ABSTRACT
Carbon dots (CDs) based room temperature phosphorescence (RTP) materials can be prepared via facile procedures and exhibit excellent photostability and biocompatibility. Furthermore, doping of hetero-atoms into CDs can afford multiple triplet levels. The RTP emission generated from the resultant CDs always displays outstanding dynamic behaviors and even can be efficiently excited by visible light. Given this, CDs-based RTP materials not only can be used for anti-counterfeiting but also exhibit great application potential in signage and illumination fields. In this contribution, a type of B, N, and P co-doped CDs are prepared in hectogram scale. Upon excitation by UV lamp and white LED, the obtained CDs emit green and yellow RTP, respectively, the lifetime of which are 851 and 481 ms, respectively. It is found that the luminescence color of the CDs can be further tuned. By controlling the degree of carbonization, the RTP color of the CDs can be facilely tuned from green to orange-red. Based on an energy transfer strategy, the luminescence color can be further tuned to red. Benefited from the dynamic and visible-excited colorful RTP emission, the application of these obtained CDs in anti-counterfeiting, fingerprint collection, and luminescent traffic signage are also explored.
ABSTRACT
The aroma of mint is well-liked by the public, and key flavor odorants in mint aroma had been found, but how these molecules interact and form a satisfying odor remains a challenge. Quality, intensity, and pleasantness are our most basic perceptions of aromas; both intensity and pleasantness can be quantified. However, compared to intensity, research on pleasantness was lacking. Pleasantness was one of the most important indicators for formulating a satisfying mint flavor, and the study of binary mixtures was fundamental to our understanding of more complex mixtures. Therefore, the purpose of this study was to explore the characteristics of pleasantness as a function of concentration and, at the same time, to investigate the relationship between intensity and pleasantness in binary mixtures. Thirty sensory evaluation volunteers participated in the evaluation of the intensity and pleasantness of six key flavor odorants of mint and five binary mixtures. The results showed that the pleasantness increased first and then decreased or stabilized with the rising of concentration; even though the interactions in binary mixtures were not the same, their pleasantness could be predicted using the intensities of the components by Response Surface Design of Experiments, and the goodness of fit was greater than 0.92, indicating that the models had the great predictive ability. PRACTICAL APPLICATION: Whether blending flavors or evaluating them, a great deal of experience is required, yet the acquisition of this experience is a long process. Performing these tasks is difficult for the novice, and it helps to quantify the feeling for the flavor and build some mathematical models.
Subject(s)
Odorants , Smell , Humans , Smell/physiology , Emotions , Models, TheoreticalABSTRACT
BACKGROUND: The encapsulation of flavor and aroma compounds has great potential in foods, while effective preparation in the food industry is still a great challenge. Inspired by leather tanning, tannic acid (TA) was used for deep crosslinking through hydrogen bond-driven assembly on soy protein isolate for encapsulating limonene with a high loading ratio. RESULTS: The added TA changed the protein structure and formed a limonene-loaded microcomplex. The morphology of these microcomplexes changed from smooth to rough, followed by the formation of smooth nanoparticle aggregates, by changing the amount of TA. The encapsulation efficiency and loading ratio were increased from 0.78% and 4.30% to 59.32% and 45.78% after increasing TA from 1.875 to 60 mg mL-1 . The result of confocal laser scanning microscopy indicated that limonene is evenly distributed in microcomplexes. Additionally, the results of thermal stability demonstrated protection of limonene by soy protein-tannic acid microcomplex. CONCLUSION: It is suggested that the added TA improved the encapsulation efficiency and loading ratio. Limonene is loaded in the complex in two ways. The present research provides a new and easy path for the preparation of the non-thermal soy protein aroma carrier. © 2022 Society of Chemical Industry.