The Use of Purple Yam (Dioscorea Trifida) as a Health-promoting ingredient in bread making

Jou

rn

al of R

esearch

in

Biology

The use of purple yam (Dioscorea trifida) as a health-promoting

ingredient in bread making

Keywords: Purple yam (Dioscorea trifida); antioxidant activity; health-promoting food; Amazon region.

ABSTRACT: The use of purple yam (Dioscorea trifida) was evaluated as possible health-promoting ingredient in bread making in the state of Amazonas, Brazil. The centesimal composition, energy, and antioxidant activity of purple yam and its incorporated bread formulations (0%, 10%, 15% and 20%) were determined. An acceptance test and microbiological analysis of the formulations 10%, 15% and 20% were also performed. Except for lipids, the centesimal composition and caloric values revealed no statistically significant differences. An addition of purple yam in natura up to 20%, instead of wheat flour in ordinary bread (0%), can be made with no effect on the diet’s energy. The free radical scavenging, 2.2-diphenyl-1-picryl-hydrazyl (DPPH) and lipid per oxidation (LPO) methods revealed that the greater the percentage of purple yam being added into the breads the higher the antioxidant activity detected. The acceptance test applied to compare the three formulations of purple yam breads revealed a significant difference only in the attribute colour. Purple yam breads showed no preferable differences. Results highlight the feasibility of purple yam bread as a health-promoting food in the Amazon region.

747-758 | JRB | 2013 | Vol 3 | No 1

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www.jresearchbiology.com

Journal of Research in Biology

An International Open Access

Research Journal

Authors:

Teixeira AP1,

Oliveira IMA1, Lima ES1

and Matsuura T2.

Institution:

1. Faculdade de Ciências

Farmacêuticas (FCF),

Universidade Federal do

Amazonas (UFAM), Rua

Alexandre Amorim, 330,

Aparecida, CEP: 69010-330,

Manaus, AM, Brasil.

2. Instituto de Ciências

Biológicas (ICB),

Universidade Federal do

Amazonas (UFAM), Av.

General Rodrigo Octávio

Jordão Ramos, 3000,

Campus Universitário,

Coroado I CEP: 69077-000,

Manaus, AM, Brasil.

Corresponding author:

Antonia Paiva Teixeira.

Email:

[email protected]

Web Address: http://www.jresearchbiology.com

document/ RA0306.pdf.

Dates: Received: 15 Nov 2012 Accepted: 27 Nov 2012 Published: 09 Jan 2013

Article Citation: Teixeira AP, Oliveira IMA, Lima ES and Matsuura T.

The use of purple yam (Dioscorea trifida) as a health-promoting ingredient in bread making. Journal of Research in Biology (2013) 3(1): 747-758.

Journal of Research in Biology An International Open Access Research Journal

Original Research

mailto:[email protected]

INTRODUCTION

Yams belong to the family Dioscoreaceae, genus

Dioscorea (Pedralli, 1988; 1997; Pedralli et al., 2002;

Pedralli, 2004). This family is made up by 6 to 9 genera

comprising over 600 species distributed throughout the

World’s tropical, subtropical and temperate regions

(Barroso et al., 1974; Pedralli, 1988; 1997; Melo

Filho et al., 2000; Pedralli et al., 2002; Pedralli, 2004).

The yams (Dioscorea spp.) yield tubers, which are very

important as staple, nutritional and healthy food, and are

still used as an ingredient in traditional Chinese herbal

medicine. They show a worldwide distribution, and are

found in many tropical countries, in South-Eastern Asia

and Western Africa, where the species were introduced

by cultivators (Rasper and Coursey, 1967; Akanbi et al.,

1996; Omonigho and Ikenebomeh, 2000; Lin et al.,

2005). They can also be found in some American

countries, particularly in Brazil, where one can find them

in all regions, from the Amazon down to the Southern

part of the country (Chu and Figueiredo-Ribeiro, 1991;

Pedralli, 1997; 2004).

Purple yam (Dioscorea trifida) is an American

native species, which was domesticated by Amerindians,

with the cultivar distribution possibly pointing out its

domestication in Brazilian and Guyana border areas,

followed by dissemination throughout the Caribbean

islands (Pedralli, 1988; Pedralli et al., 2002; Pedralli,

2004). D. trifida shows a wide distribution in Central and

South America, from the Caribbean to Peru. In Brazil it

is found all the way from the Amazon right down to the

Southern region. The species is associated to forest

environments-Amazonian highland tropical rainforests,

Coastal Atlantic Forest in Southeastern Brazil and,

mesophytic (seasonable) and gallery forests (Pedralli,

1997).

Here in the Amazonian region, purple yam

(D. trifida) may be consumed in the following ways:

baked, boiled, mashed, as ingredients for soups and meat

stews, and in the formulation of flour for making cakes,

pies and porridges. Nevertheless, this species has

undergone little scientific investigation, so little is known

about its management techniques, genetic improvement,

nutritional potential, industrial use, storage procedures,

characterization, uses as natural dye, as well as its use as

a health-promoting ingredient, among others.

By and large, the bread consumed throughout the

world is made mostly of wheat flour, salt and yeast.

Many other ingredients, have been incorporated into

bread formulation, so as to increase its diversity and

product appeals (Hsu et al., 2004).

A few studies have highlighted the great

potential of purple yam in bread making. In this case,

yam flour may replace part of the wheat flour, improving

bread quality, as well as adding economical advantages

to it (Abramo, 1990; Hurtado et al., 1997; Litvin et al.,

1998; Omonigho and Ikenebomeh, 2000; Ratti, 2001).

Hsu et al., (2004) demonstrated the presence

of antioxidants in the flour of purple yam

(Dioscorea purpurea), in five formulations of breads

prepared with this tuber’s flour, with excellent

acceptance in Taiwan supermarkets. Contado et al.,

(2009) showed yam (Dioscorea spp.) mucilage-based

loaf to present good public acceptance as to flavor,

aroma and texture with sensory attributes, demonstrating

the use of this tuber to be feasible as improvers in bread

making.

The following aspects motivated the use of

purple yam (Dioscorea trifida) in natura as a bread

manufacturing health-promoting ingredient, in the

present work: 1) its significant world consumption,

presenting a considerable, expanding tillage alternative

(Rasper and Coursey, 1967; Abramo, 1990; IITA, 2007);

2) although, as yet incipient, an increase on the

production of this tuber in the State of Amazonas, Brazil,

especially in Caapiranga and Careiro Castanho

municipalities is being observed. According to the

Instituto de Desenvolvimento Agropecuário do Estado

do Amazonas (IDAM) in 2008, 110 families of the

Teixeira et al., 2013

748 Journal of Research in Biology (2013) 3(1): 747-758

Caapiranga municipality yielded 2,475 tonnes in an area

of 165 ha; and 3) the presence of antioxidants in purple

yam, which increases the nutritional capacity in breads

made from this tuber (Hsu et al., 2004).

The main aim of the present study was to

evaluate the potential of purple yam yield in the State of

Amazonas, Brazil as a health-promoting ingredient in

bread making. On this context, it determined the

centesimal composition, caloric value, and antioxidant

properties of purple yam as well as of breads made from

this tuber in natura. Then, it undertook an organoleptic

characteristic assessment of the breads, following tasters’

panel acceptance criteria. This purple yam species is, for

the very first time, being used in the Amazonian region,

as a feasible alternative for bread making.

MATERIALS AND METHODS

Species identification and purple yam tuber

(Dioscorea trifida) collection

Identification of the species Dioscorea trifida

was accomplished by comparisons with a voucher

herbarium specimen (Exsicata number 1353) deposited

at the National Research Institute of Amazonia (INPA)

Herbarium. It is very common to find the purple yam

(D. trifida) exhibiting several color hues of its flesh

(edible portion), in Amazonas State Townships. The

types most easily identified are: roxinho (light purple

flesh); roxo (mid purple flesh); roxão (dark purple flesh);

branco (white flesh); and misto (white-purple flesh)

(Figure 1).

Purple yam samples were collected at two

Amazonas Townships: Caapiranga and Careiro

Castanho. Due to the seasonality and availability of these

tubers in the region, the centesimal composition analyses

of yams and breads were performed with Caapiranga

samples. Yam and bread antioxidant and bread sensory

and microbiological analyses were carried out with

Careiro Castanho samples.

Purple yam bread elaboration

On account of the probability of getting breads

with higher antioxidant concentration (Hsu et al., 2004),

roxão (dark purple flesh) type samples were used in the

present study (Figure 1C). Yams in natura, for replacing

wheat flour, were washed, peeled, weighed, ground

in the liquidizer together with yeast, oil and water.

Then, this mixture was added to the previously mixed

dry ingredients (wheat flour, powdered milk, sugar and

salt). Bread manufacturing formulations can be seen at

(Table 1). Homogenization (30 min.), dough underwent

initial fermentation (60 min.), intermediate time for

Teixeira et al ., 2013

Journal of Research in Biology (2013) 3(1): 747-758 749

B A

C D E

Figure 1. Flesh color varieties of the kinds of purple yam (Dioscorea trifida)

commonly found in fairs and markets of Manaus-AM. A) roxinho (light-purple

flesh); B) roxo (mid-purple flesh); C) roxão (dark purple flesh);

D) branco (white flesh); and E) misto (white-purple flesh).

bread shaping (25 min.), final fermentation (60 min.),

time for baking (30 min.) are followed for making yam

bread. After being prepared the breads were cooled to

room temperature and packed in polyethylene bags

displaying the product’s labeling.

Centesimal composition analyses of purple yam and

its incorporated breads

Centesimal composition analyses of purple yam

(Dioscorea trifida), and purple yam incorporated breads

in four formulations: 0%, 10%, 15% and 20%, were done

in triplicate. Moisture, ashes, lipid, proteins and crude

fiber contents were determined according to procedures

described by the Instituto Adolfo Lutz-IAL (2008).

Carbohydrate and caloric values were determined

according to the method of (AOAC, 2005).

Findings obtained on the bread formulation

centesimal composition analyses were subjected to



Table 1. Purple yam (D. trifida) incorporated

bread formulations.

Ingredients Type of bread*

0% 10% 15% 20%

Wheat flour (g) 500 450 425 400

Purple yam (g) 0 50 75 100

Sugar (g) 10 10 10 10

Salt (g) 5 5 5 5

Yeast (g) 10 10 10 10

Milk powder (g) 10 10 10 10

Oil (g) 10 10 10 10

Water (mL) 250 250 250 250

Total (g) † 545 545 545 545

*Percentage of wheat flour replaced by purple yam. †Total amount of ingredients used for preparing the

breads.

Parameters Yam

(D. spp.)* Yam

(D. alata)** Purple Yam (D.trifida)***

Moisture (%) 72.60 73.70 76.43 ± 0.50

Lipid (%) 0.20 0.10 1.13 ± 0.69 Protein (%) 2.00 2.30 1.83 ± 0.13

Crude Fiber (%)

0.60 7.30 1.80 ± 0.05

Ash (%) 0.90 0.90 0.78 ± 0.02 Carbohydrate

(%) 24.30 23.00 18.04 ± 0.66

Caloric value (Kcal/100g)

100.00 96.00 89.64 ± 4.52

Table 2. Yam centesimal composition.

*(Montaldo, 1977), **(TACO 2006), ***Present study Bre

ad

M

ois

ture

(%

) L

ipid

(%

) P

rote

in (

%)

Cru

de

Fib

er

(%)

Ash

(%

) C

arb

oh

yd

rate

(%

) C

alo

ric

va

lue

(kca

l/100 g

)

0%

29.7

9 ±

2.0

4a

4.4

9 ±

0.1

2ab

11.6

2 ±

0.8

1a

1.9

5 ±

0.0

8a

1.1

8 ±

0.2

8a

50.9

5 ±

2.7

9a

290.7

3 ±

7.5

6a

10%

31.0

3 ±

0.8

3a

4.2

4 ±

0,0

4a

10.6

7 ±

0,4

1a

1.9

1 ±

0,1

0a

1.4

1 ±

0.0

3a

53.4

1 ±

4.0

7a

294.4

5 ±

15.6

3 a

15%

32.6

5 ±

1.3

0a

4.8

7 ±

0.3

7ab

9.8

2 ±

1,2

4a

1.8

4 ±

0.0

7a

1.3

8 ±

0.0

7a

49.4

5 ±

2.2

6a

280.6

4 ±

3.9

5a

20%

35.0

9 ±

5.6

2a

4.7

4 ±

0.1

0b

10.0

6 ±

2,1

2a

2.3

4 ±

0.3

7a

1.2

0 ±

0.0

5a

53.4

3 ±

3.1

3a

269.1

7 ±

21.8

2a

P

0.0

752

0.0

370

0

.2699

0.1

438

0.0

683

0.2

587

0

.0862

Tab

le 3

. C

ente

sim

al

com

po

siti

on

an

d c

alo

ric

va

lue

mea

n a

nd

sta

nd

ard

dev

iati

on

on

acc

ou

nt

of

the

dry

mate

ria

l (e

xce

pt

for

the

mois

ture

con

ten

t) o

f th

e fo

ur

an

aly

zed

pu

rple

ya

m i

nco

rpo

rate

d b

read

fo

rmu

lati

on

s (0

%,

10

%,

15%

an

d 2

0%

). P

rob

ab

ilit

y (

P)

valu

es c

alc

ula

ted

fro

m K

rusk

al-

Wa

llis

AN

OV

A f

oll

ow

ed

by

post

hoc

test

s are

sh

ow

n.

Valu

es e

xh

ibit

ing

dif

fere

nt

lett

ers

in

th

e sa

me

colu

mn

in

dic

ate

sta

tist

icall

y s

ign

ific

an

t d

iffe

ren

ces

(P

<0.0

5).

statistical analysis through the statistical software

package (Statsoft STATISTICA 8.0 2007). Given to the

number of sampled observations (n=3), Kruskal-Wallis

ANOVA and post hoc tests were applied as a

non-parametric alternative to Fisher ANOVA, for

independent data, in the comparison among the bread

formulations.

Findings showing significance level of (P<0.05)

were considered as statistically significant.

Preparation of purple yam and its incorporated

breads methanolic extract

Samples of purple yam (Dioscorea trifida),

were peeled and ground with the aid of a knife. They

were then dehydrated in a laboratory oven at 60°C for

24 h. Purple yam incorporated breads of four

formulations: 0%, 10%, 15%, and 20%, were cut into

1 cm thick slices, and dehydrated in a laboratory oven at

40°C for 24 h (Hsu et al., 2004). Dehydrated yams and

breads were ground with pestle and mortar, weighed at

0.125, 0.25, 0.5 and 1.00 g (40, 80, 160 and 330 mg/mL,

respectively). They were placed into small test tubes

added with 5 mL of methanol and left in a rotary shaker

for 24 h. The material was centrifuged at 2,500 RPM

for 10 min so as to obtain the supernatant (methanolic

extract). The antioxidant activity of the samples was

determined by the free radical scavenging, 2.2-diphenyl-

1-picryl-hydrazyl (DPPH) and lipid peroxidation (LPO)

methods. The latter method evaluates the inhibition of

free radicals generated during the linoleic acid

peroxidation, and is based on spectrophotometric

measurements of discoloration (oxidation) of ß-carotene,

induced by linoleic acid oxidative degradation products

(Marco, 1968; Miller, 1971; Duarte-Almeida et al.,

2006).

Antioxidant activity determination through free

radicals scavenging methods (DPPH) in purple yam

and its incorporated breads

DPPH method, following the methodologies

described by Shimada et al., (1992) and Hsu et al.,

(2004), with some modifications, where 2 mg of DPPH

were dissolved into 15 mL of methanol, and applied so

as to determine the antioxidant activity of samples of

purple yam and its incorporated breads in the four

aforementioned formulations. A micro plate bearing

96 well was used. Thirty microliters (30 µL) of the

methanolic extract, plus 170 µL of methanol (used as the

blank) were placed in the wells. The reading was

performed on an Elisa reader (DXL 800-BECKMAN

COULTER) at a wavelength of 492 nm, using triplicate

samples. Then, 100 µL of the DPPH solution were

added, and the material was stored in a dark place for

30 min, and the reading was repeated as soon as this time

was over. Two hundred microliters (200 µL) of methanol

added to 100 µl of the DPPH solution were used as

the control. Thirty microliters (30 µL) of quercetin

(10 µg/mL), 170 µL of methanol and 100 µl of the

DPPH solution, were used as the standard. The following

formula was used so as to calculate the antioxidant

activity percentage

Antioxidant activity determination through the lipid

peroxidation (LPO) method in purple yam and its

incorporated breads

The determination of the antioxidant activity of

the samples through the LPO method was carried out

according to the method reported by Duarte-Almeida

et al., (2006), based on the methodology originally

described by Marco (1968), and later modified by Miller

(1971). The reactive mixture was prepared in

an Erlenmeyer flask, containing 50 µL of linoleic acid,

200 µL of tween 80 (emulsifying agent), 150 µL of

ß-carotene solution at 2 mg/mL in chloroform, and

500 µL of chloroform. The mixture was then subjected to

evaporation in nitrogen till there was no more

chloroform left. Later, the mixture of 25 mL of

previously oxygen saturated water was added, and during



A sample - A blank

% AA = 100 - x 100

A control

a period of 30 min it was homogenized through vigorous

shaking.

The reactive mixture showed to be clear with

absorbency ranging from 0.6 to 0.7 at a wavelength of

492 nm. A 96 well bearing micro plate was used. Two

hundred forty microliters (240 µL) of the reactive

mixture and 10 µL of the methanolic extract samples

were placed in the wells. Ten microliters (10 µL) of

methanol and an equal volume of butylhydroxytoluene

(BHT) at a concentration of 40 µg/mL were used as

control and standard, respectively. The micro plate was

incubated at 50ºC to speed up the oxidation reactions and

start β-carotene discoloration. Discoloration slope

readings of samples, control and BHT (in triplicate) were

performed readily, in an Elisa reader at a wavelength of

492 nm every 15 min for 135 min. The following

formula was used so as to calculate the oxidation

inhibition percentage:

Sensory analysis of purple yam incorporated breads

The acceptance test of purple yam in natura

incorporated breads counted with the participation of 78

non-trained volunteer judges. Each one of them was

provided with an answering card bearing a 9 point

hedonic scale (9-like extremely to 1-dislike extremely),

adapted from Stone et al., (1993) and Silva et al., (2005).

The judges were provided with three purple yam

incorporated bread samples, produced from three

formulations (10%, 15% and 20%) (Table 1). Samples

were served in white, disposable plastic plates; encoded

with three randomly chosen numbers. Samples were

evaluated according to their sensory qualities: global

feel, aroma, flavor, color and texture. Judges were

advised to always rinse their mouth with water before

testing the next sample.

The findings obtained on the acceptance test

were submitted to statistical analysis through statistical

software package (Statsoft STATISTICA 8.0 2007). The

Shapiro-Wilk test rejected the frequency distribution

normality of the three tested bread formulations, in all

their sensory attributes. However, the Levene test

accepted the homocedasticity (homogeneity of variances)

among the formulations for all sensory attributes. As

frequency distribution normality and variance

homogeneity are basic assumptions made for the

application of parametric tests, such as Fisher’s

ANOVA, and as these assumptions were not attended to,

the Friedman ANOVA followed by post hoc tests were

applied as a non-parametric alternative for paired data in

bread comparisons. Findings presenting significance

level of (P<0.05) were considered as statistically

significant.

Microbiological analysis of purple yam breads

Following the recommendation of the

Brazilian National Health Surveillance Agency

(in Portuguese, Agência Nacional de Vigilância

Sanitária, ANVISA), based on Ruling Number 12 (RDC,

2001), we carried out the microbiological analysis so as

to verify Coliforms and Salmonella in samples of the

three purple yam bread formulation samples through the

membrane filtration method (APHA, 2001).

RESULTS AND DISCUSSION

Centesimal composition and caloric value of purple

yam

Moisture (76.43±0.50), protein (1.83±0.13) and

ash (0.78±0.02) contents, as well as the caloric value

(89.64±4.52) of purple yam (D. trifida) samples analyzed

in the present study (Table 2) show to be near

those presented by Montaldo (1991) for yam

(Dioscorea spp.) and those found in the Brazilian

Food Composition Table TACO (2006), for the yam

(D. alata). Lipid content (1.13±0.69) stayed well above

that presented by Montaldo (1991) and TACO (2006).

Crude fiber content (1.80±0.05) is above the value

observed by Montaldo (1991), and well below that



A2 sample - A1 sample

% I = 100 - x 100

A2 control - A1 control

presented in TACO (2006). The high fiber content

presented by TACO (2006) might be due to the

enzymatic gravimetric method employed in the analyses.

That method warrants a higher precision for determining

the dietary fiber as compared to the acid digestion

methodology used in the present study as well as

by Montaldo (1991). Total carbohydrate content

(18.04±0.66) is well below Montaldo (1991) and TACO

(2006) values. The remaining differences in centesimal

composition values presented by Montaldo (1991) and in

the present study might be related to the different soil

types being employed on planting the tubers and/or to the

different species being utilized. Nevertheless, the

different values presented in TACO (2006) may be

related to the different yam species being analyzed.

Centesimal composition and caloric value of purple

yam incorporated breads

Based on data from Kruskal-Wallis (ANOVA)

followed by post hoc tests (Table 3), it may be asserted

that, except for the lipids (P<0.05), all other centesimal

composition and caloric values of the four purple yam

incorporated bread formulations (0%, 10%, 15% and

20%) showed to be statistically similar (P>0.05). That is,

replacing wheat flour by purple yam in natura in up to

20% neither modifies bread centesimal composition nor

caloric value. As for lipid, statistically significant

difference was only observed for 10% and 20%

formulations; this negligible 0.5% difference may be

neglected in technological applications.

Purple yam incorporated breads centesimal

composition and caloric value were compared to those of

ordinary bread loaf (OBL) (Anton et al., 2006) and

whole bread loaf (WBL) (TACO, 2006) (Table 4). One

notices, a high fiber content (6.90%) in the whole bread

loaf (WBL) (TACO, 2006), relative to the remaining

breads. It can be highlighted that in whole bread

composition, we have the presence of grain-composed

whole flour, almost wholly made up of bran, germ and

endosperm (FDA, 2006). By and large, all other values

show to be approximate. All differences found may be

related to formulations employed in the preparation of

those breads.

Antioxidant activity determination through the free

radical scavenging method (DPPH) in purple yam

and its incorporated breads

Antioxidant activity (% AA) of the methanolic

extract pertaining to purple yam (Dioscorea trifida)



Bread Moisture

(%)

Lipid

(%)

Protein

(%)

Crude Fiber

(%)

Ash

(%)

Carbohydrate

(%)

Caloric value

(kcal/100 g)

0% 29.79 4.49 11.62 1.95 1.18 50.95 290.73

10% 31.03 4.24 10.67 1.91 1.41 53.41 294.45

15% 32.65 4.87 9.82 1.84 1.38 49.45 280.64

20% 35.09 4.74 10.06 2.34 1.20 53.43 269.17

OBL 34.46 1.93 9.42 2.57 2.09 52.10 247.50

WBL 34.70 3.70 9.40 6.90 2.30 49.90 253.00

Table 4. Centesimal composition and caloric value of ordinary bread loaf (OBL) (Anton et al., 2006),

whole bread loaf (WBL) (TACO, 2006) and purple yam (D. trifida) incorporated breads at 0%, 10%,

15% and 20% (present study).

0

10

20

30

40

50

60

70

80

90

100

40 80 160 330

Concentration (mg/mL)

An

tio

xid

an

t acti

vit

y (

%)

Purple yam

0% Bread

10% Bread

15% Bread

20% Bread

Quercetin

Figure 2. Antioxidant activity expressed by free

radical scavenging percentage, of samples of purple

yam (Dioscorea trifida) and its incorporated bread

extracts in four formulations: 0%, 10%, 15% and

20%, as determined by DPPH method. The quercetin

was used as standard control. Bars indicate standard

deviation.

samples in the concentrations of 330, 160, 80 and

40 mg/mL, as determined by the DPPH method, were

higher than 70%, reaching a maximum of 88.13±0.12.

This plainly shows this species to exert DPPH radical

scavenging activity (Figure 2). This same figure reveals

purple yam incorporated breads prepared in 10%, 15%

and 20% formulations, to also present a certain

antioxidant activity, reaching 43.32±1.18; 48.13±1.17

and 53.71±1.01 maximum percentile values,

respectively. Those findings are above the values

presented by Hsu et al., (2004) (20-40% approximately),

who used breads of several formulations prepared with

flour from the purple yam tuber (Dioscorea purpurea)

representing the one with the widest variety in Taiwan,

for substituting part of the wheat flour. Bread prepared

with no purple yam at all (0%) showed certain

antioxidant activity, as well, probably due to Maillard

reaction products, where, some hot processed foods,

present free radical scavenging activity (Kim et al.,

2007; Jing and Kitts, 2000; Hsu et al., 2004; Michalska

et al., 2008). Corroborating data from Hsu et al., (2004),

it was confirmed that the antioxidant activity rose as the

percentage of purple yam substituting wheat flour

increased. The high free radical scavenging activity

observed by Hsu et al., (2004) in flour of Taiwan purple

yam (D. purpurea), was also detected in the Amazonian

region’s purple yam (D. trifida).

Antioxidant activity determination through the lipid

per oxidation (LPO) method in purple yam and its

incorporated breads

Discoloration slope (Figure 3) and free radical

inhibition activity (Figure 4) determined through the

LPO method confirmed the antioxidant activity (% I) in

purple yam (55.80±4.85) and its breads from the three

formulations (10%, 15% and 20%), with the values of

46.16±4.90; 48.20±3.72 and 49.13±2.79, respectively.



Tests Bread% Color Aroma Flavor Texture Overall impression

Shapiro-Wilk P 10 0.0009 < 0.0001 0.0023 0.0044 0.0001

15 < 0.0001 0.0009 0.0008 0.0019 < 0.0001

20 < 0.0001 0.0001 0.0002 0.0090 0.0005

Levene P 0.0519 0.5580 0.2306 0.8415 0.5184

Table 5. Probability (P) values calculated from Shapiro-Wilk and Levene tests for evaluating frequency

normality and homogeneity of variances, respectively, of the data obtained in the sensory analysis of the

three tested purple yam incorporated bread formulations.

Values were considered statistically significant at (P< 0.05).

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 15 30 45 60 75 90 105 120 135

Time (min)

Ab

s 4

92

Blank

Purple yam

0% Bread

10% Bread

15% Bread

20% Bread

BHT

Figure 3. Discoloration slope of purple yam

(Dioscorea trifida) and its incorporated bread

extracts in four formulations: 0%, 10%, 15%, 20%,

blank and BHT, as determined through the LPO

method.

0

10

20

30

40

50

60

70

80

90

Purple yam 0% Bread 10% Bread 15% Bread 20% Bread BHT

Inh

ibit

ion

(%

)

Figure 4. Inhibition percentage of free radicals of

purple yam (Dioscorea trifida) and its incorporated

bread extracts in four formulations: 0%, 10%, 15%,

20%, and BHT as determined by LPO method. Bars

indicate the standard deviations.

As it was observed by the DPPH method, the

antioxidant activity rose as the percentage of purple yam

substituting wheat flour in the breads increased.

Moreover, bread with no addition of purple yam (0%)

presented some antioxidant ability which might have

resulted from the development of Maillard reaction

products (Kim et al., 2007; Jing and Kitts, 2000; Hsu

et al., 2004; Michalska et al., 2008). Anthocyanins might

be partly responsible for the antioxidant activities

detected in the purple yam (D. trifida) and its

incorporated breads analyzed in the present study, since

these pigments were detected in purple yams, D. alata

(Rasper and Coursey, 1967) and D. trifida L.

(Carreno-Diaz and Grau, 1977; Escudero et al., 2010).

In fact, polyphenols and anthocyanins, usually detected

in plants, might be the active components for this

antioxidant activity in yams (Hou et al., 2001; Hsu et al.,

2004).

Sensory analysis of purple yam incorporated breads

Table 5 shows the rejection of the frequency

distribution normality of the three tested purple yam

incorporated bread formulations (10%, 15% e 20%)

through the Shapiro-Wilk test, and the acceptance of the

homocedasticity among the formulations through the

Levene test on all sensory attributes evaluated in the

acceptance test (i.e. statistically significant values at

(P <0.05).

Friedman ANOVA followed by post hoc tests

applied for comparing the three purple yam incorporated

bread formulations revealed a significant difference

(P<0.05), only for the colour attribute (Table 6). The

bread at 20% presented a better evaluation regarding the

remaining ones, probably due to the higher purple yam

concentration, which gives the final product a more

attractive kind of color. It was observed that the larger

the purple yam amount being added to the bread the

higher the mean score obtained (values ranging from

6.15 to 6.97).

Choosing a determined food should depend



Bre

ad

Colo

r A

rom

a

Fla

vo

r

Textu

re

Over

all

im

pre

ssio

n

Mea

n

Med

ian

M

ean

M

edia

n

Mea

n

Med

ian

M

ean

M

edia

n

Mea

n

Med

ian

10%

6.1

5 ±

1.4

6ª

6

6.7

1 ±

1.2

2ª

6

6.2

8 ±

1.4

4ª

6

6.0

3 ±

1.5

0ª

6

6.5

4 ±

1.2

3ª

6

15%

6.2

9 ±

1.3

0ab

6

6.5

1 ±

1.3

4ª

6

6.4

4 ±

1.2

2ª

6

5.9

4 ±

1.6

7ª

6

6.5

9 ±

1.1

4ª

6

20%

6.9

7 ±

1.5

5b

7

6.6

8 ±

1.2

0ª

6,5

6.4

1 ±

1.4

3ª

6

6.2

2 ±

1.6

1ª

6

6.8

8 ±

1.3

3ª

7

P

0.0

001

0.6

285

0.9

641

0.5

264

0.0

608

Tab

le 6

. S

enso

ry e

va

luati

on

res

ult

s of

the

thre

e p

urp

le y

am

in

corp

ora

ted

bre

ad

fo

rmu

lati

on

s. P

rob

ab

ilit

y (

P)

valu

e w

as

ob

tain

ed t

hro

ugh

Fri

edm

an

AN

OV

A f

oll

ow

ed b

y p

ost

hoc

test

.

Valu

es e

xh

ibit

ing d

iffe

ren

t le

tters

in

th

e sa

me

colu

mn

poin

t ou

t st

ati

stic

all

y s

ign

ific

an

t d

iffe

ren

ces

(P<

0.0

5).

mainly on its nutritional value. Nevertheless, color,

aroma and texture are the factors usually guiding the

consumer’s preference rate. Of these three factors, color

interferes the most on the product’s preference (Bobbio

and Bobbio, 2001).

Given that there were no preferential differences

among the other sensory attributes, the three breads

evaluated can be considered approved.

Microbiological analysis

Considering that the microbiological analysis

was negative for Coliforms and Salmonella (Table 7), the

purple yam incorporated breads may be considered

proper for human consumption, as long as they have

been properly handled.

CONCLUSIONS

Through such findings, one concludes that any

of the purple yam incorporated breads tested in the

present study (10%, 15% and 20%), can substitute

ordinary bread (0%), with no effect on the diet’s caloric

value, since their centesimal compositions are similar.

Due to the presence of antioxidants in purple yam

incorporated bread, and to their ability to fight free

radicals, those breads can be considered as

health-promoting food. Furthermore, these findings point

out the feasibility of the consumption of purple yam

incorporated bread, as an alternative in the local bread

making industry, and an incentive to a larger production

of this tuber in the Amazonian region.

ACKNOWLEDGEMENTS

The authors are indebted to the Fundação de

Amparo à Pesquisa do Estado do Amazonas (FAPEAM)

for the master scholarship granted to Antonia Paiva

Teixeira. To Dr. Antonio José Inhamuns da Silva and

MSc. Cynthia Tereza Corrêa da Silva of Universidade

Federal do Amazonas (UFAM) for kindly having

allowed to carry out the centesimal composition analyses

in their laboratories. To MSc. Antonio Fábio Lopes de

Sousa, Arleilson de Sousa Lima and Ana Cláudia dos

Santos for their invaluable aid in undertaking of the

laboratory analyses. To Misters Claudio Adriano

Cardoso Amanajás and Francisco de Oliveira Batista for

their logistical support in the collection of purple yam

samples.

REFERENCES

Abramo, MA. 1990. Taioba, Cará e Inhame. Ícone

Editora Ltda. Barra Funda, São Paulo. 80.

APHA. 2001. American Public Health Association.

Compendium of Methods for the Microbiological

Examination of Foods, 4th ed. Washington.

Anton AA, De Francisco A and Haas P. 2006. Análise

físico-química de pães da cidade de Florianópolis e a

situação dos alimentos Integrais no Brasil. Alim Nutr., 17

(4):381-386.

Akanbi CT, Gureje PO and Adeyemi IA. 1996. Effect

of heat-moisture pre-treatment on physical characteristics

of dehydrated yam. J Food Eng., 28(1):45-54.



Microorganism Type of bread

10% 15% 20% Based on RDC (2001)*

Coliforms (at 45°C/g) Absent Absent Absent 102

Salmonella sp/25 g Absent Absent Absent Absent

Table 7. Purple yam incorporated breads microbiological analysis.

*Ruling Number 12 (RDC 2001) recommended by the Brazilian National Health Surveillance Agency

(in Portuguese, Agência Nacional de Vigilância Sanitária - ANVISA).

AOAC. 2005. Association of the Official Analytical

Chemists - AOAC. Official Methods of Analyses 18th

ed. Gaithersburg.

ANVISA. 2001. Agência de Vigilância Sanitária.

BRASIL. Ministério da Saúde. Resolução n.12, de 02

janeiro de 2001. Dispõe sobre regulamento técnico sobre

os padrões microbiológicos para alimentos. Brasília, DF,

Disponível em: http://www.anvisa.gov.br/legis/

resol/12_01rdc.htm. Acesso em 22 de setembro de 2010.

Barroso Gm, Sucre D, Guimaraes EF, Carvalho LF,

Valente MC, Silva JD, Silva JB, Rosental FRT,

Barbosa CM, Barth OM and Barbosa AF. 1974.

Flora da Guanabara, familia Dioscoreaceae. Sellowia

25/26(25):9-256.

Bobbio PA and Bobbio FO. 2001. Química do

processamento de alimentos. 3a. ed. Revista e Ampliada.

São Paulo. 143.

Carreno-Diaz R and Grau N. 1977. Anthocyanin

pigments in Dioscorea tryphida. J food sci.,

(42):615-617.

Contado EWNF, Pereira J, Evangelista SR, Júnior

FAL, Romano LM and Couto EM. 2009. Composição

centesimal da mucilagem do inhame (Dioscorea spp.)

liofilizado comparado a de um melhorador comercial

utilizado na panificação e avaliação sensorial de pães de

forma. Ciênc Agrotec Lavras, Edição Especial

(33):1813 -1818.

Chu EP and Figueiredo-Ribeiro RCL. 1991. Native

and exotic species of Dioscorea used as food in Brazil.

Econ Bot., 45 (4):467-479.

Duarte-Almeida JM, Santos RJ, Genovese MI and

Lajolo FM. 2006. Avaliação da atividade antioxidante

utilizando sistema β-caroteno/ácido linoléico e método

de seqüestro de radicais DPPH. Ciênc Tecnol Aliment

26(2):446-452.

Escudero FR, Buelga CS, Alonso JJP, Yáñez JÁ and

Dueñas M. 2010. HPLC-DAD-ESI/MS Identification

of anthocyanins in Dioscorea trifida L. tubers (purple

sachapapa), Eur Food Res and Technol., 230(5):745-752.

FDA. 2006. Food and Drug Administration Whole

Grain Label Statement s. Available in

http://www.fda.gov/ Food/Guidance documents,

February 17, 2006, Accessed 4 July 2010.

Hou WC, Lee MH, Chen HJ, Liang WL, Han CH,

Liu YW and Lin YH. 2001. Antioxidant activities of

dioscorin, the storage protein of yam (Dioscorea batatas

Decne) tuber. J Agric Food Chem 49(10):4956–4960.

Hsu CL, Hurang SL, Chen W, Weng YM and

Tseng CY. 2004. Qualities and antioxidant properties of

bread as affected by the incorporation of yam flour in the

formulation. Int J Food Sci Tech., (39):231–238.

Hurtado JJ, Ortiz R, Rodriguez G and Dofour D.

1997. Procesamiento de ñame (Dioscorea alata;

D. rotundata). Estudio de la factibilidad tecnica y

económica para la producción de almidón y harina y de

sus propriedades fisicoquimicas. In: Seminario tecnico

sobre raices y tuberculos autóctonos, Ibagué.

IAL. 2008. Instituto Adolfo Lutz. Métodos físico-

químicos para análises de alimentos. 4ª. ed., 1ª edição

digital.

IITA. 2007. International Institute of Tropical

Agriculture. Available in: www.iita.org/cms/?z=63 and

a=268. Accessed 11 December 2008.

Jing H and Kitts DD. 2000. Comparison of the

antioxidative and cytotoxic properties of glucose-lysine

and fructose-lysine Maillard reaction products. Food Res

Int., 33(6):509-516.

Kim CH, Maga JA and Martin JT. 2007. Properties

of extruded blends of wheat dried distiller grain flour

with other flours. Int J Food Sci Tech., 24(4):373-384.



http://www.anvisa.gov.br/legis/resol/12_01rdc.htm

http://www.anvisa.gov.br/legis/resol/12_01rdc.htm

http://www.fda.gov/

http://www.iita.org/cms/?z=63&a=268

http://www.iita.org/cms/?z=63&a=268

Lin SY, Liu HY, Lu YL, Hou WC. 2005. Antioxidant

activities of mucilages from different Taiwanese yam

cultivars. Bot Bull Acad Sin 46(1):183 -188.

Litvin S, Mannheim CH and Miltz J. 1998.

Dehydration of carrots by a combination of freeze

drying, microwave heating and air or vacuum drying. J

Food Eng., 36(1):103-111.

Marco GJ. 1968. A rapid method for evaluation of

antioxidants. J Am Oil Chem Soc., 45(9):594-598.

Melo Filho PA, Santos RC, Santos RCMJW and

Anunciação Filho CJ. 2000. Classificação de

germoplasma de Dioscorea sp. através da análise das

componentes principais. Ciênc Rural (30):619-623.

Michalska A, Amigo-Benavent M, Zielinski H,

Castillo MD. 2008. Effect of bread making on formation

of Maillard reaction products contributing to the overall

antioxidant activity of rye bread. J Cereal Sci.,

48(1):123-132.

Miller HE. 1971. A simplified method for the evaluation

of antioxidant. J Am Oil Chem Soc., 48:91.

Montaldo A. 1991. Cultivo de raíces y tubérculos

tropicales. Costa Rica: Editorial. San José.

Omonigho SE and Ikenebomeh MJ. 2000. Effect of

temperature treatment on the chemical composition of

pounded white yam during storage. Food Chem.,

71:215-220.

Pedralli G. 1988. O inhame, esse desconhecido.

Ciênc Hoje 8(46):58-62.

Pedralli, G. 1997. Revisão taxonômica das espécies de

Dioscoreaceae (R.Br.) Lindley da Cadeia do Espinhaço,

Minas Gerais e Bahia. Tese doutorado PG - Botânica,

Universidade de São Paulo (USP), São Paulo, Brazil.

Pedralli G, Carmo CAS, Cereda M and Puiatti M.

2002. Uso de nomes populares para as espécies de

Araceae e Dioscoreaceae no Brasil. Hortic Bras

20(4):530-532.

Pedralli G. 2004. Flora ilustrada catarinense. Fundação

Cultural de Itajaí. Santa Catarina.

Rasper V and Coursey DG. 1967. Anthocyanins of

Dioscorea Alata L. Cell Mol Life Sci., 23(8):611-612.

Ratti C. 2001. Hot air and freeze-drying of high-value

foods: a review. J Food Eng., (49)311-319.

Shimada K, Fujikawa K, Yahara K and

Nakamura T. 1992. Antioxidative properties of xanthan

on the autoxidation of soybean oil in cyclodextrin

emulsion. J Agric Food Chem., 40(6):945-948.

Silva AF, Minim VP and Ribeiro MM. 2005. Análise

sensorial de diferentes marcas comerciais de café

(Coffea arabica L.) orgânico. Ciênc Agrotec

29(6):1224-1230.

Stone H, Bleibaum PN and Thomas HA. 1993.

Sensory evaluation practices. Second Edition. New York.

TACO. 2006. Tabela Brasileira de Composição de

Alimentos. Segunda Edição. Campinas, São Paulo.



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The Use of Purple Yam (Dioscorea Trifida) as a Health-promoting ingredient in bread making

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