Želatinski film s mikrokapsulama antocijana izoliranih iz plavog graška (Clitoria ternatea) kao prehrambena ambalaža s učinkom suzbijanja patogenih mikroorganizama

Research background. Microbial contamination of food products is one of the significant causes of food spoilage and foodborne illnesses. The use of active packaging films incorporated with antimicrobial agents can be a measure to improve food quality and extend shelf life. Nevertheless, antimicrobial agents such as silver, copper, titanium and zinc in the packaging films have raised concerns among consumers due to toxicity issues. Experimental approach. The current study aims to develop biodegradable gelatine-based edible films incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. The impact of incorporation of microcapsules with anthocyanins on the morphology, thermal, mechanical, water vapour barrier and physicochemical properties of the gelatine films was evaluated in this study. The effectiveness of the developed films against foodborne pathogens and their application for perishable food protection were also investigated. Results and conclusions. The results show that incorporating anthocyanin microcapsules enhances the gelatine film physical and mechanical properties by increasing the thickness, tensile strength, Young\u27s modulus and elongation at break of the films. Scanning electronic microscopy analysis revealed that the film surface morphology with anthocyanin microcapsules had a homogeneous and smooth surface texture compared to the control. The thermogravimetric analysis also showed a slight improvement in the thermal properties of the developed films. Agar well diffusion assay revealed that the developed films exhibit significant inhibition against a broad-spectrum of bacteria. Furthermore, the films composed of gelatine with anthocyanin microcapsules significantly reduced the total viable count of microorganisms in the bean curd during storage for 12 days compared with the control films. Novelty and scientific contribution.Increasing global awareness of healthy and safe food with minimal synthetic ingredients as preservatives has sparked the search for the use of antimicrobial agents of natural origins in active food packaging material. In this study, a safe and effective active packaging film was developed using an environmentally friendly biopolymer, gelatine film incorporated with microcapsules of Clitoria ternatea-derived anthocyanins as a natural antimicrobial agent. This study demonstrated that such a method is not only able to improve the film physical properties but can also significantly prolong the shelf life of food products by protecting them from microbial spoilage.Pozadina istraživanja. Mikrobna kontaminacija je jedan od važnijih uzroka kvarenja hrane i pojave bolesti koje se prenose hranom. Primjenom aktivnih filmova za pakiranje hrane obogaćenih antimikrobnim agensima može se poboljšati kakvoća hrane i produljiti njezina valjanost. No, potrošači su sve više zabrinuti zbog moguće toksičnosti mnogih antimikrobnih agensa koji se primjenjuju u tim filmovima, kao što su srebro, bakar, titan i cink. Eksperimentalni pristup. Svrha je ovoga rada bila izraditi biorazgradive jestive filmove od želatine obogaćene mikrokapsulama antocijana izoliranih iz plavog graška (Clitoria ternatea) kao prirodnih antimikrobnih agensa. Ispitan je utjecaj mikrokapsula s antocijanima na morfologiju, toplinska, mehanička i fizikalno-kemijska svojstva filmova, te njihovu propusnost vodene pare. Također je ispitan učinak dobivenih filmova na patogene mikroorganizme u hrani i zaštitu lako pokvarljivih proizvoda. Rezultati i zaključci. Rezultati pokazuju da su se fizikalna i mehanička svojstva filmova poboljšala s dodatkom mikrokapsula antocijana, koje su povećale gustoću, vlačnu čvrstoću, Youngov modul elastičnosti i istezljivost filma. Ispitivanjem morfoloških značajki pretražnom elektronskom mikroskopijom utvrđeno je da film obogaćen antocijanima imao homogenu i glatku površinu, za razliku od kontrolnog uzorka. Termogravimetrijskom je analizom potvrđeno blago poboljšanje toplinskih svojstava filmova. Difuzijom u jažicama agara otkriveno je da dobiveni filmovi imaju znatan inhibicijski učinak na širok spektar bakterija. Osim toga, filmovi od želatine s dodatkom mikrokapsula antocijana smanjili su ukupni broj živih stanica mikroorganizama u tofuu tijekom 12 dana skladištenja, u usporedbi s kontrolnim uzorcima. Novina i znanstveni doprinos. Veća svijest ljudi o važnosti zdrave i sigurne prehrane sa što manjim udjelom sintetičkih konzervansa potakla je potragu za antimikrobnim agensima iz prirodnih izvora koji se mogu upotrijebiti u materijalima za aktivno pakiranje hrane. U ovom je radu razvijen siguran i učinkovit aktivni ambalažni film s dodatkom ekološki prihvatljivog biopolimera, želatinskog filma obogaćenog mikrokapsulama antocijana izoliranih iz plavog graška (Clitoria ternatea) kao prirodnih antimikrobnih agensa. Istraživanje je pokazalo da se ovom metodom mogu poboljšati fizikalna svojstva filma, ali i bitno produljiti vrijeme skladištenja hrane, jer ih dobiveni film štiti od mikrobnog kvarenja

Poboljšanje mikrobiološke ispravnosti borovnica pomoću polimernih nanočestica s timolom

Research background. The presence of Yersinia enterocolitica on raw food products raises the concern of yersiniosis as most of the berries are consumed raw. This is a challenging issue from the food safety aspect since it could increase the occurrence of foodborne diseases among humans. Thus, it is crucial to implement an effective sanitation before the packaging. Experimental approach. This study aims to synthesize and characterize thymol-loaded polyvinyl alcohol (Thy/PVA) nanoparticles as a sanitizer for postharvest treatment of blueberries. Thy/PVA nanoparticles were characterized by spectroscopic and microscopic approaches, prior to the analyses of antimicrobial properties. Results and conclusions. The diameter size of the nanoparticles was on average 84.7 nm, with a surface charge of −11.73 mV. Based on Fourier transform infrared (FTIR) measurement, the Thy/PVA nanoparticles notably shifted to the frequency of 3275.70, 2869.66, 1651.02 and 1090.52 cm-1. A rapid burst was observed in the first hour of release study, and 74.9 % thymol was released from the PVA nanoparticles. The largest inhibition zone was displayed by methicillin-resistant Staphylococcus aureus (MRSA), followed by Y. enterocolitica and Salmonella typhi. However, amongst these bacteria, the inhibition and killing of Y. enterocolitica required a lower concentration of Thy/PVA nanoparticles. The treatment successfully reduced the bacterial load of Y. enterocolitica on blueberries by 100 %. Novelty and scientific contribution. Thymol is a plant-based chemical without reported adverse effects to humans. In this study, by using the nanotechnology method of encapsulation with PVA, we improved the stability and physicochemical properties of thymol. This nanoparticle-based sanitizer could potentially promote the postharvest microbiological safety of raw berries, which may become an alternative practice of food safety.Pozadina istraživanja. Prisutnost bakterije Yersinia enterocolitica u sirovim prehrambenim proizvodima izaziva zabrinutost zbog moguće pojave jersinioze, s obzirom na to da se bobičasto voće najčešće konzumira sirovo. S aspekta sigurnosti hrane ova bakterija predstavlja problem, jer može povećati učestalost pojave bolesti koje se prenose hranom. Stoga je neophodno provesti učinkovitu sanitaciju voća prije pakiranja. Eksperimentalni pristup. Svrha je ovoga rada bila sintetizirati i okarakterizirati nanočestice poli(vinil-alkohola) s timolom kao dezinficijensom za obradu borovnica prije pakiranja. Nanočestice su okarakterizirane pomoću spektroskopije i mikroskopije, a zatim su ispitana njihova antimikrobna svojstva. Rezultati i zaključci. Prosječni promjer nanočestica bio je 84,7 nm, s površinskim nabojem od −11,73 mV. Rezultati Fourier transformirane infracrvene spektroskopije (FTIR) pokazuju značajan pomak pika nanočestica poli(vinil-alkohola) s timolom prema frekvencijama od 3275,70; 2869,66; 1651,02 i 1090,52 cm-1. Iznenadni porast količine timola oslobođenog iz nanočestica opažen je u prvih sat vremena ispitivanja njegovog kontroliranog otpuštanja, a ukupno je otpušteno 74,9 % timola. Opažena je najveća zona inihbicije rasta bakterije Staphylococcus aureus otporne na meticilin (MRSA), a zatim bakterija Y. enterocolitica i Salmonella typhi. Međutim, za inhibiciju i ubijanje bakterija Y. enterocolitica bile su potrebne manje koncentracije nanočestica poli(vinil-alkohola) s timolom. Ovim je postupkom broj bakterija Y. enterocolitica uspješno smanjen za 100 %. Novina i znanstveni doprinos. Timol je spoj biljnog porijekla, koji ne narušava zdravlje čovjeka. U ovome smo radu inkapsulacijom u omotaču s poli(vinil-alkoholom) povećali stabilnost i poboljšali fizikalno-kemijska svojstva timola. Primjenom nanočestica tog dezinficijensa može se poboljšati mikrobiološka ispravnost sirovog bobičastog voća, što se u praksi može primijeniti za očuvanje sigurnosti hrane

Dual production of poly(3-hydroxybutyrate) and glutamate using variable biotin concentrations in Corynebacterium glutamicum

We previously synthesized poly(3-hydroxybutyrate) [P(3HB)] in recombinant Corynebacterium glutamicum, a prominent producer of amino acids. In this study, a two-step cultivation was established for the dual production of glutamate and P(3HB) due to the differences in the optimal concentration of biotin. Glutamate was extracellularly produced first under the biotin-limited condition of 0.3 μg/L. Production was then shifted to P(3HB) by addition of biotin to a total concentration of 9 μg/L. The final products obtained were 18 g/L glutamate and 36 wt% of P(3HB)

Characterization of bacterial cellulose produced via fermentation of acetobacter xylinum 0416

The production of plant-based cellulose products had contributed to the increasing rate of deforestation activities. Bacterial cellulose (BC) produced via fermentation process can be considered as an alternative. In this study, BC was produced by fermentation of Acetobacter xylinum 0416 and further analyzed to determine its physiochemical properties. The characterization of the BC was carried out through fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA), pH, moisture content, compressibility index and swelling properties. Then, it was compared with plant-based cellulose products which are carboxymethyl cellulose (CMC) and cellulose powder (CP). FTIR analysis demonstrated the similar properties between BC, CMC and CP while FESEM depicted a smoother surface and nanostructure of the BC. The TGA analysis indicated that BC has the highest thermal stability compared to CMC and CP. The other characterization results showed that BC displayed promising properties compared to CMC and CP. These findings further support the potential of substituting the use of plant-based cellulose products in the market with BC produced by A. xylinum 0416

Phytochemical Screening and Biological Evaluations of Garcinia atroviridis: Phytochemical and biological evaluations of G. atroviridis

Garcinia atroviridis (Clusiaceae) has been used as a postpartum medication agent in folkloric medicine. However, its biological potential has not been fully evaluated. The present study was aimed to evaluate theantioxidant efficacies, cholinesterase enzyme inhibitory and antimicrobial activity of the stem bark extracts of G.atroviridis. Successive extraction was done using solvents of varied polarity. The antimicrobial activity was performed using the disc diffusion method by determining the inhibition zone and further evaluated for their minimum inhibition concentration (MIC) and minimum lethal concentration (MLC). Anti-cholinesterase activity was determined by spectrophotometric method while antioxidant activity was evaluated by DPPH radical scavenging. The extracts showed significant inhibitory activity against food borne bacteria. However, only dichloromethane extract exhibited the anti-yeast potential against Candida utilis and none of the extracts tested showed anti-fungi activity. For cholinesterase enzyme inhibitory activity, ethyl acetate extract exhibited the strongest acetylcholinesterase (AChE) inhibitory activity with an IC50 value of 5.46 ± 2.91 μg/mL while water extract showed the lowest IC50 value (29.31 μg/mL) against butyrlcholinesterase (BChE). For antioxidant activity, methanol extract showed moderate activity against DPPH radicals with EC50 value of 71.96 μg/mL.The dichloromethane extract exhibited significant antimicrobial activity while ethyl acetate showed the strongest acetylcholinesterase (AChE) inhibitory activity. The present study showed the significance of this commercial plant as the potential source of bioactive compounds

Metabolomics analysis and antioxidant potential of endophytic <i>Diaporthe fraxini </i>ED2 grown in different culture media

Endophytic fungi are a promising source of bioactive metabolites with a wide range of pharmacological activities. In the present study, MS-based metabolomics was conducted to study the metabolomes variations of endophytic Diaporthe fraxini ED2 grown in different culture media. Total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assays were conducted to assess the antioxidant potential of the fungal extracts. Multivariate data analysis (MVDA) was employed in data analysis and interpretation to elucidate the complex metabolite profile. The supplemented culture medium of D. fraxini fungal extract stimulated the production of metabolites not occurring in the normal culture medium. Antioxidant activity studies revealed the potential of supplemented cultured fungal extract of D. fraxini as a source of antioxidants. The present findings highlight that fungal culture medium supplementation is an effective approach to unravelling the hidden metabolome in plant-associated fungal diversity

Cynometra cauliflora L.: An indigenous tropical fruit tree in Malaysia bearing essential oils and their biological activities

Cynometra cauliflora L., locally known as ‘‘nam-nam” or ‘‘katak puru-puru” in Malaysia is belonging to the Fabaceae family. The tree is native to Malaysia and has been used traditionally as folk medicine. Limited works have been conducted on C. cauliflora regarding its chemical composition. In view of this, the present study aimed to identify the essential oil (EO) composition of the leaf, twig and fruit of C. cauliflora and evaluate their antioxidant, antimicrobial and cytotoxic activities. EOs obtained from different parts of the tree were analyzed using capillary GC and GC/MS. Twenty-six, seventeen and fifty constituents were identified in the leaf, twig and fruit EOs of C. cauliflora. Results demonstrated the dominance of monoterpenes hydrocarbons in the leaf oil and oxygenated monoterpenes in the twig oil. On the contrary, fruit oil was abundant in oxygenated sesquiterpenes. Different chemical profiles were found in different parts of EOs which have contributed to varied biological activities. Twig oil (IC50 37.12 ± 2.84 mg/mL) showed better antioxidant power than the leaf (IC50 207.17 ± 2.95 mg/mL) and fruit oils (IC50 461.88 ± 12.61 mg/mL) in DPPH assay. Additionally, twig oil inhibited an entire range of microorganisms tested with inhibition zones ranging 10.3 ± 0.4 to 29.7 ± 0.4 mm. The twig oil displayed low MIC and MBC values against Staphylococcus aureus (MIC 125.0 mg/mL; MBC 250.0 mg/mL) and MRSA (MIC 125.0 mg/mL; MBC 250.0 mg/mL). In in vitro MTT assay, twig oil showed antiproliferative effects against human breast cancer MCF-7 cells

Cynometra cauliflora essential oils loaded-chitosan nanoparticles: Evaluations of their antioxidant, antimicrobial and cytotoxic activities

Nanoencapsulation has appeared as an alternative approach to protect the bioactive constituents of essential oils (EOs) and to improve their properties. In this study, Cynometra cauliflora essential oils (CCEOs) were nanoencapsulated in chitosan nanoparticles (CSNPs) using an emulsion-ionic gelation technique. Transmission electron microscopy (TEM) images illustrated a well dispersion and spherical shape of C. cauliflora EOs-loaded chitosan nanoparticles (CCEOs-CSNPs) with an average size of less than 100 nm. In addition to that, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) analyses revealed the success of CCEOs nanoencapsulation. The encapsulation efficiency (EE) was in the range of 38.83% to 44.16% while the loading capacity (LC) reached 32.55% to 33.73%. The antioxidant activity (IC50) of CCEOs-CSNPs was ranged from 21.65 to 259.13 μg/mL when assessed using DPPH radical scavenging assay. CCEOs-CSNPs showed an appreciable antimicrobial effects on diabetic wound microorganisms. Notably, cytotoxic effects against human breast cancer MCF-7 and MDA-MB-231 cells recorded IC50 of 3.72–17.81 μg/mL and 16.24–17.65 μg/mL, respectively, after 72 h treatment. Interestingly, no cytotoxicity against human breast normal MCF-10A cells was observed. Thus, nanoencapsulation using CSNPs could improve the properties of CCEOs in biomedical related applications