Encapsulation Mechanism of Oxyresveratrol by ß-Cyclodextrin and Hydroxypropyl-ß-Cyclodextrin and Computational Analysis.

In this study, the encapsulation mechanism of oxyresveratrol and ß-cyclodextrin (ß-CD) and hydroxypropyl-ß-cyclodextrin (HP-ß-CD) was studied. As this research shows, oxyresveratrol and two cyclodextrins (CDs) were able to form inclusion complexes in a 1:1 stoichiometry. However, the interaction with HP-ß-CD was more efficient, showing up as higher encapsulation constant (KF) (35,864.72 ± 3415.89 M-1). The KF values exhibited a strong dependence on temperature and pH, which decreased as they increased. From the thermodynamic parameters (ΔH°, ΔS°, and ΔG°) of the oxyresveratrol loaded ß-CD (oxyresveratrol-ß-CD) and HP-ß-CD (oxyresveratrol-HP-ß-CD), it could be seen that the complexation process was spontaneous and exothermic, and the main driving forces between oxyrsveratrol and CDs were hydrogen bonding and van der waals force. Besides, molecular docking combined with ¹H-NMR were used to explain the most possible mode of interactions between oxyresveratrol and CDs.

One-pot green synthesis of 1,3,5-triarylpentane-1,5-dione and triarylmethane derivatives as a new class of tyrosinase inhibitors.

A new method was developed for one-pot green synthesis 1,3,5-triarylpentane-1,5-dione, triarylmethane, and flavonoid derivatives from the reaction between 2,4-dihydroxybenzaldehyde and hydroxyacetophenones via Aldol, Michael, and Friedel-Crafts additions using boric acid as catalyst in polyethylene glycol 400. The synthetic compounds demonstrated significant tyrosinase inhibitory activities much stronger than that of kojic acid. More important, 1,3,5-triarylpentane-1,5-dione and triarylmethane derivatives were found to be a new class of tyrosinase inhibitors.

Characterization of a New Flavone and Tyrosinase Inhibition Constituents from the Twigs of Morus alba L.

The twigs of Morus alba L. were found to show strong tyrosinase inhibition activity, and the responsible active components in the extract were further investigated in this study. A flavone, named morusone (1), and sixteen known compounds 2-17 were isolated from M. alba twigs and their structures were identified by interpretation of the corresponding ESI-MS and NMR spectral data. In the tyrosinase inhibitory test, the compounds steppogenin (IC50 0.98 ± 0.01 µM), 2,4,2',4'-tetrahydroxychalcone (IC50 0.07 ± 0.02 µM), morachalcone A (IC50 0.08 ± 0.02 µM), oxyresveratrol (IC50 0.10 ± 0.01 µM), and moracin M (8.00 ± 0.22 µM) exhibited significant tyrosinase inhibition activities, much stronger than that of the positive control kojic acid. These results suggest that M. alba twig extract should served as a good source of natural tyrosinase inhibitors for use in foods as antibrowning agents or in cosmetics as skin-whitening agents.

The novel angiotensin-I-converting enzyme inhibitory peptides from Scomber japonicus muscle protein hydrolysates: QSAR-based screening, molecular docking, kinetic and stability studies.

Food-derived angiotensin-converting enzyme-inhibitory (ACE-I) peptides have attracted extensive attention. Herein, the ACE-I peptides from Scomber japonicus muscle hydrolysates were screened, and their mechanisms of action and inhibition stability were explored. The quantitative structure-activity relationship (QSAR) model based on 5z-scale metrics was developed to rapidly screen for ACE-I peptides. Two novel potential ACE-I peptides (LTPFT, PLITT) were predicted through this model coupled with in silico screening, of which PLITT had the highest activity (IC50: 48.73 ± 7.59 µM). PLITT inhibited ACE activity with a mixture of non-competitive and competitive mechanisms, and this inhibition mainly contributed to the hydrogen bonding based on molecular docking study. PLITT is stable under high temperatures, pH, glucose, and NaCl. The zinc ions (Zn2+) and copper ions (Cu2+) enhanced ACE-I activity. The study suggests that the QSAR model is effective in rapidly screening for ACE-I inhibitors, and PLITT can be supplemented in foods to lower blood pressure.

Characterization, Stability, and Antibrowning Effects of Oxyresveratrol Cyclodextrin Complexes Combined Use of Hydroxypropyl Methylcellulose.

Oxyresveratrol (Oxy) has attracted much attention by employing it as an antibrowning agent in fruits and vegetables. In this study, the formation of cyclodextrin (CD) inclusion exhibited a certain protective effect on Oxy oxidative degradation, while hydroxypropyl-ß-cyclodextrin (HP-ß-CD) inclusion complex showed stronger stabilizing effects than those of ß-cyclodextrin (ß-CD). The combined use of CD and hydroxypropyl methylcellulose (HPMC) greatly improved the stability of Oxy-CD inclusion complexes, with approximately 70% of the trans-Oxy retained after 30 days of storage under light conditions at 25 °C. The results of the interaction between CD and Oxy determined by phase solubility studies and fluorescence spectroscopic analysis showed that the binding strength of CD and Oxy increased in the presence of HPMC. Moreover, Oxy combined with ascorbic acid and HPMC showed an excellent antibrowning effect on fresh-cut apple slices during the 48 h test period, indicating that adding HPMC as the third component will not influence the antibrowning activity of Oxy.

Storage stability of soy protein isolate powders containing soluble protein aggregates formed at varying pH.

Soy protein is wildly used in food industry due to its high nutritional value and good functionalities. However, the poor storage stability of commercial soy protein products has puzzled both the producers and the users for a long time. The current study assessed the changes in protein solubility, aggregation, oxidation, and conformation of soy protein isolate (SPI) with various soluble aggregates formed at different pH values (pH 5-8) during storage. During storage, SPI samples showed a reduced protein solubility (p < .05), an increased protein oxidation (p < .05), and an attenuated conformational enthalpy (∆H). SPI with a higher pH produced more disulfide-mediated aggregates at the expense of sulfhydryl groups and experienced greater losses of protein tertiary structure and a faster reduction in solubility. Yet, all samples nearly shared similar rising trend during 8-week storage, which indicated the production of protein carbonyls was insensitive to pH. Soluble aggregates present in fresh SPI samples appeared to induce instability of SPI during storage. These findings suggested SPI prepared at pH 6 was in favor of its storage stability, and soluble aggregates presented in fresh samples should be paid more attention for further study of storage stability kinetics.

Natural polyphenols as direct trapping agents of lipid peroxidation-derived acrolein and 4-hydroxy-trans-2-nonenal.

Acrolein (ACR) and 4-hydroxy-trans-2-nonenal (HNE) are two cytotoxic lipid-derived alpha,beta-unsaturated aldehydes which have been implicated as causative agents in the development of carbonyl stress-associated pathologies. In this study, 21 natural polyphenols were screened to identify effective scavenging agents of ACR and/or HNE in simulated physiological conditions. It was found that flavan-3-ols, theaflavins, cyanomaclurin, and dihydrochalcones effectively trapped ACR and HNE by working as sacrificial nucleophiles. The most effective one was phloretin, which quenched up to 99.6% ACR in 90 min and 90.1% HNE in 24 h. Subsequent LC-MS/MS analysis showed that these effective polyphenols formed adducts with ACR and HNE. A major adduct formed from phloretin and ACR was purified, and its structure was characterized by LC-MS and NMR spectroscopy as diACR-conjugated phloretin. The chemical nature of interactions between ACR and polyphenols was proposed as the Michael addition reaction of phloretin to the C horizontal lineC double bond of ACR, followed by the formation of hemiacetal between the hydroxyl group in the A ring of phloretin and the C horizontal lineO carbonyl group in ACR, thus yielding more stable products. Findings of the present study highlighted certain classes of polyphenols as promising sequestering agents of alpha,beta-unsaturated aldehydes to inhibit or restrain carbonyl stress-associated diseases.

Anti-inflammatory effects of Z23 on LPS-induced inflammatory responses in RAW264.7 macrophages.

AIM OF THE STUDY: Fissistigma oldhamii (Hemsl.) Merr, a traditional Chinese herb medicine, is used for treating rheumatoid arthritis in China. In our previous study, an effective compound, 7'-(3',4'-dihydroxyphenyl)-N-[(4-methoxyphenyl) ethyl] propenamide (Z23), from this herb has showed potent immunosuppressive effects both in vitro and in vivo. However, its anti-inflammatory effect and mechanism is still need to explore. MATERIALS AND METHODS: We examined the in vitro effects of Z23 on the production of nitric oxide (NO), prostaglandin E2 (PGE2) and cytokines by lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. RESULTS: Z23 significantly decreased the production of PGE2, NO, tumour necrosis factor alpha (TNFalpha) and IL6 production. Inducible nitric oxide synthase (iNOS) and cyclooxygenase2 (COX2) gene expression were also significantly reduced. CONCLUSIONS: These results demonstrated that Z23 exerted an anti-inflammatory effect through modulating the synthesis of several mediators and cytokines involved in the inflammatory process. This study provided evidence to understand the therapeutic effects of Fissistigma oldhamii (Hemsl.) Merr and indicated that Z23 has the potential for treatment of various inflammatory diseases where the overproduction of NO, PGE2 and inflammatory cytokines has been shown to play a role, e.g. rheumatoid arthritis.

7'-(3',4'-dihydroxyphenyl)-N-[(4-methoxyphenyl)ethyl]propenamide (Z23), an effective compound from the Chinese herb medicine Fissistigma oldhamii (Hemsl.) Merr, suppresses T cell-mediated immunity in vitro and in vivo.

Fissistigma oldhamii (Hemsl.) Merr [F. oldhamii], a traditional Chinese herb medicine, is widely used for treating rheumatoid arthritis (RA) in China. Following bioactivity-guided isolation, a representative immunosuppressive compound with low cytotoxicity, 7'-(3',4'-dihydroxyphenyl)-N-[(4-methoxyphenyl)ethyl]propenamide (Z23), was been identified in this herb medicine. We investigated the immunosuppressive effects of Z23 on T cells in vitro and in vivo. The results showed that Z23 in a dose-dependent manner significantly inhibited the proliferation of splenocytes induced by concanavalin A (ConA) and by the mixed lymphocyte culture reaction (MLR), with half inhibitive concentration (IC(50)) values of 6.22 microM and 0.78 microM, respectively. Z23 also dose-dependently inhibited the proliferation and type 1 cytokine (IFN-gamma and IL-2) production of primary T cells stimulated by anti-CD3/CD28 mAbs, but did not affect IL-12 production by mouse peritoneal macrophages (pMphi) stimulated with LPS plus IFN-gamma in vitro. Administration of Z23 (6.25 mg/kg, 12.5 mg/kg, 25 mg/kg, i.p.) dose-dependently suppressed 2,4-dinitrofluorobenzene (DNFB)-induced delayed-type hypersensitivity (DTH) reactions. Furthermore, administration of Z23 (25 mg/kg, i.p.) significantly reduced the incidence and severity of type II bovine collagen (CII)-induced arthritis (CIA), which was associated with the inhibition of CII-specific T cell proliferation and type 1 cytokine (IFN-gamma and IL-2) production. In this study, we report that a representative immunosuppressive compound from F. oldhamii, Z23, effectively inhibits murine immune responses in vitro and in vivo, and that the immunosuppressive effects of Z23 might be attributed to suppression of T cell activation and function and Th1 type cytokine production.

Inhibitory effect of fruit extracts on the formation of heterocyclic amines.

Natural extracts have attracted considerable attention for development into effective inhibitors against the formation of genotoxic heterocyclic amines (HAs) in processed foods. In this study, four fruit extracts (apple, elderberry, grape seed, and pineapple) were evaluated for their effects on HA formation in fried beef patties. Apple and grape seed extracts were found to be the most effective in both the degree of inhibition in the formation of individual HAs (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), and 2-amino-1-methyl-6-henylimidazo [4,5-b]pyridine (PhIP)) and in the reduction of total HA content (approximately 70% relative to the control). Activity-guided analysis of apple extract using model systems (PhIP- and MeIQx-producing models) showed that the proanthocyanidins, phloridzin and chlorogenic acid were responsible for reducing the amount of HAs formed. Proanthocyanidins were identified as the dominant inhibitors because they were strongly active against HA formation in both the PhIP and MeIQx model systems. For phloridzin, the inhibitory effect was observed only on the formation of PhIP. In contrast, chlorogenic acid, although effective against the formation of MeIQx, significantly enhanced the formation of PhIP. This is the first report showing the inhibitory activities of apple phenolics on the formation of heterocyclic amines. The findings provide valuable information for the development of effective strategies to minimize HA content of cooked meats and to identify several new natural products that may have new applications in the food industry.

Investigating the inhibitory activity and mechanism differences between norartocarpetin and luteolin for tyrosinase: A combinatory kinetic study and computational simulation analysis.

Flavonoids are an important type of natural tyrosinase inhibitor, but their inhibitory activity and mechanism against tyrosinase are very different because of their different structures. In this study, the inhibitory activity and mechanism differences between norartocarpetin and luteolin for tyrosinase were investigated by a combination of kinetic studies and computational simulations. The kinetic analysis showed that norartocarpetin reversibly inhibited tyrosinase in a competitive manner, whereas luteolin caused reversible noncompetitive inhibition. Both norartocarpetin and luteolin showed a single type of quenching and a static-type quenching mechanism. A computational simulation indicated that the hydroxyl groups of the B ring of norartocarpetin interacted with tyrosinase residues Asn81 and His85 in the active pocket, while the hydroxyl groups of the B ring of luteolin bound residues Asn81 and Cys83. HPLC and UPLC-MS/MS further confirmed that luteolin acted as a substrate or a suicide inhibitor, yet norartocarpetin acted as an inhibitor.

A novel isoflavone profiling method based on UPLC-PDA-ESI-MS.

A novel non-targeted isoflavone profiling method was developed using the diagnostic fragment-ion-based extension strategy, based on ultra-high performance liquid chromatography coupled with photo-diode array detector and electrospray ionization-mass spectrometry (UPLC-PDA-ESI-MS). 16 types of isoflavones were obtained in positive mode, but only 12 were obtained in negative mode due to the absence of precursor ions. Malonyldaidzin and malonylgenistin glycosylated at the 4'-O position or malonylated at the 4″-O position of glucose were indicated by their retention behavior and fragmentation pattern. Three possible quantification methods in one run based on UPLC-PDA and UPLC-ESI-MS were validated and compared, suggesting that methods based on UPLC-ESI-MS possess remarkable selectivity and sensitivity. Impermissible quantitative deviations induced by the linearity calibration with 400-fold dynamic range was observed for the first time and was recalibrated with a 20-fold dynamic range. These results suggest that isoflavones and their stereoisomers can be simultaneously determined by positive-ion UPLC-ESI-MS in soymilk.

Preparation of steppogenin and ascorbic acid, vitamin E, butylated hydroxytoluene oil-in-water microemulsions: Characterization, stability, and antibrowning effects for fresh apple juice.

Oil-in-water microemulsions (O/W MEs) allow the preparation of insoluble compounds into liquid. In this study, we prepared O/W MEs to improve the solubility and stability of steppogenin (S) in aqueous liquid, and studied their ability to inhibit fresh apple juice browning. The ME technique greatly increased steppogenin solubility up to 3000-fold higher than that in water. All SMEs demonstrated good stability after acceleration and long-term storage. In particular, 0.01% SME was associated with dramatic inhibition of fresh apple juice browning after 24h at room temperature and 7days at 4°C, and its antibrowning effects were further improved when combined with 0.05% ascorbic acid. On the other hand, simultaneous encapsulation of steppogenin with vitamin E or butylated hydroxytoluene into ME did not greatly improve SME antibrowning effects. Taken together, these results suggested that steppogenin might serve as a potential antibrowning agent to preserve fresh apple juice.

Oxyresveratrol and ascorbic acid O/W microemulsion: Preparation, characterization, anti-isomerization and potential application as antibrowning agent on fresh-cut lotus root slices.

The purpose of this study is to prepare an oxyresveratrol (Oxy) microemulsion (ME) with improved Oxy's solubility and stability and to investigate its antibrowning effects on fresh-cut lotus root slices. The formula of OxyME consisted of ethyl butyrate, Tween 80, PEG400, and water with w/w of 4%, 10.67%, 5.33%, and 80%, respectively. Encapsulating Oxy into OxyME greatly increased its solubility and stability compared with that of in water. Strong antibrowning effects were observed on fresh-cut lotus root slices treated with OxyME, even better than 4-hexylresorcinol. The addition of ascorbic acid (VC) into OxyME greatly improved the Oxy stability in long-term storage and antibrowning effects on fresh-cut lotus root slices. However, the simultaneous addition of calcium chloride and VC did not obviously improve the antibrowning effects compared with the addition of VC alone. These results indicated that Oxy+VCME may be suitable as an antibrowning agent for fresh-cut vegetables.

8-C-(E-phenylethenyl)quercetin from onion/beef soup induces autophagic cell death in colon cancer cells through ERK activation.

SCOPE: Quercetin, a flavonoid, widely distributed in edible fruits and vegetables, was reported to effectively inhibit 2-amino-1-methyl-6-phenylimidazo[4, 5-b]pyridine (PhIP) formation in a food model (roast beef patties) with itself being converted into a novel compound 8-C-(E-phenylethenyl)quercetin (8-CEPQ). Here we investigated whether 8-CEPQ could be formed in a real food system, and tested its anticancer activity in human colon cancer cell lines. METHODS AND RESULTS: LC-MS was applied for the determination of 8-CEPQ formation in onion/beef soup. Anticancer activity of 8-CEPQ was evaluated by using cell viability assay and flow cytometry. Results showed that 8-CEPQ suppressed proliferation and caused G2 phase arrest in colon cancer cells. Based on immunofluorescent staining assay, western blot assay, and RNA knockdown data, we found that 8-CEPQ did not cause apoptotic cell death. Instead, it induced autophagic cell death. Moreover, treatment with 8-CEPQ induced phosphorylation of extracellular signal-regulated kinase (ERK). Inhibition of ERK phosphorylation by the mitogen-activated protein kinase kinase (MEK)/ERK inhibitor U0126 attenuated 8-CEPQ-induced autophagy and reversed 8-CEPQ-mediated cell growth inhibition. CONCLUSION: Our results demonstrate that 8-CEPQ, a novel quercetin derivative, could be formed in onion/beef soup. 8-CEPQ inhibited colon cancer cell growth by inducing autophagic cell death through ERK activation.

Inhibitory effects of selected dietary flavonoids on the formation of total heterocyclic amines and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in roast beef patties and in chemical models.

In this study, the inhibitory effects of eight kinds of dietary flavonoids on the formation of heterocyclic amines (HAs) were investigated in roast beef patties. The results showed that most of them exhibited significant inhibition on both total HAs and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), one of the most abundant HAs. Among the studied flavonoids, phlorizin, epigallocatechin gallate (EGCG), and quercetin were found to be the most effective in both the reductions of total HAs (55-70%) and PhIP (60-80%). The reaction activity between the flavonoid and phenylacetaldehyde, a key intermediate in PhIP formation, showed a good correlation with the inhibition of PhIP formation in an aqueous model system (R(2) = 0.8904) and a di(ethylene) glycol reaction system (R(2) = 0.6514). However, no significant correlation was found between the flavonoid antioxidant capacity and PhIP formation (R(2) = 0.2359). The postulated adducts of flavonoids-phenylacetaldehyde were further confirmed by LC-MS analysis in the chemical models. Since phenylacetaldehyde is the chief intermediate in PhIP formation, these results suggest that the inhibitory effects of flavonoids on PhIP formation are mainly dependent on their abilities to trap phenylacetaldehyde as opposed to their antioxidant capacities.

Encapsulation artocarpanone and ascorbic acid in O/W microemulsions: Preparation, characterization, and antibrowning effects in apple juice.

The aim of this study is to improve artocarpanone solubility by developing an O/W microemulsion with the evaluation of its antibrowning effects. The chemical and physical stabilities as well as antibrowning effects in apple juice were also evaluated. The formulation of artocarpanone microemulsion consisted of 4% w/w of ethyl butyrate, 10.67% w/w of Tween 80, 5.33% w/w of polyethylene glycol 400, and 80% w/w of water, with a maximum solubility of artocarpanone up to 10.54 ± 0.01 mg/mL, at least 3000-folds increase in solubility compared that in water. Encapsulating artocarpanone and ascorbic acid (VC) into microemulsion simultaneously decreased modest artocarpanone solubility whereas improving its stability in long-term storage. Blank, artocarpanone and artocarpanone-Vc-loaded microemulsions demonstrated steadily during accelerated and long-term storage. Artocarpanone-Vc-loaded microemulsion showed strong antibrowning effects in apple juice at room temperature in 24h, suggesting that artocarpanone-Vc-loaded microemulsion is a good antibrowning agent for apple juices.

A phenylacetaldehyde-flavonoid adduct, 8-C-(E-phenylethenyl)-norartocarpetin, exhibits intrinsic apoptosis and MAPK pathways-related anticancer potential on HepG2, SMMC-7721 and QGY-7703.

Norartocarpetin, quercetin and naringenin were found to effectively inhibit 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation through trapping its phenylacetaldehyde and form their adducts in roast beef patties. Six adducts [8-C- or 6-C-(E-phenylethenyl) flavonoids] formed between phenylacetaldehyde and three flavonoids were detected in roast beef patties by UPLC-MS analyses and compared with their synthetic references. These flavonoid-phenylacetaldehyde adducts were synthesised and further subjected to cytotoxicity tests on three liver cancer cell lines HepG2, SMMC-7721 and QGY-7703. The adduct 8-C-(E-phenylethenyl)norartocarpetin (NARA1) was found to significantly induce cancer cell death with IC50 values about 7 µM. After pre-treating with MAPK and caspase inhibitors, alteration of the cell morphology and cleaved-PARP were detected in liver cancer cell lines administered with NARA1. These data indicated that norartocarpetin could inhibit PhIP formation in roast beef patties and form norartocarpetin-phenylacetaldehyde adducts. The adduct NARA1 has anticancer potential via intrinsic caspase-dependent and cell context-dependent MAPKs pathways.

Preparation of tyrosinase inhibitors and antibrowning agents using green technology.

Chalcones and their derivatives have attracted great interests in recent years for their comprehensive biological activities. In this study, 2,4,2',4'-tetrahydroxychalcone and its two derivatives, 1,3,5-tris-(2,4-dihydroxy-phenyl)pentane-1,5-dione (new compound) and 7,2',4'-trihydroxyflavanone, were synthesized through one-pot green procedure catalyzed by boric acid in polyethylene glycol 400. Their structures were identified by ESI-MS and NMR spectral. Tyrosinase inhibitory activity and antibrowning test results showed that compounds 1-3 exhibited strong tyrosinase inhibitory activities and significant antibrowning effects on the fresh-cut lotus root slices at room temperature in 48 h. Among them, 0.01% 1,3,5-tris-(2,4-dihydroxy-phenyl)pentane-1,5-dione combined with 0.5% VC showed the best antibrowning ability. In brief, this study offers a protocol for one-pot green synthesis of high efficiency tyrosinase inhibitors which may be suitable as antibrowning agents for fresh-cut vegetables. More important, this study developed a new type of 1,5-dione derivative which may serve as new lead structures for novel tyrosinase inhibitors discovery.

Preparation, characterization, and preliminary antibrowning evaluations of norartocarpetin microemulsions.

Norartocarpetin is a flavone widely distributed in Moraceae plants with strong tyrosinase inhibitory activity. However, its poor solubility in aqueous systems and in food grade solvents (oils) limits its extensive applications. The aim of this study was to improve the solubility of norartocarpetin by developing an oil-in-water (o/w) microemulsion with food grade components. A microemulsion was developed and characterized, and its chemical and physical stabilities were also evaluated within 8 weeks. Using the construction of pseudoternary phase diagrams, the optimized formulation of 2% w/w of ethyl oleate, 12% w/w of Tween 80, 6% w/w of polyethylene glycol 400, and 80% w/w of water was obtained, with a maximum solubility of norartocarpetin up to 1.73 ± 0.21 mg/mL, at least a 1000-fold increase in solubility. The microemulsion base and norartocarpetin-loaded microemulsion were demonstrated to be stable after accelerated and long-term conditions (8 weeks). The norartocarpetin microemulsion still showed strong tyrosinase inhibitory activity and antibrowning effect on fresh-cut apple slices. These combined results indicated that norartocarpetin microemulsion may be suitable as an antibrowning agent for fresh-cut fruits.