To clarify the heat-induced gelling properties of myosin prepared from different types of porcine muscles, heat-set gel strength (rigidity) of myosin from M. longissimus lumborum (LL), M. semimembranosus (SM), M. psoas major (PM) and Diaphragm, Pars muscularis (DM) was measured and the effects of actin from LL and DM on those were investigated. Maximum rigidities of the gels were various among myosin gels though optimum pH values for gelation were around 5.7. The addition of LL actin enhanced gel strength of myosin except that from DM, but DM actin had no effect. Interactions between myosin and actin used in this study were confirmed by the measurements of light scattering intensity. It is found that actins from different types of porcine muscles have different effects on heatinduced gelation of myosin.
The influence of trehalose adding and pressure treatment on solubility and gelation of myofibrils and meat patty wasinvestigated.
Myofibrils and meat patty were prepared from chicken breast muscle (pectoralis major muscle). Myofibril was suspended in 0.1–0.2 M NaCl, 20 mM Bis-Tris (pH 6.0 or 7.0) with or without trehalose. Meat patty was mixed with NaCl and trehalose, those final concentrations were adjusted at 0.2 and 0.3 M, respectively.
Addition of trehalose to myofibrils suspension did not considerably effect on solubilization of myofibrillar proteins, myofibrillar structure, and gel strength of heat-induced gel. However, high pressure treatment of myofibrils induced solubilization of myofibrillar proteins accompanying with disorder of myofibrillar structure, and the addition of trehalose stimulates these changes, notably for the myofibrils in 0.2 M NaCl. Myosin and actin, which are a major component of myofibril, was observed in solubilized fraction. Gel strengths of pressure-heat treated myofibrillar gel and meat patty were much higher than that induced by heating alone, and the addition of trehalose improved gel strength. Combined use of the pressure treatment and trehalose adding induced solubilization of myofibrillar proteins, resulting formation of fine network structure in meat patty and increasing gel strength.
The present study demonstrates that high pressure treatment together with the addition of trehalose promotes solubilization of myofibrillar proteins and ameliorates rheological properties of a meat patty. The high pressure treatment prior to heating will be improving the quality of meat products such as sausage.
It is known that brown algae seaweed includes such functional ingredients as ω-3 fatty acid, and these ingredients are present in Ainuwakame(Alaria Praelonga) which is a kind of brown algae. Feeding Ainuwakame to layer hens is expected to improve immune function and to transfer the functional ingredients of the seaweed to eggs. We fed hens for 30 days on a feed with 5% added desalted and dried Ainuwakame powder.
With respect to the amount of change in chemotaxis by macrophages, the rates in hens that ate the 5% seaweed feed tended to be higher than those in controls (P<0.05). However, we found no differences in the amounts of ω-3 fatty acid, fucosterol, or cholesterol in yolks.
The innate immune response in layer hens was improved by the feed with 5% Ainuwakame powder, but no transfer of functional ingredients to egg yolks was observed.
In our previous report, we found that the innate immune response in hens was improved by feed to which 5% of Ainuwakame(Alara praelonga) powder had been added. However, we found no transfer of the functional ingredients of the seaweed to egg yolks. In this study, we fed hens a feed to which extracts from Ainuwakame had been added, and examined its effects on immune function and the transfer of functional ingredients to eggs.
With respect to phagocytosis by heterophils and chemotaxis by macrophages, hens fed 3% extract feed showed higher levels than those fed a feed with 0.003% vitamin E (VE hens) and control hens (P<0.05). The amounts of ω-3 fatty acid in yolk were highest in 3% extract hens at 1,435mg/100g, followed by 689mg/100 g in VE hens, and 651mg/100g in control hens (P<0.01). Furthermore, 3% extract hens showed 20mg/100g fucosterol, while fucosterol was not detected in VE or control hens.
These results indicate that innate immune response was improved by the feed with 3% added extracts from Ainu wakame, and that ω-3 fatty acid and fucosterol levels in egg yolks also increased in hens fed the 3% extract feed.
To evaluate the hygiene of meat in Samoa, we have investigated the surface microbiological profiles (Escherichia coli, coliform, and aerobic bacteria) of meat [beef carcasses (n=180), retail beef (n=18), and imported meat (n=20)] available for public consumption in Samoa. The study was supported by the University of the South Pacific and the Samoan Ministry of Agriculture and Fisheries in March 2010 and April 2011, respectively, and used 3M™ Petrifilm™ agar plates for bacterial enumeration. Mean total coliform counts for all meat samples tested were more than 2 log CFU/cm2, which is within the suspect or marginal range under Australian, New Zealand, EU, and USDA meat standards for beef. Thirty-two percent of samples had aerobic bacteria plate counts of more than 5 log CFU/cm2, and this level is generally considered to issue warning signals for meat hygienic practices and systems to be urgently improved. Retail beef and imported meat were defined as unhygienic based on mean total coliform counts of more than 2 log CFU/cm2. The imported meats originated from New Zealand, Australia, and the USA, and the microbiological counts we observed would be considered unhygienic by the standards of those countries. Overall, the study findings suggested prevailing undesirable aseptic conditions of the meat supply chain in Samoa and provide scientific evidence to support the construction of the hazard analysis critical control point (HACCP)-regulated abattoir currently proposed by the Government of Samoa.