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• Encapsulation of anthocyanins in whey protein and polysaccharides (CHC and CMC). • Intermolecular interactions occurred among ACNs, polysaccharides and proteins. • Encapsulation improved stability and delayed release of ACNs. • Encapsulated ACNs increased the antioxidant properties of a hot coffee beverage. Anthocyanins (ACNs) are naturally derived colorants and antioxidants added to manufactured foods. ACNs were encapsulated in nanocomplexes with chitosan hydrochloride (CHC), carboxymethyl chitosan (CMC) and whey protein isolate (WPI). The ACN-loaded CHC/CMC-WPI nanocomplexes (ACN-CHC/CMC-WPI) showed a preferred particle size (332.20 nm) and zeta potential (+23.65 mV) and a high encapsulation efficiency (60.70%). ACN-CHC/CMC-WPI nanocomplexes exhibited a smooth spherical shape by transmission electron microscopy. Fourier transform infrared (FT-IR) and Raman spectroscopy confirmed interactions between the ACNs and the encapsulation materials (CHC/CMC-WPI). The nanocomplexes or the nanocomplexes incorporated into coffee beverage better protected ACNs at high temperature compared to the unencapsulated ACNs. In simulated gastrointestinal fluids, the ACNs in the ACN-CHC/CMC-WPI were more stable and more slower released over time. The nanocomplexes maintained high DPPH and hydroxyl free radical scavenging activities. This study indicated that CHC/CMC-WPI nanocomplexes can improve the thermal stability and slow the release of ACNs added to food products. [ABSTRACT FROM AUTHOR]

• Ag nanoparticles (AgNPs) were green synthesized by using gellan gum (GG). • GG-AgNPs show good sensitivity and selectivity towards H 2 S. • GG-AgNPs presented visible color changes when used to monitor meat spoilage. • GG-AgNPs should have great potential for application in intelligent packaging. A colorimetric hydrogen sulfide (H 2 S) sensor based on gellan gum capped silver nanoparticles was developed to real-time monitor meat spoilage. The colorimetric sensor strategy was attributed to the ultrastrong binding ability of Ag with H 2 S to form Ag 2 S. The sensor enables the analysis of H 2 S with a limit of detection (LOD) of 0.81 μM, and it exhibited excellent selectivity toward H 2 S against other volatile components generated from chicken breast and silver carp during spoilage. By these virtues, the sensor presented visible color changes from yellow to colorless by in situ and nondestructively sensing H 2 S generated from chicken breast and silver carp in a packaging system. This strategy provided a simple but useful, non-destructive, robust, cost-effective, and user-friendly platform to real time monitor meat spoilage for intelligent food packaging. [ABSTRACT FROM AUTHOR]

• We firstly used CDs to identify eight grades of Dianhong black tea. • We firstly increased recognition rate by adding cobalt ions. • All materials we used are laboratory-synthesized, and operation is convenient. We established a novel Dianhong black tea grades discriminant analytic technique based on a fluorescence image along with carbon quantum dots (CDs) as fluorescent probes. Different grades of Dianhong black tea contain different various amounts of tea polyphenols. Tea polyphenols can quench the fluorescent intensity of CDs, resulting in different fluorescent peaks; Dianhong black tea grades can then be discriminated through the use of principal component analysis and Bayesian analysis. Compared with the additional data processing required in other methods, the advantage of our method is that the fluorescence curve can be used directly, and it achieves satisfactory results. We firstly used CDs combined with chemometrics to identify eight grades of Dianhong black tea, and we also provide a new method that improves the identification rate using nanotechnology to avoid performing complex data processing. [ABSTRACT FROM AUTHOR]