Phenolic compounds profile of macerates of different edible parts of carob tree (Ceratonia siliqua L.) using UPLC-ESI-Q-TOF-MSE: Phytochemical screening and biological activities.

Locust bean pulp and gum extracts were prepared, and phytochemical tests based on color reactions and chromatographic analyzes were performed. A profile of seventy-six phenolic compounds was obtained by the ultra-high performance liquid chromatography with electrospray ionization and quadrupole time-of-flight mass spectrometry. The main groups of phenolic compounds identified in the both extracts of Ceratonia siliqua L., were flavonoids, tannins and phenolic acids. Moreover, carob pulp and gum extracts were tested for their antimicrobial activity using disk diffusion tests which showed sensitivity of the different strains to the analyzed extracts at a concentration of 100 mg/mL. Additionally, the antioxidant activity of Ceratonia siliqua L. extracts was assessed by the 2,2-diphenyl-1-picrylhydrazyl acid test, which confirmed stronger antioxidant properties in the case of the pulp extract. To sum up, carob pulp and gum extracts present promising alternatives to synthetic additives within the medicinal industry, serving as potential antioxidant agents and preservatives that combat bacterial contamination, thereby offering a more natural approach to enhancing product safety and efficacy.

Phenolic composition, antioxidant and antiacetylcholinesterase activities of Opuntia ficus-indica peel and flower teas after in vitro gastrointestinal digestion.

BACKGROUND: The flowers and peels of cactus Opuntia ficus-indica (OFI) are by-products generally discarded. Their beneficial properties have been linked to the chemical composition without taking into account its transformations during digestion. This study evaluated and compared the phenolic composition, antioxidant and antiacetylcholinesterase activities of OFI peel and flower teas before and after in vitro gastrointestinal digestion. RESULTS: Results showed that OFI peel tea was a source of natural phenolic compounds and carotenoids, while OFI flower tea was a source of flavonoids. Both OFI peel and flower teas exhibited high antioxidant activities (AAs) measured by several tests [1,1-diphenyl-2-picrylhydrazyl radical (DPPH• ), reducing power (RP), hydrogen peroxide scavenging activity (HPSA)]. Flower teas presented a higher antiacetylcholinesterase inhibition percentage than peel teas. Significant decreases of acetylcholinesterase and AAs were obtained under in vitro gastrointestinal digestion. Fourteen phenolic compounds typical of phenolic acids and flavonoids were identified in both teas. These compounds seemed to be more affected by pancreatic than by the gastric conditions. CONCLUSION: OFI peel tea has been found as a source of natural phenolic compounds and carotenoids, while OFI dry flower tea as a source of flavonoids. The OFI flower tea phytochemicals were more stable than peel tea during the digestive process. These findings suggest that peels and flowers of OFI should be considered as sources of healthy ingredients. © 2022 Society of Chemical Industry.

Discovery and Characterization of Phenolic Compounds in Bearberry (Arctostaphylos uva-ursi) Leaves Using Liquid Chromatography-Ion Mobility-High-Resolution Mass Spectrometry.

The characterization and quantification of phenolic compounds in bearberry leaves were performed using hyphenated ion mobility spectroscopy (IMS) and a quadrupole time-of-flight mass spectrometer. A higher identification confidence level was obtained by comparing the measured collision cross section (TWCCSN2) with predicted values using a machine learning algorithm. A total of 88 compounds were identified, including 14 arbutin derivatives, 33 hydrolyzable tannins, 6 flavanols, 26 flavonols, 9 saccharide derivatives, and glycosidic compounds. Those most reliably reproduced in all samples were quantified against respective standards. Arbutin (47-107 mg/g), 1,2,3,4,6-pentagalloylglucose (6.6-12.9 mg/g), and quercetin 3-galactoside/quercetin 3-glucoside (2.7-5.7 mg/g) were the most abundant phenolic components in the leaves. Quinic acid and ellagic acid were also detected at relatively high concentrations. The antioxidant activity of the most abundant compounds was evaluated. A critical view of the advantages and limitations of traveling wave IMS and CCS for the discovery of natural products is given.

Graphene oxide/ layered double hydroxides@ sulfonated polyaniline: A sorbent for ultrasonic assisted dispersive solid phase extraction of phthalates in distilled herbal beverages.

In this study, the ultrasonic-assisted dispersive solid phase extraction (UA-d-SPE) method coupled to gas chromatography-mass spectrometry (GC-MS) was applied for the analysis of phthalate esters in drinking water and distilled herbal beverages (Rosa, Mentha, Cichorium). A new nanocomposite based on layered double hydroxide supported on graphene oxide was synthesized and modified by sulfonated polyaniline via a simple one-pot in-situ polymerization method. The structure and morphology of the nanocomposite was confirmed by means of complementary techniques: Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The effects of key parameters including adsorbent mass, type and amount of back extraction solvent, extraction and desorption time, pH of the solution and ionic strength were optimized and good precision and sensitivity were achieved. Under the optimum conditions, the limits of detection were between 0.06-0.3 ng mL-1 in aqueous solutions. The hybrid nanomaterial exhibited good adsorption ability toward phthalates in drinking water and distilled herbal beverages. The relative standard deviations (RSD%) for beverage samples varied from 0.1% to 9.9% (n = 3). The relative recoveries varied from 54.5% to 112.6%.

Migration of dihydroxyalkylamines from polypropylene coffee capsules to Tenax® and coffee by salt-assisted liquid-liquid extraction and liquid chromatography-mass spectrometry.

Migration of N,N-Bis(2-hydroxyethyl) alkyl(C8-C18)amines from five different polypropylene capsules to Tenax® and coffee powder have been studied. A single step extraction-cleanup procedure using salting out liquid-liquid extraction (SALLE) method followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was applied. The critical parameters on the SALLE procedure such as extracting solvent, extracting volume, sample pH, salt and its concentration were optimized. The recovery values were in the range of 87.5%-106.5%. The %RSD were lower than 3.7%. The limit of detection was improved from 2.3 ng/g in Tenax® to 0.8 ng/g in coffee. The results indicated that the analyzed compounds have the potential to migrate from the polypropylene capsule containers to the coffee. In most of the cases, the migrated values were higher in Tenax® than in coffee in a range between 1.8 and 61%. One sample did not comply with the specific migration limit established by the European Commission.

Predicting the antioxidant capacity and total phenolic content of bearberry leaves by data fusion of UV-Vis spectroscopy and UHPLC/Q-TOF-MS.

The total phenolic content (TPC) and antioxidant capacity have been considered as important quality parameters for plant extracts. In this study, bearberry leaves were regarded as studied subject and a reliable method was established to predict the TPC and antioxidant capacity of bearberry leaves. Ultraviolet-visible spectrometry (UV-Vis) and ultra high pressure liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) were used to provide spectral fingerprinting and metabolomic profiling. The data obtained (separately and merged) were used to build partial least squares (PLS) regression model. The PLS model built by using ultraviolet-visible spectra provided a satisfactory prediction result. Mid-level data fusion using the scores significantly improved the performance of PLS regression model, the residual predictive deviations (RPDs) for TPC and α, α-diphenyl-ß-picrylhydrazyl (DPPH) were 6.258 and 6.699, respectively, showing an excellent predictive ability. This study proved the potential of combination of UV-Vis spectrometry and UHPLC/Q-TOF-MS in the prediction of TPC and antioxidant capacity of plant extracts.

Polyamide modified with green tea extract for fresh minced meat active packaging applications.

New antioxidant polyamide was prepared by total immersion in active extract for 48 h. Its antioxidant performance was tested using DPPH (IC50 = 270 ±â€¯21 µg/g) and ORAC (1.52 µmol Trolox/g). In vivo study was done using fresh minced meat stored at 4 °C and analysed after 0, 6, 13, 19, 23 days. After 23 days metmyoglobin (MetMbBK = 31.3 ±â€¯2.9% and MetMbAOX = 25.9 ±â€¯0.8%), CIE L*a*b* (a*BK = 15.0 ±â€¯0.4 and a*AOX = 16.6 ±â€¯0.3) and TBARS (MDABK = 0.0060 ±â€¯0.0003 µg/g and MDAAOX = 0.0044 ±â€¯0.0002 µg/g) showed an improvement of meat shelf life. The results showed that this active film protected meat during 23 days. Migration study to food simulants was done by UPLC®-QqQ-MS and UPLC®-ESI-Q-TOF-MSE. A decrease of oligomers migration (for caprolactam n = 3: BK = 0.050 ±â€¯0.004 mg/Kg; AOX = 0.019 ±â€¯0.001 mg/Kg) was found. INDUSTRIAL RELEVANCE: Nowadays, food industry is focused on improving shelf life of products by controlling its lipid oxidation using natural antioxidants. The obtained results let us design a new active packaging based on natural antioxidants for extending the shelf life of fresh minced meat at industrial scale.

Influence of medicinal and aromatic plants into risk assessment of a new bioactive packaging based on polylactic acid (PLA).

A new biodegradable antioxidant active packaging for food applications based on antioxidants from medicinal and aromatic plants incorporated into a polylactic acid matrix was designed and developed. Melt blending processing technique was applied to prepare polylactic acid films loaded by sage and lemon balm leaves. Antioxidant properties of developed active films were investigated using the following methods: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl and a home-made generator of hydroxyl radicals. In addition, reducing power and total phenolic content of polylactic acid films were checked. The results of antioxidant capacity showed that percentage of hydroxylation for active film with lemon balm and sage was 55.5% ±â€¯0.1% and 67.4% ±â€¯0.3%, respectively. The reducing power of active films increased 8 times in comparison to the blank samples. Moreover, extensive investigation of influence of sage and lemon balm leaves on material safety and type of migrants was performed using migration assays. The composition of both non-volatile and volatile compounds of different active packaging films was compared with neat polylactic acid film. Three different food simulants such as 95% (v/v) ethanol, 10% (v/v) ethanol and 3% (w/v) acetic acid were checked. It was shown that the addition of sage and lemon balm leaves into a polylactic acid structure decreased the migration of both linear and cyclic polylactic acid oligomers, currently not legislated by European Union. Besides, total absence or decrease of migration of volatile compounds were observed when using the active films. Both thermal and mechanical properties of films were also evaluated.

Encapsulation of cinnamon oil in cyclodextrin nanosponges and their potential use for antimicrobial food packaging.

The main goal of this work is the encapsulation of cinnamon essential oil in cyclodextrin nanosponges and the assessment of their antimicrobial activity against foodborne pathogens. After nanosponge synthesis, a headspace-solid phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) method was validated to quantify essential oil major compounds. Results showed that essential oil was successfully encapsulated in cyclodextrin nanosponges with α-NS and ß-NS being able to encapsulate higher essential oil amounts. Cinnamon essential oil, alone and encapsulated in nanosponges, proved to have antimicrobial activity against foodborne bacteria. Time-kill assays proved that the essential oil, alone or encapsulated, had a bacteriostatic effect against all bacteria tested, with the exception of Y. enterocolitica where a bactericidal action was observed. Furthermore, the controlled release achieved by its encapsulation, allowed cinnamon essential oil to be effective at a much lower concentration in culture medium than when solely dissolved in culture medium. Thus, the results described herein encourage the use of cyclodextrin nanosponges as encapsulating agents for active food packaging applications.

Non-target screening of (semi-)volatiles in food-grade polymers by comparison of atmospheric pressure gas chromatography quadrupole time-of-flight and electron ionization mass spectrometry.

Atmospheric pressure gas chromatography (APGC) coupled to quadrupole time-of-flight (QTOF) and electron ionization mass spectrometry together with commercial library search are two complementary techniques for non-target screening of volatile and semi-volatile compounds. Optimization was first conducted to achieve easier search of correspondent peaks between the two systems. Analytical strategy for the determination of volatile and semi-volatile compound with different identification confidence levels was then proposed and applied to food contact grade polypropylene (PP) samples. Identification was found to be much easier and less time-consuming especially when correspondent peak was found in the two systems with the help of library search, exact mass of precursor and fragment ions as well as Kovats Index (KI). The behavior of APGC-QTOF-MS was also further investigated. Apart from the M+. ion and the well-known adduct [M+H]+ others such as [M-3H + O]+, [M-3H+2O]+ and [M-H+3O]+ were also observed for n-alkanes. Besides, new reaction products were found, formed by diol compounds (1-Monostearoylglycerol, 2-Monostearoylglycerol and NX 8000K) and silanediol dimethyl, which would be a transformation product of the silicone base septum or the methyl 5% phenyl polysiloxane based column. These new compounds were only detected in APGC-MS-QTOF as EI-GC-MS was not enough sensitive for this purpose.

Determination the set-off migration of ink in cardboard-cups used in coffee vending machines.

The set-off migration from printing inks can cause alterations in the safety and acceptability of food. Therefore, its control in the food industry is of special importance. The aim of this study was the determination of the migration of compounds coming from different types of cardboard-cups used in coffee vending machines. The volatile compounds present in cardboard-cups were studied and specific migration studies were carried out by solid phase microextraction with headspace coupled to gas chromatography (HS-SPME-GC-MS). The migration of compounds from the cardboard-cups manufacturing material, plastic coating (LDPE) and printing inks were identified and quantified. Those migrants listed in the Regulation No. 10/2011 presented values lower than the specific migration limit (SML), although a series of non-listed and non-authorized compounds were identified. From the results obtained the risk assessment of the vending cups from two different companies has been done.

Synergistic properties of mustard and cinnamon essential oils for the inactivation of foodborne moulds in vitro and on Spanish bread.

This work was performed to evaluate the antifungal effect of cinnamon and mustard essential oil (EO) alone and in combination against a range of mould strains. A wide range of resistance levels was observed among different mould species, being R. stolonifer the most resistant one. Mustard EO showed the biggest antifungal effect, and for this reason it was selected to study its effect in vapour phase on bread. The shelf life of bread inoculated with R. stolonifer and non- inoculated increased by 3-4 days at 25 °C, while at 4 °C the shelf-life increased beyond 50 days. However, the results from the acceptability test were negative. Based on this, the antifungal effect of cinnamon/mustard EO in combination was evaluated, with results mostly additive and synergistic. The ratio of the combination was defined taking into account the most resistant strain (100:8, cinnamon and mustard respectively) and their application was performed in vapour phase. This combination maintained the antifungal activity presented by mustard EO by itself and masked the mustard flavour, providing positive results in the acceptability tests. It was therefore suggested to be used at industrial scale.

Antioxidant and antimicrobial markers by UPLC®-ESI-Q-TOF-MSE of a new multilayer active packaging based on Arctostaphylos uva-ursi.

49 different non-volatile compounds were determined in Spanish Arctostaphylos uva-ursi leaves using UPLC®-ESI-Q-TOF with MSE technology. Both positive and negative electrospray ionization were applied. MarkerLynx® was proposed as a powerful tool to distinguish samples from eight wild populations of Spain by determining their non-volatile markers. Development of HRMS methods let to analysis of metabolites in plants. Antioxidant and antimicrobial capacities of different extracts were evaluated. Plant extract with the strongest antioxidant and simultaneous good antimicrobial capacity (Lierta) was chosen and incorporated in a multilayer packaging. Then, antioxidant capacity of the new packaging was evaluated and the efficient free radical scavenging properties were demonstrated.

Development and characterisation of HPMC films containing PLA nanoparticles loaded with green tea extract for food packaging applications.

A novel active film material based on hydroxypropyl-methylcellulose (HPMC) containing poly(lactic acid) (PLA) nanoparticles (NPs) loaded with antioxidant (AO) green tea extract (GTE) was successfully developed. The PLA NPs were fabricated using an emulsification-solvent evaporation technique and the sizes were varied to enable a controlled release of the AO from the HPMC matrix. A statistical experimental design was used to optimise the synthesis of the NPs in order to obtain different sizes of nanoparticles and the loading of these into the HPMC matrix was also varied. The physico-chemical properties of the composite films were investigated and the release of the AO was confirmed by migration studies in 50% v/v ethanol/water food simulant. The AO capacity of the GTE released from the active films was studied using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method and the results suggest that the material could potentially be used for extending the shelf-life of food products with high fat content.

Nano selenium as antioxidant agent in a multilayer food packaging material.

Selenium nanoparticles (SeNPs) were incorporated in a flexible multilayer plastic material using a water-base adhesive as vehicle for SeNPs. The antioxidant performance of the original solutions containing spherical SeNPs of 50-60 nm diameter, the adhesive containing these SeNPs, and the final multilayer plastic material to be used as food packaging were quantitatively measured. The radical scavenging capacity due to SeNPs was quantified by a free radical assay developed in the laboratory and by the diphenyl-1-picrylhydrazyl (DPPH) method. DPPH was not efficient to measure the scavenging capacity in the multilayer when the free radical scavenger is not in the surface in contact with it. Several multilayer laminated structures composed by [PET (20 m)-adhesive-LDPE (with variable thickness from 35 to 90 µm)] were prepared and measured, demonstrating for the first time that free radicals derived from oxygen (OH·, O2·, and O2H) cross the PE layer and arrive at the adhesive. SeNPs remain as such after manufacture and the final laminate is stable after 3 months of storage. The antioxidant multilayer is a non-migrating efficient free radical scavenger, able to protect the packaged product versus oxidation and extending the shelf life without being in direct contact with the product. Migration tests of both Se and SeNPs to simulants and hazelnuts demonstrated the non-migrating performance of this new active packaging. Graphical abstract ᅟ.

Molecular interactions between caffeine and catechins in green tea.

Migration of green tea components from an active packaging material containing green tea extract was performed in water and 3% acetic acid in water. The migration values for acid simulant were much higher than the values obtained in water. The influence of the acidic media in solutions of catechin standards and green tea extract was evaluated by liquid chromatography. Catechin, epicatechin, and caffeine from the green tea extract exhibited major variation in their concentrations values, with increases of 29.90, 20.75, and 15.95%, respectively, in acidic medium. The results suggested that catechins and caffeine form complexes through intermolecular interactions in neutral media and that these interactions are broken in acidic media. The continuous variation method was also performed to confirm the stoichiometry of the complexes between catechins and caffeine. Finally, a computer simulation was applied by Chem Pro 12.0, and the energies involved were calculated to confirm the experimental results obtained.

Development of an active food packaging system with antioxidant properties based on green tea extract.

A formula including green tea extract (GTE) was developed as an active food packaging material. This formula was moulded to obtain an independent component/device with antioxidant properties that could be easily coupled to industrial degassing valves for food packaging in special cases. GTE components (i.e., gallic acid, catechins and caffeine) were identified and quantified by HPLC-UV and UPLC-MS and migration/diffusion studies were carried out. Antioxidant properties of the formula alone and formula-valve were measured with static and dynamic methods. The results showed that the antioxidant capacity (scavenging of free radicals) of the new GTE formula was 40% higher than the non-active system (blank). This antioxidant activity increased in parallel with the GTE concentration. The functional properties of the industrial target valve (e.g., flexibility) were studied for different mixtures of GTE, and good results were found with 17% (w/w) of GTE. This new active formula can be an important addition for active packaging applications in the food packaging industry, with oxidative species-scavenging capacity, thus improving the safety and quality for the consumer and extending the shelf-life of the packaged food.

The additive properties of Oxygen Radical Absorbance Capacity (ORAC) assay: the case of essential oils.

The ORAC assay is applied to measure the antioxidant capacity of foods or dietary supplements. Sometimes, the manufacturers claim antioxidant capacities that may not correspond to the constituents of the product. These statements are sheltered by the general understanding that antioxidants might exhibit synergistic properties, but this is not necessarily true when dealing with ORAC assay values. This contribution applies the ORAC assay to measure the antioxidant capacity of ten essential oils typically added to foodstuffs: citronella, dill, basil, red thyme, thyme, rosemary, oregano, clove and cinnamon. The major components of these essential oils were twenty-one chemicals in total. After a preliminary discrimination, the antioxidant capacity of eugenol, carvacrol, thymol, α-pinene, limonene and linalool was determined. The results showed that 72-115% of the antioxidant capacity of the essential oils corresponded to the addition of the antioxidant capacity of their constituents. Thus, the ORAC assay showed additive properties.

Rapid analytical procedure for determination of mineral oils in edible oil by GC-FID.

A procedure for the determination of mineral oils in edible oil has been fully developed. The procedure consists of using a sulphuric acid-impregnated silica gel (SAISG) glass column to eliminate the fat matter. A chemical combustion of the fatty acids takes place, while the mineral oils are not affected by the sulphuric acid. The column is eluted with hexane using a vacuum pump and the final extract is concentrated and analysed by gas chromatography (GC) with flame ionisation detector (FID). The detection limit (LOD) and the quantification limit (LOQ) in hexane were 0.07 and 0.21 µg g(-1) respectively and the LOQ in vegetable oil was 1 µg g(-1). Only a few minutes were necessary for sample treatment to have a clean extract. The efficiency of the process, measured through the recoveries from spiked samples of edible oil was higher than 95%. The procedure has been applied to determine mineral oil in olive oil from the retailed market.

Evaluation of bacterial resistance to essential oils and antibiotics after exposure to oregano and cinnamon essential oils.

Essential oils (EOs) are excellent antimicrobial agents sometimes used in active food packaging. This work studies the susceptibility of 48 clinical isolates and 12 reference strains of Gram-negative bacilli to oregano essential oil, cinnamon essential oil, and combinations of both. Furthermore, the tendency of the clinical isolates to develop resistance to these EOs and to different antibiotics after sequential oregano or cinnamon exposure was studied. For this purpose, antibiotic susceptibility (through disk diffusion assays and minimum inhibitory concentration [MIC] determination) and oregano and cinnamon susceptibility (through MIC and minimum bactericidal concentration [MBC] determination) were compared after 50 passages in the presence or absence of subinhibitory concentrations of oregano and cinnamon essential oils. The results showed that all strains were susceptible to both EOs and their combination independently of the antibiotic resistance profile. In addition, neither synergistic nor antagonistic effects were observed between oregano and cinnamon essential oils at the concentrations tested. After the sequential exposure to both EOs, only Serratia marcescens, Morganella morganii, and Proteus mirabilis treated with oregano changed their antibiotic resistance profile and/or increased their resistance to this EO. However, the changes in antibiotic and oregano resistance were not related.