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Journal of Tea Science Research 2013, Vol.3, No.1, 1-6
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Research Article
Open Access
Fat Bloom and Polymorphism in Chocolate Prepared with Modified Tea Seed Oil
Soheila Zarringhlami , Mohammad Ali Sahari , Mohsen Barzegar , Zohreh Hamidi Esfehani
Department of Food Technology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
Corresponding author email: sahari@modares.ac.ir;
Journal of Tea Science Research 2013, Vol.3, No.1 doi: 10.5376/jtsr.2013.03.0001
Received: 6 Feb., 2013
Accepted: 28 Feb., 2013
Published: 28 Apr., 2013
Copyright
©2013 Sahari et al. This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Sahari et al., 2013, Fatbloom and Polymorphism in Chocolate Prepared with Modified Tea Seed Oil, Journal of Tea Science Research, Vol
.
3, No. 1 1-5 (doi:
10.5376/jtsr.2013.03.0001)
Abstract
In order to produce cocoa butter replacer (CBR), tea seed oil was modified with enzymatic interesterification. The
modified product was then added to dark chocolate formulation as a replacement for 10%, 15% and 20% of cocoa butter (CB) to
study fat bloom formation and polymorphic structure in these samples.
Keywords
Fat bloom; Polymorphism; Chocolate; Modified tea seed oil
Practical Applications
According to our results, higher levels of fat bloom
occurred in the chocolate sample without CBR
(chocolate containing 100% CB, CBCH), compared
with other chocolate samples. However, among the
chocolates containing enzymatic interesterified sample
(EIS) at various levels of 10%, 15% and 20%, the
chocolate sample containing 10% of EI (EICH)
showed lower fat bloom development during storage
period (20 days). The results of polymorphic structure
evaluation using X-ray diffractometer (XRD) showed
new β-crystalline form with the XRD pattern close to
that of β-VI and the m.p. appeared similar to β-V in
CB. Also, XRD pattern of EIS showed β′-crystalline
form in this sample. Presence of two crystalline forms
(β and β′) in the EICH revealed that, adding 10% of
the CBR prepared in the current study to chocolate
formulation had probably no adverse effect on
β-crystal formation in the chocolate sample.
Introduction
Fat bloom is a physical defect that during storage
appears as dusty white spots or as a white film on the
chocolate surface (Loisel et al., 1998; Sonwai and
Rousseau, 2006). This defect is a major concern to
chocolate industry because it makes the visual and
textural quality of the product undesirable to
consumer (Schenk and Peschar, 2004). Although fat
bloom has been studied extensively for many years,
the blooming mechanism is not clearly understood
(Walter and Camillon, 2001; Smith et al., 2007).
Nevertheless, it is now accepted that bloom occurs
through polymorphic transition of CB (Guthrie et al.,
2005; Smith et al., 2007). Polymorphism is defined as
the ability of a substance to exist in more than one
crystalline form in a crystal lattice (Oh and Swanson,
2006). This polymorphism, is a critical step in
chocolate making, and has been studied extensively in
the last century (Wille and Lutton, 1966; Chapman et
al., 1971; Malssen et al., 1996; Schenk and Peschar,
2004). Several techniques such as differential scanning
colorimetery, light microscopy, pulsed nuclear magnetic
resonance, and X-ray diffractometer (XRD) have been
used to determine polymorphic structures of lipids
(Guthrie et al., 2005). Among these methods, XRD is
a powerful tool, which provides direct structural
information for identifying the types of crystals
(Malssen et al., 1996; Langevelde et al., 2001; Schenk
and Peschar, 2004; Guthrie et al., 2005). The
technique shows at least five different crystalline
forms with different characteristic patterns; γ, α, β′
and β (V, VI), in CB (Figure 1). In high quality
chocolates, CB is crystallised in the β-V form.
However, β-VI is the most stable polymorph and the
transition of β-V to β-VI is one of the important
theories in fat bloom formation (Wille and Lutton,
1966; Bricknell and Hartel, 1998; Graef et al., 2005;
Khan and Rousseau, 2006). It is known that
production parameters and storage conditions,
including poor tempering, incorrect cooling methods,
presence of soft fats in the centers of chocolates, warm
storage conditions, and addition of fats as CBRs, can
cause fat bloom formation in the chocolate formulation
(Walter and Camillon, 2001; Lonchampt and Hartel, 2006).
Due to CB’s unique physico-chemical properties,