Salmon (Salmo salar) Cooking: Achieving Optimal Quality on Select Nutritional and Microbiological Safety Characteristics for Ready-to-Eat and Stored Products

This study was performed in order to assess technological characteristics, proximate composition, fatty acids profile, and microbiological safety of sous-vide processed salmon in comparison with steaming and roasting. The cooking loss was lower in the sous-vide method (6.3-9.1%) than in conventional methods (11.6-16.2%). The preparation of salmon using sous-vide was more time- and energy-consuming than steaming. The dry matter content of the salmon fillets was higher in conventionally processed samples than sous-vide due to the evaporation of water, and it was connected with total protein (r = 0.85) and lipid content (r = 0.73). Analysis of the fatty acids profile only revealed significant differences in six fatty acids. All of the heat treatment methods ensured microbiological safety with regard to coagulase-positive Staphylococcus, E. coli, Listeria monocytogenes, and Salmonella spp. However, in sous-vide (57 °C, 20 min) and steamed samples after storage Enterobacteriaceae bacteria (<104) was detected. Summing up, high parameters of sous-vide salmon cooking, when considering both technological parameters, nutritional value, and microbiological status should be recommended.

Impact of green tea extract addition on oxidative changes in the lipid fraction of pastry products

BACKGROUND

Alongside flour, fat is the key ingredient of sponge cakes, including those with long shelf lives. It is an unstable food component, whose quality and nutritional safety depend on the composition and pres- ence of oxidation products. Consumption of fat oxidation products adversely affects the human body and contributes to the incidence of a number of medical conditions. Qualitative changes in fats extracted from thermostat sponge cakes with and without antioxidant additions were determined in this study.

METHODS

In the study, two types of antioxidant were used: natural - green tea extract in three doses (0.02%; 0.2% and 1.0%) and synthetic BHA (0.02%) and 100%, solid bakery shortening. Sponge-cakes were thermostatted at temperatures 63°C after twenty-eight days. In this study, the quality of the lipid fraction was analyzed. The amount of primary (PV) and secondary (AnV) oxidation products was determined, and   a Rancimat test was performed.

RESULTS

Adding antioxidants to fats varied in the degree to which oxidation processes of lipids fractions were inhibited. The peroxide value after twenty-eight days of thermostatting ranged from 3.57 meq O/kg (BHA) and 11.14 O meq/kg (extract content - 1%) to 62.85 meq O/kg (control sample). In turn, the value of AnV after the storage period ranged from 4.84 (BHA) and 6.71 (extract content - 1%) to 16.83 (control sample).

CONCLUSIONS

The best protective effects in the process of oxidation was achieved by BHA. The longest in- duction time and the lowest peroxide value and anisidine value were obtained for this antioxidant. It was achieved after twenty-eight days of fat thermostatting. Nonetheless, the results demonstrated it is possible to use the commercially available green tea extract to slow the adverse process of fat oxidation in sponge cake products.

Comparison of Fatty Acid Composition of Milk from Simmental and Polish Holstein-Friesian Cows in Different Production Seasons

The aim of this study was to determine the fatty acid (FA) profile of Simmental cow milk in relation to lipid intake in feeds and their composition, and to compare it with FA composition of milk from cows of Polish Holstein-Friesian (PHF) breed. To this end, 104 milk samples were collected from Simmental cows and 52 milk samples derived from PHF breed were taken over a 2-year period. The season significantly influenced both contents of lipid, dry matter and crude protein as well as FA content in lipids extracted from forages. Winter and autumn seasons were characterized by a significantly higher intake of lipids with forages resulting from the intake of fresh silages, compared with the other seasons when the animals were fed stored silages. This was reflected in the highest content of conjugated linoleic acid (CLA) c-9 t-11 C18:2 in milk from the autumn season. Compared with PHF, milk from Simmentals had a higher content of short-chain saturated FAs (SCSFAs) and was characterized by great differences in FA contents determined in the group of odd- and branched-chain FAs (OBCFAs). Milk from Simmental cows had the butyric acid C4:0 and iso C15:0 content of 4.99 and 1.20 g/100 g FA on average, respectively, which have been associated with benefits for human health.

[The importance of γ-linolenic acid in the prevention and treatment]

The etiology of diet-related disorders is closely associated with dietary factors. A special role is attributed to intake of fat and fatty acid profile, both quantitative and qualitative. For prevention and treatment of the abovementioned diseases a proper supply of unsaturated fatty acids plays a significant role, because of their particular importance to health. γ-Linolenic acid (GLA), with three double bonds in the carbon chain, also known as all-cis 6,9,12-octadecatrienoic acid, belongs to the n-6 family of fatty acids. It plays biologically important functions in the human body, such as being a substrate for eicosanoids synthesis, involvement in the transport and oxidation of cholesterol, and being one of the components of lipid membrane. Its inadequate dietary intake or impaired formation is the cause of many inflammatory and degenerative diseases. A rich source of this fatty acid is vegetable oils, until recently used mainly in folk medicine. Nowadays, studies conducted both in animal models and in humans suggest its health-promoting properties in the prevention and treatment of atopic dermatitis, cardiovascular diseases, diabetes, cancers and rheumatoid arthritis.

Consumption Safety of Pastries, Confectioneries, and Potato Products as Related to Fat Content

STUDY AIM

To determine the content of the main groups of fatty acids in pastries, confectionery, and potato products, paying special attention to trans fatty acids and the products of fat oxidation and hydrolysis, as factors affecting the safety of consumption.

METHODS

A total of 157 products were collected in Poland in 2009-2010. In fats extracted from samples, products of oxidation and hydrolysis were assayed using peroxide (PV), anisidine (AnV), and acid (AV) values. The fatty acid (FA) composition, especially the trans FAs (TFAs) content, was determined by gas chromatography. When assessing the TFA intake, Household Budget Surveys were considered.

RESULTS

Highest content of fat was found for wafers with filling and crisps (32.3% and 29.3%, respectively). In 4 out of 9 groups of pastry and confectionery products studied, the quality of fat was decreased due to an excessive oxidation, as evidenced by a substantial content of secondary products of fat oxidation. The extracted fat was rich in SFA (on average, 50 g SFA/100 g FA) except fries and mixes. A great diversity of TFA content in fat of the products was found (0.1-24.8 g TFA/100 g FA). Wafers were characterized by the highest average content of TFA in the group of pastries (1.94 g TFA/100 g of product). Products of natural origin supplied 0.496 g of TFA per day, and those of industrial origin supplied about 1.5 g.

CONCLUSIONS

The average TFA consumption, about 2 g/day, does not seem to affect health. However, an excessive consumption of pastry and confectionery products may present a risk, due not only to TFA but also to a high consumption of toxic secondary oxidation lipid products. Moreover, because 75% of TFAs in the diet were isomers of industrial origin, their further limitation and monitoring of their level in food seems highly recommendable.

Effects of replacing extracted soybean meal with rapeseed cake in corn grass silage-based diet for dairy cows

The aim of the study was to assess the effects of partial replacement of soybean meal with a protein-equivalent amount of rapeseed cake in the diet on milking parameters and fatty acid (FA) composition of milk in dairy cows. Two groups of Holstein-Friesian cows, 8 each, consisting of randomised blocks were studied: a control group (C) was given a traditional high-protein supplement (extracted soybean meal) and the experimental group (E), had part of extracted soybean meal replaced with rapeseed cake. Dry matter intake and milk yield in both groups were not affected by the diet but milk fat percentage and yield were decreased in both groups. Rapeseed cake had no effect on milk acidity or on protein (including casein) and lactose contents. A lower concentration of urea in milk in E group indicated a proper ratio of protein to energy in the fodder. Health condition of mammary gland and indicators of metabolic profile were not affected by rapeseed cake supplementation. In E group, the share of atherogenic saturated fatty acids (FA) was reduced after 11 weeks: palmitic, by 26% and myristic, by 22%; moreover, as compared with control cows, the content of monounsaturated FA in milk increased by 44% after 3 weeks and by 68% after 11 weeks, t-18:1 and c-9 t-11 isomer of CLA increased about 2.5-fold after 11 weeks. In E group, the atherogenic index (AI) was significantly (P < 0.001) lower than in C (by 54% on average) and the decrease with time was considerable (by 29%, P < 0.001). Contents of odd- and branched- chain FA in milk were not significantly affected thus reflecting proper rumen function. Partial replacement of soybean meal with rapeseed cake in the diet of cows may improve both milking indices and FA profile of milk.

Rapid increase in the incidence of type 1 diabetes in Polish children from 1989 to 2004, and predictions for 2010 to 2025

AIMS/HYPOTHESIS

We analysed the temporal changes in the incidence of childhood type 1 diabetes and its demographic determinants in Poland from 1989 to 2004, validating the model with data from 1970 to 1989. We also estimated a predictive model of the trends in childhood diabetes incidence for the near future.

METHODS

Children under 15 years with newly diagnosed type 1 diabetes mellitus and drawn from seven regional registries in Poland were ascertained prospectively using the Epidemiology and Prevention of Diabetes study (EURODIAB) criteria. The type 1 diabetes incidence rates (IRs) were analysed in dependency of age, sex, seasonality, geographical region and population density. Time trends in IR were modelled using several approaches.

RESULTS

The average incidence, standardised by age and sex, for 1989 to 2004 was 10.2 per 100,000 persons per year and increased from 5.4 to 17.7. No difference was found between boys and girls, or between urban and rural regions. In children above 4 years, IR was significantly higher in the population of northern Poland than in that of the country's southern part, as well as in the autumn-winter season, this finding being independent of child sex. Based on the trend model obtained, almost 1,600 Polish children aged 0 to 14 years are expected to develop type 1 diabetes in 2010, rising to more than 4,800 in 2025. The estimates suggest at least a fourfold increase of IR between 2005 and 2025, with the highest dynamics of this increment in younger children.

CONCLUSIONS/INTERPRETATION

These estimates show that Poland will have to face a twofold higher increase in childhood type 1 diabetes than predicted for the whole European population. The dramatic increase could have real downstream effects on Poland's healthcare system.

[Quality of the various vegetable oils available on the Polish market]

The aim of this work was the examination of the quality of 17 different vegetable oils (13 refined and 4 extra virgin olive oils) available on the domestic market. The quality of oils was expressed by the following factors: conformity of fatty acid composition that as declared by manufacturer, content of oxidation products (PV, AnV, Totox), content of free fatty acids (LK) and oxidative stability. It was found that 40% of oils did not comply with the requirements concerning oxidative stability. The fatty acid composition of only 1 oil out of 17 investigated did not comply with the declaration by manufacturer. The oxidative stabilities of extra vergin olive oils: 6.44-8.24 hrs., were considerably higher that of other refined oils 2.34 to 8.24 hrs.

[Quality of shortenings available on the home market]

The aim of this work was to examine the quality of shortenings available on Polish market, produced home or imported. The quality of twelve 100% vegetable fats and lard was estimated. Both chemical (fatty acids composition, especially trans isomers content, acid value, peroxide value, anisidine value, Totox, iodine value and oxidative stability--Rancimat test) and physical (melting point, solid fat content--at temperatures from 5 to 50 degrees C) properties were measured. The fats were subject to sensoric examination. The parameters defining the freshness of examined fats and their shelf life for all examined samples were good and proved the good quality. Induction time (150 degrees C) for examined fats varied from 1,79 to 4,29h. Examined fats differed significantly in saturated fatty acids content (from 14,0 do 60,2%) and trans isomers (from 0,1 to 56,6%). Fats produced from palm oil are also present and there are fats with smaller trans fat acids content. Examined shortenings contained very small content of essential fatty acids (from 0,5 to 10,4), and they showed very different melting points (from 19,6 to 42,1 degrees C) and solid phase contents. In general the examined fats were of good sensoric value. Summing up the received results, it should be underlined that large disparity in the content of trans isomers in analysed samples was observed and definitely TFA content should be lowered.