SPME-GC-MS and Multivariate Analysis of Sensory Properties of Cheese in a Sack Matured with Probiotic Starter Cultures

RESEARCH BACKGROUND

Cheese in a sack is a traditional cheese produced in Croatia. Types of cheese with similar production technology are made in other countries but chemical and microbiological composition varies between regions. Traditionally, cheese in a sack is produced without the addition of starter cultures. Addition of beneficial probiotic cultures to numerous dairy products has documented advantages. Effects that the addition of probiotic bacteria to traditional cheese have on aroma compounds and sensory properties have not been fully investigated. The aim of this study is to determine the sensory properties and differences in the aromatic profiles between cheese samples ripened in a lambskin sack, produced traditionally without the addition of any starter culture, or with the addition of probiotic bacteria.

EXPERIMENTAL APPROACH

In this study, cheese in a sack was produced with the addition of probiotic cultures Lactobacillus plantarum B and L. lactis ssp. lactis S1. During ripening volatile aroma compounds were analysed with a solid-phase microextraction gas chromatography-mass spectrometry. Sensory properties were evaluated by trained tasters who are familiar with the traditional taste of the cheese from a sack. The results of aroma composition and taste scores were then compared using factorial and principal component analyses.

RESULTS AND CONCLUSIONS

Chromatography showed differences in the composition of aroma compounds and the sensory properties between the cheese produced with Lactobacillus starter cultures and the control cheese, traditionally produced without a starter culture. The addition of probiotic cultures L. plantarum B and L. lactis ssp. lactis S1 resulted in products with better sensory properties and chemical profile of volatile aromatic compounds.

NOVELTY AND SCIENTIFIC CONTRIBUTION

This study investigates the usage of naturally present probiotic cultures as starter cultures in cheese in a sack production. Their effects on aroma profiles and sensory characteristics have been compared for the first time using factorial and principal component analyses.

The Lipid Composition of Subcutaneous Adipose Tissue of Brown Bears (Ursus arctos) in Croatia

The composition of adipose tissue in brown bears (Ursus arctos) is highly variable and depends on an individual's feeding habits. Fatty acid composition of subcutaneous adipose tissue (SAT) may provide insight into brown bear feeding habits, for which data are scarce. The aim of this study was to determine the lipid composition of SAT and variations in the composition of fatty substances with regard to gender and to assess SAT relative to season and body mass (BM) of brown bears in Croatia. Seventy-six tissue samples of brown bear SAT were analyzed in this study. We found that gender, season, and BM significantly affected the lipid composition of SAT. Both females and males had higher percentages of saturated fatty acids and monounsaturated fatty acids (MUFAs) in SAT in spring than in autumn, while the percentage of polyunsaturated fatty acids (PUFAs) was higher in autumn. The prevalence of MUFAs in SAT and the greater presence of PUFAs in autumn, together with the presence of odd-chain saturated fatty acids, indicate the importance of these fatty acids in brown bear physiology. We suggest that the lipid content of adipose tissue may provide valuable information on changes in brown bear condition in response to feeding habits and the effects of supplemental feeding.

Oxidative status and the severity of clinical symptoms in patients with post-traumatic stress disorder

BACKGROUND

The aim of this study was to measure the parameters of oxidative stress in the blood of patients with post-traumatic stress disorder.

METHODS

The study included 80 male war veterans who participated actively in the Homeland war in Croatia. Volunteers were divided into two groups: 50 veterans diagnosed with post-traumatic stress disorder and 30 without diagnosis. The self-assessment Hospital Anxiety and Depression Scale and the Beck Depression Inventory were used to detect the severity of depression and anxiety in the post-traumatic stress disorder patients. Catalytic concentrations of superoxide dismutase and glutathione peroxidase in erythrocytes and the concentration of malondialdehyde in serum were measured spectrophotometrically.

RESULTS

Although the catalytic concentrations of erythrocyte superoxide dismutase and erythrocyte glutathione peroxidase were within the reference range for both groups, the values obtained for the post-traumatic stress disorder group were significantly lower (P<0.001). For serum malondialdehyde concentrations, no statistically significant differences between the groups were found.

CONCLUSIONS

Lower catalytic concentrations of erythrocyte superoxide dismutase and erythrocyte glutathione peroxidase in patients with post-traumatic stress disorder may indicate a weaker response to oxidative stress due to impaired enzyme activity and/or decreased synthesis. Conversely, no significant changes in serum malondialdehyde concentrations suggest a compensated balance and adaptive response to (oxidative) stress.

Eicosapentaenoic acid in serum lipids could be inversely correlated with severity of clinical symptomatology in Croatian war veterans with posttraumatic stress disorder

AIM

To explore the association between plasma fatty acids composition and the severity of clinical symptoms in Croatian war veterans with posttraumatic stress disorder (PTSD).

METHODS

This cross-sectional study included 62 men diagnosed with PTSD caused by combat activities during the War in Croatia 1991-1995. Clinician-Administered PTSD Scale (CAPS), Hamilton Anxiety Rating Scale (HAM-A), and Hamilton Depression Rating Scale (HAM-D-17) were used. Plasma fatty acids composition was determined by gas chromatography. Data about life-style habits were collected by a structured interview. To evaluate the association between plasma fatty acid levels and PTSD severity scales, multivariate general linear models (GLM) were applied while controlling for different confounders.

RESULTS

Significant negative correlations were found between plasma eicosapentaenoic acid (EPA, 20:5n-3) level and the scores on psychological scales (τ = -0.326, P<0.001 for CAPS; τ-0.304, P =0 .001 for HAM-A; and τ = -0.345, P<0.001 for HAM-D-17). GLM confirmed that PTSD severity was affected by EPA (Wilks'Λ = 0.763-0.805, P = 0.006-0.018, ηp 0.195-0.237), arachidonic acid (AA)/EPA (Wilks'Λ = 0.699-0.757, P = 0.004, ηp 0.243-0.301), and dairy products consumption (Wilks'Λ = 0.760-0.791, P = 0.045-0.088, ηp 0.128-0.111). No other fatty acid or dietary/lifestyle variable was significant ( P = 0.362-0.633).

CONCLUSION

The study suggests that lower EPA levels are associated with the severity of clinical symptoms in PTSD.

Effect of non-protected sunflower oil supplementation on milk fatty acid profile and oxidative status in Simmental cows

Abstract. Milk production, milk composition, milk fatty acid profiles, and antioxidant status of Simmental cows supplemented with non-protected sunflower oil were studied. Ten Simmental cows in mid-lactation were appointed for change over feeding trial with one of the diet applied: the control (WSO) diet consisted of 26 % corn silage, 33 % perennial ryegrass haylage, and 41 % concentrate in dry matter (DM), and the experimental diet (SO) consisted of control diet supplemented with 2 % of unrefined sunflower oil per cow and day. The cows were kept in indoor housing system with feeding and milking system two times daily and ad libitum water supply. The milk production and standard milk components remained unchanged during the study. The partial modification of fatty acid composition was remarked with the significantly higher linoleic and conjugated linoleic acid (CLA) (cis-9, trans-11 C 18:2) concentration and significantly lower palmitic acid during the SO treatment. The blood gluthathion peroxidase (GPx) activity significantly increased and the thiobarbituric acid reactive substances (TBARS) concentration decreased significantly in the SO treatment. The non-protected sunflower has a perceptible effect on the milk fatty acid composition in Simmental cows of our research. The lower index of lipid peroxidation and higher GPx activity in blood of cows during the SO treatment could be a consequence of the antioxidant components that are normally present in the unrefined vegetable oils. The enzyme activity reflects appropriate functioning of the antioxidant defence of cows that emphasise importance of well balanced diet during the unsaturated fatty acid supplementation.