Characterization of spray-dried soy sauce powders using maltodextrins as carrier
Wei Wang, Weibiao Zhou
Food Science and Technology Programme, c/o Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
Received 10 September 2011
Received in revised form 10 November 2011
Accepted 12 November 2011
Available online 22 November 2011
Powdered soy sauce
Soy sauce powders were made by spray drying liquid soy sauce using maltodextrin as the drying aid.
Three types of maltodextrin, i.e. DE 5, DE 10 and DE 15, were studied and compared. Each type was incor-
porated into soy sauce with concentration levels of 20% and 40% (w/v), respectively, as a carrier. The
spray-dried soy sauce powders were mixtures of amorphous substances and crystalline salts. Caking
related properties including particle size distribution, hygroscopicity, glass transition temperature, ﬂow-
ability and caking strength of the powders were characterized. Soy sauce powders produced from the
feed solution of maltodextrin concentration of 40% had a larger particle size dispersion, reduced hygro-
scopicity, higher glass transition temperatures and smaller cohesive index than their 20% concentration
counterparts. Maltodextrin of a smaller DE value produced soy sauce powders with less cohesion, higher
glass transition temperature and reduced hygroscopicity. Maltodextrin concentration and DE value
greatly inﬂuenced the caking strength of the soy sauce powders, with different mechanisms and effects
under different storage conditions.
Ó 2011 Elsevier Ltd. All rights reserved.
Soy sauce is a traditional condimentpopularlyproducedand con-
sumed in East Asian countries such as Japan, Korea and China. Soy
sauce was mainly used in liquid form from the past, but recently, dif-
ferent types of soy sauce powders have been developed and mar-
keted. Soy sauce powders commercially available are mainly
manufactured by spray drying, although other dehydration methods
such as freeze drying and drum drying can also be used. Powdered
soy sauces were ﬁrstly used in the soup base of instant noodles.
Now their application has been expanded to powdered seasoning,
frozen food, processed meat, etc. (Okayasu and Hamano, 2003).
However, caking or stickiness as one of the major degradation
problems hindered the development of soy sauce powders (Hama-
no and Sugimoto, 1979; Okayasu et al., 2005). The problem is
mainly due to the existence of low molecular weight sugars with
low glass transition temperatures (T
). Moreover, the high hygro-
scopicity of small molecular sugars and organic acids in powder
materials can reduce T
through moisture adsorption from sur-
rounding air. Water as a signiﬁcant plasticizer can greatly reduce
(Liu et al., 2006). When T
is reduced below ambient tempera-
ture, particle bridging and agglomerations happen though the
drive of surface tension or external force (Aguilera et al., 1995;
According to Hartmann and Palzer (2010), crystalline and
amorphous powders have different caking mechanism. Moreover,
particle sizes of powders inﬂuence the degree of caking (Palzer,
2005). Therefore, to study the caking characteristics of soy sauce
powders, their particle size distribution and crystallinity need to
be characterized. So far, there have been no universally agreed
methods on quantitative measurement of caking degree (Listiohadi
et al., 2008).
Using maltodextrins as a drying carrier to produce food powders
is a popular method today (Bhandari et al., 1997; Sablani et al.,
2008; Cai and Corke, 2000; Ersus and Yurdagel, 2007; Tonon
et al., 2008). It can signiﬁcantly increase the T
and reduce the
hygroscopicity of dried products (Goula and Adamopoulos, 2008a,
2010). However, there have been very limited researches on the
properties of soy sauce powders using maltodextrins as a carrier.
The objective of this study was to spray dry soy sauce by using
maltodextrins as a drying carrier and characterize powder proper-
ties relevant to caking. It aimed to lay a foundation for the industrial
development and application of powdered soy sauce products.
2. Materials and methods
2.1. Raw materials
Naturally brewed soy sauce was obtained from Kikkoman Pte.
Ltd. (Singapore); its composition included 10.3% of proteins, 8.1%
of carbohydrates, 16.5% of NaCl and the rest being water. Malto-
dextrins STAR-DRI 5
, STAR-DRI 10
and STAR-DRI 15
obtained from Tate & Lyle (USA); their dextrose equivalent (DE)
values were 4–7% (DE 5), 9–11% (DE 10), and 13–17% (DE 15),
0260-8774/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
Corresponding author. Tel.: +65 6516 3501; fax: +65 6775 7895.
E-mail address: firstname.lastname@example.org (W. Zhou).
Journal of Food Engineering 109 (2012) 399–405
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