Physiological behavior and quality of fresh ginseng stored in modified atmospheres generated by several package films.

Physiological behaviors and quality attributes of fresh ginseng (Panax Ginseng) stored in modified atmospheres generated by several package films were investigated. The chemical compositions were also measured before and after storage. The respiration rates of fresh ginseng were inhibited effectively by film package, especially in package with lower gas permeability coefficient film. The polyphenol oxidase (PPO) activity reduced markedly and high Hunter L (*) value was maintained. Significant differences (p < 0.05) in firmness, weight loss, decay rate and pectin content were found between 0.10 mm packages and 0.05, 0.07 mm packages after 5 months of storage. The best quality parameters of fresh ginseng were obtained from the combination of 0 °C-0.10 mm. Significant difference (p < 0.05) in total saponin content was not found, and the highest total saponin content was also obtained from the combination of 0 °C-0.10 mm. The content of total sugar and reducing sugar increased significantly (p < 0.05), especially for package film with higher gas permeability coefficient. The storage life of fresh ginseng was extended significantly by film packages to 5 months with good quality and lower decay rate, especially for package film with low gas permeability coefficient.

Unnatural isotopic composition of lithium reagents.

Isotopic analysis of 39 lithium reagents from several manufacturers indicates that seven were artificially depleted in (6)Li significantly in excess of the variation found in terrestrial materials. The atomic weight of lithium in analyzed reagents ranged from 6.939 to 6.996, and δ(7)Li, reported relative to L-SVEC lithium carbonate, ranged from -11 to +3013‰. This investigation indicates that (6)Li-depleted reagents are now found on chemists' shelves, and the labels of these (6)Li-depleted reagents do not accurately reflect the atomic and (or) molecular weights of these reagents. In 1993, IUPAC issued the following statement: "Commercially available Li materials have atomic weights that range between 6.94 and 6.99; if a more accurate value is required, it must be determined for the specific material." This statement has been found to be incorrect. In two of the 39 samples analyzed, the atomic weight of Li was in excess of 6.99.