The effects of ultrapasteurization with and without homogenization on the chemical, physical, and functional properties of aseptically packaged liquid whole egg

Manothermosonication - A potential alternative to thermal pasteurisation of liquid whole egg: Comparison of physico-chemical attributes

Liquid egg products are typically exposed to a defined thermal load to achieve the required safety level, under which their functional properties can be adversely affected. In this study, manothermosonication (MTS) (132 μm, 300 kPa) was investigated as alternative preservation for liquid whole egg (LWE) compared to thermal pasteurisation (60 °C, 3.5 min), assessing results against untreated (fresh) LWE in terms of selected physico-chemical properties. Results showed that MTS resulted in improved LWE foaming properties, increasing foam capacity by a 3.2-fold factor compared to thermal treatment. Emulsion stability was also enhanced after MTS, exhibiting smaller droplet size, and a higher elasticity of gels was obtained. Regarding the protein properties, favourable protein changes (protein unfolding) were identified for MTS through direct (asymmetric flow field flow fractionation) and indirect (surface hydrophobicity and sulfhydryl group content) measurements. In addition, an increase in protein solubility of 11.4 % was observed in MTS compared to thermal treatment.

The characterization and incidence of pale, soft, exudative turkey meat in a commercial plant

Pale, soft, exudative (PSE) turkey meat is a growing problem for industry and has been associated with rapid postmortem pH decline and loss of protein functionality, similar to PSE pork. This study was designed to estimate the incidence of PSE meat in a commercial plant and use response surface methodology to characterize the relationship between pH, lightness (L* value), and water-holding capacity (WHC). One hundred thirty-four turkey breast fillets were selected from the processing line so that 67 had normal color (lightness), and the other 67 were more pale than normal. Fillets were analyzed at time of deboning (1.5 h postmortem) and at 24 h postmortem for color (L* value), pH, drip loss, expressible moisture, and temperature. Additionally, L* values were measured on 2,995 turkey breasts from the processing line to determine the commercial incidence of PSE meat based on color. The pale fillets had significantly lower pH, greater L* value, and less WHC but equal temperature when compared with the fillets with normal color. The L* value and pH were correlated with WHC as measured by expressible moisture, but L* value seems to have more predictive value. By using the L* value range (>53) from the pale-selected fillets as an indication of paleness, approximately 40% of the 2,995 fillets would exhibit poor WHC. These results suggest that PSE meat can represent a significant portion of commercially processed turkey breast meat and that the L* value measurement could be used to sort turkey meat so that PSE type meat could be used in specialized formulations.

Using response surface analysis to optimize the quality of ultrapasteurized liquid whole egg

Response surface analysis (RSA) is used to show the effects of a range of heat pasteurization times and temperature combinations on several quality factors of liquid egg. The purpose of this paper is not to suggest the rigid processing time and temperature combinations to give maximum quality but to illustrate that RSA can be used as a tool to predict individual and multiple egg functional properties resulting from various processing conditions. The application of heat will change the quality and functional properties of the liquid egg. This paper describes the application of RSA to the changes in soluble protein, alpha-amylase, solids content, viscosity, and the height of cakes made with processed liquid whole egg (LWE). The Mallow's Cp statistic is used to determine the best model while minimizing the number of terms in the model. By using this method of choosing the model, the number of terms desired in the model can be first determined then the best fit can be determined from the possible models. The time and temperature combinations are in the ultra-high temperature range for eggs (30, 60, and 95 s each at 64, 68, and 72 C). The RSA may be used to optimize the quality and functionality of LWE while ensuring the safety of the product. This information can be used (with further testing) to maximize desirable and minimize undesirable product properties.