Application of glucose to prepare Aspergillus oryzae koji as an adjunct to prevent rancidity in cheese products.

Koji made using Aspergillus oryzae shows potential for application as a cheese adjunct; however, flavor defects resulting from volatile free fatty acid (FFA) accumulation should be avoided. Hence, a modified glucose-containing whey solid medium was used to culture A. oryzae AHU 7139, and the triacylglycerol (TG) lipase activity and lipase gene (tglA and mdlB) expression were compared with those of a culture using a conventional whey solid medium.

Identification of cheese rancidity-related lipases in Aspergillus oryzae AHU 7139.

The adjunct product with enzymatic activity from Aspergillus oryzae is beneficial for flavor enrichment in the ripened cheese. However, an excessive lipolytic reaction leads to the release of volatile free fatty acids. Accordingly, a strong off-flavor (i.

Zinc Protoporphyrin-Rich Pork Liver Homogenates as Coloring Ingredients in Nitrite-Free Liver Pâtés.

This study aimed to investigate the coloring ingredient potential of liver homogenates that form Zn protoporphyrin (ZnPP), a natural red pigment, after anaerobic incubation. Liver homogenates were used to develop nitrite-free sterile pork liver pâtés. These homogenates were applied in the formulation of pâtés directly or after centrifugation to obtain a pellet that was highly concentrated in ZnPP.

Water extractability of the zinc protoporphyrin IX-myoglobin complex from Parma ham is pH-dependent.

The bright red color of Parma ham is mainly derived from zinc protoporphyrin IX (ZnPP), which exists in both water-soluble and insoluble states. Water-soluble ZnPP mainly binds to hemoglobin, however, the presence of water-insoluble ZnPP remains unexplained. Therefore, we aimed to elucidate how ZnPP exists in a water-insoluble state by focusing on its binding substance.

Dissociation of ferriheme from oxidized heme proteins and re-reduction of ferriheme to ferroheme are crucial for the formation of zinc protoporphyrin IX in nitrite/nitrate-free dry-cured meat products.

Zinc protoporphyrin IX (ZnPP) is the dominant red pigment in nitrate/nitrite-free dry-cured meat products such as Parma ham, and it is considered to be a potential alternative to nitrite/nitrate for reddening dry-cured meat products. Ferroheme and ferriheme dissociated from heme proteins in meat were proposed as substrates to form ZnPP. To elucidate their specific formation mechanism, nitric oxide, carbon monoxide, and azide were used to stable heme in heme proteins.

L-histidine inhibits the heat-induced gelation of actomyosin in a low ionic strength solution.

The heat-induced gelation of actomyosin plays a key role in meat processing. Our previous study showed that L-histidine could affect the characteristics of a heat-induced gel of myosin on a low ionic strength. To apply the specific effect of L-histidine to meat processing, the heat-induced gel properties of actomyosin in the presence of L-histidine were investigated.

Supplementary effect of whey components on the monascin productivity of Monascus sp.

Background: Monascus sp. has been used in fermented foods for centuries. It can synthesize yellow, red, and orange pigments as secondary metabolites.

Evidence of the mechanism underlying zinc protoporphyrin IX formation in nitrite/nitrate-free dry-cured Parma ham.

A large amount of zinc protoporphyrin IX (ZnPP) is found in nitrite/nitrate-free dry-cured meat products, such as Parma ham, and is known to contribute to the favorable bright red color of the latter. ZnPP is a metalloporphyrin, in which zinc is coordinated, instead of iron, in the porphyrin ring. ZnPP proved to be more stable than heme, and its formation should be favored in dried meat products to improve color without the addition of nitrites or nitrates.

Zinc protoporphyrin IX predominantly exists as a complex non-enzymatically bound to apo-hemoglobin in Parma ham.

Most of the water-soluble zinc protoporphyrin IX (ZnPP) in Parma ham mainly exists as complexes with hemoglobin and myoglobin (ZnPP-Hb and ZnPP-Mb). To elucidate the formation mechanism of these complexes, a new experimental model to produce higher amount of water-soluble ZnPP complexes was established. ZnPP-Hb was detected as the main water-soluble ZnPP complex in this model, which is the same as that in Parma ham.

A study of lipolysis induced by adjuncts from edible Aspergillus sp. solid culture products on ripened semi-hard cheese.

Background: Aspergillus sp. has been used in traditional Japanese fermented foods. Protease-containing culture products of A.

High ZnPP-forming food-grade lactic acid bacteria as a potential substitute for nitrite/nitrate to improve the color of meat products.

Zinc protoporphyrin IX (ZnPP)-forming food-grade lactic acid bacteria (LAB) were screened from various sources for their ability to improve the color of meat products. The effects of salt and nitrite on the ZnPP-forming ability of these bacteria were also investigated. Finally, these bacteria were applied in salt-added minced meat to assess their ability to improve the color.

Subsp. Produces Zinc Protoporphyrin IX Both Aerobically and Anaerobically and Improves the Bright Red Color of Fermented Meat Products.

This study assessed the color improvement via zinc protoporphyrin IX (ZnPP) formation in nitrite-free, dry-cured sausages processed using five varieties of ZnPP-forming lactic acid bacteria (LAB). The ZnPP contents and color intensity of the sausages and other technological properties were analyzed during the processing of sausages. LAB count and acidity significantly increased in the LAB-inoculated sausages compared to the control group.

Adjunctive application of solid-state culture products and its freeze-dried powder from Aspergillus sojae for semi-hard cheese.

Background: Species belonging to the genus Aspergillus have been used in traditional Japanese fermented foods. Aspergillus sojae is a species responsible for strong proteolytic activity. Freeze-drying treatments followed by physical disruption enables the pulverization of the mycelia of A.

Searching for high ZnPP-forming edible bacteria to improve the color of fermented meat products without nitrite/nitrate.

In order to improve the color of meat products by producing zinc protoporphyrin IX (ZnPP) in meat, we searched for edible bacteria with high ZnPP-forming ability. Eleven bacteria used in different animal products and 126 bacteria isolated from environmental and probiotic sources were assessed for their ability to form ZnPP. Many bacteria from both sources showed a high ZnPP-forming ability.

Improving the color of meat products without adding nitrite/nitrate using high zinc protoporphyrin IX-forming microorganisms.

Zinc protoporphyrin IX (ZnPP) mainly contributes to the red color of dry cured ham without nitrites/nitrates. Here, we examined the effects of acids used for pH adjustment, pH, and microorganisms on ZnPP formation. The results showed that ZnPP formation and optimal pH were dependent upon the acid type.

Investigation of contributors to zinc protoporphyrin IX formation at optimum pH 5.5 in pork.

We investigated zinc protoporphyrin (ZnPP) formation in pork at pH 5.5, identified the contributors to ZnPP formation, and verified the involvement of myoglobin in this process. When pork homogenate was separated into two water-soluble fractions (>10 and <10 kDa) and an insoluble fraction, ZnPP formation was suppressed.

Enhancement of sperm motility and viability by turmeric by-product dietary supplementation in roosters.

Improving sperm motility and viability are major goals to improve efficiency in the poultry industry. In this study, the effects of supplemental dietary turmeric by-product (TBP) from commercial turmeric production on sperm motility, viability, and antioxidative status were examined in domestic fowl. Mature Rhode Island Red roosters were divided into two groups - controls (groupC) without TBP administration and test subjects (groupT) fed a basal diet supplemented with 0.

Myosin substitution rate is affected by the amount of cytosolic myosin in cultured muscle cells.

In striated muscles, approximately 300 myosin molecules form a single thick filament in myofibrils. Each myosin is continuously displaced by another myosin to maintain the thick filament structure. Our previous study using a fluorescence recovery after photobleaching (FRAP) technique showed that the myosin replacement rate is decreased by inhibition of protein synthesis, but myosin is still exchangeable.

Diet-Induced Thermogenesis and Expression Levels of Thyroid Hormone Target Genes and Their Products in Rats Differ between Meat Proteins.

We compared the effects of purified meat proteins on postprandial thermogenesis and on the secretion of and responsiveness to thyroid hormones (THs) in rats. Body temperatures at 2 h after feeding were significantly higher in the chicken and mutton protein groups than in the other groups, and these proteins seem to have a strong thermogenic effect. There were no significant differences in plasma TH concentrations among the groups, but levels of TH-responsive Spot 14 protein in the liver and brown adipose tissue were significantly higher in the chicken and mutton protein groups than in the other groups.

Dynamics of myosin replacement in skeletal muscle cells.

Highly organized thick filaments in skeletal muscle cells are formed from ~300 myosin molecules. Each thick-filament-associated myosin molecule is thought to be constantly exchanged. However, the mechanism of myosin replacement remains unclear, as does the source of myosin for substitution.

Comparative study of muscle regeneration following cardiotoxin and glycerol injury.

In the present study, we examined muscle regeneration following two types of chemical injuries, cardiotoxin (CTX) and glycerol, in order to compare their effect on the morphological characteristics during muscle regeneration, in addition we studied the structural changes of the intramuscular connective tissue (IMCT) during the regeneration process, by scanning electron microscopy (SEM) after digestion of the cellular elements of the muscle with sodium hydroxide. Tibialis anterior (TA) muscles of adult male mice were injected either with CTX or glycerol. Muscle degeneration was greater in the CTX-injured model than in the glycerol-injured model at day 4 post injection.

Role of Heavy Meromyosin in Heat-Induced Gelation in Low Ionic Strength Solution Containing L-Histidine.

The gelation of myosin has a very important role in meat products. We have already shown that myosin in low ionic strength solution containing L-histidine forms a transparent gel after heating. To clarify the mechanism of this unique gelation, we investigated the changes in the nature of myosin subfragments during heating in solutions with low and high ionic strengths with and without L-histidine.

A comparative study of zinc protoporphyrin IX-forming properties of animal by-products as sources for improving the color of meat products.

The objective of this study was to obtain fundamental data for improving the color of meat products by using animal by-products. We investigated zinc protoporphyrin IX (ZnPP)-forming properties of various internal organs from pigs and chickens. ZnPP was formed in the liver, heart and kidney, whereas the porcine spleen and bile, which are involved in the metabolism of heme, did not have ZnPP-forming properties.

Postprandial thermic effect of chicken involves thyroid hormones and hepatic energy metabolism in rats.

We investigated the postprandial thermic effect of chicken and its mechanisms in rats. A chicken diet showed a strong thermic effect after consumption, and the removal of fat induced more rapid and stronger thermogenesis. Although thermogenesis induced by a purified chicken protein diet was also strong, the thermic reaction was not so rapid and a remarkable rise of peripheral temperatures was not observed.

Laminin binds to myostatin and attenuates its signaling.

Myostatin is a growth and differentiation factor and acts as a negative regulator of skeletal muscle mass. Although the mechanism whereby myostatin controls muscle cell growth is mostly clarified, the regulation of myostatin activity after its secretion into the extracellular matrix (ECM) is still unclear. In the present study, we investigated the interaction between laminin and myostatin and the effect of laminin on myostatin signaling in vitro.