The sterilization of freshly squeezed juices typically results in a compromise to the natural flavor, bio-active components, and nutritional value. Developing a new sterilization method for controlling the diverse effects has emerged as a significant challenge. This research aims to explore the potential application of thermosonication (TS) for freshly squeezed tomato juice. Results revealed that both TS (temperature 50, 60, and 70 ℃; time 5, 10, and 15 min) and thermal pasteurization (TP, 85 ℃/10 min) effectively inactivated microorganisms. No significant differences were observed in the basis properties (pH, total soluble solids (TSS) and titratable acidity (TA)) of tomato juice. Notably, TS effectively enhanced the juice quality, and the optimal condition is TS 60 ℃ 15 min. Its retention rates in color and suspension stability were greatly enhanced. Meanwhile, TS (60 ℃, 15 min) not only significantly increased lycopene content (42.13 %), ascorbic acid content (36.64 %), flavonoids content (33.94 %), and total phenols content (34.06 %), but also maintain a higher antioxidant capacity compared to PJ samples. Moreover, the sensory quality and volatile substances of TS treated were enhanced. It can be inferred that TS through ultrasonic cavitation ensured the microbial safety, improved nutritional value and sensory quality of tomato juice. This report provide a basis that a proper lower pasteurization temperature produced better effect in tomato juice when combined with ultrasound.

The purpose of this study was to clarify the effect of CA (controlled atmosphere, 2–3% O₂ + 3% CO₂) and NO (nitric oxide, generated by 0.4 nM sodium nitroprusside), alone or combined (CA + NO), on the physio-chemical properties, enzyme activities and antioxidant capacities of chestnuts during storage at 0 °C for 180 d. Compared with control (CT), CA and CA+NO both improved the storage quality of the samples, but only CA resulted in more ethanol production. Moreover, these improvements were further enhanced and ethanol synthesis was inhibited by the addition of NO. A spectrometer was used to assess the production of phenolic content (TPC) and activities of phenylalanine ammonia-lyase (PAL), superoxide dismutas (SOD), peroxidase (POD), catalase (CAT) and polyphenol oxidase (PPO) as influenced by CA or CA+NO treatments. Higher TPC, PAL, SOD, POD, CAT, and lower PPO were observed in CA alone, and more so in the combination with NO group. The increased antioxidant production and enhanced antioxidant activities contributed to scavenging reactive oxygen species (ROS) and reducing malondialdehyde (MDA). This study unveiled the correlations and differences between the effects of CA and CA+NO on storage quality, providing valuable insights into postharvest preservation and suggesting that the combination (CA+NO) was more beneficial for quality maintenance in chestnuts.

Antioxidant capacity is one of the most important biological activities in fruits and vegetables and is closely related to human health. In this study, ‘Eureka’ lemons were used as experimental materials and stored at 7–8 °C MT (melatonin, 200 μmol, soaked for 15 min) and CA (controlled atmosphere, 2–3% O₂ + 15–16% CO₂) individually or in combination for 30 d. The changes in lemon fruits’ basic physicochemical properties, enzyme activities, and antioxidant capacities were studied. Comparing the combined treatment to the control, the outcomes demonstrated a significant reduction in weight loss, firmness, stomatal opening, and inhibition of polyphenol oxidase (PPO) and peroxidase (POD) activities. Additionally, the combined treatment maintained high levels of titratable acidity (TA), vitamin C (VC), total phenolic content (TPC), and antioxidant capacity and preserved the lemon aroma. Meanwhile, the correlation between fruit color, aroma compounds, and antioxidant capacity was revealed, providing valuable insights into the postharvest preservation of lemons. In conclusion, the combined treatment (MT + CA) was effective in maintaining the quality and antioxidant capacity of lemons.

The color and aroma of nectarines experience adverse effects from cutting, resulting in the fast senescence of fruit tissue. Therefore, 1-methylcyclopropene (1-MCP) was used to treat postharvest nectarines before cutting, and its effect on the surface browning and aroma alteration were investigated. The results indicated that 1-MCP restrained the soluble quinone (SQC) accumulation in fresh-cut nectarines by regulating the peroxidase (POD) and polyphenol oxidase (PPO) activities and the metabolism of phenolic compounds. Compared with the control, 1-MCP pre-cutting treatment maintained the ultrastructural integrity of the cell wall in fresh-cut nectarines, which also showed reduced malondialdehyde (MDA) content and reactive oxygen species (ROS) and enhanced the 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) radical scavenging activities. Electronic nose and GC-MS analysis revealed that the aroma profiles presented significant differences in the control and 1-MCP treatment during the storage at 0 °C for 10 days. The browning value of the 1-MCP pre-cutting treatment was 29.95% lower than the control, which prevented the loss of aroma on day 10. The fresh-cut nectarines could still maintain the characteristic flavor, while the flesh maintains its firmness. The 1-MCP pre-cutting treatment improves the sensory and aroma characteristics of fresh-cut fruits, which is beneficial to the preservation of fresh-cut fruits, improves transportation efficiency, and then improves the overall quality and market attractiveness of the fruit.

Elevated oxygen is regarded as an effective approach to maintaining the quality of fresh plant products. To elucidate the role of elevated oxygen in polyphenol biosynthesis and antioxidant capacity, we evaluated the impact of different concentrations of oxygen on polyphenol metabolism, individual polyphenol contents, and antioxidant levels of strawberries during storage. Elevated oxygen (40%, 60%, and 80%) promoted the accumulation of polyphenols, including tannin, flavone, and anthocyanin. At the end of storage, total polyphenol contents of strawberries treated with 60% and 80% oxygen were 1.11 and 1.13 times higher, respectively, than the control group. In addition, elevated oxygen effectively enhanced DPPH and FRAP, which was consistent with the observed changes in polyphenol contents. Additionally, most genes involved in polyphenol biosynthesis were found to be upregulated during storage, with elevated oxygen resulting in higher expression levels compared to controls. These findings show that presumably, the main reason for the improvement in the commercial and edible quality of strawberries is physical treatments, such as elevated oxygen.