Rapid voltammetric method for quinine determination in soft drinks

Cortical Representation of Food-Related Odors in Gustatory Areas Differs According to Their Taste Association: An fMRI Study

Background/Objectives: Gustatory stimuli are primarily processed in the insula, while the primary olfactory cortex involves the piriform cortex. Relatively little is known about the central-nervous integration of stimuli from foods. The main aim of this study in healthy participants was to evaluate the processing of olfactory stimuli which are associated with gustatory sensations. Methods: Using a 3T MRI scanner, 47 healthy, right-handed women (mean age: 26.2 ± 4.7 years) with normal senses of taste and smell underwent functional scans. During the analysis, we presented isointense odors (2 "sweet" and 2 "sour") to subjects using air-dilution olfactometry. Odor delivery (8 s) was alternated with the presentation of odorless air (12 s) and was repeated 10 times. Between each session, participants were asked to associate a taste with the odor. Results: The gustatory areas (insula and frontal operculum) were activated by exposure to odors. In addition, increased activations were observed in the bilateral angular gyrus, orbitofrontal cortex, and right caudate and nucleus accumbens during the perception of sour-like odors compared to sweet-like odors. Conclusions: The distinct neural responses to different odor categories suggest that the brain processes odors with varying hedonic and sensory characteristics through distinct neural pathways. Future research could explore how these findings translate to real-world food preferences and dietary behaviors, particularly in relation to individual differences in taste perception.

A dual-functional monomer-based molecularly imprinted fluorescent aptasensor employing near-infrared carbon dots for selective detection of quinine in food

A molecularly imprinted fluorescent aptasensor was designed for selective detection of quinine (Qn) based on dual functional monomers. In the sol-gel polymerization of molecularly imprinted polymers (MIPs), 3-aminopropyltriethoxysilane (APTES) and quinine aptamer (Apt) were employed as dual functional monomers, and Qn was the template molecule. Near-infrared carbon dots (RCDs) were used as fluorescence signal probe, and effectively avoided the interference of fluorescence emitted by Qn. Due to the diverse interaction among APTES, Apt and Qn, the near-infrared fluorescent molecularly imprinted aptasensor (RCDs-Apt@MIPs) exhibited higher specificity towards Qn than the sensor with APTES or Apt as a single functional monomer. The sensor had a wide linear range of 5.0-110.0 μM with a low detection limit of 1.7 μM. Satisfactory recovery between 93.4% and 104.0% with relative standard deviation from 1.30% to 3.60% in drinks, which showed great potential that this method can be used to detect Qn in food.

The Protective Action of Coutarea hexandra (Rubiaceae) on the Neuromuscular Blockade Induced by Lachesis muta muta (Viperidae: Crotalinae) Venom

Envenomations by snakes represent a neglected health problem in tropical and subtropical countries. In South America, Lachesis muta occasionally causes severe human envenomation, with treatment being conditioned to an unspecific antivenom. In this work, we examined the neutralizing ability of Coutarea hexandra stem bark hydroalcoholic extract (Ch-E), including the commercial phytochemicals coumarin and quinine, on the neuromuscular blockade induced by L. m. muta venom in mouse phrenic nerve-diaphragm preparation. Biological assays were performed following conventional myographic technique ex vivo. Ch-E was phytochemically characterized to detect the presence of coumarin and quinine using analytical methods. Ch-E and commercial phytochemicals were tested separately or combined under pre- and post-venom incubation protocols. Ch-E attenuated the venom-induced neuromuscular blockade only under the pre-venom incubation protocol. Quinine was not detected in Ch-E. Commercial coumarin and quinine exhibited a concentration-dependent counteracting effect on the venom-induced neuromuscular blockade. The pre-venom incubation protocol showed to be efficient in attenuating the L. m. muta venom-induced neuromuscular blockade, most likely due to the presence of coumarin derivatives and unknown alkaloids in this extract.

A Novel Equipment-Free Paper-Based Fluorometric Method for the Analytical Determination of Quinine in Soft Drink Samples

A simple, equipment-free, direct fluorometric method, employing paper-based analytical devices (PADs) as sensors, for the selective determination of quinine (QN) is described herein. The suggested analytical method exploits the fluorescence emission of QN without any chemical reaction after the appropriate pH adjustment with nitric acid, at room temperature, on the surface of a paper device with the application of a UV lamp at 365 nm. The devices crafted had a low cost and were manufactured with chromatographic paper and wax barriers, and the analytical protocol followed was extremely easy for the analyst and required no laboratory instrumentation. According to the methodology, the user must place the sample on the detection area of the paper and read with a smartphone the fluorescence emitted by the QN molecules. Many chemical parameters were optimized, and a study of interfering ions present in soft drink samples was carried out. Additionally, the chemical stability of these paper devices was considered in various maintenance conditions with good results. The detection limit calculated as 3.3 S/N was 3.6 mg L^-1, and the precision of the method was satisfactory, being from 3.1% (intra-day) to 8.8% (inter-day). Soft drink samples were successfully analyzed and compared with a fluorescence method.

Multifunctional Portable System Based on Digital Images for In-Situ Detecting of Environmental and Food Samples

The development of a portable device created by 3D printing for colorimetric and fluorometric measurements is an efficient tool for analytical applications in situ or in the laboratory presenting a wide field of applications in the environmental and food field. This device uses a light-emitting diode (LED) as radiation source and a webcam as a detector. Digital images obtained by the interaction between the radiation source and the sample were analyzed using a programming language developed in Matlab (Mathworks Inc., Natick, MA, USA), which builds the calibration curves in real-time using the RGB colour model. In addition, the entire system is connected to a notebook which serves as an LED and detector power supply without the need for any additional power source. The proposed device was used for the determination in situ of norfloxacin, allura red, and quinine in water and beverages samples, respectively. For the validation of the developed system, the results obtained were compared with a conventional spectrophotometer and spectrofluorometer respectively with a t-test at a 95% confidence level, which provides satisfactory precision and accuracy values.

Do meat anti-consumption opinions influence consumers' wellbeing?–The moderating role of religiosity

The study aims to determine the role of personal factors, consumer social responsibility, and social marketing among meat anti-consumers. The study tests a model of anti-consumption using a sample of 597 (n = 597) participants from a cluster of young consumers through the distribution of the questionnaires in the Pakistani market. SEM employing the AMOS model for path relationships along with the Johnson-Neyman technique for moderation was mainly used. Results prescribe religiosity as the moderating driver of the anti-consumption of meat among young consumers in Pakistan. Consumer social responsibility is a robust antecedent, while social marketing is significantly documented for sustainability motives. Consumers apprise the personal health and environmental domain as an auspicious component for meat anti-consumption. The study reveals social marketing motivations for anti-consumption that eventually steers marketers and policymakers in shaping the concerned strategies. Our study delivers new insights into food anti-consumption behavior that provides guidelines for policymakers who heed consumer eating behaviors. The study is among pioneer work that establishes the moderating role of religious motivations and meat anti-consumption behavior among Muslim consumers to acquire healthy wellbeing.

Determination of quinine in tonic water at the miniaturized and polarized liquid-liquid interface

In this work we report an electrochemical approach to quantitative and qualitative analysis of quinine (QN) at the interface between two immiscible electrolyte solutions (ITIES). This was done at the macroscopic (macroITIES) and microscopic (µITIES) systems using ion transfer voltammetry (ITV). The linear response of the peak current vs. increasing concentrations of QN at the µITIES was from 2.50 µM to 29.13 µM and the corresponding calculated limit of detection (LOD) for the current signals originating from QN transfer from the aqueous to the organic phase was equal to 0.49 µM. Additionally, the influence of pH (2-12) of the aqueous phase on the recorded QN signals was investigated. We have found that our method is fully applicable for QN direct determination in non-treated tonic water, as confirmed on three different real samples from three different manufacturers. Finally, a number of validation parameters for the developed method are provided and discussed.

Design of an automatic spectrophotometric system

A Multi-Syringe Flow Injection Analysis (MSFIA) fluorometric system based on a 3D printing device hosting a CCD detector has been designed for the determination of quinine in soft drinks. A LED controlled by an electronic circuit was used as a radiation source. The entire system is connected to two USB outputs of a computer. The AutoAnalysis program has been used for data acquisition and treatment. The results are more accurate and precise than those obtained with a manual method using a conventional spectrofluorometer. This developed system is a viable alternative to reduce the consumption of reagents, the impact on the environment and reduce measurement costs.

New, inexpensive and simple 3D printable device for nephelometric and fluorimetric determination based on smartphone sensing

A new, inexpensive and easy to use 3D printable device was developed for nephelometric and fluorimetric determination. Its applicability was tested for the quantification of quinine in tonic drinks and sulfate in natural water with good analytical accuracy. In this way, sulfate determination was carried out by nephelometry using a red LED, while quinine was determined using a blue LED by fluorimetry. A smartphone camera was used to take the pictures and afterwards transform them into the RGB color space using the software ImageJ by a personal computer. The linear range was 2.0–50.0 mg L⁻¹ for sulfate with a LOD of 0.13 mg L⁻¹, and the corresponding quantification limit (LOQ) was 0.43 mg L⁻¹. The linear range for quinine was from 0.42 to 3.10 mg L⁻¹. The LOD and LOQ were 0.11 mg L⁻¹ and 0.38 mg L⁻¹, respectively.

A new, inexpensive and easy to use 3D printable device was developed for nephelometric and fluorimetric determination.

“Drink It or Not”: Soft Drink Anticonsumption Behavior and the Mediating Effect of Behavioral Intentions

Increased health risks and obesity resulting from soft drink consumption have received considerable attention worldwide. The purpose of this empirical study was to explore the antecedents of soft drink anticonsumption behavior in China using structural equation modeling techniques by analysis of moment structures (AMOS). Soft drink anticonsumers think that these drinks are unhealthy, and consumer attitude and behavioral intention towards anticonsumption behavior were found to be significant. Individual and sociocultural factors were also positively associated with anticonsumption of soft drinks in China. Future studies could examine gender differences in anticonsumption behavior. A large sample size would be more reflective in other contexts. Regarding health and obesity-reduction concerns, this study provides useful implications for marketers and policymakers. Soft drink marketers can integrate obesity-reduction efforts through social marketing. This study has put forward a conceptual framework for soft drink anticonsumption behavior focusing on health concerns and the effect of sociocultural factors on anticonsumption.