For better understanding of the antistaling effect of starch-hydrolyzing enzymes, maltose-, maltotriose-, or maltotetraose-producing enzymes were applied to bread mix and the retrogradation rate of the bread was determined using differential scanning calorimetry. A new amylase isolated from Bacillus subtilis SUH 4-2, which selectively produces maltose and maltotriose from starch solution (amylase II), and another amylase from Streptomyces albus KSM-35, mainly producing maltotetraose and maltotriose (amylase IV), were cloned, characterized, and evaluated as antistaling agents for bread. Addition of amylase II or amylase IV significantly reduced the bread staling rate during 7 days of storage (p < 0.05), and especially amylase IV was as effective as a commercial enzyme, Novamyl. Analyses of the maltooligosaccharide composition of bread suggest that maltotriose and maltotetraose produced by the enzyme reaction are responsible for retarding bread retrogradation.

Cetylpyridinium chloride (1-hexadecylpyridinium chloride, CPC) was evaluated for its effectiveness in removing or killing salmonellae attached to poultry skin. Two different treatment methods were used: (i) spraying 0.1% CPC solution at 15 degrees C or 50 degrees C against inoculated skin surface for I min at 138 kPa, and (ii) immersing inoculated skin surface in 0.1% CPC solution at room temperature for either 1 min, 1 min plus 2 min holding without CPC, or 3 min. After rinsing, cells on the skins were enumerated by conventional plating as well as direct counting from scanning electron microscopy (SEM). Compared with controls, CPC spraying reduced the numbers of salmonellae by 0.9 to 1.7 log units (87 to 98%) assayed by the plating method (P < 0.05). SEM gave results similar to plating. Generally 50 degrees C CPC spraying showed greater reduction than 15 degrees C CPC spraying; however, the differences were not always significant. Water spraying at either temperature did not show any reduction compared to nonsprayed skins. In the immersion test, significant differences also were noticed among the control and the three other CPC-immersed groups (P < 0.05) as assayed by plating, ranging from 1.0 to 1.6 log units, which were similar to the CPC spraying results. However, no difference was noticed among the three CPC-immersed groups. Direct counting from SEM was not a suitable method for recovering cells in CPC immersion tests because dead cells were still attached to the skin while retaining their intact morphology. On the basis of the amount of CPC used, immersion appears to be more cost-effective than spraying CPC on poultry skin.

Trisodium phosphate (TSP) was evaluated as a means to reduce Campylobacter on chicken carcasses. Post-chill chicken carcasses were dipped into a 10% TSP solution at 50°C for 15 s. After storing the TSP-treated carcasses for 0, 1 or 6 days at 4°C, the carcasses were subjected to the recovery of Campylobacter. The incidence and reduction of Campylobacter attached to the carcasses were measured using a nitrocellulose (NC) membrane lift, conventional culture method, and a most probable number (MPN) technique. In trials 1 and 2, the incidence of Campylobacter was measured. For 1 day-stored groups, Campylobacter was present on 96 and 100% of control carcasses and present on 24 and 28% of TSP-treated carcasses as measured by NC membrane lift method. The reduction was less (4 to 36%) when measured by culture method. For carcasses immediately subjected for the recovery of cells after treatment, there was no difference between TSP-treated and control carcasses by either NC membrane or culture method. In trial 3, the reduction levels of Campylobacter were quantified by using a MPN method. The levels of Campylobacter on carcasses were decreased by 1.5 and 1.2 logs in 1- and 6-day stored, TSP-treated carcasses, respectively (p &lt; 0.05). However, TSP treatment at 10°C reduced the level of Campylobacter only by 0.16 log (p &gt; 0.10).

Hypoxic training is believed to be generally useful for improving exercise performance in various athletes. Nowadays, exercise intervention in hypoxia is recognized as a new therapeutic modality for health promotion and disease prevention or treatment based on the lower mortality and prevalence of people living in high-altitude environments than those living in low-altitude environments. Recently, resistance training in hypoxia (RTH), a new therapeutic modality combining hypoxia and resistance exercise, has been attempted to improve muscle hypertrophy and muscle function. RTH is known to induce greater muscle size, lean mass, increased muscle strength and endurance, bodily function, and angiogenesis of skeletal muscles than traditional resistance exercise. Therefore, we examined previous studies to understand the clinical and physiological aspects of sarcopenia and RTH for muscular function and hypertrophy. However, few investigations have examined the combined effects of hypoxic stress and resistance exercise, and as such, it is difficult to make recommendations for implementing universal RTH programs for sarcopenia based on current understanding. It should also be acknowledged that a number of mechanisms proposed to facilitate the augmented response to RTH remain poorly understood, particularly the role of metabolic, hormonal, and intracellular signaling pathways. Further RTH intervention studies considering various exercise parameters (e.g., load, recovery time between sets, hypoxic dose, and intervention period) are strongly recommended to reinforce knowledge about the adaptational processes and the effects of this type of resistance training for sarcopenia in older people.