Hetong Lin

To meet consumer expectations for larger litchi fruits and better postharvest storage quality, this study assessed the effects of preharvest chitosan application on litchi fruit size, weight, postharvest quality and storage performance. Litchi fruits were sprayed with a commercial aqueous chitosan formulation (Kadozan) in five different concentrations, namely, 1:250 (V_Kadozan: V_{Kadozan + Water}), 1:500, 1:750, 1:1000 and 0:1000 (control), at 45, 55, and 65 days after full blossom (AFB), and then harvested at commercial maturity (90 days AFB). After harvest, the fruit were cleaned, air-dried, packaged, and subsequently stored at room temperature (25 ± 1 °C). The results revealed that preharvest Kadozan treatment produced heavier and larger fruits with higher vitamin C at harvest. During storage, it delayed the decline in total soluble solids, soluble sugars, and vitamin C in the aril while preserving higher pericarp anthocyanin, chlorophyll, carotenoid, and flavonoid contents. Kadozan treatment also reduced respiration rate, weight loss, and cell membrane permeability, increased total phenolics and decreased polyphenol oxidase activity, leading to a lower browning index. Notably, it enhanced lignin, upregulated phenylalanine ammonia-lyase, chitinase and β-1,3-glucanase activities, and accordingly suppressed disease development and improved marketable fruit rate. In conclusion, among the tested treatments, the 1:750 Kadozan application was the most effective in improving fruit quality at harvest, delaying postharvest senescence, and enhancing storage performance, thus offering a practical strategy for both preharvest quality improvement and postharvest quality maintenance of litchi fruits.

Traditional chemical hair dyes are associated with potential health risks, while botanical alternatives are often hampered by poor stability and limited color longevity. In this study, discarded squid ink was used to prepare bionic hair colorants of high performance. By synergizing ultrasound disruption with enzymatic hydrolysis, the crude ink aggregates were transformed into highly uniform squid ink melanin nanoparticles (SIMNPs) with size and zeta potential of ~174 nm and −37.5 mV, respectively. This effectively improved the solubility but reduced the steric limitation of natural melanin. To overcome the weak affinity between melanin and human hair, a biomimetic interface where Fe(III) ions act as supramolecular bridges was further engineered to stably bind the SIMNPs to hair keratin. Under optimized conditions (pH 8.0, 45 °C, and 80 min), the dyed hair achieved a natural deep black with a total color difference (ΔE*) of 68.79 ± 0.29, which was maintained at 63.19 ± 0.27 even after 13 consecutive water washing cycles. Unlike destructive oxidative dyes, this SIMNP dyeing system assisted by coordination-driven assembly preserved the native α-helical architecture and disulfide bond networks of hair keratin. Furthermore, the deposited SIMNP layer effectively protected hair fibers from ultraviolet (UV) damage due to its powerful UV-shielding capacity. Crucially, in vitro and in vivo evaluations confirmed the exceptional biosafety of this formulation, demonstrating robust cellular tolerance and absence of murine skin irritation. The work demonstrates a green, low-damage paradigm for the development of bio-based hair colorants of high performance and presents a promising pathway for the high-value utilization of marine by-products.

Glehniae Radix, the dried root of Glehnia littoralis Fr. Schmidt ex Miq. (Apiaceae), exhibits diverse biological activities. However, research on the hypoglycemic effects of Glehniae Radix polysaccharides (GRPs), particularly in vivo studies clarifying their mechanisms of action, remains limited. This study aimed to verify the in vivo hypoglycemic activity of crude GRP in a diabetic model and to elucidate its mechanism. GRP was extracted by water extraction and ethanol precipitation, yielding an extraction rate of 38% and a polysaccharide content of 73.48%. Its hypoglycemic effects and mechanisms were investigated in female B6.BKS(D)-Leprdb/J (db/db) mice following daily administration of GRP at doses of 300 and 600 mg/kg for five consecutive weeks. Following GRP administration, mice in the CH group (600 mg/kg) exhibited a mean reduction in fasting blood glucose levels of approximately 40.7% and an improvement in insulin tolerance test (ITT) outcomes by about 28.4%. Additionally, GRP alleviated damage to the liver, kidney, and colon; decreased hepatic total cholesterol (TC) and triglycerides (TGs) by approximately 40.8% and 24.6%, respectively; and increased colonic Zonula Occludens-1 (ZO-1) expression by an average of 49.5%. Mechanistically, GRP significantly upregulated the expression of peroxisome proliferator-activated receptor-α (PPAR-α) and PPAR-γ in the liver, while also increasing the abundance of beneficial gut bacteria such as Alistipes and suppressing harmful bacteria including Escherichia-Shigella. Furthermore, GRP activated the galactose metabolism pathway and inhibited abnormal enrichment of the steroid biosynthesis pathway, collectively ameliorating glucose metabolic disorders in female db/db mice via the “gut microbiota–PPAR signaling axis”. In light of these results, GRP exerts significant in vivo hypoglycemic effects by modulating gut microbiota balance and activating the PPAR signaling pathway.

Chinese olive, a fruit of significant economic and nutritional value in South China, is susceptible to chilling injury (CI) during cold storage, which is a primary factor leading to substantial postharvest fruit losses. The purpose of this exploration is to enunciate the impacts of 0.4 mM exogenous melatonin (MT) treatment on fruit quality attributes and CI occurrence in Chinese olive during 120 d of storage at 2 °C, with a particular focus on energy metabolism. The outcomes displayed that, compared to the control fruit, the MT-treated fruit showed a lower CI index, reduced weight loss, and decreased carotenoid content, while maintaining a higher percentage of commercially acceptable fruit, as well as higher L*, h°, and b* values and chlorophyll content. Furthermore, MT treatment sustained higher levels of total soluble solids, total phenolics, flavonoid, and tannin. Additionally, MT application alleviated the drops of energy charge, adenosine diphosphate, and adenosine triphosphate contents, and maintained higher activities of H⁺-ATPase, Ca²⁺-ATPase, and Mg²⁺-ATPase in the membranes of mitochondria, vacuoles, and plasma. Collectively, these data imply that 0.4 mM MT treatment elevated the activities of enzymes associated with energy metabolism, and sustained a higher energy status (energy charge and adenosine triphosphate), thereby mitigating quality deterioration and suppressing CI development in Chinese olive during cold storage.