Evaluation of analysis of polycyclic aromatic hydrocarbons by the QuEChERS method and gas chromatography-mass spectrometry and their formation in poultry meat as affected by marinating and frying

The objectives of this research were to develop a method for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in poultry meat by combining the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method with gas chromatography-mass spectrometry (GC-MS) and study their formation during marinating and frying. The recoveries of 16 PAHs ranged from 94.5 to 104% in blank samples and from 71.2 to 104% in poultry meat samples. The quantitation limits of 16 PAHs were from 0.02 to 1 ng/mL, with the intraday variability being from 2.4 to 6.6% [percent relative standard deviation (RSD%)] and interday variability being from 3.3 to 7.1% (RSD%). Most PAHs followed a time-dependent increase over a 24 h marinating period, with naphthalene being generated in the largest amount. Among the various poultry meat, chicken gizzard produced the highest level of total PAHs after 24 h of marinating. A similar tendency was observed for most PAHs during frying of poultry meat, but a high amount of total PAHs was shown in duck drumstick after 15 min of frying.     

乳酸杆菌对断奶仔猪生长性能的影响

试验选用32头品种、胎次、饲养水平相同、健康的断奶仔猪随机分为4组,对照组饲喂剔除抗生素和抗菌素的仔猪基础日粮,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组分别在仔猪基础日粮的上添加12、15、18mL／kg乳酸杆菌,通过30天的试验期后,测定4组的生长性能指标。结果表明:对照组的腹泻率明显高于试验组,腹泻率最低的是试验Ⅲ组;头平均日增重试验Ⅲ组与其它3组差异显著(P＜0．05),对照组和试验Ⅱ组差异显著(P＜0．05),其中试验Ⅲ组头平均日增重最高,为358g,对照组最低,为303g;试验Ⅲ组与其它3组料重比差异显著(P＜0．05),试验Ⅱ组与试验Ⅰ组差异不显著(P＞0．05),和对照组差异显著(P＜0．05),料重比较为理想的是试验Ⅲ组,其次是试验Ⅱ组。     

Protective effects of bilberry (Vaccinium myrtillus L.) extract on KBrO3-induced kidney damage in mice

Potassium bromate (KBrO3) is an oxidizing agent used as a food additive which causes kidney damage as a potent nephrotoxic agent, and the mechanism may be explained by the generation of oxygen free radicals. Our experiments showed that single intraperitoneal administration of 200 mg/kg KBrO3 could induce serious kidney damage, with an increase in serum blood urea nitrogen (BUN) and creatinine levels. Five-day oral administration of bilberry ( Vaccinium myrtillus L.) extract at 50, 100, and 200 mg/kg resulted in a reversal in serum BUN and creatinine to normal levels and decreased kidney malondialdehyde (MDA), nitric oxide (NO), and xanthine oxidase (XOD) levels. Also, bilberry extract improved oxygen radical absorbance capacity (ORAC) levels in kidney tissue, which showed that bilberry extract reduced the degree of oxidative stress and kidney damage induced by KBrO3. These findings demonstrate that the protective effect of bilberry extract is attributed to its free radical scavenging activity and lipid peroxidation inhibitory effect.     

Protective effects of bilberry (Vaccinium myrtillus L.) extract on restraint stress-induced liver damage in mice

Our experiments showed that 18 h restraint stress could induce serious liver damage, with an increase in plasma alanine aminotransferase (ALT) level (107.68 +/- 3.19 U/L vs 18.08 +/- 1.46 U/L). Meanwhile, we observed increased malondialdehyde (MDA) levels and lowered oxygen radical absorbance capacity (ORAC) values in plasma and liver of restraint mice compared with starved mice. Bilberry extract (containing 42.04% anthocyanins) was oral administrated to mice at 50, 100, and 200 mg/(kg x day) for five days, which remarkably decreased plasma ALT level to 17.23 +/- 2.49 U/L at the dose of 200 mg/(kg x day) and thus alleviated stress-induced liver damage. In addition, bilberry extracts increased glutathione (GSH) and vitamin C levels and significantly decreased MDA and nitric oxide (NO) levels in the liver tissues. These results suggest that bilberry extract plays an important role in protecting against restraint stress-induced liver damage by both scavenging free radicals activity and lipid peroxidation inhibitory effect. This study showed the beneficial health effects of bilberry extract through its antioxidative action.     

A specific, highly active malate dehydrogenase by redesign of a lactate dehydrogenase framework

Three variations to the structure of the nicotinamide adenine dinucleotide (NAD)-dependent L-lactate dehydrogenase from Bacillus stearothermophilus were made to try to change the substrate specificity from lactate to malate: Asp197----Asn, Thr246----Gly, and Gln102----Arg). Each modification shifts the specificity from lactate to malate, although only the last (Gln102----Arg) provides an effective and highly specific catalyst for the new substrate. This synthetic enzyme has a ratio of catalytic rate (kcat) to Michaelis constant (Km) for oxaloacetate of 4.2 x 10(6)M-1 s-1, equal to that of native lactate dehydrogenase for its natural substrate, pyruvate, and a maximum velocity (250 s-1), which is double that reported for a natural malate dehydrogenase from B. stearothermophilus.     

Taiwanese bed and breakfast business performance: A geographic region perspective

Taiwan has prioritized bed and breakfast (B&B) business performance improvement in its tourism policies because B&Bs are a sustainable business model that can boost local economy through rural tourism. In order to identify the factors that can improve business performance, this research uses directional distance function and metafrontier approach to evaluate the technical efficiency of 18 cities and counties with B&Bs in Taiwan from 2011 to 2016. Results are divided into four geographic regions: Northern, Central, Southern, and Eastern Taiwan; technology gap ratios are computed to determine the degree of technical gaps for each region in order to provide information to potential B&B owners when selecting their accommodation location or region, to aid B&B managers in tailoring their business models and marketing strategies to maximize total revenues or minimize inputs, and to facilitate tourism, small businesses, and local economy with the support of the Taiwanese government.     

Low genetic diversity of cultivated spotted hard clam (Meretrix petechialis) in Taiwan

The aquaculture of spotted hard clams, Meretrix petechialis, is a well‐developed industry in Taiwan. Spats have been produced for decades through artificial propagation using broodstocks selected from neighbouring culture farms on the basis of size and maturity, and the produced spats are resold to these culture farms. Although mass mortality occurs frequently in this practice, the effect of inbreeding depression has never been evaluated. Therefore, genetic diversity of 173 spotted hard clams from museums, two culture farms and three purchased populations was examined in this study. Phylogenetic analyses, based on either COI or cyt b fragments, indicated a division into lineages A and B among the samples. Cultured clams, except for one clustered with M. lusoria, museum specimens, and purchased samples from Hsinchu were all grouped into lineage A. The remaining two purchased populations were placed in both lineages. Compared with cultured clams from the Chinese coast in a previous study, our results exhibited a much lower haplotype (0.354 vs. 0.900) and nucleotide diversity (0.00113 vs. 0.00543). However, whether the loss of genetic variation is a consequence of inbreeding or the founder effect in the initial small broodstocks is unclear. The introduction of broodstocks from northern Vietnam and southern China may facilitate the management of genetic diversity. Environmental factors that potentially cause mass mortality require further investigation.     

Effects of synbiotic containing Lactobacillus plantarum 7–40 and galactooligosaccharide on the growth performance of white shrimp,Litopenaeus vannamei

This study aimed to develop a synbiotic combination with probiotic, Lactobacillus plantarum 7–40 and one of three prebiotics, fructooligosaccharide (FOS), galactooligosaccharide (GOS) and mannan oligosaccharide (MOS). The best in vitro growth was observed when probiotic was cultured in the medium containing either FOS or GOS as the sole of carbon source. The analysis of enzyme activity revealed that GOS induced the highest activities of protease and β‐galactosidase of probiotic. Based on the findings, probiotic + GOS were selected as synbiotic to evaluate if it could promote the growth of white shrimp, Litopenaeus vannamei. For this, four diets, including a basal diet with no GOS or probiotic (control), 0.4% GOS (PRE), 10⁸ CFU probiotic kg^?1 (PRO) and 0.4% GOS in combination with 10⁸ CFU probiotic kg^?1 (SYN), were fed to shrimp for 60 days, and then the growth performance, intestinal microbiota (including total Vibrio counts, VBCs; and lactic acid bacteria, LAB) and digestive enzyme (including protease, leu‐aminopeptidase and β‐galactosidase) were evaluated. The weight gain (WG) of shrimp fed the PRO did not significantly differ from those of control (p > .05). Shrimp fed the SYN had significantly higher WG compared with the other treatments (p < .05). In addition, the SYN‐fed shrimp had significantly higher LAB and protease, leu‐aminopeptidase and β‐galactosidase activity (p < .05). The lowest presumptive Vibrio count (VBC) was also observed in intestines of SYN‐fed shrimp. Therefore, we suggested that Lac. plantarum 7–40+ GOS can be used as a synergistic synbiotic for shrimp culture.     

Comparison of prevalence of Felis catus papillomavirus type 2 in squamous cell carcinomas in cats between Taiwan and Japan

Felis catus papillomavirus (FcaPV), especially type 2 (FcaPV2) is considered as one of the causative agents in squamous cell carcinoma (SCC) in cats. However, our previous study detected FcaPV3 and FcaPV4, but not FcaPV2 in feline SCCs collected in Japan, suggesting that the prevalence of FcaPV2 in SCC may vary depending on geographic locations. To evaluate this hypothesis, two conventional PCR reactions targeting E1 and E7 genes were performed to detect FcaPV2 in feline SCC samples collected in Taiwan and Japan. While 46.9% (23/49) of feline SCC cases from Taiwan were PCR positive for FcaPV2, only 8.6% (3/35) cases from Japan were positive. Our result suggests that the prevalence of FcaPV2 in feline SCCs may depend on the region.