title: Assays to control the development of the green staining alteration in Spanish-style green olives of the Gordal variety.
abstract: BACKGROUND
  Olives of the Gordal variety processed according to the Spanish style sometimes develop an alteration in color known as green staining (GS), due to the formation of harmless copper-chlorophyll complexes, which makes the product less valuable. The aim of this study was to investigate methods to minimize the impact that this alteration has for the table olive industry.
  
  
  RESULTS
  Calcium chloride, sorbic, benzoic and ascorbic acids and SO2 did not inhibit the development of the alteration in olives packed under their own fermentation brine or new fresh brine. It was also discovered that the incubation of olive samples at 45 °C for 20 days accelerates the formation of GS and can be a very useful tool to predict the incidence of the alteration in advance. By applying this test to numerous industrial tanks for four consecutive seasons, it was found that GS was mainly present in olives harvested at the beginning of the season.
  
  
  CONCLUSIONS
  The formation of GS in olives of the Gordal variety is time- and temperature-dependent, and none of the additives tested avoided or retarded the development of the alteration. However, an accelerated test to predict the development of GS formation has been proposed that could contribute to minimize the effects of the alteration. © 2015 Society of Chemical Industry.
authors.affiliation: Food Biotechnology Department, Instituto de la Grasa (IG-CSIC), Campus University Pablo de Olavide, Building 46, Ctra. Utrera km 1, E-41013, Seville, Spain.
authors.forename: Antonio Higinio
authors.initials: AH
authors.lastname: Sánchez
authors.affiliation: Food Biotechnology Department, Instituto de la Grasa (IG-CSIC), Campus University Pablo de Olavide, Building 46, Ctra. Utrera km 1, E-41013, Seville, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Romero
authors.affiliation: Food Biotechnology Department, Instituto de la Grasa (IG-CSIC), Campus University Pablo de Olavide, Building 46, Ctra. Utrera km 1, E-41013, Seville, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: de Castro
authors.affiliation: Food Biotechnology Department, Instituto de la Grasa (IG-CSIC), Campus University Pablo de Olavide, Building 46, Ctra. Utrera km 1, E-41013, Seville, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Rejano
authors.affiliation: Food Biotechnology Department, Instituto de la Grasa (IG-CSIC), Campus University Pablo de Olavide, Building 46, Ctra. Utrera km 1, E-41013, Seville, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Brenes
mesh_terms: D002734:Chlorophyll / Q000096:biosynthesis*; D003300:Copper / Q000737:chemistry*; D005285:Fermentation; D019649:Food Industry; D005519:Food Preservation; D006801:Humans; D031658:Olea / Q000378:metabolism*; D010860:Pigments, Biological / Q000096:biosynthesis*
chemical_list: D010860:Pigments, Biological; D002734:Chlorophyll; D003300:Copper
keywords: Gordal; alteration; color; copper-chlorophyll; table olives