Danijela Vranić

Physico-Chemical Characteristics and Sensory Quality of Dry Fermented Sausages with Flaxseed Oil Preparations

Abstract The aim of this study was to determine the extent of changes in physico-chemical and sensory properties of dry fermented sausages where pork backfat was partly replaced by flaxseed oil used as liquid (FXL), after encapsulation (FXE), and pre-emulsified with alginate (FXA) and soy protein isolate (FXI). During production and storage, similar pH values of all products were observed. FXL sausages had significantly lower (p<0.05) weight loss which led to significantly higher moisture content, significantly lower fat content, hardness and chewiness. Also, FXL sausages had the lowest grades in terms of sensory attributes, such as colour, odour, taste, texture and overall acceptability. Flaxseed oil preparations affected the parameters of instrumental colour analysis of sausages. All modified products had significantly higher yellowness (relative to control) and FXI sausages relative to other modified products. Regarding consumer sensory evaluation, FXA sausages stood out among modified products because all other modified products had significantly lower grades relative to control. The thirty-day storage period did not lead to significant changes (p>0.05) in any of the observed sensory characteristics.

Canned sea fish marketed in Serbia: their zinc, copper, and iron levels and contribution to the dietary intake

Abstract The aim of this study was to determine the levels of Zn, Cu, and Fe in three canned fish species marketed Serbia to see if they meet recommended daily intake requirements or exceed safety limits. We collected a total of 207 samples of canned tuna, sardine, and mackerel, in oil or tomato sauce and analysed them with inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. The highest levels were obtained for Zn (15.1 mg kg-1) and Cu (1.37 mg kg-1) in sardine in oil and tomato sauce, respectively, and for Fe (18.98 mg kg-1) in mackerel in tomato sauce. Our results keep within the ranges reported by several national food databases and available literature data, with a few exceptions. Our findings also single out canned sardines as the richest source of the three essential elements combined. The estimated daily intake (EDI) of the three essential elements, however, was subpar, and ranged between 0.14 % and 0.72 % of the recommended dietary allowance (RDA) for Zn, Cu, and Fe.

Comparison of results of sensory and chemical and physico-chemical investigations of fresh chilled beef packaged in vacuum during storage in retail conditions

Vacuum packaging of fresh meat can contribute to prolonged shelf-life, slower chemical changes in meat, and maintaining of desirable sensoric properties. The main goal of this work was the comparative examination of sensory and chemical properties relevant for oxidative and hidrolytic changes of cooled fresh beef cuts (m.quadriceps femoris) in vacuum packaging, and the determination of interdependence of hydrolytical and oxidative changes regarding to sensory characteristics. The beef flank cuts taken from primal cuts (quarters) of 3 Simmental steers (average weight of 400 kg; one steer per testing cycle) after slaughtering, dressing and cooling were taken for the experiment. Cutting and packaging in vacuum thermo-shrinkable multilayered bags was performed in the industrial meat establishment, within 40 hours after slaughtering. The vacuum packaged beef cut samples were stored under controlled temperature conditions (0-2°C) in refrigerated retail show case. During the night, samples were removed from show case and stored in cold storage room in the same establishment (0-4°C). This method was repeated as daily routine during examination period. Sensory and chemical examination dynamics was set as: day 1 (immediately after packaging), days 15, 21 and 28 in each particular testing cycle (3). Sensory properties were evaluated by using quantitative-descriptive test, on a scale of 1 to 5. The following properties were evaluated: appearance of meat, the colour of meat surface, the colour of meat intersection, structure, texture, smell of the fresh meat, smell of the meat after cooking, taste of the meat after cooking and roasting. The examined chemical properties indicating oxidative and hydrolytic changes were: acid value, peroxide number, TBA test (test with thiobarbituric acid to determinate malonaldehide content), TVB-N (total volatile basic nitrogen), aw (water activity value) and pH. Sensory and chemical qualities of vacuum packaged beef flank under established storage conditions were acceptable in all three testing cycles, ending with the 21st day. In the first and second cycle, in most cases, there were confirmed medium to strong correlations of all examined chemical parameters with the sensoric characteristics of beef. In the third cycle, the registered above mentioned correlations between chemical parameters and sensory properties were classified as negative weak correlations.

Study of antimicrobial activity of cinnamaldehyde and carvacrol against foodborne microorganisms

Aim of the paper was to study antimicrobial activity of cinnamaldehyde and carvacrol at different concentrations on the panel of 12 selected and characteristic food pathogens and spoilage microorganisms. Cinnamaldehyde and carvacrol were diluted in a set of lipophilic and hydrophilic diluents down to concentrations of 0.5%, 1%, 2% and 3%, respectively. Suspensions of the test microorganisms were diluted down to 1 McFarland turbidometric unit and 0.1 mL of prepared inoculum was surface inoculated on tryptic soy agar. After absorption of inoculum, a nanofybrillic cellulose disc has been applied at the center of the each Petri dish and 32 μL of respective dilution of cinnamaldehyde and carvacrol was pipetted. After subsequent incubation, radius of inhibition zone for each tested microorganism had been measured. Results of the study indicated that the strongest inhibitory effect of cinnamaldehyde occurred in C. perfringens (5.29-20.60 mm), E. faecalis (8.28-19.40 mm) and L. sakei (4.80-11.10 mm) even at the lowest concentration (0.5%). S. cerevisiae proved to be absolutely resistant at all concentrations tested. Faecal Enterobacteriaceae contaminants (E. coli, E. coli O157:H7, P. mirabilis and S. Typhimurium) have also been quite inhibited, while the difference of E. coli inhibition zones (0,00-5.40 mm) compared to those of S. Typhimurium (0.86-6.93 mm) were not statistically significant (p = 0,910). Strain of enterohaemorrhagic E. coli (O157:H7) exhibited statistically significant wider zone of inhibition when being compared with nonpathogenic E. coli (p = 0.037) at all concentrations tested. When it comes to spoilage-related microbiota, B. thermosphacta and P. aeruginosa, there were no growth inhibition at 0.5% of cinnamaldehyde. However, at concentration range from 1% to 3%, B. thermosphacta has been more strongly inhibited (p = 0.0048) than P. aeruginosa (2.20-6,98 mm versus 0.32-1.48 mm, respectively). Regarding antimicrobial activity of cinnamaldehyde to L. monocytogenes and S. aureus, both microorganisms were inhibited, where as S. aureus was statistically significantly inhibited than L. monocytogenes (p = 0.0248). The most potent inhibition on growth carvacrol exhibited on S. aureus (7.24-15.10 mm) and L. sakei (5.23-9.32 mm). S. cerevisiae and P. aeruginosa were absolutely resistant to it. E. faecalis and L. monocytogenes were resistant at concentration range from 0.5%-2%, while the inhibition zone at 3% was minimal (2.09 mm and 1 mm, respectively). P. mirabilis and S. Typhimurium were inhibited at 2% and 3%, respectively and there was no statistically significant difference in radius of inhibition zones (p = 0.412), while absolute values of inhibition radius were as similar as those of E. faecalis and L. monocytogenes (1.21-2.80 mm and 1.56-3.38 mm, respectively). E. coli and E. coli O157:H7 were resistant at 0.5% and 1% carvacrol, respectively, whereas there was no statistically significant difference in radius of inhibition zones which occurred at 2% and 3% (p = 0.254). Food-spoilage microbiota, B. thermosphacta and C. perfringens were sensitive to carvacrol starting at 1%. B. thermosphacta had throught all concentrations tested, wider and statistically significant inhibition zones compared to C. perfringens (p = 0.0112). These results establish starting point for experimental application of the natural antimicrobial additives in active food packaging.

Perception of salty taste and preference to sodium chloride.

Sodium chloride is the main food additive contributing to salty taste. It also has preserving effect and participates in acquiring desirable textural characteristics and properties of the food. Main role of sodium in human organism is presented in this paper, as well as mechanisms of the regulation of sodium metabolism and negative effects of excessive intake of sodium. Excessive sodium intake is one of the causes of essential hypertension as direct risk of myocardial infarction, left ventricular hypertrophy, clinical and idiopathic edema, reduced elasticity of blood vessels, proteinuria, risk of coronary and kidney disease, risk of stomach cancer, incidence of renal celluloses, decreased bone density, exacerbation of asthma attacks, increased insulin resistance and incidence of obesity. Also, in this paper, development of the sense of taste is presented, neural regulation of the taste for salt, as well as development of preference to salt occurring in early childhood and transmitted through adolescence to adulthood, which may have lifelong implications. Reduced intake of salt, compared to usual intake available through food, can have long lasting effects and at the same time, it can develop the sense of taste in children in a way that they consume food with less sodium chloride as adults. Studies in this field are very limited, but it is important to point out that exposure to salt in the early years of life greatly determines the preference to salt in the adulthood, which is important from the aspect of, either preservation, or health impairment, depending on the sodium intake.