Supplemental linseed oil and antioxidants affect fatty acid composition, oxidation and colour stability of frozen pork

The aim of this study was to evaluate the influence of dietary linseed oil and antioxidants on the quality of fresh and frozen pork neck stored at -20 °C for six and 12 months. Polish Landrace x Duroc pigs were fed a standard diet (C), a diet supplemented with 3% linseed oil (L1), or a diet with 3% of linseed oil, 1 mg organic selenium (SE)/kg, and 100 mg vitamin E/kg (L2). Chemical components, fatty acid profile and vitamin E content were determined in the fresh meat. Colour, pH and change in the profiles of certain volatile compounds (alcohols, aldehydes, ketones, and esters) were monitored during frozen storage. An electronic nose technique, which was based on ultra-fast gas chromatography, was used to evaluate changes in the profiles of the volatile compounds. After six months of frozen storage, oxidative processes were slower and similar in groups L1 and L2, but less so in meat from C. In pork that was stored for six months, lipid oxidation was not affected by supplementation only with linseed oil (L1). After 12 months of frozen storage, a reduced rate of increase in alcohols, aldehydes and ketones was observed in pork from L2 relative to L1 and C. Lipid oxidation processes in long-stored frozen pork neck were inhibited by the addition of antioxidants to L2. However, a total colour change (ΔE*) of the pork from L1 and L2 was found during storage, which might influence consumers’ decisions to purchase the product.Keywords: colour, fatty acids, freezing, meat quality, volatile component

Wplyw nawozenia mineralnego i biohumusu na zawartosc niektorych skladnikow mineralnych w warzywach

In a pot experiment lettuce and carrot were cultivated. Lettuce was sown twice in a vegetative period. Both plants were fertilized with biohumus at rates of 5,10, 15, 20% in relation to soil mass. The rates of mineral fertilizers used to lettuce pots were: 0.5, 1.0, 1.5 and 2.0 g N; 0.22 g P, and 0.42 g K, and the rates applied to carrot pots were 0.5 g N, 0.22 g P and 0.42 g K. The contents of total nitrogen in lettuce and carrot increased according to the increase of fertilizer doses. Carrot fertilized with mineral fertilizers and biohumus showed increased K and Na contents at invariable P; Ca and Mg contents. The P, K, Ca and Na concentration was higher in the lettuce cultivated in autumn than in the spring. Fertilizing with biohumus increased the sugar contents in both cultivated plants. Lettuce cultivated in spring contained higher a mount at sugars than the lettuce cultivated in autumn.W doświadczeniu wazonowym uprawiano sałatę, którą wysiano dwukrotnie w sezonie wegetacyjnym, oraz marchew. Pod obydwie rośliny stosowano 5,10,15, 20% biohumusu w stosunku do masy gleby. Nawozy mineralne stosowano pod sałatę w dawkach: 0,5, 1,0, 1,5 i 2,0 g N; 0,22 g P i 0,42 g K. Zawartość azotu ogólnego w sałacie i marchwi wzrastała w miarę wzrostu nawożenia. Nawożenie marchwi nawozami mineralnymi i biohumusem powodowało wzrost zawartości K, Na, natomiast nie miało większego wpływu na wzrost zawartości P, Ca i Mg. Koncentracja P, K, Ca i Na była wyższa w sałacie uprawianej w terminie jesiennym niż wiosennym. Nawożenie biohumusem wpłynęło na wzrost zawartości cukrów w obu uprawianych warzywach. Sałata uprawiana w terminie wiosennym zawierała większe zawartości cukrów aniżeli sałata uprawiana jesienią

The influence of mineral fertilization and biohumus on some soil properties

Celem badań było określenie wpływu nawożenia mineralnego i biohumusem na niektóre właściwości gleby po uprawie rzodkwi i sałaty.Doświadczenie wazonowe przeprowadzono na glebie brunatnej. Zastosowane nawożenie mineralne wynosiło w przeliczeniu na wazon w ilości 0,5, 1,0, 1,5 i 2,0 g N oraz 0,22 g P i 0,42 g K. Biohumus zastosowano w przeliczeniu na wazon w ilości 5, 10, 15 i 20% w stosunku do masy gleby. Na podstawie oznaczeń właściwości chemicznych gleby po sprzęcie roślin stwierdzono, że nawożenie mineralne nie miało większego wpływu na zawartość oznaczonych składników w glebie. Nawożenie biohumusem wpłynęło na wzrost pH gleby, zawartość węgla i azotu ogólnego oraz zwiększyło zawartość fosforu przyswajalnego.A pot experiment was conducted in a greenhouse. The test plants were radish and lettuce. The growing medium was a IV class soil of good rye complex. This was a brown soil formed from light loamy sand. Mineral fertilizers were applied at the rates of 0.5 to 2.0 g per pot. Biohumus was added at rates 5, 10, 15 and 20% relatively to the weight of soil. On the basis of chemical analyses after plant harvest, it was found that mineral fertilization did not markedly influence the contents of estimated soil elements. Fertilization with biohumus increased soil pH, as well as the contents of C, total N and available forms of phosphorous and magnesium in soil