Investigating the influences of different sterilization methods on overall juice quality is essential for the production of high-quality juice. The effects of ultra-high temperature instantaneous sterilization (UHT), thermosonication (TS), high hydrostatic pressure sterilization (HHP), and irradiation sterilization (IS) on the physicochemical properties, functional components, and color of Aronia melanocarpa juice (AMJ) were investigated. In addition, anthocyanin target metabolomics were used to explore the influences of different sterilization methods on the AMJ anthocyanin profile. All sterilization treatments effectively ensured the microbial safety of AMJ, and the AMJ viscosity was noticeably declined after sterilization (p < 0.05). Except for HHP, the other treatments aggravated AMJ browning (p < 0.05). Both TS and HHP treatments significantly enhanced or preserved the total polyphenols, flavonoids, and anthocyanins in AMJ and retained the original juice color, whereas UHT and IS treatments were not conducive to maintaining these characteristics. TS treatment significantly increased cyanidin-3-O-galactoside (C-3-O-gal) and cyanidin-3-O-arabinoside (C-3-O-ara) contents in AMJ by 7.98% and 5.90%, while IS resulted in a significant decrease of 15.74% and 10.46% (p < 0.05). C-3-O-gal and C-3-O-ara were the major reasons for the significant upregulation and downregulation of the total monomeric anthocyanins contents (TMAC) in the AMJ after TS and IS treatment, respectively. Malvidin-3-O-glucoside (M-3-O-glu), Cyanidin-3-O-(6-O-malonyl-β-D-glucoside) and Kaempferol-3-O-rutinoside (K-3-O-rut) might be markers of differential metabolites produced by the TS, HHP, and IS treatments, respectively. Correlation analysis indicated that Cyanidin-3-O-xyloside (C-3-O-xyl), C-3-O-ara, and Pelargonidin-3-O-arabinoside (P-3-O-ara) might be the principal contributed to the antioxidant capacity of AMJ. The research results are anticipated to supply technical reference for AMJ processing.

The impact of microwave-assisted thermal sterilization (MATS) on three natural pigments and their storage stability in vegetable purees was investigated. We selected carrot puree for beta carotene, red cabbage puree for anthocyanins, and red beetroot puree for betalains. The purees were packaged in multilayer flexible pouches of AlOx-coated PET (12 μm)//AlOx-coated PET (12 μm)//AlOx-coated PET (12 μm)//ONy (15 μm)//CPP (70 μm), then processed with the MATS system to Fo = 6 to 11 min. After MATS treatment, the pouches were stored for 6 months at a storage temperature of 37.8 °C. The MATS treatment had a significant impact (p < 0.05) on the instrumental colors of three purees, with the total color difference (ΔE) ranging between 6.0 and 10.5. Similarly, the concentration of betalains experienced degradation by 20%−29% after the MATS treatment, while beta-carotene concentration showed a high retention. In addition, the pH of the purees declined considerably (p < 0.05) after the MATS treatment. Over the 6 months of storage at 37.8 °C, the PET-metal oxide pouches maintained the moisture content in all the purees, as the weight loss was only 0.43%−0.45%. The pigments in the MATS-processed purees had different levels of stability; ΔE values varied between 4.23 and 12.3. Beta-carotene was the most stable pigment, followed by betalains and anthocyanins. The degradation of both betalains and anthocyanins during storage was explained by first and fractional conversion models. MATS processing and packages with high gas barriers can therefore be used to preserve selected vegetable purees rich in natural pigments.

The promising future of natural colors in the food industry aligns with the shift in consumer preference toward healthier food options. These naturally derived ingredients gradually replace their artificial counterparts and find applications in a wide range of food categories, and aquatic products have emerged as one of them. In this work, we introduced the characteristics and extraction of several main types of natural pigments and also explored the positive outcomes of integrating the pigments, such as carotenoids, curcumin, anthocyanins, and betalains, in aquatic product processing and preservation. Their outstanding antioxidant and dyeing properties contribute to the production and storage of various aquatic products. This review aims to provide a comprehensive understanding of the current state of natural pigment applications in aquatic products and to provide inspiration for future research and industry practices.

Carotenoids are colored bioactive substances increasingly used due to their antioxidant properties, vitamin A precursor role, and ability to function as a natural food color. Knowledge of carotenoid behavior during high-heat processing and subsequent storage in emulsified food matrix is essential to expand their application natural food colors and neutraceuticals. Firstly, the physical, thermal, and colloidal stability of emulsions constructed from octenyl succinic anhydride-modified starch (OSA starch)-chitosan multilayered interfaces were investigated. Results of charge reversal from −32.4 ± 1.9 mV to +38.0 ± 0.8 mV indicate that multilayered interfaces were formed in emulsions. As measured by Z-average size, the emulsions were stable after the thermal treatment at 121 °C for 60 min, thus demonstrating a novel heat-stable multilayered emulsion. Subsequently, a select multilayered emulsion was loaded with β-carotene, and its storage stability was assessed. The degradation of β-carotene in an oil-in-water emulsion was better described with zeroth order kinetics; β-carotene dissolved in bulk oil was better described using a second-order kinetic equation. The presence of an encapsulating material around the oil droplets loaded with β-carotene enhanced its stability, which makes it instrumental in extending shelf-life and maintaining a consistent appearance. The results can be used to predict the availability of β-carotene during storage.

Essential oils (EOs) are plant aromas used in the food industry. They have attracted considerable attention due to their diverse properties, i.e., antimicrobial, antifungal, and antioxidant activities, with natural aroma and flavor as beneficial food additives. However, the instability, degradability, and hydrophobicity of EOs have limited their practical use in the food industry. Nanoencapsulation, a process where EOs are enclosed in a protective shell at the nanoscale, promises to enhance the biological properties of EOs. This process empowers EOs with excellent physiochemical stability and solubility, allowing for better distribution in food systems and controlled release for prolonged availability of EOs without rapid evaporation and instability. This review summarizes the recent works on encapsulating EOs to enhance their biological properties, providing a comprehensive overview of various specific nano-carriers and their applications in the food industry.

Designing a wound dressing that offers excellent antibacterial properties while providing dual pH/glucose responsiveness for diabetic wound healing remains a considerable challenge. Herein, a 3D cross-linked native protein hydrogel was constructed through a Schiff base reaction based on -NH2 in paramyosin (PM) and -CHO in oxidized dextran (ODA) under mild conditions. Within the hydrogel, both amikacin and glucose oxidase were encapsulated during gelation. The resulting hydrogel exhibited favorable rheological properties, featuring self-healing, antibacterial activity, tissue adhesiveness, and excellent biocompatibility. Notably, the hydrogel demonstrated excellent pH/glucose dual-responsive properties. In infected wounds, the Schiff base bonds dissociated due to low pH, while in uninfected wounds with high blood glucose levels, the encapsulated glucose oxidase was functional, which also lowered the local pH level and dissociated the Schiff base bonds. Furthermore, the hydrogel quickly achieved pH/glucose dual responsiveness, leading to increased amikacin release to reduce bacterial invasion, alleviate oxidative stress, promote re-epithelialization and collagen deposition, and eventually accelerate diabetic wound healing. Collectively, the constructed hydrogel offers brand-new viewpoints on glucose-responsive biomaterials for diabetic wound therapy.

In this study, microfluidization was explored to inactivate autolytic spoilage enzymes (polyphenol oxidase, PPO, and peroxidase, POD) that significantly impact the nutritional and sensory qualities of tender coconut water (TCW). TCW was treated at three different pressure levels (70, 140, and 210 MPa) and five different number of passes/cycles (3, 5, 7, 9, and 11). The highest percentage reduction was obtained in the case of PPO (~61% in the 11th pass, at 210 MPa), while for POD, ~45% reduction was achieved in the 9th pass, at 70 MPa. The impact of different treatment conditions on the physicochemical properties of TCW, such as color, turbidity, total soluble solids (TSS), pH, titratable acidity, total phenolic content (TPC), and protein content was assessed. The pH and TSS remained unaffected; whereas, turbidity showed an increase with treatment intensity from 2.59% ± 0.14% (untreated) to 8.62% ± 0.39% (30,000 psi, 11 passes), and the highest color difference was observed for this sample (ΔE = 4.61 ± 0.018). Furthermore, TPC and antioxidant activity showed minimal changes upon treatment. Overall, the findings of this research provide new insights into the application of microfluidization for the processing of thermally sensitive products such as TCW, extending their shelf life without any additives and providing a clean label solution.

Chilling injury (CI) is a highly common physiological disorder in pomegranates during cold storage. Although several approaches have been investigated to mitigate the CI symptoms among some pomegranate cultivars, the fundamental and crucial environmental factor — the precise storage temperature for the 'Mengzi' cultivation remains unknown. This research evaluated the impact of storage temperatures of 0, 1, 2, 3, and 4 °C on the post-harvest quality of pomegranates. Results indicated that pomegranates stored at 2 °C exhibited the slightest color change and browning index. After storage of 130 d, pomegranates stored at 2 °C exhibited the lower CI index (82.79% reduction) and the lowest decay incidence (24.68% reduction) compared to those stored at 0 °C. The respiratory rate of pomegranates (2 °C) was also evidently suppressed (16.60%), along with a reduction in weight loss (3.46%). Furthermore, pomegranates stored at 2 °C exhibited the lowest activities of polyphenol oxidase (PPO) and peroxidase (POD), accompanied by the highest total phenolic content, which contributed to a reduction in malondialdehyde (MDA) accumulation. Relatively higher concentrations of soluble solids and titratable acid, as well as a higher sensory evaluation, were found in pomegranates stored at 2 °C. Consequently, it was inferred that the optimal temperature maintained cell membrane integrity modulated normal respiratory metabolism, and oxidative balance, and therefore alleviated CI and deterioration. This report can provide the guiding significance for the long-term storage of 'Mengzi' pomegranates under the condition of precise temperature control in phase temperature storage.

Marselan wine, one of the most important wines in the Ningxia Hui Autonomous Region of China, has attracted much attention due to its unique quality. This study focused on determining and analyzing the changes in volatile flavor compounds and antioxidant activity during different stages of Marselan winemaking. A total of 40 volatile aroma compounds were identified by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). Among these compounds, ethyl hexanoate, isoamyl acetate, ethyl formate, ethyl acetate, ethyl butanoate, ethyl octanoate, 3-methyl-1-butanol, ethanol, and 2-methyl-1-propanol showed significant increases after fermentation. Flavonoid and phenol contents in Marselan wine samples also significantly increased after fermentation, demonstrating high antioxidant capacity. Principal component analysis (PCA) successfully distinguished the fruit juice processing stage, alcohol fermentation stage, and malolactic fermentation stage, while the malolactic fermentation stage and wine stable stage could not be distinguished, This indicates that the formation of aroma profiles primarily occurs during the malolactic fermentation stage. The study successfully established flavor fingerprints of samples from different stages of Marselan wine production based on the detected volatile compounds.

The loss of pericarp greenness, wrinkling of the pericarp, and alteration of aroma are indicators of the ripening and senescence of lemons. In this study, lemons were soaked in 100 mg∙L-1 of gibberellin (GA) solutions for 5 min and stored at 14°C for 36 d under three relative humidity (RH) levels of 30%, 60%, and 90%, respectively. The changes in visual appearance, pigment metabolism, pericarpic microstructure, and volatile compounds of lemons during storage were evaluated. The results showed that GA pretreatment inhibited the color transformation from green to yellow of the flavedo and restrained fruit senescence. In addition, RH 90% effectively maintained the structural integrity of the oil gland, waxes, and stomata in the flavedo. GAs + RH 90% treatment maintained the fruit color index (L*, a*, b*, a*/b*, H°, C*) by inhibiting chlorophyll degradation and regulating carotenoid biosynthesis. Green lemons treated with GAs + RH 90% also showed reduced epidermal wrinkling, well-preserved cuticle, and stomatal structure, with a smooth and intact wax layer on the lemon pericarp. In addition, GAs + RH 90% treatment maintained the content of volatile aroma compounds, especially terpene. GAs + RH 90% had a great advantage in maintaining visual quality, delaying the deformation of tissue microstructure, preserving nutritional quality, and improving aroma. Thus, this treatment is potentially applicable for maintaining the storage quality of green lemons and extending their shelf life.