Journal of Microbial & Biochemical Technology

Physical, mechanical properties and antifungal activity of bioactive film containing Williopsis saturnus var. saturnus antagonistic yeast

Joint Event on 4^th World Congress and Expo on Applied Microbiology & 2^nd International Conference on Food Microbiology

November 29-December 01, 2017 Madrid, Spain

Gulsah Karabulut and Arzu Cagri Mehmetoglu

Sakarya University, Turkey

Posters & Accepted Abstracts: J Microb Biochem Technol

Abstract:

The mold growth leading physical, chemical and sensory changing in food products and carrying health risks with toxin production is a main problem in the food industry. In our study, as an alternative solution, bioactive materials were developed by incorporating Williopsis saturnus var. saturnus at different concentrations (0; 3.2; 6.8 and 8.8 cfu/cm2) into whey protein concentrate (WPC) based edible films. Viability of W. saturnus var. saturnus in the films was investigated during the time of the storage. Moreover, the antifungal activity of the films incorporated with W. saturnus var. saturnus was also tested against Penicillium expansum and Aspergillus niger. The effect of the antagonist yeast occurrence in the film on physical properties and microstructural properties of the films were analyzed. The optical properties and the mechanical properties of the film samples were also observed by SEM and Instron, respectively. The results showed that bioactive WPC films containing 8.8 log cfu/cm2 W. saturnus var. saturnus were able to maintain more than 60% of the initial antagonist yeast population. In addition, the films incorporated with the antagonist yeasts reduced mycelium growth of P. expansum and A. niger on the medium by more than 29% and 19% at pH 4.5, respectively. Incorporation of more than 3.2 log cfu/cm2 antagonist yeasts significantly increased water vapor permeability of the films (P<0.05). Increased population of the yeasts also significantly increased percent water solubility of the films (P<0.05). Moreover, the distribution of the antagonistic yeasts in the films presented homogenous microstructure at SEM. Increasing concentration of the killer yeasts in the films presented a significant tendency to greenness and yellowness as well as lightness values (P<0.05). The concentrations more than 3.2 log cfu/cm2 of killer yeast population in the films significantly increased tensile strength but decreased percent elongation at break (P<0.05). Recent Publications 1. Fan Y, Xu Y, Wang D, Zhang L, Sun J, Sun L and Zhang B (2009) Effect of alginate coating combined with yeast antagonist on strawberry (Fragaria�?ananassa) preservation quality. Postharvest Biology and Technology 53:84�??90. 2. Aloui H, Licciardello F, Khwaldia K, Hamdi M and Restuccia C (2015) Physical properties and antifungal activity of bioactive films containing Wickerhamomyces anomalus killer yeast and their application for preservation of oranges and control of post-harvest green mold caused by Penicillium digitatum. International Journal of Food Microbiology, 200:22�??30. 3. Cota L V, Maffia L A, Mizubuti E S, Macedo P E and Antunes R F (2008) Biological control of strawberry gray mold by Clonostachys rosea under field conditions. Biological Control, 46(3):515-522. 4. Parafati L, Vitale A, Restuccia C and Cirvilleri G (2016) The effect of locust bean gum (LBG)-based edible coatings carrying biocontrol yeasts against Penicillium digitatum and Penicillium italicum causal agents of post-harvest decay of mandarin fruit. Food microbiology 58:87-94. 5. Pereira J O, Soares J, Sousa S, Madureira A R, Gomes A and Pintado M (2016) Edible films as carrier for lactic acid bacteria. LWT-Food Science and Technology, 73:543-550.

Biography :

Gulsah Karabulut graduated from Ankara University, Department of Food Engineering in 2011. She started her graduate studies in Sakarya University Department of Food Engineering. She is currently working as a research assistant at the Department of Food Engineering at Sakarya University. Work areas include food microbiology, edible films, biodegradable packaging, biocontrol applications.