Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 34

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Attempts to work out a test for predicting the stability of Advocaat egg liqueurs revealed that centrifuging method appeared to be the most efficient in their quick destabilization. Measurements of conductivity, lipid droplet diameter as well as imbalance of emulsion with MgS04 addition may also be used as auxiliary indicators for evaluating the predicted stability of alcoholic egg emulsions. Making several tests at the same time is a condition for evaluation of credible liqueur stability time.
Celem pracy było określenie możliwości wykorzystania ekstraktów alkoholowych propolisu jako dodatku do wódek czystych i gatunkowych. Do badań użyto surowego propolisu i etanolowego wyciągu propolisowego. Propolis charakteryzuje się gorzkim, lekko piekącym smakiem, który uwydatnia się zwłaszcza w roztworach etanolowych. Po obróbce próbek (ekstrakcja, filtracja i obróbka termiczna) oznaczono suchą masę i wydajność ekstrakcji. Wyznaczono progowe zapachowe i smakowe stężenia propolisu. Stabilne ekstrakty propolisu użyto do zestawiania wódek z użyciem innych dodatków smakowych. Wykonane wódki poddano filtracji, dojrzewaniu i ocenie sensorycznej. Największą wydajność ekstrakcji surowego propolisu uzyskano stosując etanol o stężeniu 50-96% obj. Gotowe wyciągi spirytusowe, rozcieńczone do mocy ekstraktów surowego propolisu miały mniejszą zawartość suchej masy. Ekstrakty o wyższej mocy, od 50%, były klarowniejsze i stabilniejsze. Optymalnym czasem ekstrakcji było 5-6 godzin. Próg wyczuwalności zapachu i smaku określono na poziomie stężeń odpowiednio - w próbkach laboratoryjnych: 75 i 45 mg/l, w próbach handlowych: 100 i >50 mg/l. Ocena sensoryczna wykazała, że preferowane były wódki propolisowe słodkie, z dodatkiem morsu jarzębinowego i miodu pszczelego. Wódki (czyste i gatunkowe) zestawione z niewielkim dodatkiem przygotowanych wyciągów odznaczały się oryginalnym zapachem i specyficznym smakiem (tzw. nuta propolisowa).
Alcoholic emulsion creams are characterized with high viscosity and density, which makes the alcohol content and other physical and chemical parameters determination of products significantly difficult. Analytical methods applied for the determination of ethanol, are labor-consuming, they are characterized with low precision, require the sample distillation and the achieved results are mostly underestimated. On a base of comparison of various distillation techniques and determination methods, it can be stated that ethanol concentration measurements in alcoholic creams using pycnometric and DMA-58 density-meter after previous sample distillation (100 cm3 of cream + 200 cm3 of water), are distinguished with relatively high precision and result repeatability. Also applying the SPME extraction in gaseous phase along with chromatographic analysis seems to be advantageous. The method based on the refractometric measurement of toluene and benzene extracts of egg emulsions is characterized with short performance time, sufficient precision and very low costs.
Alkohol heksylowy i jego pochodne (związki C6 przyczyniają się do ostrego, trawiastego smaku oraz zapachu napojów alkoholowych. Prekursorem komponentów C6 jest kwas linolowy i linolenowy, które występują w zielonych częściach roślin, niedojrzałych owocach, warzywach i zbożach. Biokonwersja tych kwasów do odpowiednich aldehydów i alkoholi odbywa się przy udziale enzymów (lipooksygenaza, oksydoreduktaza alkoholowa i liaza aldehydowa), które zawarte są w surowcach roślinnych i mikroorganizmach. W celu zmniejszenia zawartości związków C6 w napojach alkoholowych należy eliminować z przerobu surowce niedojrzałe, zielone części roślin oraz ograniczyć napowietrzenie w czasie ich rozdrabniania. Dodatek SO2 oraz kwasu askorbinowego wpływa hamująco na tworzenie heksanolu podczas obróbki owoców, ich maceracji oraz fermentacji.
Celem artykułu jest przedstawienie zawartości związków polifenolowych w winach owocowych oraz zwrócenie uwagi na możliwość ich korzystnego wpływu na zdrowie ze względu na obecność aktywnych biologicznie składników. Najczęściej procesowi fermentacji poddawane są jabłka, wiśnie oraz owoce czarnej porzeczki i aronii. Wina jabłkowe i wiśniowe należą do produktów o średniej zawartości polifenoli, jednak są one bogatsze w te związki niż białe wina gronowe. Duży potencjał antyoksydacyjny mają napoje fermentowane z aronii i czarnej porzeczki. W winie aroniowym związki polifenolowe występują na poziomie zbliżonym do czerwonego wina gronowego. Równie wysoka zawartość polifenoli cechuje wina porzeczkowe.
The objective of the investigations performed was to assess the antioxidant properties of the seeds and peels of selected fruits. The antioxidant activity as well as total polyphenol and tannin content were determined. The results obtained revealed essential diversities of the analysed parameters among the material examined. The peels were characterized by higher ability to scavenge free radicals and higher polyphenols concentration than the seeds, particularly those of citrus fruits imported to Poland. The highest antioxidant activity was observed in the peels of the Šampion cultivar of apples and white grapes, and in the seeds of the Idared cultivar apples and oranges. Tannins play a meaningful role as antioxidants in grape, apple and goosberry fruits. The peels and seeds of various fruits, which are waste products in fruit and vegetable industry, may be a potential source of antioxidants
Addition of anti-oxidative agents into the liqueurs (particularly 0.1% tocopherol) contributes to the reduction of compounds responsible for the product’s colour (mainly carotenoids) determined by spectrophotometric means. However, applied modification does not completely inhibit the Advocaate’s browning during storage. Components formed during non-enzymatic browning, as a result of Maillard’s reaction, are the reason of liqueur’s negative colour change. An emulsion prepared from sodium soap, plant oil, distilled water and methyl orange may be a proper standard of egg liqueur colour
Alcoholic emulsion creams produced using hen’s egg yolks (Advocaats) are dense, sweet liqueurs that are characterised by specific sensoric traits satisfying a wide spectrum of consumers. Despite long tradition of liqueur production, the technology in use does not ensure their full uniformity, nor stability during long-term storage. The destabilization rate is determined by many factors, e.g. homogenization technique, temperature, aeration as well as the quantitative and qualitative composition of a solution. We demonstrated that enrichment of the creams with lecithin (0.3%) or sodium caseinate (0.2%) enabled the “full” five-month storage stability. Sodium caseinate addition caused a significant reduction in fat droplets size measured directly after homogenization, but did not inhibit the formation of larger agglomerates via droplets joining. It also resulted in the cream’s viscosity increase. Advocaats containing elevated lecithin rates were characterised by high resistance to coalescence regardless of the fact that their viscosity was similar to the control samples. Furthermore, the synergistic effect of lecithin and sodium caseinate on storage durability of alcoholic emulsion creams was observed. Samples enriched with both compounds simultaneously, were stable over the five-month storage period, with their lipid phase being more dispersed and the coalescence being slower than in the control. The dispersion to size below 20 μm prolonged the durability of the tested emulsions to a significant extent. The combined application of lecithin (0.1%) and sodium caseinate (0.1%) employed to improve cream stability during storage proved to be efficient in industrial scale samples. Moreover, it was found that pressure homogenization under industrial conditions caused higher (by about 20%) dispersion of lipid fraction in reference to a high-rotation laboratory homogenizer.
In the paper taxonomie classification, morphological characteristic and growth requirements of three little known plant species: Japanese quince (Chaenomeles japonica L), Cornelian cherry (Cornus mas L), Black mulberry (Morus nigra L.) are presented. The chemical constitution, pro-health properties and the most important technological parameters of those fruits are discussed as well as possibilities of their industrial treatment and utilization.
The main aim of the study was to evaluate the antioxidant activity and total polyphenol content in fifteen popular herbal products often used in treatment of various diseases. The studied material were, among others, chamomile flower head, oak bark, St. John’s-wort herb, hawthorn flower, dog rose and elder fruits, lingonberry leaf. Herbal extracts or infusions were prepared according to protocols provided by producer on the packaging. The highest antioxidant activity and polyphenols concentration were obtained for lingonberry leaves (725 mg Trolox/g d.w. and 109 mg catechin/g d.w., respectively). The oak bark, St. John’s-wort herb, and lime flower were also a very rich source of antioxidant compounds, independent of their typical therapeutic action. Several herbs, such as dog rose fruit, lose their antioxidant activity when prepared at home conditions.
Background. Style and pace of life make consumers more willing to reach for snack products. This group of processed food includes, among others, fruit chips. Due to the increasing incidence of diseases associated with the excessive exposure to free radicals foods enriched with antioxidant compounds, eg. polyphenols, can be introduced into the sale. Objective. The aim of the study was to use the fruit extracts for the production of apple chips with enhanced antioxidant activity. Material and methods. ‘Golden Delicious’ variety of apple fruit was used to produce chips. Apple chips were prepared by slicing, soaking in a sugar solution and pre-drying in a microwave oven. Chips were enriched with extracts prepared from fruits of chokeberry, five-flavor berry, Cornelian cherry, woodland hawthorn, goji berry, Japanese quince and cranberry microcarpa. For this purpose, pre-dried apple slices were soaked (5 min) in ethanolic extract of fruits and then dried to achieve a 5% moisture content. Chips were sensory evaluated and their antioxidant activity and total polyphenols content were determined. Results. All enriched apple chips were characterized by high antioxidant activity and a relatively high value of total polyphenols content. Chips soaked in extracts of five-flavor berry, cranberry and goji berry were characterized by the highest antioxidant potential. Samples obtained by using chokeberry and Cornelian cherry extracts showed the highest content of polyphenols. High sensory attractiveness of enriched chips was also showed. The chips with the addition of fiveflavor berry extract were exceptions. Their taste was not acceptable. Conclusions. Fruit extracts are a valuable material for chips enrichment. Taking into account all the analyzed differentiators, extracts of Japanese quince, goji berry and woodland hawthorn were found to be the best enriching additives. The chips soaked in extract of five-flavor berry, despite their high antioxidant activity, were disqualified due to very low score of sensory evaluation.
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Lotne zwiazki szescioweglowe w napojach alkoholowych

51%
Alkohol heksylowy i jego pochodne (związki C6) przyczyniają się do ostrego, trawiastego smaku oraz zapachu napojów alkoholowych. Prekursorem komponentów C6 jest kwas linolowy i linolenowy, które występują w zielonych częściach roślin, niedojrzałych owocach, warzywach i zbożach. Biokonwersja tych kwasów do odpowiednich aldehydów i alkoholi odbywa się przy udziale enzymów (lipooksygenaza, oksydoreduktaza alkoholowa i liaza aldehydowa), które zawarte są w surowcach roślinnych i mikroorganizmach. W celu zmniejszenia zawartości związków C6 w napojach alkoholowych należy eliminować z przerobu surowce niedojrzałe, zielone części roślin oraz ograniczyć napowietrzenie w czasie ich rozdrabniania. Dodatek SO2 oraz kwasu askorbinowego wpływa hamująco na tworzenie heksanolu podczas obróbki owoców, ich maceracji oraz fermentacji.
Celem pracy była ocena składu i właściwości owoców pigwowca japońskiego oraz derenia jadalnego. Oznaczono zawartość: suchej masy, ekstraktu, glukozy, fruktozy, błonnika, polifenoli ogółem oraz kwasowość ogólną i aktywność antyoksydacyjną. Stwierdzono, że owoce derenia jadalnego, w stosunku do owoców pigwowca japońskiego, charakteryzują się większą zawartością suchej masy, ekstraktu i cukrów prostych. Kwasowość pigwowca japońskiego i derenia jadalnego wynosiła odpowiednio 4,11 i 3,91 %. Oceniane owoce charakteryzowały się silnymi właściwościami antyoksydacyjnymi oraz dużą zawartością polifenoli.
The aim of the study was to assess the possibility of using different yeast biomasses for lead removal from aqueous solution. The material for the study comprised baker’s yeast (BY), spent waste brewer’s yeast (WBY), and fodder yeast (FY), which can be easily obtained as production waste. An amount of each yeast biomass (BY, FY, or WBY) that equals 0.1 g of dry weight was suspended in 100 cm3 of lead solution (concentration of 200, 500, or 1000 mg dm–3) and biosorption was carried out for 20, 40, 60, 90, 120, 240, and 300 minutes. The concentration of lead remaining in solution was determined using atomic absorption spectroscopy. The lead uptake by yeast biomass was calculated using the mass balance equation for the biosorbent and the results were fitted to the Langmuir isotherm model. The yeast biomasses were able to remove more than 90% of lead present in solution within 20 minutes. With BY biomass, it was possible to reduce the lead level below 1 mg dm–3 from the initial lead solutions of 200 and 500 mg Pb dm–3. The value of qmax and affinity parameter b, calculated for BY after 300 minutes of biosorption, were very high (1,250 mg Pb g–1 d.w. and 0.363, respectively). The best efficiency was achieved for BY when the initial concentration of lead was 500 mg dm–3. The final concentration of the metal (after 300 minutes of sorption) was 0.66 mg dm–3, which means that 99.86% of lead was removed from the solution by the biomass of baker’s yeasts.
The characteristic of cool climate arid recommended grapes variety are presented in the paper. Polish winemaking regions are presented with special attention focused on their location and suitability for viticulture.
The aim of the work was to evaluate the efficiency of extraction of compounds of high antioxidant potential from waste fruit pomace. In the experiments whole fruits and pomaces of apples, grapes and black chokeberries were used for maceration, extraction by Soxhlet method and percolation. Extracts prepared from pomaces of black chokeberries and grapes were characterized by significantly higher antioxidant potential than extracts obtained from the whole fruits. Among analyzed material, the black chokeberries pomace had the highest antioxidant activity. Relatively high antioxidants recovery was achieved by Soxhlet extraction. The most efficient solvent was 50% aqueous solution of acetone, however only slightly lower values were demonstrated for 50% solution of ethanol.
Relationship between the occurrence of selected metals in vineyard soil and their concentrations in fruits of the grapevine cultivated on this soil were studied. That issue is weakly recognized up to now. The methods used for analyzing this relation, which are aimed at determination of optimal mineral and chemical fertilizer doses, still need development. On the basis of the obtained results it was found that analyzed grapes cultivars (Aurora and Rondo) showtendency to accumulate potassium and magnesium in higher concentrations than zinc. The results of such analysis could allow determining the nutrient demand of grapevine that can result in its enhanced suitability for wine production. It should be emphasized that such kind of analyses should be realized regularly and be applied to broader spectrum of elements and heavy metals.
Background. Recently, many studies have been oriented towards improving methods and efficiency of antioxidants recovery from different fruit and their wastes. The aim of the study was to evaluate antioxidant potential of apple seeds and peel, which constitute the fruit industry wastes, and compare it to apple flesh. Antioxidant activity of apples at different maturity and storage stage were analysed too. Material and methods. The Idared and the Šampion cultivars of apples were used in the study. Antioxidant activity was estimated using ABTS and DPPH assays, and polyphenols profile was determined by HPLC method. Results. Seeds of analysed apple cultivars were characterised by a significantly higher antioxidant capacity and by higher concentrations of polyphenols analysed when compared to their peel and flesh. There were present two predominant compounds: phloridzin in seeds (84% and 72%) and quercetin glycosides in peels (54% and 38%, Idared and Šampion cultivars, respectively). No quercetin glycosides in seeds were found. The capacity to scavenge an ABTS radical, but not DPPH, decreased during ripening of apples, while cold storage resulted in enhanced antioxidant potential. Conclusion. It can be concluded that unripe apples together with apple seeds and peel (fruit industry wastes) constitute a valuable source of polyphenols.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.