title: The effect of ZnCl2 on green Spanish-style table olive packaging, a presentation style dependent behaviour.
abstract: BACKGROUND
  Zinc chloride has been used previously as a preservative in directly brined olives with promising results. However, this is the first time that the effects of ZnCl2 addition (0-1 g L(-1) ) on green Spanish-style table olive (cv. Manzanilla) packaging has been studied.
  
  
  RESULTS
  The presence of ZnCl2 affected the physico-chemical characteristics of the products; the presence of the Zn led to lower pH values (particularly just after packaging) and titratable and combined acidity values than the control but did not produce clear trends in the colour parameters. No Enterobacteriaceae were found in any of the treatments evaluated. At the highest ZnCl2 concentrations, the lactic acid bacteria were inhibited while, unexpectedly, its presence showed a lower effect than potassium sorbate against the yeast population. Regardless of the use of potassium sorbate or ZnCl2 , the packages had a reduced microbial biodiversity because only Lactobacillus pentosus and Pichia galeiformis were found at the end of the shelf life. With respect to organoleptic characteristics, the presentations containing ZnCl2 were not differentiated from the traditional product.
  
  
  CONCLUSIONS
  Zinc chloride was less efficient than potassium sorbate as a yeast inhibitor in green Spanish-style olives, showing clear presentation style dependent behaviour for this property. Its presence produced significant changes in chemical parameters but scarcely affected colour or sensory characteristics.
authors.affiliation: Department of Food Biotechnology, Instituto de la Grasa (CSIC), Avda\Padre García Tejero, n° 4, 41012, Seville, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Bautista-Gallego
authors.forename: Francisco Noé
authors.initials: FN
authors.lastname: Arroyo-López
authors.forename: Verónica
authors.initials: V
authors.lastname: Romero-Gil
authors.forename: Francisco
authors.initials: F
authors.lastname: Rodríguez-Gómez
authors.forename: Antonio
authors.initials: A
authors.lastname: Garrido-Fernández
mesh_terms: D000328:Adult; D055598:Chemical Phenomena; D002712:Chlorides / Q000494:pharmacology*; D004755:Enterobacteriaceae / Q000302:isolation & purification; D005260:Female; D005285:Fermentation; D005520:Food Preservatives / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry* / Q000187:drug effects* / Q000382:microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D031658:Olea; D010843:Pichia / Q000302:isolation & purification; D013011:Sorbic Acid / Q000494:pharmacology; D013030:Spain; D013649:Taste; D017967:Zinc Compounds / Q000494:pharmacology*
chemical_list: D002712:Chlorides; D005520:Food Preservatives; D017967:Zinc Compounds; C016837:zinc chloride; D013011:Sorbic Acid
keywords: green Spanish-style olive; preservation; shelf life; table olive packaging; zinc