ABSTRACT
This study was carried out to assess the quality properties, components associated with taste and aroma of beef as a function of breed. For this purpose, steers from four Korean native cattle breeds: Hanwoo (n=10), Chikso (n=10), black Hanwoo (n=12, BHW) and Jeju black cattle (n=12, JBC) were used. The steers all were raised under identical conditions and finished at a similar age of around 30-months old. Following 24 h of slaughter, all longissimus lumborum muscles were collected and used for analysis of meat quality, fatty acids, and flavor-related components (metabolic compounds, free amino acids, and aroma volatiles). The Hanwoo presented a significantly higher intramuscular fat content (IMF, 22.85%) than the BHW (11.78%), Chikso (9.25%), and JBC (9.14%; p<0.05). The meat of Hanwoo breed showed lighter and redder color, and lower shear force value (p<0.05). The JBC presented a "healthier" fatty acid profiles as it had a higher total unsaturated fatty acids content (p<0.05). With regard to flavor-related components, Hanwoo also had higher total contents of free amino acids and metabolites associated with umami and sweet tastes, and fat-derived volatile compounds (aldehydes, alcohols, and ketones) associated with fatty aroma. It may be concluded that there was a considerable difference in the meat quality properties among breeds. The variations of IMF content and flavor-related components may be the main factors contributing to the typical flavors of beef among the four Korean native cattle breeds.
ABSTRACT
Recent studies have indicated that Ginsenoside Rb1, one of the major components of ginseng root, may play an important role in protecting cells from damage. Here, we investigated the neuroprotective activity of Rb1 after hypoxic injury in young rats. About 50% animals were dead by exposing hypoxic condition three times in three consecutive days. Then, the pretreatment with Rb1 prior to hypoxic stimulation reduced animal death to 12%, and also significantly reduced the recovery time from hypoxia-related, compromised symptoms in survived animals. Rb1 also significantly reduced levels of lactate dehydrogenase (LDH) release from primary hippocampal neurons which were maintained at low oxygen concentration, indicating increased neuronal survival by Rb1. Ca(2+)/calmodulin-dependent kinase II (CaMKII) activity in the hippocampal tissues of hypoxia-induced rats was decreased to about 50% of the control animal. Then Rb1-treatment prior to hypoxic stimulation significantly elevated Ca(2+)-independent kinase II activity when measured 48 hr after hypoxic stimulation. Thus, the present data suggest that calcium independent CaMKII activity may be involved in the process of ginsenoside Rb1-mediated recovery of neuronal cells after hypoxic damage.
