Effect of quercetin-containing preservatives and modified atmospheric packaging on the production of biogenic amines in Pacific white shrimp(Litopenaeus vannamei)

To investigate the productions of biogenic amines(BAs)in Pacific white shrimp treated by compound preservatives(P,0.05 g/L quercetin,0.025 g/L 4-hexylresorcinol,and 0.025 g/L cinnamic acid)in combination with modified atmosphere packaging(M,80% CO_(2)/10% O_(2)/10% N_(2)),four groups of samples treated with or without preservatives and alone or in combination with modified atmosphere packaging(A,A+P,M,M+P)during storage at 4℃for 12 days were analyzed.Most BAs increased in all samples,especially,putrescine and cadaverine.MAP inhibited the increase of most BAs(except for tyramine)and psychrotrophic bacterial counts.The inhibitory effect of the compound preservatives on bacterial growth and BAs was limited in aerobically-and MAP-stored samples,but they retarded the production of tyramine,which accumulated more rapidly in MAP.Lowest total BAs and bacterial counts were found in sample M+P(78.3 mg/kg and 5.82 log cfu/g,day 12),indicating that the combined treatment of the preservatives and MAP could reduce the risk of disorders caused by BAs.

Reply to Letter by Dr. Christoph Kupferschmid： Commentary on ＂Countries with high circumcision prevalence have lower prostate cancer mortality＂

Dear Editor, We thank Dr. Kupferschmid for his interest in our study, which examined male circumcision （MC） and prostate cancer mortality〉2 Considerable strong evidence has been accumulated since 1951.3 Most of his references4-10 do not address MC and the risk of death from prostate cancer. That is a different question than MC and the risk of developing prostate cancer, which none of his references validly assess. One reference addressed bacterial colonization,6 not prostate cancer. Another7 concerned sexually transmitted infections and prostate cancer.

Countries with high circumcision prevalence have ower prostate cancer mortality

The present study determined the relationship of male circumcision （MC） prevalence with prostatic carcinoma mortality rate in the 85 countries globally for which data on each were available. MC prevalence in different countries were obtained from a WHO report and allocated to WHO categories of 81%-100%, 20%-80%, and 0%-19%. Prostatic carcinoma mortality data were from Globoscan, gross national income per capita as well as male life expectancy were from a World Bank report, and percentages of Jews and Muslims by country were from the Pew Research Institute and the North American Jewish Data Bank. Negative binomial regression was used to estimate prostatic carcinoma mortality rate ratios. Compared to countries with 81%-100% MC prevalence, prostatic carcinoma mortality rate was higher in those with MC prevalence of 0%-19% （adjusted OR [adjOR] =1.82; 95% CI 1.14, 2.91） and 20%-80% （adjOR = 1.80; 95% CI, 1.16, 2.78）. Higher Muslim percentage （adjOR = 0.92 [95% CI 0.87, 0.98] for each 10% increase） and longer life expectancy （adjOR = 0.82 [95% CI 0.72, 0.93] for each 5 additional years） were associated with lower prostatic carcinoma mortality. Higher gross national income per capita （adjOR = 1.10 [95% CI 1.01, 1.20] for double this parameter） correlated with higher mortality. Compared with American countries, prostatic carcinoma mortality rate was similar in Eastern Mediterranean countries （adjOR = 1.02; 95% CI 0.58, 1.76）, but was lower in European （adjOR = 0.60; 95% CI 0.50, 0.74） and Western Pacific countries （adjOR = 0.54, 95% CI 0.37, 0.78）. Thus, prostate cancer mortality is significantly lower in countries in which MC prevalence exceeds 80%.