The keeping quality of LPS-activated milk in the western highlands of Cameroon

摘要

Thepotentialsofapplyingthelactoperoxidasesystem(LPS)inextendingtheshelflifeofrawmilkatambienttemperatureswasinvestigatedinthewesternhighlandsofCameroon.RawmilkwasLPS-activatedbyaddingvariousconcentrations(ppm)ofthiocyanateandperoxideanddenotedas0:0,7:10ppm,10:10ppmand20:20ppm.Thekeepingqualityoftheactivatedmilksampleswasassessedbythealcoholstabilityandclot-on-boilingtests,pHchangesandtitratableacidity.Themilkinallthetreatmentsremainedfreshduringthefirst12hoursbutthecontrolwasspoiledbythe15thhour.TherewasacontinuousdropinpHvaluesmatchedbyasteadyriseintitratableacidity.Forallparametersmeasured,20:20ppmwasthelasttreatmenttospoil,suggestingthattheshelflifeofmilkincreaseswithincreasingconcentrationsofthiocyanateandperoxide.Withsmallamountsofthiocyanate(20ppm)andperoxide(20ppm)theshelflifeofrawmilkcaneffectivelybeextendedunderCameroonianconditionsbyapproximately9hourswithoutrefrigeration.ThusLPS-activatedmilkcanbestoredforaslong21hours,allowingsufficienttimeforitsappropriatedisposal.