Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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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 Antimicrobial Effects in Food and Prevention of Contamination in Food Industry(VTT Technical Research Center of Finland, 2007) Hütt, Pirje; Songisepp, Epp; Güldaş, Metin; Tamme, Terje; Ormancı, Fatma Seda; Ayaz, Naim Deniz; Korel, Figen; Aarnisalo, Kaarina; Hradecka, Helena; Mikelsaar, MarikaThe most commonly recognized food-borne infections are caused by Campylobacter jejuni and Salmonella spp. In the past 25 years, Listeria monocytogenes has become increasingly important as a food-associated pathogen. Though, an annual incidence of human listeriosis is between two and ten reported cases per million in EU countries. Because of its high case fatality rate, listeriosis ranks among the most frequent causes of death due to food-borne illness. L. monocytogenes and C. jejuni has been shown to adapt to different environmental stress factors, including disinfectants. Salmonella enteritidis, C. jejuni and L. monocytogenes may also form a biolfim which helps to survive in the environment. For that reason, the food industrial hygiene has become important to avoid contamination of raw food and food products with these pathogens.