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Oxidative stress significantly contributes to ageing and disease, with antioxidants holding promise in mitigating its effects. Functional foods rich in flavonoids offer a potential strategy to mitigate oxidative damage by free radicals. We investigated the protective effects of mulberry leaf flavonoids (MLF) against H2O2-induced oxidative damage in HepG2 cells. It assessed the inhibitory effect of MLF (62.5–500 μg/mL) on H2O2-induced oxidative damage by analyzing cellular morphology and oxidative stress markers, including ROS production, mitochondrial membrane potential, antioxidant enzyme levels, MDA, and apoptosis-related proteins. The results demonstrated that MLF prevented spiny cell formation triggered by 750 μM H2O2 and significantly reduced ROS levels, restored mitochondrial membrane potential, decreased lactate dehydrogenase and alanine transaminase leakage, and reduced MDA content induced by H2O2. MLF also modulated antioxidant enzymes and attenuated oxidative damage to HepG2 cell DNA, as confirmed by staining techniques. These findings indicate the potential of MLF as a hepatoprotective agent against oxidative damage in HepG2 cells. [ABSTRACT FROM AUTHOR]

In recent years, with the improvement of people's living standards, the enhancement of health awareness and the acceleration of the pace of life, fresh-cut fruits and vegetables are increasingly favored by consumers due to its characteristics of convenient, safe, nutritious and fresh. However, cutting causes fruit and vegetable suffer irreparable mechanical damage, which may active its own defense system to synthesize phenolic substance secondary metabolites in order to resist and repair mechanical damage and enhance the antioxidant activity of fresh-cut fruits and vegetables. The pretreatment fresh-cutting operation improved the antioxidant and health benefits of fruits and vegetables has received widespread attention from postharvest scholars. In particular, it has the important progress on improving the potential nu-tritional value of fresh-cut fruits and vegetables based on physiological and biochemical studies on the biosynthesis mechanism of phenolic substances. Collectively, this paper reviewed the biosynthetic mechanism of phenolic substances and their antioxidant activity in fresh-cut fruits and vegetables, which aimed to provide a theoretical basis for elucidating that fresh-cut fruits and vegetables, as pre-processed products, produced more phenols and further improved the antioxidant activity of fresh fruits and vegetables. Meanwhile, this paper will provide new insights into the method that can effectively improve the phenolic substances content and antioxidant activity in fresh-cut fruits and vegetables. [ABSTRACT FROM AUTHOR]

To evaluate the antioxidant activity of flavonoids extracted from Chinese herb mulberry leaves (ML), flavonoids from mulberry leaves (FML) were extracted and purified by using ultrasonic-assisted enzymatic extraction and D101 macroporous resin. Using LC-MS/MS-Liquid Chromatography with tandem mass spectrometry analysis, hesperidin, rutoside, hyperoside, cyanidin-3-o-glucoside, myricitrin, cyanidin, and quercetin were identified, and NMR and UV were consistent with the verification of IR flavonoid characteristics. The antioxidant activity of FML has also been evaluated as well as the protective effect on 2,2 0-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress. The results showed that FML exhibited powerful antioxidant activity. Moreover, FML showed dose-dependent protection against AAPH-induced sheep erythrocytes' oxidative hemolysis. In the enzymatic antioxidant system, pretreatment with high FML maintained the balance of SOD, CAT, and GSH-Px; in the non-enzymatic antioxidant system, the content of MDA can be effectively reduced after FML treatment. This study provides a research basis for the development of natural products from mulberry leaves. [ABSTRACT FROM AUTHOR]

Phenolic compounds are secondary metabolites and widely distributed in higher plants. When plants are subjected to injury stress, the rapid synthesis of more phenols is induced to result in injury defense response for wound healing and repair. Fresh-cut fruits and vegetables undergo substantial mechanical injury caused by pre-preparations such as peeling, coring, cutting and slicing. These processing operations lead to activate the biosynthesis of phenolic compounds as secondary metabolite. Phenolic compounds are important sources of antioxidant activity in fresh-cut fruits and vegetables. The wound-induced biosynthesis and accumulation of phenolic compounds in fresh-cut fruits and vegetables have been widely reported in recent years. This article provides a brief overview of research published over the last decade on the phenolic compounds and antioxidant activity in fresh-cut fruits and vegetables. It is suggested that fresh-cut processing as mechanical wounding stress can be used as an effective way to improve the nutritional composition and function of fresh-cut produces. [ABSTRACT FROM AUTHOR]

In order to clarify an efficient and convenient method to increase the antioxidant activity in broccoli, this study intended primarily to elucidate the effect of cutting type on the quality parameters, antioxidant substance contents and antioxidant activity of broccoli using different floret diameters of 10 × 10 cm (CS1), 5 × 5 cm (CS2), 2.5 × 2.5 cm (CS3) and shredded florets (CS4). The results showed that chlorophyll, total soluble solid, vitamin C and reduced glutathione contents of fresh‐cut broccoli were decreased obviously during the storage. However, there was a significant influence of cutting type on the enzymatic activities involved in phenolic synthesis and oxidation including phenylalanine ammonia‐lyase, cinnamate 4‐hydroxylase, and polyphenol oxidase, which contributed to increasing phenolic content by 26.8%, 30.9%, 46.0%, and 51.3% in CS1, CS2, CS3 and CS4, respectively, and further enhanced the antioxidant activity by more than 60% in fresh‐cut broccoli. Moreover, the activities of antioxidant‐related enzymes, including superoxide dismutase, peroxidase and catalase, were increased significantly in fresh‐cut broccoli. In conclusion, the cutting types had no significant effect on quality but clearly influenced the antioxidant substances and activities of broccoli; therefore, this study provided an efficient and convenient method to enhance the potential nutritional value of broccoli. [ABSTRACT FROM AUTHOR]

Herein, we examined the effects of plasma-activated water (PAW) treatment on the native microflora survival, quality maintenance, and antioxidant activity of fresh-cut pears, which were washed with PAW under three different conditions (peak voltage = 6, 8, and 10 kV) for 5 min and then stored at 4 °C for 12 days. Distilled water and sodium hypochlorite treatment were used as control and comparison, respectively. Results showed that all PAW treatments significantly inhibited the growth of aerobic bacteria, yeast, and mold during storage, with the 8-kV PAW treatment maintaining the lowest growth rate. Additionally, no significant change was observed in the soluble solid content and titratable acidy of fresh-cut pears treated with PAW. Treatment by 6-kV PAW significantly slowed down the softening of fresh-cut pears, while the 8-kV PAW treatment significantly reduced the mass loss and the total phenolic content (P < 0.05). The ascorbic acid content and radical scavenging activity (DPPH and ABTS) of fresh-cut pears were affected by PAW treatment only at the beginning of storage. After 8 days of storage, no significant differences were found in ascorbic acid content and radical scavenging activity among the samples (P > 0.05). Furthermore, PAW outperformed sodium hypochlorite in antimicrobial effectiveness and quality maintenance. Taken together, these results suggest that PAW treatment might be a promising strategy to control microbial growth and maintain the quality of fresh-cut pears. [ABSTRACT FROM AUTHOR]

Fresh-cut potatoes (Solanum tuberosum L.) are appreciated by consumers for their convenience and freshness. In the process of home cooking and food industry, different cutting styles of potato are needed. In order to explore the effect of cutting styles on quality, antioxidant activity, membrane lipid peroxidation, and browning in fresh-cut potatoes, potatoes were cut into pieces, strips, slices and the whole potatoes were used as control. The results indicated that vitamin C content of pieces, strips, and slices potatoes was gradually reduced, while glutathione content increased significantly (P < 0.05) compared with whole potatoes. Simultaneously, cutting induced phenylalanine ammonia-lyase activity and further enhanced phenol content by 40.48%, 74.88%, and 108.86% in pieces, strips and slices, respectively. And this combined with the enhancement of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase activity, which contributed to the total antioxidant capacity increasing by 1.37–1.46 times compared with control. Furthermore, the increase of lipoxygenase, polyphenol oxidase and peroxidase activity induced by cutting resulted in malondialdehyde content accumulation and browning phenomenon. In conclusion, the degree of membrane lipid peroxidation and browning was slice > strip > piece. Therefore, this study provides useful information to illuminate the mechanism of quality change and browning in fresh-cut potatoes subjected to different cutting styles and makes suggestions on the appropriate cutting style for commercial or home use of potatoes. [Display omitted] • Wounding stress induced the accumulation of phenols of potato. • Wounding stress improved the antioxidant capacity of potato. • This work reveals physiological changes in potato with different cutting styles. • This work reveals the mechanism of quality change in wounded potato. [ABSTRACT FROM AUTHOR]

• Cutting style has obvious influence on individual phenols content and antioxidant capacity in wounded broccoli. • Illuminate the critical genes expression involved in phenolics synthesis mechanism in wounded broccoli. • Cell antioxidant capacity of shredded broccoli increased by 86.5%. • Wounding stress might be applied as an effective way to get more antioxidants in industrial and domestic processing. To explore the effect of cutting style on the biosynthesis of phenolic compounds and cellular antioxidant capacity in wounded broccoli subjected to different cutting styles (heads, florets, 1/2 florets and shredded florets), the mechanism of the accumulation of phenolic compounds was investigated at the transcriptional level, and cellular antioxidant capacity was measured using a breast cancer cell MCF-7 culture model. The results indicated that the relative expression of the genes encoding phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase and 4-coumarin coenzyme A ligase, three enzymes involved in phenylpropanoid metabolism, was upregulated and that contributed to the synthesis of individual phenolic compounds, including catechin, hydroxybenzoic acid, chlorogenic acid, caffeic acid, sinapic acid, catechin gallate, rutin, cinnamic acid and quercetin. This research constructes the phenol synthesis pathway in wounded broccoli. Moreover, the relative expression of critical genes including superoxide dismutase, peroxidase, catalase, glutathione peroxidase and glutathione reductase involved in the metabolism of reactive oxygen species (ROS) increased, resulting in enhanced antioxidant capacity in wounded broccoli. Cell antioxidant capacity (CAA) of heads, florets, 1/2 florets and shredded florets increased by 52.7%, 59.2%, 64.8% and 86.5%, respectively, compared to whole broccoli. The enhancement of CAA was greater as the intensity of wounding increased, indicating that enhancement of antioxidant activity occurred at the cellular level. This research helps provide a reliable and persuasive theoretical basis for nutritional value assessment at the cellular level in wounded broccoli. [ABSTRACT FROM AUTHOR]

• Adsorption was well fitted by the pseudo-second-order model and Langmuir model. • An efficient method for the enrichment of total flavonoids was developed. • Enrichment improved antioxidant and antiproliferative properties. The aim of this work is to develop an efficient and economical method for the enrichment of total flavonoids from Pteris ensiformis Burm. extracts. Resin screening, adsorption kinetics, adsorption isotherms and thermodynamics were successively researched prior to the dynamic adsorption and desorption tests. NKA-II resin was chosen as the best adsorbent, and the adsorption data were best described by the pseudo-second-order kinetics model and Langmuir isotherm model. The optimum enrichment conditions were as follows: for adsorption the total flavonoids concentration, flow rate and volume of sample were 1.84 mg/mL, 2 BV/h and 5 BV, respectively, and for desorption the flavonoids-loaded NKA-II resin column was desorbed by 7 BV of 50% ethanol at a rate of 2 BV/h. The product had a 6.63-fold higher total flavonoids content than crude extracts, and the recovery yield of total flavonoids was 80.65%. Furthermore, flavonoids-enriched extracts exhibited higher in vitro scavenging activity against superoxide anion radical and hydroxyl radical than crude extracts. In addition, higher antiproliferative activity of flavonoids-enriched extracts against MCF-7 and HepG-2 cell lines was also found as compared to the crude extracts. The developed method is appropriate for large-scale enrichment of total flavonoids from Pteris ensiformis Burm. extracts in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

In the present work, the ultrasonic-assisted extraction (UAE) of total flavonoids (TF) from Pteris cretica L. was optimized by response surface methodology (RSM) on the basis of a single-factor experiment. The optimized UAE parameters were as follows: Ethanol concentration 56.74%, extraction time 45.94 min, extraction temperature 74.27 °C, and liquid/solid ratio 33.69 mL/g. Under the optimized conditions, the total flavonoids yield (TFY) was 4.71 ± 0.04%, which was higher than that obtained by heat reflux extraction (HRE). The extracts were further analyzed by HPLC, and five major flavonoids, including rutin, quercitrin, luteolin, apigenin, and luteolin-7-O-glucoside, were identified and quantified. Furthermore, the results of the antioxidant test showed that the TF extract obtained under optimized UAE conditions exhibited good 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS+•), nitric oxide radical (NO•) scavenging activities, and ferrous ion (Fe2+) chelating capacity, with IC50 values of 74.49, 82.92, 89.12, and 713.41 µg/mL, respectively. Results indicated that the UAE technique developed in this work was an efficient, rapid, and simple approach for the extraction of flavonoids with antioxidant activity from P. cretica. [ABSTRACT FROM AUTHOR]

Packaging affects the physiological processes and maintains the quality and safety of food products, which is a critical element in the storage and sale of fresh-cut fruits and vegetables. Thus, the current study sought to establish optimal packaging for fresh-cut cabbage by assessing the physiological and biochemical reactions, nutritional changes, and microbial contamination of samples packaged with five different packaging films. Results demonstrated that polyvinylidene chloride (PVDC) was most efficient in maintaining colour, anthocyanin and phenolic content, inhibiting polyphenol oxygenase activity, limiting browning, delaying weight loss, and reducing the respiration rate. Moreover, the PVDC samples exhibited the highest activity of free-radical scavenging enzymes (peroxidase, superoxide dismutase, and catalase), providing superior reactive oxygen-species scavenging. Meanwhile, the polyethylene samples had the lowest total plate counts and total coliform counts after 6–12 d of storage. Whereas, the poly (butylene adipate-co-terephthalate)/poly lactic acid group exhibited superior inhibition of yeast and mold. After 12 d of storage, the microbial indices of all samples were within 105 CFU g−1, which was within the safety range for fresh-cut vegetables. Therefore, based on the sensory evaluation, physiological quality, antioxidant activity and microbial safety, PVDC film was identified as the best packaging candidate for fresh-cut red cabbage. • This work illuminates the mechanism of quality change in fresh-cut red cabbage. • Reveal the mechanism of regulating quality and safety by different packaging films. • Polyvinylidene chloride (PVDC) best retained colour and nutrients content. • For all films, microbial growth remained within food safety thresholds. • PVDC is recommended, performing best overall, and meeting safety requirements. [ABSTRACT FROM AUTHOR]

In order to develop a biodegradable agent for food preservation, β-cyclodextrin (β-CD) inclusion complexes containing p -Anisaldehyde (PAA) were prepared using co-precipitation method. Physical properties including moisture content, bulk density, hygroscopicity, entrapment efficiency and loading capacity of the inclusion complexes showed considerable results for food applications. SEM and particle size test showed notably difference between the prepared inclusion complexes and the other formulations including the raw β-CD, physical mixture, and the recrystallized β-CD in both shape and size distribution. FTIR, XRD, TGA and DTA were also carried out and confirmed the formation of inclusion complexes and inhibition of the volatility of encapsulated PAA. As a potential preservation agent, inclusion complexes demonstrated a sustained released behavior in phosphate buffer saline (PBS). Comparing with pure PAA, the inclusion complexes presented a better storage stability in low humidity environment, a higher antioxidant activity, and equal MICs against Escherichia coli and Staphylococcus aureus. • The p -Anisaldehyde was encapsulated into β-CD by co-precipitation method. • Various characterization techniques confirmed the formation of inclusion complex. • Encapsulation ensured the slow release of p -Anisaldehyde from inclusion complexes. • The inclusion complex has better storage stability than pure p -Anisaldehyde. • The inclusion complex showed considerable antibacterial and antioxidant activity. [ABSTRACT FROM AUTHOR]