PLA films loaded with Achillea millefolium: In vitro antibacterial effects

Antimicrobial packaging as active food packaging represents a suitable packaging form for food in products in particular for foods where microbial contamination occurs primarily at the surface. Poly (lactic acid) (PLA) is one of the most frequently used bio-polymers because of its similarities to conventional polymeric materials used in food packaging, however its use is still limited to short-term packaging applications. This research has been focused on preparation of PLA packaging films modified with bioactive compounds from Achillea millefolium (AM) plant extract as possible active packaging solution. Addition of specific natural compounds could give improvements in mechanical, thermal or barrier properties, as well as the antimicrobial effect with significant impact on prolonging the food shelf-life and its quality and safety. Accordingly, the aim of this study was to determine chemical and antimicrobial properties of crude AM ethanolic extract and PLA composite films loaded with two concentrations of AM extract expressed in weight percent (2 wt. % and 5 wt. %). The AM ethanolic extract showed very good antimicrobial activity against E. coli and S. aureus, while PLA films loaded with 5% AM extract showed significant reduction of initial S. aureus after 24 h contact time compared to neat PLA films (up to 90%). PLA films with 2% and 5% AM content did not show any antimicrobial activity against E. coli. Furthermore, the chemical composition of the ethanolic extract was determined considering its phenolic composition. These results indicated promising potential of incorporation of A. millefolium extract in PLA as an antimicrobial agent for food packaging applications

ANTIMICROBIAL NANOMATERIALS FOR FOOD PACKAGING APPLICATIONS

ABSTRACT: Food packaging industry presents one of the fastest growing industries nowadays. New trends in this industry, which include reducing food as well as packaging waste, improved preservation of food and prolonged shelf-life together with substitution of petrochemical sources with renewable ones are leading to development of this industrial area in diverse directions. This multidisciplinary challenge is set up both in front of food and material scientists. Nanotechnology is recently answering to these challenges, with different solutions-from improvements in materials properties to active packaging solutions, or both at the same time. Incorporation of nanoparticles into polymer matrix and preparation of hybrid materials is one of the methods of modification of polymer properties. Nano scaled materials with antimicrobial properties can act as active components when added into polymer, thereby leading to prolonged protective function of pristine food packaging material. This paper presents a review in the field of antimicrobial nanomaterials for food packaging in turn of technology, application and regulatory issues

Edible mycorrhizal species Lactarius controversus Pers. 1800 as a source of antioxidant and cytotoxic agents

The aim of this work was to study chemical profile and antioxidant and cytotoxic activities of ethanol and water extracts of Lactarius controversus (Pers.) 1800 mushroom species growing in eastern Serbia. The chemical characterization of phenolic compounds performed by HPLC-MS/MS demonstrated the presence of quinic acid among others. Determination of antioxidant activity, including radical scavenging effects on DPPH•, NO•, OH• and SOA radicals and ferric reducing ability was investigated. The highest DPPH radical scavenging effect was obtained for water extract (LcAq) while ethanol extract (LcEtOH) demonstrated the highest FRAP activity. Hexane extract applied in antibacterial assay against three pathogenic strains demonstrated antibacterial effect only against S. aureus ATCC25922. Anti-proliferative properties against estrogen dependent MCF 7 breast cancer cell lines using MTT showed higher activity for ethanolic extract. [Projekat Ministarstva nauke Republike Srbije, br. III 46001 i br. 172058

AN INSIGHT INTO IN VITRO BIOACTIVITY OF WILD-GROWING PUFFBALL SPECIES LYCOPERDON PERLATUM (PERS) 1796

ABSTRACT: Lycoperdon perlatum (Pers) 1796 is saprobic puffball species with a global distribution. It is edible if young, when the gleba is still homogeneous and white. Since this species has a pleasant texture and taste, it has been used in soups as a substitute for dumplings. The aim of this work was to study bioactivity of crude extracts prepared from wild-growing sporocarps of L. perlatum collected from Eastern Serbia during 2012. The bioactivity screens included antioxidant (DPPH • and FRAP assays), antiproliferative (human breast MCF-7 cancer cell-line; MTT and SRB assays) and antibacterial (three referent ATCC strains; microdilution assay) effects. Polar extracts (aqueous -LycAq and ethanol -LycEtOH) and a nonpolar extract (hexane -LycHex) of the examined mushroom species were screened. In addition, LycAq and LycEtOH were primarily characterized by UV-VIS spectrophotometry, due to determination of chemical composition (total phenol and flavonoid contents). The highest anti-DPPH radical activity was observed for LycAq (IC 50 = 46.56 µg/ml). In comparison with LycAq, less polar LycEtOH showed slightly better ferric reducing antioxidant power (FRAP) (IC 50 = 21.87 µg/ml and IC 50 = 19.28 µg/ml, respectively). However, total phenol contents of both extracts were similar (≈ 2.0 mg GAE/g d.w.). Conversely, modest activities were found against Staphylococcus aureus ATCC 25922 (LycHex, MIC = 3.12 mg/ml) and MCF-7 cells (with the highest one obtained for LycEtOH after 72 h, IC 50 = 367.54 µg/ml and IC 50 = 390.03 µg/ml, MTT and SRB assays, respectively). According to the obtained experimental data, L. perlatum can be considered as a good source of novel and potent natural antioxidants for use in regular diet