Sweet and sour are the most important taste of blueberries, and they are produced by sugar and acid, respectively.  Their contributions to the taste depend not only on the levels of sugar and acid, but also on the types and relative proportions of sugar and acid.  Therefore, it is very important to evaluate the composition and levels of sugar and acid in blueberries.  Regional differences and variety diversity also affect the sugar and acid characteristics of fruits.  Therefore, this study selected two main producing regions in northern China (Weihai and Yingkou) to examine the sugar and acid characteristics of 11 common blueberry cultivars.  The indexes measured included soluble sugars, organic acids, soluble solid content and titratable acidity.  The results showed that glucose and fructose were the major sugars, and citric acid and quinic acid were the major organic acids.  Correlation analysis showed that glucose, fructose, and sucrose were positively correlated with total sugar content; the citric acid content was positively correlated with the titratable acidity and total organic acids.  Titratable acidity, glucose, fructose, sucrose, total sugar content, citric acid, shikimic acid and total acid content of the blueberries varied significantly between regions (P<0.05).  In general, compared with Weihai blueberries, Yingkou blueberries had higher sugar content and lower acid content.  The results of this study may provide useful references for the evaluation of sweet and sour flavors and cultivar selection of blueberries.

In this study, 15 mycotoxins were detected in 233 nut and dried fruit samples from China.  The 15 mycotoxins included aflatoxins (AFs: AFB₁, AFB₂, AFG₁ and AFG₂), trichothecene toxins (TCs: T-2, ZEA, ENA, ENA1, ENB, ENB1 and BEA), Alternaria toxins (ATs: TEN, AOH and AME) and ochratoxin A (OTA).  The mycotoxins were detected in 47.6% of the samples and all 15 of the mycotoxins were found.  Two samples were positive for AFB1 and exceeded the maximum tolerable levels allowed in China.  The contamination levels of the mycotoxins found in nuts, dried jujubes, raisins, dried figs and dried longans were in the ranges of 0.1–462.7, 0.2–247.3, 0.8–10.1, 0.2–384.1 and 0.1–89.2 μg kg^–1, respectively.  Dried figs (80.0%) had the highest incidence of mycotoxins, followed by dried longans (60.0%), dried jujubes (57.1%), nuts (43.6%) and raisins (26.7%).  The estimated daily intake (EDI) values of each individual mycotoxin and all of the mycotoxins collectively were calculated by both the deterministic approach (DA) and the probability approach (PA).  For risk characterization, dietary exposure to TCs, ATs and OTA through consumption of nuts and dried fruits according to both approaches, showed no health risk to Chinese adults by exposure to either individual mycotoxins or in combination.  To the best of our knowledge, this is the first work in which risk assessment of multimycotoxins is performed, specifically including the emerging ENNs and BEA, in nuts and dried fruits of China.