A sensory study on consumer valuation for plant-based meat alternatives: What is liked and disliked the most?

The food sector has witnessed a surge in the production of plant-based meat alternatives that aim to mimic various attributes of traditional animal products. However, overall sensory appreciation remains low. This study employed open-ended questions, preference ranking, and an identification question to analyze sensory drivers and barriers to liking four burger patties, i.e., two plant-based (one referred to as pea protein burger and one referred to as animal-like protein burger), one hybrid meat-mushroom, and one 100 % beef burger. Untrained participants (n = 175) were randomly assigned to blind or informed conditions in a between-subject study. The main objective was to evaluate the impact of providing information about the animal/plant-based protein source/type, and to obtain product descriptors and liking/disliking levels from consumers. Results from the ranking tests for blind and informed treatments showed that the animal-like protein was the most preferred product, followed by the 100 % beef burger. Moreover, in the blind condition, there was no significant difference in preferences between the beef burger and the hybrid and pea protein burgers. In the blind tasting, people preferred the pea protein burger over the hybrid one, contrary to the results of the informed tasting, which implies the existence of affecting factors other than pure hedonistic enjoyment. In the identification question, although consumers correctly identified the beef burger under the blind condition, they still preferred the plant-based 'animal-like' burger.

The minimum inhibitory concentration (MIC) assay with Escherichia coli: An early tier in the environmental hazard assessment of nanomaterials?

There are now over a thousand nano-containing products on the market and the antibacterial properties of some nanomaterials has created interest in their use as cleaning agents, biocides and disinfectants. Engineered nanomaterials (ENMs) are being released into the environment and this raises concerns about their effects on microbes in the receiving ecosystems. This study evaluated the bacterial toxicity of a wide range of nanomaterials with different surface coatings on Escherichia coli K-12 MG1655. The minimum inhibitory concentration (MIC) assay, which quantifies the threshold for growth inhibition in suspensions of bacteria, was used to rank the toxicity of silver (Ag), cupric oxide (CuO), cadmium telluride (CdTe) quantum dots, titanium dioxide (TiO₂), nanodiamonds and multi-walled carbon nanotubes (MWCNTs). Bacteria were exposed for 12 h at 37 °C to a dilution series of the test suspensions in 96-well plates. The precision and accuracy of the method was good with coefficients of variation < 10%. In terms of the measured MIC values, the toxicity order of the ENMs was as follows: CdTe quantum dots ammonium-coated, 6 mg L^-1 > Ag nanoparticles, 12 mg L^-1 > CdTe quantum dots carboxylate-coated, 25 mg L^-1 > CdTe quantum dots polyethylene glycol-coated, 100 mg L^-1. The MIC values were above the highest test concentration used (100 mg L^-1) for CuO, TiO₂, nanodiamonds and MWCNTs, indicating low toxicity. The MIC assay can be a useful tool for the initial steps of ENMs hazard assessment.