Influence of ingredients on the thermo-rheological behaviour of batters containing methylcellulose

This study investigated the effect of a number of commercial-grade ingredients, either polysaccharides (wheat starch, corn starch and dextrins) or with a high protein content (gluten and dried egg), on the viscous and dynamic viscoelastic behaviour of a batter containing methylcellulose (MC) employed in a process that does not require a pre-frying step. Replacing part of the wheat flour present in a reference batter formula with either gluten or dried egg yielded an increase in the actual concentration of proteinic material, which resulted in batters that exhibited more marked shear-thinning behaviour at 15°C. Conversely, the consistency of batters dropped when wheat flour was partially replaced with either wheat starch or modified corn starch, probably due to the 'dilution' effect of the polysaccharidic material on the wheat flour proteins which, in practice, form the network responsible for viscosity development in the batters studied at 15°C. A similar approach is used to explain the dynamic viscoelastic results at 15°C. The storage and loss moduli both increased upon adding proteinic ingredients but decreased when some of the polysaccharide ingredients partially replaced the wheat flour. However, at 60°C the opposite tendency was observed, since both viscoelastic moduli decreased in protein-enriched batters as a consequence of the disruption of starch gelatinisation. On the other hand, both storage and loss moduli were observed to be higher in batters where wheat flour was partially replaced by native wheat starch or corn starch, which were already beginning to gelatinise at 60°C. The characteristic gelling pattern of MC, which is the key component to avoid the pre-frying step, was practically unaffected by the ingredients studied. Finally, the thermoreversibility of the gelation process after a sudden increase in temperature up to 45, 60 or 80°C, was progressively less evident as the final temperature increased. This is attributed to the fact that gelatinised starch reinforced the batter structure to a greater degree as the temperature was raised.

Bibliographic Details

Main Authors:	Sanz Taberner, Teresa, Salvador, Ana, Vélez, Genovera, Muñoz, José, Fiszman, Susana
Other Authors:	Comisión Interministerial de Ciencia y Tecnología, CICYT (España)
Format:	artículo biblioteca
Published:	Elsevier BV 2005-09
Subjects:	Batter, Methylcellulose, Thermorheology, Ingredients,
Online Access:	http://hdl.handle.net/10261/333654
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