Gelation and microstructural properties of fish myofibrillar protein gels with the incorporation of l‐lysine and l‐arginine at low ionic strength

Abstract

BACKGROUND: The solubility limitation and poor gelation properties of myofibrillar proteins at low ionic strength are the most challenging obstacle to limit salt reduction in meat products. In the present study, five amino acids with different concentrations of 5, 10 15, and 20 mmol L -1 , L-lysine (Lys), L-arginine (Arg), L-histidine (His), L-proline (Pro) and L-glycine (Gly), were introduced into myofibrillar protein (MP) suspensions at low ionic strength to improve solubility and gelation properties. RESULTS:The dynamic rheological analysis showed that the MPs at 100 mmol L -1 NaCl containing 15/20 mmol L -1 Lys/Arg exhibited similar gelling behaviors to MPs at 600 mmol L -1 NaCl. Similarly, 15/20 mmol L -1 Lys/Arg significantly increased the solubility of MPs and the water holding capacity (WHC) and gel strength of MP gels, which was comparable to those of MPs at 600 mmol L -1 NaCl. Furthermore, Lys and Arg promoted the formation of aggregation-type gel with a dense and compact structure observed by scanning electron microscopy. The gels containing 15/20 mmol L -1 Lys/Arg exhibited a significant increase in the proportion of immobilized water (P 21 ).CONCLUSION: The enhancement of WHC, gel strength, and P 21 was closely associated with the increased solubility and the dense microstructure induced by Lys and Arg with high concentrations of 15 and 20 mmol L -1 . The knowledge obtained from this study may be useful for the improvement of gelation properties of MPs at low ionic strength using L-lysine and L-arginine.

Effects of hydrodynamic cavitation on physicochemical structure and emulsifying properties of tilapia (Oreochromis niloticus) myofibrillar protein

“…The changes in the pH of TMP suspension as affected by HC treatment are shown in Table 1 . Compared with control group (0 min), HC increased the pH of TMP suspension significantly ( P < 0.05) by approximately 0.06 units ( Table 1 ), indicating that HC induced a pH transition to alkaline, which was beneficial to the solubilization of TMP ( Table 1 ) ( 21 ). However, with the extension of HC treatment time, pH only decreased slightly, indicating that pH was not the main factor in solubility reduction, which might be due to the thermal effect generated by long HC treatment time ( 17 ), resulting in TMP aggregation.…”

“…The TMP extraction procedures were adopted from a recent study ( 21 ), with slight modifications. Briefly, after small pieces of tilapia fish and a small amount of frozen isolation buffer (25 mmol/L KCl, 3 mmol/L MgCl 2 , 0.1 mol/L NaCl, 4 mmol/L EDTA-2Na, 20 mmol/L phosphate buffer, pH 7.0) were ground in a meat grinder (ZG-L74A, Ningbo Zhao Ji Electric Appliance Co., Ltd., Ningbo, China), the cooling isolation buffer (4°C) was added until the total volume of isolation buffer was five times (w/v) the weight of the tilapia fish.…”

“…The pH of TMP samples was measured as described by Wang et al ( 21 ), using a pH meter (PHS-3E, INASE Scientific Instrument Co., Ltd., Shanghai, China).…”

Effect of Ultrasound Combined with Glycerol-Mediated Low-Sodium Curing on the Quality and Protein Structure of Pork Tenderloin

“…As depicted in Figure 5 a, the MPs in the control group showed a loose and rough structure, probably due to the electrostatic interactions caused by low ionic strength to form myosin filaments [ 53 ]. There was no significant change in the microstructure of MPs in the group with 1% glycerol addition ( Figure 5 b) compared to the control group.…”

Effect of combined treatment of l-arginine and transglutaminase on the gelation behavior of freeze-damaged myofibrillar protein

“…As a potential substitute for NaCl and polyphosphates in meat processing, Arg is a functional amino acid that exhibits multiple beneficial physiological functions to the human body. It has also been proved to cause the unfolding of myosin molecules and the exposure of functional groups, 24 resulting in enhancing the accessibility of TG to substrates. Therefore, this study was designed to explore the effect of Arg-induced structural changes on the crosslinking of TG on freeze-damaged myofibrillar protein (MP), and the influence of their combination (Arg + TG) on the heat-induced gel performance of freeze-damaged MP was also investigated.…”