4th EucheMs chemistry congress

Poster Session 2
s1168
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - food chemistry
P - 0 6 1 2
Study on AnALytiCAL Method of Liquid
PArAffin in foodS
S. J. PArK 1 , J. C. Choi 1 , d. w. Shin 1 , h. S. LiM 1 ,
J. M. oh 1 , S. J. JAnG 1 , S. h. KiM 1
1 Korea Food and Drug Administration, Food additives and
Packages Division, Cheongwon-gun Chungcheongbuk-,
Republic of Korea
Liquid paraffin is a mixture of heavier alkanes derived from
petroleum. Liquid paraffin can be used as a lubricant in processing
machinery, a coating agent for fruits and a releasing agent. There
is a growing interest in food contaminated with liquid paraffin.
The purpose of this study is to develop the analytical method of
liquid paraffin in foods. To develop the time and cost effective
method, gravimetric analysis and gas chromatography-flame
ionized detector(GC-FID) were compared. Recovery tests were
performed in cakes, capsules and dried fruits. Liquid paraffin was
extracted by hexane and purified by alkaline permanganate
oxidation and passing through a silica cartridge. GC-FID method
was validated for liquid paraffin by measuring the limit of
detection(LOD), the limit of quantification(LOQ) and the linearity
of calibration curve. The amount of liquid paraffin in foods was
determined by using the optimized analytical method.
Keywords: Food additive; Liquid paraffin; Anayltical method;
4 th EucheMs chemistry congress
P - 0 6 1 3
non ProteoLytiC AMinoACyL derivAtiveS in
CheeSeS
S. SforzA 1 , C. BotteSini 1 , e. SGArBi 2 ,
G. GALAvernA 1 , M. GAtti 2 , t. tedeSChi 1 ,
A. doSSenA 1 , r. MArCheLLi 1
1 University of Parma, Organic and Industrial Chemistry,
Parma, Italy
2 University of Parma, Genetics Biology of Microorganisms
Anthropolgy Evolution, Parma, Italy
Cheeses are complex mixtures of amino acids, peptides and
proteins, mostly derived from the proteolysis of the caseinic
fraction precipitated in the curd during cheese production. In the
last years several studies have demostrated that small aminoacyl
dipeptide-like derivatives of non proteolytic origins are present
in not negligible amount in several cheeses, like
Parmigiano-Reggiano, Grana Padano and Asiago [1, 2] . These
compounds were identified as gamma-glutamyl-amino acids,
lactoyl-lamino acids and pyroglutamyl-amino acids, and
collectively named Non Proteolytic Aminoacyl Derivatives
(NPAD). NPADs were found to be only formed by L-glutamic,
lactic and pyroglutamic acids (although in cheese their
D-counterparts are abundant) linked to lipohylic amino acids
(mostly Phe, Leu, Ile), suggesting a common enzymatic origin,
and their amount was found to increase with the ageing time. By
using LC/MS technologies, a deep investigation on their origin
was undertaken. The cheeses where their amount was found to be
higher (up to 50 mg /100 g of cheese) were those with a long
ageing time and a consistent presence of lactic acid bacteria.
Several strains of lactic acid bacteria, both starters and non
starters, isolated from Parmigiano-Reggiano cheese, were found
to have the ability to produce gamma-Glu-Phe e Lac-Phe.
Experiments with Parmigiano-Reggiano extracts and isotopically
labelled precursors indicated the presence in the cheese of an
enzymatic activity able to produce these compounds starting from
glutamic and lactic acid. Further investigations are now in
progress in order to identify and isolate the producing enzyme(s).
These compounds demonstrate that the peptidic fraction of
Parmigiano-Reggiano is more complex than usually thought, and
that enzymatic activities on proteins are not only reponsible for
their hydrolysis, but starting from free amino acids can also form
new unusual aminoacyl derivatives.
references:
1. Sforza et al., 2009, Int. Dairy J., 19, 582-587.
2. Toelstede et al., 2009, J. Agr. Food Chem., 56, 2795-2804.
Keywords: Peptides; Liquid chromatography; Mass
spectrometry; Amino acids;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc