Rheology, Microstructure, and Baking Characteristics of Frozen Dough Containing Rhizopus chinensis Lipase and Transglutaminase

Abstract

The beneficial effects of a new recombinant lipase (Rhizopus chinensis lipase [RCL]) and transglutaminase (TG) were investigated on frozen dough systems and their breadmaking quality. Rheological properties and microstructure of doughs were measured using a dynamic rheometer, rheofermentometer F3, and scanning electron microscopy (SEM). Measurements of viscoelastic properties showed that both G′ and G″ of dough containing RCL and TG were greater than those of the control after 35 days of frozen storage. The SEM micrographs showed that dough containing RCL and TG had the most starch granules embedded in or attached to the gluten network, and the gluten seemed more powerful and resilient than for the control dough after 35 days of frozen storage. Results of the gas production and dough development tests indicated that RCL and TG improved the rheofermentative characteristics of frozen dough. RCL and TG could improve water‐holding capacity and significantly increase the glycerol content of the control dough. Image analyses showed that bread crumbs containing RCL and TG had a more open network and uniform crumb structure, which resulted in higher specific volume. This combination also yielded a product with higher sensory scores for test breads.

Advances in present‐day frozen dough technology and its improver and novel biotech ingredients development trends—A review

“…In an earlier study (Huang, Yuan, Kim, & Chung, 2008), the use of transglutaminase improved frozen dough quality through its protein polymerization ability which stabilized the gluten structure embedded in the starch granules. Similar synergistic findings were reported in doughs containing recombinant lipase (Rhizopus chinensis lipase) and transglutaminase enzymes stored at −18°C for 7-35 days; rheofermentative and water holding capacities of the frozen dough were improved (Li et al, 2011). In another study , transglutaminase treatment significantly decreased the ratio of HMW-GS: LMW-GS and GMP content in fresh dough and GMP particle size increased.…”

“…This notion was confirmed in a study by Steffolani, Ribotta, Perez, Puppo, and León (2012), where transglutaminase added at intermediate levels resulted in the largest bread volume compared to control (without added enzymes) and other two enzyme (pentosanase and glucose oxidase) samples of frozen dough stored at −18°C for 0-9 weeks. Additionally, the samples had a more open network and uniform crumbs, higher specific volume with higher sensory scores for the product (Li et al, 2011). However, lipase known to catalyze hydrolysis and/or synthesize the ester bond (s) of glycerol (phospho-or glycol) lipids (Gerits, Pareyt, Decamps, & Delcour, 2014) had no effect on GMP particle size , but its specificity to lipid fractions in frozen dough may exert major roles in gas incorporation and stabilization after frozen storage (Pareyt, Finnie, Putseys, & Delcour, 2011).…”

The Combination of Rhizopus chinensis Lipase and Transglutaminase Affects the Rheology and Glutenin Macropolymer Properties of Frozen Dough

“…Among other reasons, the loss of GMP after TG treatment has been attributed to an increased SDS solubility owing to structure changing of glutenins (Steffolani et al 2008). TG catalyzes the formation of isopeptide bonds producing large protein polymers, which increase the water-holding capacity of dough and reduce its freezable water content (Li et al 2011). The GMP content decreased as the frozen storage time increased (Table I).…”

“…Changes in free thiol groups were determined according to the method of Li et al (2011) using Ellman's reagent, which contained 4 mg of 5,59-dithiobis-2-nitrobenzoic acid in 1 mL of Tris-glycine buffer (pH 8.0) and was prepared daily. First, 0.2 g of dough (fresh or thawed) was suspended in 1 mL of guanidine hydrochloride (GuHCl)/Tris-glycine solution, which consisted of Tris-glycine buffer (8.5mM Tris, 9.2mM glycine, and 0.3mM ethylenediaminetetraacetic acid, pH 8.0) and 5M GuHCl.…”

“…In our earlier research, we were able to show how Rhizopus chinensis lipase (RCL), a new recombinant lipase from R. chinensis CCTCC M201021 (Yu et al 2009) and TG could be properly utilized in frozen dough to increase yeast viability and keep the integrity of the gluten network (Li et al 2011). However, it is necessary to understand the effect of frozen storage on the particle size and composition of GMP, particularly when frozen dough improvers such as enzymes are added.…”