BS EN 1104:2018 pdf free.Paper and board intended to come intocontact with foodstuffs – Determination ofthe transfer of antimicrobial constituents.
BS EN 1104 Petri dishes (each Petri dish is inoculated from a separate tube) or all the washings over the surface ofthe Roux flask.
Incubate for 7 days at 30 °C.Wash off the colonies from the Petri dishes with 3,0 ml of sterile tryptonesalt solution (6.7) or the flask with 30,0 ml of sterile tryptone salt solution (6.7). Bring the suspensioninto a sterile flask.
Heat the solution with occasional shaking, for 30 min in a water bath at approx.85 C in order to killthe vegetative forms. After heating, transfer the spore suspension to a sterile centrifugating flask of40,0 ml and centrifuge for 10 min at 10 000 g.Eliminate the liquid. Wash the residue with 30,0 ml ofsterile tryptone salt solution (6.7) and centrifuge again.
Repeat the washing 3 times.Suspend the spores in 20,0 ml of the sterile tryptone salt solution (6.7).The spore suspension may be stored at 2 °C to 8 C not longer than 4 weeks. NOTE The spore suspension is also commercially available.
Preparation of inoculating spore suspension of Aspergillus niger.Transfer aliquots of about 15 ml of the Sabouraud medium (6.4), cooled to approx. 45 C to at least 5sterile Petri dishes (d = 90 mm) and allow to solidify.
With an inoculation loop, inoculate the Aspergillus niger strain from the working cultures(6.8.2) ontothe Petri dishes. Each Petri dish is inoculated from a separate tube.The flask is inoculated from at leastfive test tubes.
Incubate for 8 to 10 days at 25 °C± 2 °C.Transfer the conidia with an inoculating ring moistened withthe tryptone salt solution (6.7) to a sterile test tube containing 10,0 ml of tryptone salt [6.7) mix with0,01 ml of a non ionic wetting agent (6.2) and seal with a sterile stopper.Shake the suspension well before using. The inoculation suspension may be stored at 2 °C to 8 C notlonger than 4 weeks.Distribute the suspension evenly by careful shaking. Dispense aliquots of approx.15 ml into each sterilePetri dish (d =90 mm).Lay three test pieces on the still semi-solid nutrient medium using sterile forcepsor tweezers. Press the test pieces down slightly with a suitable sterile device (5.2), ensuring that no aircushions are formed.Repeat the procedure twice in order to obtain three Petri dishes containing threetest pieces each (nine test pieces in total).BS EN 1104 pdf download.