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Wroniak M.,Katedra Technologii Zywnosci
Zywnosc. Nauka. Technologia. Jakosc/Food. Science Technology. Quality | Year: 2012

The objective of the study was to assess the quality and nutritional value of cold-pressed rapeseed oils on the basis of fatty acid composition and content of tocopherols and sterols. The scope of the study comprised the pressing of oil from rapeseed in an expeller under laboratory conditions, the analysis of quality and chemical composition of pressed oils, and comparing them with other commercial cold pressed and refined oilss. The following basic quality parameters of the oil samples were determined: acid value, peroxide value, anisidine value, Totox index, and oxidative stability in the Rancimat test at a temperature of 120 °C. The composition of fatty acids was analyzed, as were the composition and contents of tocopherols and sterols The cold-pressed rapeseed oils produced under laboratory conditions as well as other commercial oils were characterized by a high quality and a diverse oxidative stability (induction time from 3.82 to 7.32 h). The high nutritional value of rapeseed oils was confirmed owing to the optimal composition of fatty acids, i.e.: the high content of unsaturated fatty acids from 92.6 % to 93.1 %, the low content of saturated fatty acid from 6.7 to 7.3 %, and the optimal ratio of n-6 to n-3 acids, 2.1:1 on average. The oils did not contain trans-fatty acids except for the refined oil (0.8 %). Moreover, all the oils tested proved to be a valuable source of both the tocopherols from 44.82 to 57.60 mg/100 g and the sterols from 547.06 to 676.25 mg/100 g.

The objective of the study was to assess the effect of partial substitution of pork jowl with a mixture of plant oils (replacement rate: 20 % or 40 %) in the composition of chicken burgers recipe, as well as of the addition of inulin (1%) or wheat fibre preparation (2 % or 3 %) on the quality of final product. It was found that the applied modifications in the recipe composition caused the thermal processing yield to significantly differ and the fat content in the burgers to decrease. All types of the burgers produced were highly positively assessed as regards their sensory properties, and significant differences were found only in the juiciness assessment scores. Despite significant differences in the shear force of products, measured using an instrumental method, the differences between sensory assessment results of the hardness of individual burger types were statistically insignificant. Based on the analysis results of fatty acid composition, it was confirmed that the addition of plant oils favoured the improvement of the nutritional value of fat contained in the product. The results obtained indicate that as regards the recipe of chicken burger, it is possible to replace 20 % of pork jowl with plant oils, and, at the same time, to add a selected dietary food preparation such as inulin or wheat fibre.

Changing preferences of consumers are the main reason why scientists and food manufacturers have been searching for new concepts and directions in the food product development. In this paper, the applications were presented of high pressure technology to manufacture convenience food from poultry meet in order to guarantee its safety and high quality. In the case of meat products designated as a convenience food type, the food preservation method using a high hydrostatic pressure seems to be an interesting techniqueto prolong their shelf life; in particular, this refers to the tightly packed products since the secondary contamination thereof during their portioning or slicing is quite possible. Owing to the improper technological treatment, cross-contaminations, or improper storing, pathogenic micro-organisms can develop in this kind of products, especially in those made from poultry meat. Such pathogens are extremely dangerous for people with a decreased immunity, children, the elderly, and pregnant women. In addition, the high pressure processing can be applied to inactivate those human health threatening pathogens.

Marciniak-Lukasiak K.,Katedra Technologii Zywnosci | Zbikowska A.,Katedra Technologii Zywnosci
Zywnosc. Nauka. Technologia. Jakosc/Food. Science Technology. Quality | Year: 2013

The objective of the research study was to determine the impact of the type of frying medium and of the frying parameters of instant noodles onto their quality. The scope of the research covered the assessment of the quality of frying medium and instant noodles produced. A mixture of palm olein and rapeseed oil, their proportion being 1:1, was used for frying. In the frying medium, the parameters of fat were measured: acid value, peroxide value, and content of polar compounds. Moreover, the composition of fatty acids (FA) was analyzed quantitatively and qualitatively using a gas chromatography method. In the end product produced, measured were the moisture, fat content, colour, and hydration time of the noodles. Based on the results obtained, it was found that both the type of frying medium and the heat treatment parameters impacted the quality of instant noodles. The frying temperature caused the moisture and fat content to differentiate. Its growth caused the fat content to increase and, at the same time, the moisture of the product to decrease. The increase in the length of frying time by 50% did not impact the moisture, fat content, and colour brightness of the end products under analysis. Thus, the frying time had no statistically significant impact on the above named quality parameters of the end products under analysis (p = 0.05).

The objective of the study was to determine the qualitative changes in black current nectars stored at 20 °C during a period of 1, 2, and 4 months with no access to light. Three variants of nectars were analysed: nectars without the additives, nectars enriched in an echinacea purpurea extract, and nectars enriched in a green tea extract. In the nectars analysed, the following contents were determined: total polyphenols, anthocyanins, L-ascorbic acid, and, also the antioxidant activity was determined. Immediately after the production, the nectars without the additives, as well as those enriched in the echinacea extract and in the green tea extract were characterized by the following antioxidant activity levels: 9.3 μmol Troloxu/ml, 11.8 μmol Troloxu/ml, and 16.3 μmol Troloxu/ml, respectively. In the same nectars, the content of anthocyanins was 89.7, 100.2, and 105.2 mg/100 ml, respectively, whereas the content of polyphenols was 96.3, 110.1, and 124.2 mg/100 ml, respectively. It was found that during the 4 months of storage the content of total polyphenols, anthocyanins, and vitamin C decreased in all nectars, and this decrease caused the antioxidant activity to fall. After the 4 month storage, the content of anthocyanins in the nectars was 70% lower compared to the initial samples.

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