Discovery, The Student Journal of Dale Bumpers College of

Agricultural, Food and Life Sciences

Volume 14 Article 14

Fall 2013

Textural and sensory qualities of muffins prepared with fermented

rice bran
Breeanna Williams
University of Georgia

Navam Hettiarachchy
University of Arkansas, Fayetteville

Srinivas J. Rayaprolu
University of Arkansas, Fayetteville

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Recommended Citation
Williams, B., Hettiarachchy, N., & Rayaprolu, S. J. (2013). Textural and sensory qualities of muffins
prepared with fermented rice bran. Discovery, The Student Journal of Dale Bumpers College of
Agricultural, Food and Life Sciences, 14(1), 80-85. Retrieved from https://scholarworks.uark.edu/
discoverymag/vol14/iss1/14

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 Textural and sensory qualities
of muffins prepared with
fermented rice bran
Breeanna S. Williams*, Navam Hettiarachchy†, and Srinivas J. Rayaprolu§

ABSTRACT

Rice is one of the most popular cereal grains in the world. Rice bran, a by-product of the rice
milling process, contains an abundance of nutrients including protein, fiber, vitamin B complex,
vitamin E, and other nutraceuticals. However, rice bran is underutilized in the food industry. In
this project muffins were prepared with varying concentrations (2.5%, 5.0%, 7.5%, 10.0%, 15.0%,
20.0%, and 25.0%) of 60 mesh (250 µm) fermented rice bran (60 mFRB) and 80 mesh (180 µm)
fermented rice bran (80 mFRB). A cappuccino muffin formulation was used as flavor for all the
samples. The control sample was prepared without the fermented rice bran for comparison. Initial
taste evaluations using student panelists demonstrated muffins incorporated with 80 mFRB were
too dense, unacceptable, and discontinued for further study while the muffins prepared with 60
mFRB were found to be acceptable. The sensory qualities (texture, color, mouthfeel, aroma) and
overall consumer acceptability of the muffins with 2.5%, 5.0%, 7.5%, and 10.0% 60 mFRB have
lower firmness values in comparison to the control representing a softer texture. Three out of five
sensory panelists considered muffins with 20.0% and 25.0% 60 mFRB to be acceptable in terms of
color, texture, mouthfeel, and aroma. Hence, this project demonstrates that fermented rice bran
products can be used in the preparation of breakfast food products like muffins. This innovative
ingredient formulation concept can be useful in creating successful commercial bakery products
that will provide protein, fiber and other nutrients.

* Breeanna Williams is a 2013 graduate of the University of Georgia with a major in Food Science and a minor in Nutrition
Science. This paper is based on research conducted with the Department of Food Science at the University of Arkansas
during her internship in 2012 funded through the Masterfoods USA, IFT Foundation.
† Navam Hettiarachchy is the faculty mentor and a University Professor in the Department of Food Science.
§ Srinivas J. Rayaprolu is a Program Technician and a Ph.D. candidate in the Department of Food Science.

80 DISCOVERY • Vol. 14, Fall 2013

 MEET THE STUDENT-AUTHOR

I am from Stone Mountain, Georgia. I attended Southwest DeKalb

High School and graduated in the top 10% of my class in May, 2009.
I am a senior at The University of Georgia majoring in Food Science
with a minor in Nutrition Science. I am a recipient of both the Zell
Miller Scholarship and the USDA Multicultural Scholars Program.
This year, I will serve as the Community Service Chair for both
the Food Science Club and Minorities in Agriculture, Natural Re-
sources, and Related Sciences. I was privileged to conduct this re-
search at the University of Arkansas in Fayetteville through a 10-
week food science research program funded by Masterfoods USA,
IFT foundation. I would like to thank Dr. Navam Hettiarachchy for
her guidance during this project and the opportunity to participate
in this Summer Research Internship. We would like to thank Dr. Es-
waranandam Satchithanandam for technical help and providing pro-
cedures for analysis.

Breeanna Williams

INTRODUCTION et al., 2009). The high quality protein generated peptides

tend to reduce hypertension and oxidative stress, both of
Rice is one of the most widely consumed cereal grains which are risk factors for cardiovascular diseases (Kan-
in the world and is grown in over 100 countries. It is also nan et al., 2008).
responsible for almost 25% of the world’s food grain pro- The nutritional and functional properties of rice bran
duction (Wadsworth and Hui, 1992). Although rice is a have contributed to the success of rice bran as an addi-
staple food for two-thirds of the world population, the tive in baked goods such as cookies, crackers, pancakes,
United States’ per capita rice consumption is not large muffins, and breads (Barber et al., 1981). Although in re-
compared to world standards (Batres-Marquez et al., cent years rice bran has been used in baked goods, not
2009). Because of the noted health benefits provided by all products show improvements in sensory qualities and
rice and rice components, an increase in rice consump- consumer acceptability when rice bran is incorporated.
tion may be helpful in improving the health of many A decrease in cookie spread and bread volume has been
Americans. A part of the rice grain, the aleurone layer observed while muffin volume increased (Sekhon et al.,
that forms a major part of the rice bran contains a large 1997). Even though there has been some research done
amount of the nutritious components found in rice. A investigating the effect of fermented cowpea flour addi-
study by Kennedy and Luo (2012) states that rice con- tion on the rheological and baking properties of wheat
sumption is associated with a lower BMI, smaller waist flour, applications of fermented rice bran have not been
circumference and tricep skinfolds, and low serum insu- utilized fully (Hallén et al., 2004). Co-/by-products like
lin measures. rice bran from rice processing when used as ingredients
Rice bran can be identified as the brown, powdery in the food products have excellent health benefits as well
material that is separated from rice during the milling as an economical advantage.
of rough rice. It contains nutrients such as tocopherols, Muffins are a popular breakfast item in the United
beta-glucan, and pectin and is composed of approxi- States and are suitable products for incorporating rice
mately 20% oil, 15% protein and 50% carbohydrate (Her- bran to improve nutritional value with health benefits.
nandez, 2000). In addition to such qualities, rice bran Fermented rice bran is being utilized rather than rice
can be a food ingredient that contains protein that can bran that has not been fermented to possibly reduce the
be cleaved into active protein fragments called peptides. amount of leavening agents used during the baking pro-
Researchers have found that the peptides from rice bran cess. An acceptable fermented rice bran muffin product
exhibit anti-obesity and anticancer properties (Kannan is capable of increasing fiber and protein intake that may

The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences 81
assist in creating a more balanced and healthier human texture profile analysis with a TA-XT2 Texture Analyzer
diet. Hence, the objectives of this study were 1) to incor- (Texture Technologies Corp., Scarsdale, N.Y.). The TA-
porate defatted and fermented rice bran at varying levels XT2 Texture Analyzer was calibrated using a 5-kg weight.
and prepare muffins and 2) to study the physiochemical A 5-mm cylinder probe with a radius edge was used. The
properties and sensory characteristics of muffins made muffin sample was compressed at a constant rate of 1.0
with rice bran. mm/s to 25% of the original thickness. In this experi-
ment, muffin firmness is defined as the force in grams,
MATERIALS AND METHODS kilograms, or Newtons required to compress the muffin
by 25%. To determine muffin springiness, the force af-
Materials. Heat stabilized de-fatted rice bran (HDRB) ter 30 seconds was recorded (F30 sec), then divided by the
was obtained from Riceland foods (Stuggart, Ark.). All- maximum force (Fmax) and that quotient was then multi-
purpose flour, unsalted butter, salt, sugar, baking powder, plied by 100% according to Eq. 1:
milk, cinnamon, vanilla extract, chocolate chips, instant
coffee, eggs and canola cooking spray were purchased
⎛ F30sec ⎞
⎜ ⎟ ×100 = % recovery
from local grocery stores. Xanthan gum was purchased ⎝ Fmax ⎠ Eq. 1
from Danisco USA, Inc.
Preparation of Fermented Heat Stabilized De-fatted A value closer to 100% indicates a more spring-like
Rice Bran. Fermented HDRB was prepared by a patent muffin.
pending and proprietary procedure by Hettiarachchy Sensory Analysis. A group of five volunteer panelists
(2009). The post fermented rice bran is dried, ground, evaluated color, texture, mouthfeel, and smell of muffins
and sieved through 60 and 80 mesh sizes to prepare the on a 5-point scale, with 5 being desirable for a trait. Muf-
60 mesh (250 µm) fermented rice bran (60 mFRB) and 80 fins prepared for sensory analysis included chocolate chips.
mesh (180 µm) fermented rice bran (80 mFRB). Data Analysis. The values were analyzed using stu-
Preparation of Muffins. The dry ingredients including dent’s t test with a P value < 0.05. Color was measured six
all-purpose flour (64.3 g), sugar (41.4 g), baking powder times to calculate its mean value and standard deviation.
(2.5 g), cinnamon (0.7 g), and salt (0.7 g) were homoge- Firmness and springiness were measured three times to
nously mixed in a bowl using a metal whisk. In a separate calculate its mean value and standard deviation.
bowl, instant coffee (2.8 g) was dissolved into milk (60.5 g)
and added to the dry ingredients. To this mixture, melted RESULTS AND DISCUSSION
butter (15.1 g), a beaten egg (13.9 g) and vanilla (1.1 g)
and chocolate chips (11.7 g) were added. The muffin bat- The color, firmness, springiness, and overall consum-
ter was poured into a greased mini-muffin tin tray until er acceptability of muffins prepared with fermented rice
three-quarters full and baked at 185 °C for 17-20 minutes. bran were analyzed in this study.
To prepare the treatments, muffins were prepared by add- Evaluation of Textural Quality. Texture analysis cal-
ing FRB at 2.5%, 5.0%, 7.5%, 10.0%, 15.0%, 20.0%, and culations for firmness confirmed that all 80 mFRB treat-
25.0% of the total weight of ingredients. The 20.0% and ments are firmer than the control and all 60 mesh muffin
25.0% rice bran muffins contain more milk, vanilla ex- treatments except for the 60 mesh 25% (Table 1). Firm-
tract and xanthan gum, 90.8 g, 1.6 g, and 0.01 g, respec- ness of the control was determined by the texture ana-
tively. Muffins were cooled to ambient temperature before lyzer to be 90.1 ± 10.5 g and the springiness was 41.3 ±
being evaluated for texture and color, and sensory analysis. 6.3%. Firmness in the muffin with 15% 80 mFRB was
Physiochemical Properties of Muffins. The color of the 243.5 ± 47.3 g and springiness was 28.1 ± 4.4%. During
muffin crumb was measured using a Minolta Chroma the textural analysis, it was also observed that the leaven-
Meter (CR -300 Osaka, Japan) by calculating the L*, a*, ing agents used in the muffins, yeast and baking powder,
and b* values. The L* value is the lightness variable, with created several air pockets in the crumb structure of both
values ranging from 100 (white) to 0 (black). The a* value muffin treatments. The textural and color quality of the
measures the color of the sample, positive values being muffins was influenced by the air pockets formed. Xan-
more red and negative values more green. The b* value than gum was added to the 20% and 25% 60 mesh muffin
also measures the color of the sample, positive values be- treatments to achieve a more desirable texture consider-
ing more yellow and negative values more blue. Six sam- ing the increase in amount of rice bran added.
ples were measured and the mean and standard deviation The firmness of 60 mesh muffin treatments with less
of the values were calculated. than 25% was lower than the firmness of all 80 mesh
Textural Properties of Muffins. Textural properties of muffin treatments. The reason for this could be due to
muffins, firmness and springiness were determined using finer bran produced from 60 mFRB in comparison to

82 DISCOVERY • Vol. 14, Fall 2013

80 mFRB. A study by Chin et al. (2009) suggested that CONCLUSIONS
increased yeast level resulted in decreased bread density.
This study also investigated the correlation between aera- The results of this study show that incorporation of
tion and rheology of breads and suggests that there is a fermented rice bran in breakfast muffin formulations is
linear proportional relationship between bread density a possibly feasible and applicable idea. Yeast fermented
and bread firmness. This supports the findings of a less rice bran adds dietary fiber to the muffin which makes
firm muffin with 60 mFRB compared to muffins with 80 it a healthy breakfast that is sought by the health con-
mFRB. Hence, a lighter, fluffier crumb texture was found scious consumers. The muffins prepared with 60 mFRB
in the muffins in comparison to the control treatment appealed sensory panelists and had some textural quali-
(0% fermented HDRB). ties similar to a regular muffin.
As the percentage of 60 mFRB increased, muffin firm-
ness also increased. Firmness of the muffins with no more ACKNOWLEDGMENTS
than 20% 60 mFRB, although higher than the control, was
Funding for this project was provided by Masterfoods
lower when compared to firmness measurements for muf-
USA, IFT Foundation.
fins with 80 mFRB. The springiness for most of the 60
mFRB muffin treatments is statistically similar to the
LITERATURE CITED
control, while the springiness of 80 mFRB muffin treat-
ments is lower than that of the control. Since springiness Barber, S., B.C. de Benedito, and J. Martenz. 1981. Rice
values closer to 100 represent a muffin that is most likely bran proteins: Potential value of rice bran fractions
to be a spring (textural quality), it is evident that the fer- as protein food ingredients. Rev. Agroquim. Tecnol.
mented rice bran added to the muffins has an effect on 21:247-256.
the texture of the muffins. Batres-Marquez, S., Helen H. Jensen, and J. Upton. 2009.
Evaluation of Color. The color measurements were taken Rice Consumption in the United States: Recent Evi-
only for the 60 mFRB muffins while the 80 mFRB muffins dence from Food Consumption Surveys. J. Amer.
were discontinued. The lightness variable, L* of several of Diet Assoc. 109:1719-1727.
the muffin treatments were higher than the control sam- Chin, N.L., L.H. Tan, Y.A. Yusof, and R.A. Rahman.
ple, although L* values of muffins with 10.0 and 20.0% 60 2009. Relationship Between Aeration and Rheology
mFRB were similar to the control (Table 2). The a* value of Breads. Journal of Texture Studies. 40:727-738.
measures the color of the sample, where the positive val- Hallén, E., S. Ibanoglu, and P. Ainsworth. 2004. Effect of
ues denote more redness while the negative values denote fermented/germinated cowpea flour addition on the
green. The a* value for the control (0 %) was 5.8 ± 0.2. All rheological and baking properties of wheat flour. J.
muffins with 60 mFRB have a* values that are statistically Food Engineer. 63:177-184.
similar to the control. The b* value for the color of the Hernandez, N., M.E. Rodriguez-Alegría, F. Gonzalez,
sample denotes yellow to blue, where positive values are and A. Lopez-Munguia. 2000. Enzymatic treatment of
more yellow and negative values are more blue. The b* rice bran to improve processing. JAOCS. 77:177-180.
value for the control (0%) was 14.9 ± 0.4. All muffin treat- Hettiarachchy, N. 2009. UAF ID 04-27. Yeast fermenta-
ments except for 20% 60 mFRB have a higher b* value tion of rice bran extracts. Patent filed by the Board of
than the control. There was no significant difference in a* Trustees of The University of Arkansas in April 2006.
values of the treatments compared to the control. How- Intl. appli. num. PCT/US2006/011625, published: 02-
ever, there was a significant difference in b* values among 05-2009.
the muffin treatments and the control (Table 2). Kannan, A., N. Hettiarchchy, M.G. Johnson, and R. Nan-
Analysis of Sensory Data. The most preferred muffin napaneni. 2008. Human Colon and Liver Cancer Cell
sample was the control which did not contain any HDRB. Proliferation Inhibition by Peptide Hydrolysates De-
However, 2 of 5 panelists preferred muffin samples with rived from Heat-Stabilized Defatted Rice Bran. J. Ag-
10% HDRB and 20% HDRB (Fig. 1). All the 5 panelists ric. Food Chem. 56(24):11643-1647.
said they would recommend the product to family and Kannan, A., N. Hettiarachchy, and S. Narayan. 2009. Co-
friends. Four of the 5 panelists responded with confi- lon and Breast Anti-cancer Effects of Peptide Hydro-
dence that they would be willing to purchase a similar lysates Derived from Rice Bran. The Open Bioactive
product with HDRB in a commercial setting if reason- Compounds Journal. 2:17-20.
ably priced. These results show that with further testing Kennedy, E. and H. Luo. 2012. Association between Rice
and adjustments to the formulation, it is possible to in- Consumption and Select Measures of Health and Nu-
corporate HDRB into a bakery product such as a muffin trition. USA Rice Federation. <<http://www.usarice.
to provide protein, fiber, and other nutrients. com/doclib/229/5922.pdf> Accessed July 12, 2012.

The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences 83
Sekhon, K.S., S.S. Dhillon, N. Singh, and B. Singh. 1997. Wadsworth, J.I. and Y.H. Hui. 1992. Encyclopedia of
Functional suitability of commercially milled rice Food Science and Technology. John Wiley & Sons,
bran in India for use in different food products. Plant New York.
Foods for Human Nutrition. 50:127-140.

 
Table 1. Textural properties of muffins as
†
measured by a texture analyzer.
‡
HDRB Level % Firmness (g) Springiness %
§
Control (0) 90.1 ± 10.5d 41.3 ± 6.3a
60 mesh 2.5 65.8 ± 9.9f 37.4 ± 1.4a
60 mesh 5.0 66.3 ± 1.8f 33.7 ± 2.9a
60 mesh 7.5 81.0 ± 8.8e 38.8 ± 4.0a
60 mesh 10.0 78.0 ± 7.3e 32.1 ± 2.6a
60 mesh 15.0 103.0 ± 7.2d 37.7 ± 2.3a
60 mesh 20.0 123.4 ± 62.0c 28.9 ± 14.3b
60 mesh 25.0 156.1 ± 38.9c 40.1 ± 3.0a
80 mesh 2.5 130.1 ± 17.9c 23.9 ± 3.6b
80 mesh 5.0 189.5 ± 33.4b 24.0 ± 1.1b
80 mesh 7.5 148.8 ± 14.0c 28.7 ± 2.7b
80 mesh 10.0 233.3 ± 27.6a 22.2 ± 2.8b
80 mesh 15.0 243.5 ± 47.3a 28.1 ± 4.4b
†
Mean of three measurements ± standard deviation
(P < 0.05).
‡
HDRB = heat stabilized de-fatted rice bran.
§
Values within a column represented with different letters
are significantly different from each other.

Table 2. Color properties of muffins as

†
measured by a chroma meter.
‡ §
HDRB Level % L* a* b*
¶
Control (0) 41.4 ± 0.7b 5.8 ± 0.2a 14.9 ± 0.4b
60 mesh 2.5 46.0 ± 0.6a 6.0 ± 0.1a 17.2 ± 0.8a
5.0 43.5 ± 5.7a 5.7 ± 0.2a 16.6 ± 0.5a
7.5 42.5 ± 0.2a 6.1 ± 0.1a 16.8 ± 0.3a
10.0 41.4 ± 1.4b 5.4 ± 0.2a 15.2 ± 0.8a
15.0 43.9 ± 0.7a 5.9 ± 0.2a 16.6 ± 0.4a
20.0 41.2 ± 0.8b 5.3 ± 0.3a 13.4 ± 0.6b
25.0 43.9 ± 0.7a 5.8 ± 0.3a 15.9 ± 1.5a
†
Values are mean of six measurements ± standard
deviation (P < 0.05).
‡
HDRB = heat stabilized de-fatted rice bran.
§
The L* value is the lightness variable, with values ranging
from 100 (white) to 0 (black). The a* value measures the
color of the sample, positive values being more red and
negative values more green. The b* value also measures
the color of the sample, positive values being more yellow
and negative values more blue.
¶
Values within a column represented with different letters
are significantly different from each other.

84 DISCOVERY • Vol. 14, Fall 2013

 60 mFRB at 2.5% 60 mFRB at 5%
60 mFRB at 10%

60 mFRB at 7.5% 60 mFRB at 15% 60 mFRB at 20%

60 mFRB at 25% Control

Fig. 1. Muffins prepared with 60 mesh fermented rice bran (mFRB) at varying concentrations and control sample;
whole muffin and transverse section.

The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences 85