Antioxidant and tyrosinase inhibitory activity of Rosa roxburghii fruit and identification of main bioactive phytochemicals by UPLC‐Triple‐TOF/MS

The content of bioactive phytochemicals, antioxidant activity and tyrosinase inhibitory activity of the hydroalcoholic extracts of Rosa roxburghii were determined. Yellow fruits of cultivated R. roxburghii showed the highest phenolic content (154.81 mg gallic acid g^?1), and the green fruits of wild R. roxburghii showed higher content of flavonoid and triterpenoid. Rosa roxburghii fruits from different cultivars and maturity stages all demonstrated as good antioxidant agents and tyrosinase inhibitors, with IC50 value about twice of the positive standard in the DPPH assay and triple of the standard in the tyrosinase inhibitory activity assay. Nineteen compounds, mainly ellagic acids and its derivatives, flavonoids and their glycosides were identified by UPLC‐Triple‐TOF/MS analysis. As the first study of bioactive phytochemicals of R. roxburghii by UPLC‐MS, the present research may provide valuable information for fulfilling the potential of R. roxburghii in the functional food area.     

Determination of antioxidant activity and phenolic compounds of Muntingia calabura Linn. peel by HPLC‐DAD and UPLC‐ESI‐MS/MS

Antioxidant activity in Muntingia calabura Linn. peel was evaluated by DPPH radical, ORAC, ABTS cation radical, FRAP assays and total phenolic contents by different extraction conditions. In addition, a method for determination of phenolic compounds in calabura peel samples harvested in Brazil using methanol:water and magnetic stirring as the extraction method, HPLC‐DAD and UPLC‐ESI‐MS/MS analysis were developed. Calabura peel showed antioxidant activity for all extraction conditions and assays evaluated, the most polar solvents being more effective. The developed HPLC‐DAD method allowed the accurate determination of phenolic compounds, with recoveries in the range of 72–107% and precision values ≤4%, with exception for chlorogenic acid. Gallic acid was determined at the highest concentration levels, followed by myricetin, ferulic acid and vanillic acid. However, all the five proposed phenolic compounds were identified in calabura peel samples by UPLC‐ESI‐MS/MS. Thus, calabura peel, an uncommon edible fruit part, can be appointed as a rich source of phenolic compounds.     

Isolation and identification of two major acylated anthocyanins from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) by UPLC‐QTOF‐MS/MS and NMR

In recent years, researches on the isolation and preparation of monomeric anthocyanins have intensified because of the requirements of quantitative and structure–bioactivity relationship analyses. However, simple and effective methods about the scale of monomeric anthocyanins from the natural purple sweet potato powder are rarely reported. In this study, high molecular weight acylated monomeric anthocyanins were isolated from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) via the combination of column chromatography and semi‐preparative HPLC technology and identified mainly by ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry/mass spectrometry (UPLC‐QTOF‐MS/MS) and ¹H and ¹³C nuclear magnetic resonance (NMR). Two major acylated anthocyanins were unambiguously determined as peonidin 3‐O‐(6‐O‐(E)‐caffeoyl‐(2‐O‐(6‐O‐p‐hydroxybenzoyl)‐β‐D‐glucopyranosyl)‐β‐D‐glucopyranoside)‐5‐O‐(β‐D‐glucopyranoside) and peonidin 3‐O‐(6‐O‐(E)‐caffeoyl‐(2‐O‐(6‐O‐(E)‐feruloyl)‐β‐D‐ glucopyranosyl)‐β‐D‐glucopyranoside)‐5‐O‐(β‐D‐glucopyranoside). The results of this study may help promote the purification of high molecular weight acylated anthocyanins from purple sweet potato as well as from other plant materials in nature.     

Mineral composition,antioxidant and cytotoxic biopotentials of wild‐growing Ganoderma species (Serbia): G. lucidum (Curtis) P. Karst vs. G. applanatum (Pers.) Pat.

The aim of this work was to analyse mineral composition and chemical profile of two nonedible fungal species: Ganoderma lucidum and Ganoderma applanatum (Fru?ka Gora, Serbia) vs. their antioxidant (ABTS and A.E.A.C. assay) and cytotoxic biopotentials (MTT assay on MCF‐7). Both species were analysed for their content of macro‐ and microelements by atomic absorption spectrophotometry, while phenolic profile of EtOH and H₂O extracts was examined by LC‐MS/MS technique. Both species mostly contained the following ions: K⁺ > Ca²⁺ > Mg²⁺ > Mn²⁺ > Zn²⁺ > Cu²⁺ > Cr³⁺. Among nine phenolic compounds, the highest content of vanillic acid was detected in G. applanatum extracts while protocatechuic acid in EtOH extract and quinic acid in H₂O extract were mostly contained in G. lucidum. Ganoderma applanatum EtOH extract showed the best antioxidant activities related to its phenolic and flavonoid content. Further, the best cytotoxic effect after 72 h was observed in this extract as well.     

Identification of Low Molecular Weight Peptides in Chinese Rice Wine (Huang Jiu) by UPLC‐ESI‐MS/MS

The aim of this work was to increase the general knowledge of peptide identification and to examine the low molecular weight peptides in Chinese rice wine (Huang Jiu) as there are very few publications in the literature on this topic. Chinese rice wine (Huang Jiu) has a high content of peptides and more than 500 peptides have been tentatively identified by ultra‐performance liquid chromatography‐quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐ESI‐MS/MS), including 43 potential bio‐active peptides and 3 sensory‐active peptides, based on published references to date. These peptides have been tentatively identified according to the MS/MS spectra which produced sufficient information of product ions (complementary y ions and b ions). Results from this work indicated that it is feasible to produce rice wine with rich bioactive peptides and that there is potential to examine for rice wine authenticity and traceability based on the origin of the peptides.     

The Hypolipidemic Effect of Total Saponins from Kuding Tea in High‐Fat Diet‐Induced Hyperlipidemic Mice and Its Composition Characterized by UPLC‐QTOF‐MS/MS

Kuding tea are used as a traditional tea material and widely consumed in China. In this study, total saponins (TS) from water extract of Kuding tea was prepared by D101 macroporous resins and analyzed by UPLC‐QTOF‐MS/MS. Then the hypolipidemic effect of TS extract was investigated in high‐fat diet‐induced hyperlipidemic mice. For comprehensive identification or characterization of saponins in TS extract, 3 major saponins of Kudinoside A, Kudinoside F, and Kudinoside D were isolated and used as standards to investigate the MS/MS fragmentation pattern. As a result, 52 saponins were identified or characterized in TS extract from Kuding tea. In addition, the increased levels of mice serum TC, LDL‐C, HDL‐C, and atherogenic index (AI) were significantly reduced after the treatment of TS extract. Also, the liver protective effect of TS extract was obviously judged from the photographs stained with oil red‐O staining. Meanwhile, TS extract significantly upregulated the expression of hepatic scavenger receptors including SR‐AI, SR‐BI, and CD36. Therefore, it is reasonable to assume that the overexpression of hepatic scavenger receptors was involved in the hypolipidemic effect of Kuding tea on the high‐fat diet‐induced hyperlipidemic mice. The TS extract could influence these scavenger receptors, and this could be the potential mechanism of TS extract from Kuding tea in the treatment of lipid disorders. These results give the evidence that the saponins in Kuding tea could provide benefits in managing hypercholesterolemia and may be a good candidate for development as a functional food and nutraceutical.     

Phenolic acid analysis and antioxidant activity assessment of oil palm (E. guineensis) fruit extracts

Phenolic compounds in oil palm fruit (E. guineensis) were extracted in soluble free (SFP), insoluble-bound (ISBP) and esterified (EFP) forms. The total phenolic content (TPC) of the oil palm fruit extracts was determined using the Folin–Ciocalteu method and found to range from 5.03 to 9.04 g/L per g of dried weight (DW). The antioxidant activities of oil palm phenolic extracts were analysed using free radical scavenging assays and results showed that oil palm phenolic extracts contained antioxidant activities in the order of ISBP > EFP > SFP. Eight different phenolic acids were identified and quantified using a simple reversed-phase high performance liquid chromatography (HPLC) with a diode array detector (DAD) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Ferulic, p-hydroxybenzoic and p-coumaric acid were the dominant phenolic acids found in oil palm fruit extracts and ranged from 55 to 376 μg/g of DW.     

Effects of UV‐C irradiation on the physiological and antioxidant responses of button mushrooms (Agaricus bisporus) during storage

Novel postharvest technology not only preserves the freshness of fruits and vegetables, but also triggers the biosynthesis of antioxidant compounds as a secondary response. This study examined the browning and antioxidant properties of button mushrooms (Agaricus bisporus) treated with UV‐C irradiation in combination with cold storage. Three sample preparation methods for antioxidant activity analysis, simulative gastrointestinal digestion (GAR), direct evaluation (QUENCHER) and traditional solvent extraction (TSE), were used to evaluate the samples, and followed analysing by both FRAP and ABTS assays. Broadly, the results indicated that, following an initial increase, UV‐C irradiation suppressed browning during a cold storage period of 18 days. And the total phenolic content of the treated mushrooms were higher than that of the control, while the ascorbic acid content decreased sharply during storage, and UV‐C treatment had negative effects on ascorbic acid content. Results from the QUENCHER and GAR methods showed that UV‐C treatment significantly increases the total antioxidant capacity (TAC) of mushrooms throughout the entire storage period, and have a larger magnitude than that of TSE method. In conclusion, the combination of UV‐C irradiation and cold storage showed great potential for improving mushroom quality as a new postharvest technology.     

Effect of extrusion variables on antioxidant activity,total phenolic content and dietary fibre content of gluten‐free extrudate from germinated Chenopodium (Chenopodium album) flour

A Box‐Behnken design was used to study the effects of feed moisture content (18–20%), barrel temperature (115–135 °C) and screw speed (225–275 rpm) on the responses; antioxidant activity, total phenolics, dietary fibre, colour (L‐value), hardness, expansion ratio, water absorption index and overall acceptability for development of gluten‐free extrudate based on germinated Chenopodium album flour. Second‐order polynomial fitted model showed that temperature most significantly (P ≤ 0.05) affected the antioxidant activity (AoxA), total phenolics (TPC), expansion ratio, hardness and overall acceptability (OA). Antioxidant activity, total phenolic content and dietary fibre of extrudate varied from 11.56 to 15.93%, 56.77 to 81.28 mg/100 g and 18.65 to 22.06 g/100 g, whereas the lightness and hardness of extrudates ranged from 64.02 to 68.35 and 12.26 to 19.49 N, respectively. The results of this study validate the production of functional and acceptable snack product made from C.  album flour by extrusion cooking.     

Optimisation of Novozym‐435‐catalysed esterification of fatty acid mixture for the preparation of medium‐ and long‐chain triglycerides (MLCT) in solvent‐free medium

Novozym‐435‐catalysed esterification of caprylic acid, capric acid and oleic acid with glycerol for the synthesis of medium‐ and long‐chain triglycerides (MLCT) in vacuum and solvent‐free system was investigated in this study. Response surface methodology with a three‐level, four‐factorial design was applied to optimise the enzymatic esterification for the synthesis of MLCT. The optimum conditions were as follows: reaction temperature 90 °C, 4.80 wt% enzyme load (relative to the weight of total substrates) and substrate molar ratio (fatty acids/glycerol) of 3:1 and 12.37 h. Under above‐mentioned conditions, Triglycerides (TG) yield, MLCT and the residual free fatty acids (FFA) content in the product were 93.54%, 72.19% and 4.21%, respectively. The content of caprylic acid, capric acid and long‐chain fatty acids of TG was 24%, 10% and 66%, respectively. Novozym 435 in the study showed no selectivity for the different fatty acids and also could be used 14 times without obvious loss of enzyme activity.     

Comparison of Polyphenol Profile and Inhibitory Activities Against Oxidation and α‐Glucosidase in Mulberry (Genus Morus) Cultivars from China

Mulberry (genus Morus) is a significant source of polyphenols, which can promote positive effects on human health. China has various mulberry cultivars, however, many Chinese mulberry cultivars have been only minimally studied. To solve this lack of research, 8 mulberry cultivars (Da10, Tang10, Yueshen74, Yuefenshen, Longsang, Ningxia1hao, Taiwanguosang, and Baiyuwang) from 4 regions of China were assessed to determine their polyphenol profiles using HPLC‐MS/MS and then tested for their antioxidant and anti‐α‐glucosidase activities in vitro. A total of 18 nonanthocyanins and 4 anthocyanins were quantified in mulberry cultivars; among these polyphenols, chlorogenic acid, quercetin 3‐O‐rutinoside, and cyanidin 3‐O‐glucoside were confirmed as the major phenolic acid, flavonol derivative, and anthocyanin, respectively. Two types of stilbene compounds, piceid, and piceatannol, were detected for the 1st time in all mulberry cultivars. Moreover, the methanolic extracts of different mulberry cultivars showed disparate antioxidant and α‐glucosidase inhibitory activities, and this discrepancy was mainly attributed to varying the anthocyanin content. Based on our results, Taiwanguosang is proposed to be a good candidate suitable for further process due to its high level of anthocyanins.     

Identification,characterisation, and quantification of phenolic compounds in the antioxidant activity-containing fraction from the seeds of Korean perilla (Perilla frutescens) cultivars

The present research was the first to investigate phenolic compound profiles and antioxidant properties in the seeds of various perilla (Perilla frutescens) cultivars. The 80% methanol extract (50 μg/ml) of this species showed potent antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals. Phenolic compounds were characterised by nuclear magnetic resonance (NMR) spectroscopy, and ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass (UPLC-PDA-ESI/MS) analysis. Nine compounds were elucidated as caffeic acid-3-O-glucoside (1), caffeic acid (2), luteolin-7-O-glucoside (3), apigenin-7-O-glucoside (4), rosmarinic acid-3-O-glucoside (5), rosmarinic acid (6), luteolin (7), apigenin (8), and chrysoeriol (9). The individual and total phenolic contents were remarkably different, especially rosmarinic acid-3-O-glucoside (5) and rosmarinic acid (6) which were the predominant compounds (>95%) in all perilla cultivars. Additionally, Yeupsil cultivar exhibited the highest phenolic content (5029.0 μg/g) and antioxidant activity, whereas the lowest was shown by Dasil (2138.7 μg/g). Therefore, these results suggest that antioxidant effects of perilla seeds are correlated with phenolic contents.     

Biological evaluation and quantitative analysis of antioxidant compounds in pulps of the Amazonian fruits bacuri (Platonia insignis Mart.), ingá (Inga edulis Mart.), and uchi (Sacoglottis uchi Huber) by UHPLC‐ESI‐MS/MS

Bacuri, ingá, and uchi are Amazon fruits consumed specially in the North region of Brazil. Due to their large consumption and the lack of knowledge regarding its chemical composition, these fruits were studied in relation to their Antioxidant chemical constitution. The total phenolic content ranged from 3.86 ± 0.47 to 33.38 ± 1.51 mg GAE/100 g, and the total flavonoid content ranged from 1.75 ± 0.22 to 19.44 ± 0.87 mg QUERE/100 g, where the contents showed a significant correlation with DPPH and ABTS antioxidant assays. Thus, UHPLC‐MS/MS was applied do quantify selected compounds, been citric acid the most abundant for all fruits. Furthermore, samples were screened for their α‐glycosidase and lipase inhibitory effects, in addition to their antimicrobial potentials. Bacuri showed the highest antioxidant and α‐glycosidase inhibitory capacity (IC₅₀ 15.20 μg/mL), whereas uchi and its main metabolite bergenin displayed moderate antimicrobial activities. The results shed light into the potentials of Amazonian fruit sources.

Practical applications

Plant phenolics are essential components of functional foods, due to their antioxidant and enzyme inhibition activities, which are directly linked to several diseases prevention. This is the first study about the quantification of antioxidant compounds in the Amazonian fruits: bacuri, ingá, and uchi. Although they are quite consumed in the North region of Brazil, there are no bio‐products made from them. This study aimed to elucidate the knowledge about the chemical composition and potentialities within these fruits with the practical purpose of highlighting them to future commercial applications. In addition, once we indicate their capabilities, we contribute with local populations in respect to the production of such fruits, which still is a family activity.     

Stir‐frying treatments affect the phenolics profiles and cellular antioxidant activity of Adinandra nitida tea (Shiyacha) in daily tea model

Adinandra nitida tea (Shiyacha) is a well‐known resource of functional foods with many healthful features. Effect of stir frying on phenolics, aromatic compounds, cellular antioxidant and antiproliferative activities in A. nitida tea was investigated. Stir‐fried samples depicted a significant increase in total water‐soluble solid, phenolics and flavonoids contents, respectively. In stir‐fried treated samples, main compounds were higher than in corresponding untreated samples. Similar trend was observed in aromatic compounds. Hydrophilic peroxyl radical scavenging capacity and oxygen radical absorbance capacity were enhanced immensely in the treated samples. Furthermore, cellular antioxidant activities of treated samples were higher than those of untreated samples. Stir‐fried samples exhibited higher antiproliferative activity on HepG2 cells, whereas an lack in untreated samples. These findings suggest that stir frying could be an effective technique to improve A. nitida tea quality, and support that A. nitida tea could act as a potential functional food against intracellular oxidative stress and inhibitor of liver cancer.     

Isolation,purification and characterisation of angiotensin I‐converting enzyme–inhibitory peptides derived from catfish (Clarias batrachus) muscle protein thermolysin hydrolysates

The angiotensin I‐converting enzyme (ACE)‐inhibitory activities of catfish (Clarias batrachus) muscle protein hydrolysates were investigated. Thermolytic digests of C. batrachus sarcoplasmic and myofibrillar proteins exhibited inhibitory activity towards ACE and were purified with the aim of ultrafiltration, gel filtration and reversed‐phase high‐performance liquid chromatography (RP‐HPLC). The amino acid sequences of hydrolysates with the highest ACE‐inhibitory activities were determined using electrospray quadrupole time‐of‐flight tandem mass spectrometry (ESI‐TOFQ MS/MS). The sequences of GPPP (IC₅₀ = 0.86 μm ) and IEKPP (IC₅₀ = 1.2 μm ) corresponding to the fragments 986–989 and 441–445 of myosin‐I heavy chain were identified for the sarcoplasmic and myofibrillar protein hydrolysates, respectively. Peptide GPPP exhibited a mixed‐type inhibition whereas peptide IEKPP could only bind to the active sites of ACE. The results demonstrate that hydrolysates of C. batrachus muscle proteins obtained by thermolysin may contain bioactive peptides.