title: Aerobic stability of maize silage stored under plastic films with different oxygen permeability.
abstract: BACKGROUND
  The most important factor that can influence silage quality is the degree of anaerobiosis maintained during conservation. The quality of the plastic film is a key factor, since the permeability of polyethylene to oxygen is too high for silage conservation. The aim of this work was to assess the effects of the interaction between three plastic films with different degrees of oxygen permeability and two different maize silage conservation times on fermentation, microbial quality and aerobic stability.
  
  
  RESULTS
  The conservation time affected the pH, lactic and acetic acids, 1,2-propanediol and lactic/acetic acid ratio, with higher pH, lower lactic acid concentration and lactic/acetic acid ratio but higher acetic acid and 1,2-propanediol concentrations being found in silages conserved for 110 days versus silages conserved for 55 days. The plastic film affected the pH, lactic and acetic acids and lactic/acetic acid ratio. The yeast count was lower and aerobic stability higher for silage conserved under the oxygen barrier film for both conservation periods.
  
  
  CONCLUSIONS
  The positive interaction between length of storage and the increased anaerobiosis of silage during conservation provided by the oxygen barrier compared with polyethylene film helped reduce the yeast count and increase the aerobic stability of maize silage, even when less acetic acid was produced during ensiling.
authors.affiliation: Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Via Leonardo da Vinci 44, I-10095, Grugliasco, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Borreani
authors.forename: Serenella
authors.initials: S
authors.lastname: Piano
authors.forename: Ernesto
authors.initials: E
authors.lastname: Tabacco
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D015169:Colony Count, Microbial; D016984:Enterococcus faecium / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D005285:Fermentation; D061353:Food Storage; D005658:Fungi / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007558:Italy; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism; D007778:Lactobacillus / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D008567:Membranes, Artificial; D010100:Oxygen / Q000737:chemistry; D010539:Permeability; D010969:Plastics / Q000737:chemistry*; D020959:Polyethylene / Q000737:chemistry; D019946:Propylene Glycol / Q000032:analysis / Q000378:metabolism; D012820:Silage / Q000032:analysis* / Q000382:microbiology; D013997:Time Factors; D015003:Yeasts / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry* / Q000382:microbiology
chemical_list: D008567:Membranes, Artificial; D010969:Plastics; D019344:Lactic Acid; D019946:Propylene Glycol; D020959:Polyethylene; D019342:Acetic Acid; D010100:Oxygen
keywords: aerobic stability; maize silage; oxygen barrier plastic film