Safety assessment of MIBK (methyl isobutyl ketone)

The potential correlation between the succession of microflora and volatile flavor compounds during the production of Zhenba bacon

Microbial composition plays an important role in the quality and flavor of bacon. The aims of this study were to detect bacterial community succession using high-throughput sequencing (HTS) and volatile flavor compound changes using gas chromatography-ion mobility spectrometry (GC-IMS) during the production of Zhenba bacon. The results showed that a total of 70 volatile compounds were detected. Among them, ketones, hydrocarbons, aldehydes, esters and alcohols were the main substances in the curing and smoking stages. In addition, the fungal abundance was greater than the bacterial abundance, and there was obvious succession of the microbial community with changes in fermentation time and processing technology. The main functional bacterial genera in the curing and smoking stages were Staphylococcus, Psychrobacter and Latilactobacillus, and the main fungal genera were Fusarium and Debaryomyces. Through correlation analysis, we found that pyrrole, 2-pentanol, methyl isobutyl ketone (MIBK) and ethyl acetate (EA) were significantly correlated with Staphylococcus, Psychrobacter, Pseudomonas and Myroides (p < 0.01), and it is speculated that they contribute significantly to flavor formation. The results of this study are helpful for understanding the microbial dynamics and characteristic volatile flavor compounds in Zhenba bacon, and provide new insights into the relationship between microorganisms and flavor through potential correlations.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Colorimetric acetone sensor based on ionic liquid functionalized drug-mediated silver nanostructures

The current work reports the drug-mediated synthesis of silver nanoparticles (AgNPs) and their functionalization with ionic liquid (IL) for acetone determination. The rationale behind the selection of the Augmentin drug was the aromaticity in its structure and the functional groups attached. These properties are not only supposed to work in the synthesis of the nanoparticles but also enhance their electron density. The nanoparticles were further coated with 1-H-3-methylimidazolium acetate IL, having conductivity and aromaticity in their structure. The synthesized nanoparticles have been characterized by different techniques such as FTIR, XRD, SEM, and EDX. Colorimetric determination of acetone was done by using IL capped AgNPs with the assistance of NaCl solution and results were analyzed by UV-Vis spectrophotometry. Low-cost, stable eosin dye works as a substrate and is consumed resulting in a color change from brown to transparent. The IL capped AgNPs act as a reducing agent for the production of reduced radical form of acetone which act on the carboxylate moiety and bubble it out in the form of CO₂. Different parameters such as (concentrations, loading of nanoparticles, time and pH, etc.) were optimized to get the best results of the proposed sensor. The sensor shows a wide linear range of (1 ×10^-8-2.40 ×10^-6 M), low limit of detection 2.66 × 10^-9 M, and limit of quantification 8.86 × 10^-9 M with an R² value of 0.997. The proposed sensor has been successfully applied to diabetic patient's urine samples for acetone detection with a visible colorimetric change. It showed good sensitivity and selectivity towards acetone detection.