Abstract:

This study attempted to reduce the content of sodium ion in low-temperature gel-type meat products byinvestigating the effect of partial substitution of NaCl by calcium diglutamate on processing properties of rabbit myofibrillarproteins. Rheological properties and water-holding capacity (WHC) of heat-induced gels from myofibrillar proteins extractedfrom rabbit Pasoas major (PM) muscle with the addition of 1.25% calcium diglutamate and 0.4%, 0.8%, 1.2%, 1.6% or 2.0%salt (comprised of 70% NaCl and 30% KCl) as well as emulsification capacity, emulsion stability, and water- and oil-bindingcapacities of myofibrillar protein-lipid emulsion composite gels were measured and compared with those observed when 3%salt was added (control). The results showed that the storage modulus (G’) of heat-induced myofibrillar gels was increasedwith increasing salt concentration and showed a significantly higher level at a salt content of 1.2% than at 3% (P ＜ 0.05);however, the WHC was decreased after an initial increase and reached the best level when the amount of added salt was1.2%. In addition, the emulsification capacity of myofibrillar protein-lipid emulsion composite gels was positively dependentupon salt concentration, and the highest emulsion stability was achieved at 0.8% and 1.2% without significant difference ascompared with the control group (P ＞ 0.05). The 1.2% and 1.6% salt groups exhibited significantly increased water- andoil-binding capacities compared with the control group (P ＜ 0.05). In conclusion, low sodium conditions caused by addingcalcium diglutamate improves the viscoelasticity and water- and oil-binding capacities of rabbit myofibrillar proteins. Hence,the NaCl content of gel-type low-temperature meat products can be reduced to 0.84%.

Key words: calcium diglutamate, low sodium, myofibrillar proteins, heat-induced gel properties, emulsification