During fresh-cut processing, potatoes lose their inherent protective cellular structure, leading to enzymatic browning that compromises sensory and edible quality. Tea polyphenols (TPs), natural preservatives with potent reducing properties, are hypothesized to impact this browning process. However, their influence and regulatory mechanism on the enzymatic browning of fresh-cut potatoes remain poorly understood. This study used the “Holland Seven” potato as the research material to explore the effects of a treatment with different TP concentrations (0.1 g L⁻¹, 0.2 g L⁻¹, and 0.3 g L⁻¹) on the browning phenomenon and quality of fresh-cut potatoes during storage. The results showed that appropriate concentrations of TP treatment had a good preservation effect on the appearance and edible quality of fresh-cut potatoes. Furthermore, exogenous TP treatment reduced the content of enzymatic browning substrates (caffeic acid, p-coumaric acid, and ferulic acid) by regulating phenylpropanoid metabolism. Meanwhile, TP treatment augmented the activities of antioxidative enzymes (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase), maintained higher levels of ascorbic acid (Vc), and reduced glutathione (GSH). Consequently, the TP treatment could inhibit enzymatic browning by regulating reactive oxygen species (ROS) metabolism and the Vc-GSH cycle in fresh-cut potatoes.

The Lanzhou lily is a regionally distinctive vegetable; the emergence of lightly processed lilies has addressed the inconvenience of consuming fresh lilies. However, the cleaning and impurity removal during the processing of lightly processed lily may strip off its original protective barrier and affect the edible quality. As one of the preservation methods, tea tree essential oil (TTEO) has the characteristics of being green, safe, and efficient preservative properties. This study focused on investigating the effects of different concentrations (25 μL/L, 50 μL/L, and 100 μL/L) of TTEO on the quality and microbiological safety of lightly processed lily. The results showed that compared with the control, appropriate concentrations of TTEO treatment could delay weight loss, improve appearance, firmness, and sensory quality, and maintain microbiological safety with the best effect observed at 50 μL/L. Meanwhile, TTEO treatment induced phenylalanine ammonia-lyase activity, thereby increasing the total phenolic content. Furthermore, TTEO enhanced the superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity, which reduced O₂-· production rate and H₂O₂ content. TTEO inhibited lipoxygenase (LOX) activity, reducing the relative conductivity and malondialdehyde content, thereby delaying lipid peroxidation and quality deterioration. This indicates that TTEO could enhance antioxidant capacity by regulating reactive oxygen species (ROS) metabolism and delay the quality deterioration of lightly processed lily by inhibiting lipid peroxidation.

Nonconjugated clusteroluminogens (CLgens) become increasingly important in photophysics and advanced bioelectronic applications. Most CLgens show ultraviolet emission, and it remains an enormous challenge to change the electronic structures of CLgens to improve their photophysical properties by precisely regulating the intramolecular through-space interactions (TSI). Herein we propose a general strategy to construct a higher-level intramolecular TSI in multiaryl-substituted alkanes, namely the secondary through-space interaction (2nd TSI), which is constructed by the primary through-space interaction (1st TSI) and TSI linker. By introducing methyl and phenyl into 1,1,3,3-tetraphenylpropane (TPP) respectively, butane-1,1,3,3-tetrayltetrabenzene (Me-TPP) and propane-1,1,1,3,3-pentaylpentabenzene (Ph-TPP) both show bright visible clusteroluminescence (CL), whose fluorescence quantum yield is up to ~40% and the emission wavelength extends to 530 nm. Advanced theoretical studies relating to their emission mechanism are quantitatively performed to analyze the photophysical properties of these CLgens in different states. It is found that molecular rigidity and proper conformation both play pivotal roles in improving the 1st TSI, enhancing the TSI linker and constructing 2nd TSI. Experimental and calculation results prove that the hierarchical TSIs and CL have been successfully regulated in these multiaryl-substituted alkanes (MAAs). This work not only provides a feasible strategy to achieve controllable manipulation of TSI and CL but also paves the way to the in-depth mechanistic understanding of CL.

Different from traditional organic luminescent materials based on covalent delocalization, clusteroluminescence (CL) from nonconjugated luminogens relies on noncovalent through-space conjugation (TSC) of electrons. However, such spatial electron delocalization is usually weak, resulting in low luminescent efficiency and board emission peak due to multiple vibrational energy levels. Herein, several nonconjugated luminogens are constructed by employing biphenyl as the building unit to reveal the structure-property relationship and solve current challenges. The intramolecular TSC could be gradually strengthened by introducing building units and stabilized by rigid molecular skeleton and multiple intermolecular interactions. Surprisingly, narrowband CL with full width at half-maximum of 40 nm and 100% efficiency is successfully achieved via an asymmetric conformation, exhibiting comparable performance to the traditional conjugated luminogens. This work realizes highly efficient and narrowband CL from nonconjugated luminogens and highlights the essential role of structural conformation in manipulating the photophysical properties of unconventional luminescent materials.

Unlocking the potential of weak interactions to govern the electronic structure of organic molecules remains a significant challenge. This study constructs a quantitative relationship between conformations and strength of electronic through-space interactions (TSI) for tetraarylethanes (TAEs). To identify long-wavelength emitters, a sophisticated virtual screening is executed for TAE by constructing a TSI-based database. Consequently, an ultra-small emitter (o-2Md), distinguished by a highly concentrated n-electron configuration, is synthesized and shows a remarkable near-infrared (NIR) emission with a luminescence quantum yield of 25% and an emission wavelength extending beyond 800 nm. Notably, the o-2Md stands out as one of the smallest known organic NIR emitters, showcasing the robustness of n-n TSI in designing efficient emitters. This work not only systematically reveals the important role of weak interactions in manipulating the electronic structure at the single-molecule level but also provides a new platform, the TSI database, for designing advanced optoelectronic materials.