Plant Extracts and Essential Oils at Concentrations Acceptable to a Sensory Panel Inactivate Salmonella Typhimurium DT104 in Ground Pork

A potential method to inhibit pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. Because these antimicrobials may also adversely affect the sensory characteristics of the meat, the objectives of this study were 1) to define the appropriate concentrations of olive extract, apple extract, oregano oil, and cinnamon oil added to ground pork that are acceptable to a sensory panel, and 2) to determine their antimicrobial activities against Salmonella Typhimurium DT104 in inoculated ground pork. Plant extracts were evaluated against two initial inoculum levels (6 and 4 log CFU/g of pork) of Salmonella. Sensory tests showed that acceptable concentrations of oregano and cinnamon oils were 0.5% and of olive and apple extracts were 3%, respectively. Ground pork samples were inoculated with Salmonella, treated with antimicrobials at various concentrations (0.1% - 0.5% cinnamon and oregano essential oils and 3% - 5% olive and apple extracts), and stored at 4°C for 7 days. Survivors were enumerated at days 0, 3, 5, and 7. Cinnamon oil at 0.5% and olive extract at 3% induced a 1.0 and a 0.9 log CFU/g (from 6-log CFU/g initial inoculum) reduction, respectively, at day 7. At 3%, olive extract showed a 1.06 log CFU/g maximum reduction of Salmonella from a 4-log CFU/g initial inoculum. Pork samples containing oregano oil and apple extract did not show a significant reduction compared to the control without the antimicrobials. The results indicate that cinnamon oil and olive extract can potentially be applied at consumer-acceptable concentrations against low levels of S. Typhimurium DT104 in ground pork.

Adsorption Dynamics of Calyx Aroma onto Basic Tea in Scenting Process of Calyx-scented Tea

[Objective] The paper was to study adsorption dynamics of calyx aroma onto basic tea in scenting process of calyx-scented tea, so as to increase aroma and quality of products. [Method] Adsorption experiment was carried out in a hermetic container, and the effect of calyx amount, contact time, moisture content of basic tea and temperature on the scenting process was studied. [Result] The optimal moisture and temperature for scenting process was 4% and 10 ℃, respectively. [Conclusion] The scenting process accorded pseudo-first-order kinetic model, and the adsorption dynamic data of total process could better fit pseudo-second-order kinetic model.

A preliminary study on volatile organic compounds and odor in university dormitories:Situation,contribution,and correlation

Many dormitories have a high population density,and occupants exposed to volatile organic compounds(VOCs)could suffer severe physical and mental issues,so it is important to ensure good indoor air quality(IAQ).Currently,indoor VOC analysis using only chemical concentration cannot accurately reflect the effect of odor on human comfort.Therefore,the sensory evaluation of indoor odor acts as a supplementary method for an IAQ assessment.Here,we measured indoor VOC concentrations in 10 dormitories under occupied and unoccupied conditions.The contribution of building materials and human-related emissions was analyzed.An odor activity value(OAV)was calculated using the VOC concentration and odorant threshold.In addition,recruited sensory odor panel members assessed the odor intensity of each dormitory and the correlation between odor intensity and chemical measurements was analyzed.The indoor total VOC(TVOC)concentration under occupied conditions ranged from 242.2 to 1063.1μg/m^(3),with a mean value of 454.1μg/m^(3).The TVOC concentration under unoccupied conditions varied from 97.2 to 1055.2μg/m^(3),with a mean value of 342.2μg/m^(3).The TVOC concentration of 90% of the dormitories under the two conditions met the national IAQ standards.An average of 53.6% indoor TVOC emissions are related to building materials,the outdoor-related TVOC concentration accounts for 15.7%,and the average human-related TVOC emissions are 1519.4μg/(h·person),which accounts for 30.7%.Compared to TVOC concentration,odor intensity-OAV(OAV_(sum),OAV_(max))could better characterize subjective and objective correlations.However,the goodness-of-fit is not satisfactory.Weber–Fencher's law has limitations in characterizing the correlation between odor intensity and OAV when applied to the indoor air mixture,based on this small-scale study.