluation of passion nectar 16

CHAPTER THREE 18

3.0 RESULTS AND DISCUSION 18

3.1 EFFECTS OF THE STABILIZERS ON PASSION NECTAR 18

3.2 SENSORY ANALYSIS TABLES 22

Discussion 23

CONCLUSION 26

RECOMMENDATION 26

REFERENCE 27

APPENDIX I 28

Analysis of variance guar gum 28

APPENDIX II 30

Analysis of variance for starch 30

6

CHAPTER ONE

1.0 INTRODUCTION

1.1 LITERATURE REVIEW

1.1.1 Passion Fruit

Originally native to Brazil, the leading exporter, passion fruit (Passiflora eduils) is

widely distributed throughout tropics. The two major varieties which are processed

commercially are the purple passion or granna dilla (p.Edulis sims) and the yellow

passion (p.Edulis sims f.flavicarpa Deg) upon ripping passion fruit falls from the vine and

is hand harvested from the ground. If not processed immediately they could be stored for

4-5 weeks at 6.5degrees (85_90%R4) - Jagtiani etal 1988 Chan 1993)

Purple passion is sweeter due to its large sugar content than the larger more prolific

Yellow variety -Chan 1980. Rutledge 2001

The mechanized processing of passion fruit starts with washing. Strong sprays of water

are directed on a belt conveyor sorting removes rotten and unfit fruits. The rids are sliced

open by serrated rotating circular knives. The sliced fruit is fed into a continuous basket

centrifuge. The juice, pulp and seeds are forced by centrifugal action through holes in the

walls and the rinds slide up the sloping walls into a waste conveyor. A screened pulpier

separates the seed from the pulp and the juice which is passed through a screened finisher

to further remove remaining seeds and fiber particles (Woodroof 1976-1agtiani etal 1988

Chan 1980, 1993)

7

Another extraction ofthe pulp involves dropping the fruit between two rotating

converging cones where it is caught in the nip and burst as the cones rotate towards the

bottom of the machine. The clearance is reduced to the thickness of the skin of the fruit.

The skins are carried through the cones but the pulp drops in a finisher then removes

pieces ofthe skin and seeds (Jagtian etall988, Rutleg 2001)

The juice can be sweetened then diluted with water or other juices (esp. orange or

pineapple juices) to make cold drinks. Passion juice can be concentrated to syrup which

can be used to make sauce gelatin e1esserts, cold fruit soups and cocktails.

The frozen juice can be kept for a year and is a very appealing product. The juice can also

be dehydrated in a freeze-dryer or vacuum dryer.

The juice is taken as a digestive stimulant and is used for treatment for gastric cancer.

There is currently a revival of interest in the pharmaceutical industry in the use of

glycosides and sedatives or tranquilizers. (Yiu Hui eta1200l)

1.1.2 Passion fruit utilization

Passion fruit is utilized in making juices due to its flavor and aroma. However aroma

components and flavor are extremely heat sensitive so pasteurization leads to some loss

of change of the flavor. Another concern in processing is the high starch content in juice

which causes accumulation of gelatinous deposits on the heating tubular and plate heat

exchangers affecting efficiency. It also results in localized scorching and deterioration in

flavor(Huime,1971:chan 1980;Jagtiani etall988)The high starch content also results to a

thick juice viscosity that could be desirable in some products by a decanting centrifuge

separation for free flowing concentrates.

8

The delicate flavor permits its use as pure juice; its strong acidic flavor calls for dilution

(1:6) when consumed as nectar. (Edwin etal (2003 investigated methods to increase the

pH of the juice from 2.9-4.0.Precipitates with calcium hydroxide and electro dialysis

processes based on sensory evaluation.

Passion juice is a refreshing component when blended with banana, mango, papaya

guava, orange apple and carrot and brings out the flavor of these juices. Fresh juice and

concentrates can be mixed with tropical fruit cocktail, frozen and heat processed punches,

alcohol beverages and serves as a flavoring to cakes, sauces, salad pies Sherbets jellies

and jams.

Passion fruit products from different countries include:

• Carbonated drinks and ice cream in Kenya

• Swiss passion fruit-based soft drink called passaia marketed in Western Europe.

• Blending with milk and alginate in South Africa

• Pulp added to yoghurt in Australia.

Passion juice boiled down to syrup is used in making sauce, gelatin desserts, candy, ice

cream, sherbet ,caking/filling meringue or chaff on pie and cold fruit soup.

The juice yield from Yellow passion averages from 30% to 33%,purple varieties have

average yield of 45% to50%.The use of recti no lytic enzymes increases yield by 35%

(Jagtiani etal1988:Chan 1993)Physical chemical properties of enzymes treated juice

were similar to untreated juice except or the increased consistency from the high content

of rectin released during treatment.

9

Alpha amylases have been used to reduce the viscosity of the juice brought about by

starch genatinization. After primary juice extraction, some processors employ enzymatic

process to obtain secondary juice from double juice sacs surrounding each seed.

1.1.3 Heat Processed Juice

Pasteurization causes the loss of 35% of sensitive volatile flavor components (Na

Kasome and Pau1.1998). To reduce the effect of heat juices can be diluted or blended

with other fruit juices.

An alternative processing utilizes a spin cooker for canned juice where can rotation

transfers heat rapidly. Pasteurization to 88 0, centre temperature is achieved in about

11114 min and cans are rapidly cooled (Chan 1980)

1.2 PROBLEM DESCRIPTION

Passion juice is utilized in making juice due to its unique flavor and aroma. Its strong

acidic flavor calls for dilution (l :6) when consumed as nectar.

This product has achieved a relatively high degree of commercial acceptance.

A known difficulty with the fruit juice or nectar, however, is that the insoluble solids in

juice separate over a prolonged period of time. As a result, at the time of purchase and

consumption of the product the fruit juice or nectar insoluble solids often will have

settled towards the bottom ofthe container. The container usually has a clear or

translucent appearance except for the discrete sediments.

Although agitation of the fruit juice containing product container prior to use generally

will provide the desirable uniform drink, many consumers either forget to take this

measure or find it cumbersome or difficult to do so.

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Particularly where the juice is packaged in a large volume container such that the product

will be poured there from on a periodic basis i.e. after being re-stored for a time sufficient

enough to result in resaparation of insoluble solids.

Passion fruit juice and nectars packaged in transparent or translucent (e.g. glass or

plastic) containers present an added difficulty with respect to the aesthetically undesirable

visible presence of insoluble solids at the bottom at the time of purchase by the consumer.

Prior attempts at overcoming these difficulties typically make use of natural or synthetic

additive materials as stabilizers in an effort to maintain the juice insoluble solids in

suspension .Most such additive system proposed simply are ineffective for this purpose,

particularly in highly acidic products having a pH of about 4.0 or less where passion juice

and nectar are included.

More over, the additives proposed often rely on their ability to increase the viscosity of

the product in order to more effectively maintain the insoluble solids in suspension or

contribute this property incident to their stabilizing function. As a result the final product

is undesirable and often exhibits an undesirable mouth feel.

Low viscosity propylene glycol arginate and sodium Carboxymethyl cellulose are the

most commonly used stabilizers. They are added to juice containing products in amounts

of 0.015% to 0.20%w/w and 0.01% to O.l%w/w respectively based on the weight of

single strength juice containing product.

The addition of these amounts of stabilizing agent significantly reduces the undesirable

separation of insoluble solids without significantly increasing the viscosity of the product.

11

Although the stabilizers are effective to some extent in reducing sedimentation the

stabilizing agent used are relatively expensive and hence their use in relatively large

quantities greatly increases production costs for the stabilized juice or nectar. In addition

separation of insoluble solids would still occur over periods of time. Most passion juice

processors therefore to make their products have reasonable price, tend to avoid addition

of stabilizers and indicate on the label of the products 'Shake Well Before Use.

Previously packaging has been in tetra packs and this again is phasing out as the cost of

producing the packets is high, making the plastic transparent containers the only

alternative and the most affordable.

This project therefore aims at providing a stabilizing system and method for further

reducing the separation of passion juice insoluble solids in the juice or nectar. In the

process of improving the acceptability of the juice and at the same time not aggregating

the price of juice as a result of the stabilizer used.

1.3 OBJECTIVES:

Main

• To stabilize passion nectar using guar gum and starch.

Specific

• To determine the most effective stabilizer of passion nectar

• To determine the effect of each stabilizer on sensory quality of passion nectar.

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1.4 JUSTIFICA TION

Stability is a critical parameter for compositions which comprise one or more materials

such as, for, example, opacifiers and nutrients. Unstable compositions may lead to the

following:

• Separation of layers (phase separation) wherein the layers have different

colors and/or densities; and

• Increase in particle size of the material(e.g. flocculation or aggregation)

In such unstable conditions, the material may settle to the bottom of the container

which holds the composition, which results in "caking' formation (i.e. phase

separation),float to the top of the container (for example, wherein the material is

an oil),or otherwise separate.

Accordingly, stability of compositions is critically important since the materials

thereof can provide benefits such as, for example, opacity or cloud (e.g. for the

purpose of providing a desirable appearance) or nutrition or other efficacious

benefits. Wherein materials (which would normally deliver one or more of these

benefits) are not stable in the corresponding composition, these benefits will be

lost. For example a composition exhibiting a noticeable flocculation will be

unpalatable and unattractive to the consumer. Additionally a composition

comprising a vitamin or a mineral intended for ingestion will be less nutritive to

the consumer wherein such vitamins and minerals are not stable in composition

(i.e. such vitamins and minerals will settle and not be ingested, or ingested at a

decreased dosage) Therefore it is critically important to provide stable

13

compositions comprising materials such that the benefits of the materials are

provided to the consumer. This project therefore aims at providing a stabilizing

system and method for reducing the separation of passion nectar insoluble solids.

In the process of improving the acceptability of the nectar at the same time not a

Aggregating the price of the product

1.5 HYPOTHESIS

• Guar gum is more effective in the stabilization of passion nectar than starch

• Both guar gum and starch have no effect on the flavour of the passion nectar

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CHAPTER TWO

2.0 METHODOLOGY

2.1 PRODUCTION OF PASSION NECTAR

WASHING

SORTING To remove rotten and unfit fruits

SLICING Rids sliced open by knife manually

SCOOPING OF THE PULP Pulp scooped out into a bowel

PULPING To separate juice from seeds

DILUTION TO FORM NECTAR (1 :4)

APORTIONMENT (For purpose of treating with different stabilizers)

ADDING STABILIZER (Different types and at different concentrations

ranging from ( 0.1% to 1%)

HEATING AT LOW TEMPERATURE (88 degrees Celsius)

HOMOGENIZA nON

PACKAGING Transparent bottles used.

STORAGE (Followed by daily test on physical stability.)

15

2.2 Sensory evaluation of passion nectar

A multiple comparison test was conducted to determine how much guar gum could be

added to the nectar without the tasters detecting a difference in flavor. The nectar tested

contained no guar gum (0), 7g/litre, 8g/litre, 9 gllitre and 10gllitre.A reference sample

labeled "R" that contained no guar gum was provided and 14 tasters were asked to

evaluate the samples according to the score sheet provided. The ratings were given

numerical 1 to 9 by the person analyzing the results with 'no difference' equaling 5,

'extremely better than R' equaling 1 and 'extremely inferior to R' equaling 9. The

analysis of variance was calculated.

To determine how much of starch could be added to passion nectar without tasters

detecting a difference in flavor a multiple comparison test was also done as above. The

passion nectar tested contained no starch (0),1 Ogllitre, 11g/litre 12g/litre 13g Ilitre 14g

/litre and 15g/litre.A reference sample labeled R that contained no starch and 7 coded

samples were given to each taster. The score sheet as above was used.

The score sheet for evaluating the stabilizers was as shown below

~Arv1~----------------------------------------- [)AT~------------------------------

Questionnaire

You are provided with samples of passion nectar to compare for flavor .A reference

sample marked R is given to which you are to compare each sample. Test each sample

16

and show whether it is better than, comparable to , or inferior to the reference. Mark the

amount of difference that exists.

Sample Number __

Better than R ---

Equal to R

Inferior to R _

Amount of difference

None

Slight

Moderate

Much

Extreme

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CHAPTER THREE

3.0 RESUL TS AND DISCUSION

3.1 EFFECTS OF THE STABILIZERS ON PASSION NECTAR

Table 1

Concentration of guar 1 2 3 4 5 6 7 8 9 10gum in g / litreDay when separation 1 1 3 5 15 18 31 41 No Noobserved separati separation

on_J~

50[:0•• 40eCU"'CQ.Cl) 30m ~[: Cl)Cl) I/) 20.J:.c3: 0I/) 10~CUC 0

1 2 3 4 5 6 7 8

Concentration of guar gum in g/litre

Graph 1: Graph showing the day when separation in nectar was observed against

concentration of guar gum in g / litre.

18

Table 2

Panelist Level of Guar gum used in grams / litre

0 7 8 9 10

PI 1 4 1 7 9 22

P2 5 5 4 7 7 28

P3 4 3 5 6 8 26

P4 3 3 7 8 8 29

P5 3 4 6 5 9 27

P6 4 5 9 8 2 28

P7 5 6 4 6 3 24

P8 4 3 2 7 6 22

P9 5 6 3 4 9 27

PI0 7 5 6 3 6 26

Pll 4 6 7 5 1 23

P12 5 4 1 2 8 20

P13 7 5 8 5 7 32

P14 5 6 4 7 7 29

62 65 67 80 89 363

Table 2 above shows the results of sensory analysis obtained from 14 panelists who

tested samples of passion nectar containing different concentrations of guar gum.

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Analysis of variance is calculated as in appendix 1

The ANOV A table

Source of Df SS MS F

variance

Samples 4 37.51 9.38 1.97

Panelist 13 28.99 2.23 0.47

Error 52 247.09 4.75

Total 69 313.59

The calculated F value was checked from statistical table to determine if the difference ~ •

between samples was significant. The value of 1.97 is not significant at the 5 % . ~

Level (2.52) and 1% level (3.65). The addition of up to 1% of guar gum does not make a

detectable difference in the flavour of passion nectar.

Table 3

Concentration of com 10 11 12 13 14 15starch in g / litreDay when separation 5 12 16 23 44 Noobserved separatioln--..-/

20

fn 50~c 400+iCU"tJ•••• Q) 30CU >c. •...Q) Q)fn fn 20c.cQ) 0.c::: 10fn~CU 0c

10 11 12 13 14Concentration of starch in gtmt/litre

Graph 2: Graph showing the day when separation in nectar against concentration of com

starch in g / litre

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3.2 SENSORY ANAL YSIS TABLES

Panelist Level of starch added in g !litre0 10 11 12 13 14 15

PI 1 3 4 2 8 6 9 33

P2 2 4 5 4 9 8 8 40

P3 6 2 5 3 6 7 8 37

P4 6 6 6 4 7 5 7 41

P5 4 5 4 3 8 8 9 41

P6 2 2 2 2 9 6 7 30

P7 4 4 4 4 2 7 6 31

P8 3 3 2 3 6 4 3 24

P9 1 2 3 3 5 3 6 23

PI0 2 2 3 6 4 5 9 31

P11 4 5 1 4 6 3 7 30

P12 5 1 4 3 9 4 8 34

P13 3 3 2 4 1 7 4 24

P14 2 1 3 5 2 4 7 24

45 43 48 50 82 77 98 443

Analysis of variance calculations are on appendix 2

22

ANOVA Table

Source of df SS MS F

variance

Samples 6 207.10 34.52 9.41

Panelists 13 76.75 5.90 1.61

Error 78 286.61 3.63

Total 97 570.46

The value of9.41 is significant at both 5 % level (2.52) and at 1% level (3.65). JI- .

There was therefore a significant difference in flavour between the samples.

From 13 g / litre onwards the nectar a detectable flavour from the real passion nectar

DiscussionGuar gum or guaran is the endosperm polysaccharide of the seed of Cyamopsis

tetragonolobus. It is a galactomanan, containing a backbone of (1-4) - 13 -a-

mannopyranosyl units with every second unit bearing a (1 - 6) - a -D - mannopyranosyl

unit. The polymer is relatively large.

The stability was as a result of increase in viscosity of the nectar. The viscosity

however depends on concentration, Ionic strength and the presence of other food

components. Dissolution of the gum is hastened by heating but the gum is degraded at

very high temperatures. Guar gum produced nectar of high viscosity at concentrations of

about 1% and above. At concentrations between 0.4 - 0.6 % stability was lost within a

period of less than one month. At 0.7 - 0.8 % the product remained stable for a period of

23

31 and 42 days respectively. For a product that is to stay for a period of about one month

guar gum at 0.75 % can be recommended. A concentration of 0.9 - 1 % increased the

viscosity of the nectar and the product remained stable for the period being tested. The

standards given for the fruit nectar by the FAa / WHO (1969) indicate that the soluble

solids content of the product shall be not less than 13 % by weight as determined by a

refractometer at 68 0 F. The apparent viscosity of the product is to be such that the flow

time is not less than 30 seconds according to the Lamb and Lewis method. Guar gum at

around 1% increases the viscosity to a point beyond the given standards. If it is to be

used in the stabilization of passion nectar and such a case the product should have a

different name.

However the guar gum produces a product of good body and pleasant mouth feel.

Passion fruit juice has a high starch content of about 3.4 mg/iOOgm. The nector of I litre

before addition of external starch contain 5.75mg litre of starch. Addition of com starch

in the range of 109 - 13g per litre bring the level to approximately 1.6 - 1.8%.

Commercial com starch usually has a maximum of 65% amylase. As a general rule

solutions of linear polysaccharide will be more viscous than solutions of branded polysac.

The primary reason for using polysaccharide in foods is to provide viscosity, structure or

gelling therefore linear polysaccharide like the amylose are generally most useful.

Stability of passion nectar with the use of starch was as a result of increase in viscosity.

The viscosity of starch solutions and the characteristics of starch gels depend on

temperature and the kinds and amounts of other constituents present. Undarmage starch is

not soluble in cold water or drink, but can reversibly imbibe water and swell slightly.

However as the temperature is increased, the starch molecules vibrate more vigorously

24

breaking intermolecular bonds and allowing hydrogen binding site to engage more water

molecules.

During gelatinization, granules swell extensively. A Surry of 1 - 1.4% on heating

produced a thick paste that remained stable for a short period of time. At that low pH

hydrolysis of starch may have occurred yielding non thickening dextrin hence loss of

stability. High sugar concentrations decrease the rate of starch gelatinization, the peak

viscosity and gel strength. Disaccharides are more effective in delaying gelatinization and

in reducing peak viscosity than are monosaccharide. Sugars decrease the gel strength by

exerting a pasteurizing action and interfering with the formation of junction zones.

Sucrose was added as a sweetener this may have had an effect on viscosity attainment

hence stability.

Starches are difficult to gelatinize some requiring temperatures in excess of 100°C. The

granules can protect micro-organisms hence pasteurization at a rather high temperature of

about 120°C. This high temperature destroy most vitamins especially vitamin C.

Starch though it can stabilize the product at about 1.5%, the final nectar was undesirable

both in flavor, color and mouth feel.

25

CONCLUSION

Guar gum at the level of 1% stabilizes passion nectar. Stability is as a result of increase in . ,

~~ ~

~~viscosity. The properties of the nectar are changed and in this case; the body and mouth- -(;

fe~. The product is changed from a liquid dispersion to a sol.

Starch stabilizes passion nectar at about 1.5%. Stability is influenced by temperature.

Guar gum is more effective in stabilization of passion nectar though it relies on the ability

to increase viscosity in order to maintain the insoluble solids in suspection. /

RECOMMENDATION

Since passion fruit contain substantial amounts of starch in steady of adding more starch

pectin can be added to check the effect of two on stability of the passion nectar

26

REFERENCE1. Owen Fennema, Food Chemistry, 2nd edition.

2. Tressler D.K, Fruit and Vegetable Juice Processing Technology.

3. P.R. Ashurst and Associates, Production and Packaging of None Carbonated

Fruit Juices and Fruit Beverages

4. Yiu H Hui. Jozsef Barita and M. Pilar Cano. Handbook offruits andfruit

27

APPENDIX I

Analysis of variance guar gumCorrection factor = (Totali / No of resources (14 x 5)

70

131769

70

CF = 1882.4143

Sum of square samples =

Sum of the square of the total for each sample

Number of judgments for each sample

14

3844 + 4225 + 4489 + 6400 + 7921 - CF

14

1919.93 - 1882.41

= 37.51

Sum of square panelist

sum of square of the total for each panelist

28

- CF

No of judgments made by each

222+ 282 + 262+ 292 + 272 + 282+ 242+ 222+ 272+ 262 + 232 + 202 +322 + 292_____________________________________________________ -CF

5

= 9557

5- CF

= 1911.4 - 1882.41

= 28.99

The sum of squares = sum of squares of each judgment - CF

= 12+ 42 + 12+ 72 42 + 72 + 72 - CF

=2196-1882.41 =313.59

The analysis of variance chart was set up as follows

Source of variance Df Ss Ms F

Samples 4 37.51 9.38 1.97

Panelists 13 28.99 2.23 0.47

Error 52 247.09 4.75

Total 69 313.59

29

APPENDIX II

Analysis of variance for starchCorrection factor = (443)2

98 = 2002.54

Sum of square sample

452 + 432 + 482 + 502 822 + 772 + 982 - CF

14

= 2209.64 - 2002.54

=207.103

Sum of square panelist

332 + 402 + 312 + 412 + 412 + 302 + 312 + 242+ 232+ 312 + 302 + 342 + 242 + 242 .

= 2079.29 - 2002.54

= 76.75

Total sum of squares

2573 - 2002.54

= 570.46

Sum of square error

570.46 - (76.75 + 207.10)

= 286.61

30

Anova Table

Source of Variance Df Ss Ms F

Samples 6 207.10 34.52 9.51

Panelists 13 76.75 5.90 1.63

Error 79 286.61 3.63

Total 98 570.46

With 6 degrees of freedom in the numerator and 79 degrees in the denominator, the

variance ratio (F value) exceeded 2.52 to be significant at the 5% level and it must

exceed3.65to be significant at the 1 percent level. The value of 9.51 is therefore

significant at both the 5% level and 1% level.

Since there was a significant difference between the samples, the ones that are different

can be determined by using Duncan's multiple range.

Sample score

0 109 l l g 109 13 14 15

45 43 48 50 82 77 98

Sample score mean

45114 43/14 48114 50114 82/14 77/14 98/14

3.2 3.1 3.4 3.6 5.9 5.5 7

The sample mean arranged according to magnitude

A B C D E F G

14g 13g 14g 12g llg Og 109

7 5.9 5.5 3.6 3.4 3.2 3.1

The standard error of sample mean = 0.51

5E ~msError~

31

w _

14

~0.26

A-7-3.1 =3.9> 1.65

1.63 - 1.44 = 0.19

1.63 - 1.52 = 0.11

1.63 - 1.57 = 0.06

1.63 - 1.6 = 1.03

1.6 - 1.44 = 0.16

1.6 - 1.52 = 0.08

1.6 - 1.52 = 0.08

1.6 - 1.57 = 0.03

1.57 - 1.44 = 0.13

1.57 - 1.52 = 0.05

1.52 1.44 = 0.08

2

I3

I

4

I

5

I

6

I 1

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