Wydawnictwo
Uniwersytetu Przyrodniczego w Poznaniu

WYKAZ SKRÓTÓW I SYMBOLI

1. WSTĘP

2. CEL I ZAKRES PRACY

3. MATERIAŁ I METODY BADAŃ
3.1. Materiał badany
3.2. Metody badań
3.3. Analiza statystyczna

4. WYNIKI BADAŃ I DYSKUSJA
4.1. Tłuszcz roślinny w produkcji wędliny podrobowej typu pasztetowa jako składnik wpływający na jakość
4.2. Wpływ przeciwutleniaczy na jakość i trwałość wędliny podrobowej typu pasztetowa
4.3. Wpływ dodatku wodnego ekstraktu z liści morwy na jakość prozdrowotną modelowych wędlin podrobowych typu pasztetowa

5. PODSUMOWANIE

6. STWIERDZENIA I WNIOSKI

LITERATURA

Introduction. Offal products such as liver pâté are susceptible to oxidation processes due to the high fat content. Stages of the production process, such as the grinding and mixing of meat ingredients, high temperature during thermal processing as well as cold storage also significantly determine the oxidation of fats because these processes stimulate the formation of free radicals. Oxidation products adversely affect the taste, smell and texture of finished products and they significantly reduce their nutritional value. The oxidation of lipids can be limited by using additives. Therefore, the aim of the study was to assess the oxidative stability and sensory quality of liver pâté, where animal fat was partly replaced with vegetable oil and natural antioxidants were added.

Material and methods. The research was conducted on offal products such as liver pâté, where animal fat was partly replaced with vegetable oil and natural antioxidants were added. The products were characterised in terms of their content of fatty acids. During storage the content of primary and secondary fat oxidation products was measured periodically.

The samples were also subjected to sensory evaluation. The meat products with an aqueous mulberry leaf extract were also characterised for the inhibition of cholinesterase and angiotensin converting enzyme. Their microbiological quality was also assessed.

Results. The research showed that the partial replacement of animal fat with vegetable oils resulted in products characterised by high sensory attractiveness and oxidative stability. In comparison with the samples containing linseed oil, maize oil, sunflower oil or soybean oil, the samples with rapeseed oil were characterised by the highest oxidative stability and the most favourable n-6 to n-3 fatty acids ratio, which was similar to nutritional recommendations. On average, the content of α-linolenic acid in these products was 8 times greater than in the samples with corn or sunflower oil. The research showed that the addition of natural antioxidants, such as lactic acid, sodium lactate, rosemary extract, mulberry leaf and yellow tea extract to the liver pâté and the replacement of 20% of fine animal fat with rapeseed oil, increased the stability of the fat fraction in the experimental products.

Among the antioxidants under study, the water mulberry leaf extract was the most effective inhibitor of the increase in the peroxide value and the TBARS index in the experimental meat products during their storage. Apart from that, the samples with the water mulberry leaf extract were characterised by better sensory quality. The extract increased the content of flavonols and phenolic acids, especially chlorogenic, caffeic, vanillic and gallic acids, as well as the content of rutin and quercetin in the processed meats. The water mulberry leaf extract inhibited AChE more than BChE. The extract also inhibited the activity of angiotensin I converting enzyme, which depended on the concentration of the extract in the sample.

Conclusions. The partial substitution of fine animal fat with rapeseed oil enriched the liver pâté products with unsaturated fatty acids (MUFA+PUFA). The resulting products with higher content of unsaturated fatty acids meet the requirements for functional foods. The addition of the water mulberry leaf extract, which is rich in bioactive compounds such as polyphenols, to the experimental meat products resulted in products which can be a new group of foods with targeted health-promoting effect.