UDC 637.133.7
DOI: 10.36871/vet.zoo.bio.202403008
Authors
Natalya A. Malofeeva,
Elena S. Orlova,
Valentina M. Bachinskaya,
Moscow State Academy of Veterinary Medicine and Biotechnology – MVA by K. I. Skryabin”, Moscow, Russia
Abstract
In order to preserve the initial organoleptic, physico-chemical and microbiological parameters,
raw milk samples for veterinary and sanitary examination are transported to the laboratory in a
chilled form within a short period of time. Preservatives, which eliminate the need to cool samples,
affect the initial milk parameters, pose a danger to laboratory workers and change organoleptics.
This paper presents data on the effect of the safe food additive nizin (E-234) at a concentration
of 0,03 g/0,5 l on the initial organoleptic (taste, color, odor and consistency) and physico-chemical
(mass fraction of fat, protein, skimmed milk residue (SOMO), density, titrated acidity) indicators
milk stored at room temperature. It was found that nisin slows down the change in physico-chemical
parameters due to spoilage, but causes an increase of 0,14 % in the mass fraction of protein,
1,28 kg/ m3 in density, 0,32 % in the mass fraction of SOMO after 24 hours of experiment.
Two methods
of reducing the concentration of nisin in the samples were tested: heat treatment of milk and dilution
of the preservative before each application. Heat treatment had a weak effect, the indicators
decreased by an average of 0,04 %, 0,07 %, 0,22 kg/m3 for protein, SOMO and density, respectively.
The second method turned out to be simpler and more effective – the true values of protein, SOMO
and density indicators were preserved for the first 6–18 hours of sample storage.
Keywords
preservation of milk samples; nisin; veterinary and sanitary examination of milk; laboratory tests; preservatives for milk samples; quality control of raw materials
