This study developed a double-layered active packaging film based on chitosan and zein loaded with cinnamic acid@mesoporous silica and nano-silica. The film was composed of a hydrophobic zein outer layer that acted as a moisture barrier, and a hydrophilic chitosan inner layer that provided moisture retention. Cinnamic acid was encapsulated within mesoporous silica. The resulting composite (cinnamic acid@mesoporous silica) demonstrated excellent safety, stability, and antibacterial efficacy. The effects of cinnamic acid@mesoporous silica and nano-silica on physical properties of the film were investigated, and the effect of the film on blueberry preservation was evaluated. The results indicated that both components improved the interfacial compatibility of the film materials by forming a denser structure within the film-forming matrix, thereby significantly improving the overall performance of the films. The optimal film performance was obtained by adding 2.5% cinnamic acid@mesoporous silica, as evidenced by markedly improved mechanical strength, thermal stability, and ultraviolet barrier property, as well as enhanced barrier properties against water vapor, oxygen, and carbon dioxide. This film effectively reduced the decay rate and mass loss of blueberries, extending the shelf life to 8 days. It also minimized changes in firmness, total soluble solids, and titratable acidity. These findings indicate the promising potential of the film for commercial application in postharvest fruit preservation.

To explore the effect of halogen substitution on the sweetness inhibition properties of 2-(4-methoxyphenoxy) propionic acid (HPMP), six halogenated derivatives of HPMP were synthesized through halogen (F, Cl or Br) substitution at the 2- or 3-position of the benzene ring of HPMP and characterized structurally, and their sweetness inhibition properties were evaluated by electronic tongue. The results showed that the six halogenated derivatives could competitively inhibit sweetness. In addition, a significant dose-effect relationship was observed for the derivatives with halogen atoms introduced at the 2-position of the benzene ring. All six derivatives exhibited inhibitory effects on sucrose, fructose, glucose, xylitol and erythritol. Furthermore, the fluorinated and chlorinated derivatives showed stronger inhibitory effect on the sweetness of the aforementioned sweeteners. Therefore, it was speculated that the size and electronegativity of halogen substituents may be the key factors causing different sweetness inhibitory activity. This study indicates the importance of halogen substitution in the sweetness inhibition effect of HPMP, and provide a reliable theoretical basis for the study of the structure-activity relationship of sweetness-inhibiting compounds.

This study aims to investigate the influence of the carboxyl substituent groups and the carbon chain length of acrylic acid of ferulic acid (FA) on its bitterness inhibitory effect. Molecular dynamics simulations were employed to analyze the conformational differences in the interaction between bitter taste receptors and bitterness inhibitors, including FA and 4-(2,2,3-trimethylcyclopentyl) butyric acid, and the bitterness activator Acesulfame K in order to determine the inhibitory structure F4 of FA for bitter taste receptors. Based on the interaction modes of F4, a series of FA derivatives were constructed. The structure-activity relationship of FA as a bitterness inhibitor was explored by electronic tongue. The results revealed that based on the premise that the interaction modes of the ligand and F4 would be consistent, the charge amount of the hydrogen bond acceptor on FA’s carboxyl substituent group was inversely proportional to the intensity of bitterness inhibition. Adjusting the length of FA’s acrylic acid carbon chain to two carbons destabilized the interaction between the ligand and the key residues, resulting in a reduction in the intensity of bitterness inhibition. In contrast, extending the carbon chain length to four carbons enhanced the bitterness inhibitory intensity. As a new bitterness inhibitor, FA has the potential for development to improve food quality.