Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
Browse
2 results
Search Results
Article Citation - WoS: 17Citation - Scopus: 18Incorporation of Organic Acids Turns Classically Brittle Zein Films into Flexible Antimicrobial Packaging Materials(Wiley, 2022) Sozbilen, G.S.; Çavdaroğlu, E.; Yemenicioglu, A.This study aimed to turn classically brittle zein films into flexible antimicrobial ones by the use of lactic (LA), malic (MA) and tartaric acids (TA). The most effective plasticizer was LA (400% elongation at break [EB] at 4%), while MA (189% EB at 4.5%) and TA (68% EB at 5%) showed moderate and limited plasticizing effects, respectively. The LA- and MA-loaded films maintained their flexibility during 30-day storage at 4°C or 25°C. Fourier transform infrared (FTIR) analysis suggested that the plasticization of LA and MA could be related to secondary structural changes in zein such as increased α-helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) β-sheets. Atomic force and scanning electron microscopy showed that LA and MA gave more homogenous and smoother films than TA. Films with LA showed the highest water vapour permeability followed by those of control, MA- and TA-loaded films. Films with 3%–4% LA or MA formed clear zones on Listeria innocua and Klebsiella pneumonia, but only films with LA formed clear zones on Escherichia coli. All OA-loaded films gave unclear zones on Staphylococcus aureus in disc-diffusion tests, but this bacterium was inactivated rapidly in antimicrobial tests based on surface inoculation tests. LA is the best OA to develop flexible antimicrobial films from zein, an industrial by-product that films could not have been utilized as a widespread packaging material due to their brittleness. © 2021 John Wiley & Sons, Ltd.Conference Object Potential Application of Natural Phenolic Antimicrobials and Edible Film Technology Against Bacterial Plant Pathogens(International Society for Horticultural Science, 2020) Alkan, Derya; Yemenicioğlu, AhmetIn this study, antimicrobial edible film technology used frequently for inhibition of human pathogens in processed food was employed as a postharvest bio-based preservation method to prevent bacterial spoilage of fresh fruits and vegetables. Antimicrobial edible zein films were developed by incorporation of pure phenolic acids (PAs) such as gallic acid (GA), cinnamic acid (CA), vanillic acid (VA); essential oils (EOs) such as carvacrol (CAR), thymol (THY), eugenol (EUG) and citral (CIT) and phenolic extract (PE) from clove. In order to test synergetic effect of PAs, different amounts of PAs were added into film solution to obtain films containing mixture of GA and CA, GA and VA, CA and VA at different concentrations. The antimicrobial performances of edible films were tested on selected plant pathogenic bacteria including Pseudomonas syringae, Erwinia amylovora, Xanthomonas vesicatoria and Erwinia carotovora. The overall results of antimicrobial tests showed that films containing PAs between 1 and 4 mg cm-2 inhibited all pathogens while EOs at concentrations between 2 and 4 mg cm-2 and clove extract between 4 and 8 mg cm-2 were found effective against pathogens except P. syringae. Morover, the incorporation of combination of different PA showed greater inhibitory activity on plant pathogens than incorporation of a single PA into films. The edible zein coatings have already been applied for coating of fresh fruits and vegetables at the postharvest stage to suppress their respiration rate and prolong their refrigerated storage. This work clearly showed the benefit of incorporating a single or mixture of antimicrobial phenolic compounds, EOs and PEs in edible zein films against bacterial plant pathogens. The developed films might be employed against plant pathogens by coating fresh fruits and vegetables, seeds, seedlings, tree stems, soil as well as agricultural tools and constructions without using toxic chemicals. © 2020 International Society for Horticultural Science. All rights reserved.