Evaluation of sugar replacers in short dough biscuit production

E. Gallagher a,b, C.M. O’Brien a, A.G.M. Scannell c, E.K. Arendt a,*

a Department of Food Science, Food Technology and Nutrition, University College Cork, National University of Ireland, Cork, Irelandb Teagasc, The National Food Centre, Dunsinea, Castleknock, Dublin 15, Irelandc Department of Food Science, National University of Ireland, Dublin, Ireland

Received 21 October 2001

Abstract

Sugar inhibits gluten development during dough mixing by competing with the flour for the recipe water, resulting in less tough

and more crumbly biscuits. Commercially available Raftilose, which acts as an oligofructose and a sugar replacer was used in the

recipes where the sugar was reduced by 20–30%. It was found that the sugar replacer did not exert the same hardening effect on the

dough as the granulated sugar, therefore values for dough hardness were found to be lower than those obtained for the standard

biscuit. Peak force values of the reduced sugar biscuits were found to be significantly lower than the control biscuit (P < 0:05),indicating a lower snapping characteristic, and therefore softer eating characteristics. Only those biscuits with the highest level of

sugar replacement showed different surface colour attributes. At the lower and medium levels of sugar replacement, oligofructose

can be used successfully to reduce sugar in short dough biscuits.

� 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Sugar replacers; Oligofructose; Biscuit texture

1. Introduction

Semi-sweet short dough biscuits contain high levels of

fat and sugar. The sugar affects flavour, dimensions,

colour, hardness and surface finish. Sugar can inhibit

glutted development during dough mixing by competing

with the flour for recipe water. Sucrose is the main sugar

utilised in the biscuit industry. However today such highlevels of sugar are undesirable. Therefore the objective

of this study was to replace sugar with a sugar replacer

named Raftilose. Raftilose is a chicory based ingredient

that can be used to improve taste and texture, replace fat

or improve low-fat formulations, replace carbohydrates

and help reduce the caloric content of food while in-

creasing fibre content Young, 1997. Raftilose is an oli-

gosaccharide and has been successfully used in foodproducts as a sugar replacer, but no information is

available on its use in short dough biscuits.

2. Materials and methods

The biscuits were produced as described by Wehrle,

Gallagher, Neville, Keogh, and Arendt (1999), except

that 20–30% of the original sugar weight was replaced

by Raftilose (R20%, R25%, R30%). The quality of the

dough and biscuits were evaluated using the following

tests: dough hardness, biscuit snap test, moisture con-tent, water activity, surface colour and dimensions. All

test methods are described by Wehrle et al. (1999).

Statistical analysis was carried out according to Wehrle

et al. (1999).

3. Results and discussion

3.1. Dough hardness

The effects of the sugar replacer, Raftilose, on the

texture profile analysis of a standard short dough are

shown in Fig. 1. Significant differences in dough hard-

ness were revealed. Values for the standard biscuit av-eraged 24,800 g, whereas values for the test biscuits

ranged from 20,400 g at the lower level of addition to

10,400 g at the highest level (30%). Significantly lower

Journal of Food Engineering 56 (2003) 261–263

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*Corresponding author. Tel.: þ353-21-4902064; fax: þ353-21-4270213.

E-mail address: e.arendt@ucc.ie (E.K. Arendt).

0260-8774/02/$ - see front matter � 2002 Elsevier Science Ltd. All rights reserved.

PII: S0260-8774 (02 )00267-4

hardness levels (P < 0:01) were found when the level ofsugar replacer used increased. A positive correlation was

found (r ¼ 0:675, P < 0:05) between dough hardnessand texture of the final biscuit, i.e. those doughs having

high levels of sugar substitute yielding low hardness

values and low peak force values as measured by the

snap test.

3.2. Snap test

Maximum force values, which measure how difficult

it is to break a biscuit are shown in Fig. 2. Results varied

from �3500–2200 g for those biscuits in which sugarwas replaced. All test biscuits revealed results that were

significantly lower than the standard biscuit (P < 0:01).Olinger and Velasco (1991) found similar softening ef-

fects, when they substituted sugar with sugar alcohols

during biscuit manufacture. Olewnik and Kulp (1984)described how sugar, by crystallising as the biscuit is

being cooled, causes hardening effects on the biscuit.

Acesulfame K was used as a sugar replacer by Bullock,

Handel, Segall, and Wasserman (1992). They also found

that peak force was higher for the control biscuits than

the test biscuits.

3.3. Surface colour: L� values

The effects of Raftilose on the surface colour of thebiscuits are shown in Fig. 3. All biscuits containing the

sugar replacer gave lower L� readings at 24 h, indicating

a darker surface colour, with values ranging from 62.6

to 66.58. In general L� values decreased as the level of

substitution increased. Therefore in relation to surface

brightness/darkness, the use of Raftilose performed

positively as the effects of Maillard browning reactions

between reducing sugars and amino acids produced a

brown colour similar to that of ordinary sugar. Only

biscuits containing 30% Raftilose were statistically dif-ferent from the standard biscuit (P < 0:05). Followingeight weeks storage, significant increases in L� values

were noted for the test biscuits i.e. they became lighter in

colour. In contrast to the initial set of readings, values

for biscuits with 30% were not now significantly different

(P < 0:05) to the standard product. However, those

biscuits with lower levels (20%, 25%) of Raftilose did

have significantly different readings (P < 0:05).

4. Conclusions

Raftilose was added to the original short dough bis-

cuit formulation to replace 20–30% of the originalweight of granulated sugar. Differences were observed

with respect to dough characteristics and baked product

quality. Peak force values of the test biscuits were found

to be significantly lower than the control biscuit

(P < 0:05), indicating a lower snapping characteristic,and therefore softer eating characteristics. Only those

biscuits with the highest level of sugar replacement

showed significantly different surface colour attributes.It was found that the sugar replacer did not exert the

same hardening effect on the dough as the granulated

sugar, therefore values for dough hardness, springiness

and cohesiveness were found to be lower than those for

the standard biscuit.

References

Bullock, L. M., Handel, A. P., Segall, S., & Wasserman, P. A. (1992).

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Olewnik, M. C., & Kulp, K. (1984). The effect of mixing time and

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Chemistry, 61(6), 532–537.Fig. 2. Effect of raftilose addition on snap test values.

Fig. 3. Effects of sugar replacers on the L� value of biscuits 24 h and

eight weeks after baking.Fig. 1. Effect of raftilose addition on dough hardness values.

262 E. Gallagher et al. / Journal of Food Engineering 56 (2003) 261–263

Olinger, P. M., & Velasco, V. S. (1991). Opportunities and advantages

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E. Gallagher et al. / Journal of Food Engineering 56 (2003) 261–263 263