PL EN


Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników
2016 | 23 | 3 |
Tytuł artykułu

Zmiany właściwości fizykochemicznych i sensorycznych mięsa wołowego w zależności od warunków jego dojrzewania

Treść / Zawartość
Warianty tytułu
EN
Changes in physicochemical and sensory properties of beef meat depending on its ageing conditions
Języki publikacji
PL
Abstrakty
PL
Pod względem wartości odżywczej wołowina jest bardzo cenionym gatunkiem mięsa. W celu uzyskania wysokiej wartości kulinarnej surowiec ten wymaga zabiegów, prowadzących przede wszystkim do wykształcenia pożądanych właściwości sensorycznych. Znaczącą poprawę cech jakościowych wołowina uzyskuje w trakcie odpowiednio długiego okresu dojrzewania, tj. naturalnego procesu zachodzącego po ustąpieniu fazy rigor mortis w każdym mięśniu tuszy. Proces dojrzewania wołowiny w warunkach chłodniczych stosowany jest od ponad stulecia. Współcześnie na skalę przemysłową stosuje się dojrzewanie suche lub mokre. Ma ono charakter zamierzony (celowy) lub prowadzone jest przypadkowo, jako jeden z elementów dystrybucji i sprzedaży mięsa. W pracy przedstawiono różne metody i warunki, w jakich prowadzone jest dojrzewanie wołowiny (w tym pakowanie) oraz ich wpływ na cechy jakościowe mięsa (wodochłonność, kruchość i smakowitość). Oprócz bezsprzecznie pozytywnych aspektów związanych z poubojowym dojrzewaniem mięsa przedstawiono również procesy mogące negatywnie wpływać na końcową jego jakość, wynikającą przede wszystkim z oksydacji składników tkanki mięśniowej (lipidów, barwników i białek). Odpowiednio prowadzony (najczęściej w warunkach próżniowych) proces poubojowego dojrzewania wołowiny pozwala na uzyskanie produktu o wysokiej jakości, tzn. odpowiedniej kruchości i smakowitości oraz bezpieczny pod względem zdrowotnym. Analiza dostępnej literatury pozwala na stwierdzenie, że kulinarne mięso wołowe osiąga pełnię swoich walorów sensorycznych w trzecim tygodniu dojrzewania w temp. 2 ÷ 4 ºC.
EN
In terms of nutritional value beef is a very valued variety of meat. In order to obtain a high culinary value, this raw material requires treatments to develop desirable sensory properties of meat. The quality characteristics of beef are substantially improved during a reasonably long period of ageing, which is a natural process that takes place in each muscle of the carcass after a rigor mortis phase. Beef has been aged in cold storage conditions for over a century. Dry or wet ageing are currently used on an industrial scale. They are carried out either intentionally (with a target set) or incidentally as one of the elements of meat distribution and sales. The paper presents various methods and conditions of beef ageing (including packaging) and their effect on the quality properties of meat (water-holding capacity, tenderness, and palatability). In addition to the unquestionably positive aspects of post-slaughter ageing of beef, those processes are also shown, which may negatively affect the final meat quality, mainly because of the oxidation of muscle tissue components (lipids, pigments, and proteins). When conducted properly (usually under the vacuum conditions), the post-mortem ageing process of beef meat makes it possible to obtain a product of high quality, i.e. properly tender and palatable as well as safe in terms of health. The analysis of the reference literature available shows that the culinary beef meat achieves its full sensory values in the third week of ageing at 2 ÷ 4 ºC.
Wydawca
-
Rocznik
Tom
23
Numer
3
Opis fizyczny
s.35-53,tab.,bibliogr.
Twórcy
  • Katedra Towaroznawstwa i Przetwórstwa Surowców Zwierzęcych, Wydział Biologii i Hodowli Zwierząt, Uniwersytet Przyrodniczy w Lublinie, ul.Akademicka 13, 20-950 Lublin
  • Katedra Hodowli i Ochrony Zasobów Genetycznych Bydła, Wydział Biologii i Hodowli Zwierząt, Uniwersytet Przyrodniczy w Lublinie, ul.Akademicka 13, 20-950 Lublin
autor
  • Katedra Towaroznawstwa i Przetwórstwa Surowców Zwierzęcych, Wydział Biologii i Hodowli Zwierząt, Uniwersytet Przyrodniczy w Lublinie, ul.Akademicka 13, 20-950 Lublin
  • Katedra Towaroznawstwa i Przetwórstwa Surowców Zwierzęcych, Wydział Biologii i Hodowli Zwierząt, Uniwersytet Przyrodniczy w Lublinie, ul.Akademicka 13, 20-950 Lublin
Bibliografia
  • [1] Ba H. V., Hwang I., Jeong D., Touseef A.: Principle of meat aroma flavors and future prospect. In.: Latest research into quality control. Ed. I. Akyar. InTech, Rijeka 2012, pp. 145 - 175.
  • [2] Ba H. V., Park K., Dashma D., Hwang I.: Effect of muscle type and vacuum chiller ageing period on the chemical compositions, meat quality, sensory attributes and volatile compounds of Korean native cattle beef. Anim. Sci. J., 2014, 85, 164 - 173.
  • [3] Bauer F.: Free glutamic acid in meat products. Ernahrung, 1983, 7, 688.
  • [4] Bekhit A. E. D., Hopkins D. L., Fahri F. T., Ponnampalam E. N.: Oxidative processes in muscle systems and fresh meat: Sources, markers, and remedies. Compr. Rev. Food Sci. F., 2013, 12, 565 - 597.
  • [5] Brewer S., Novakofski J.: Consumer sensory evaluations of aging effects on beef quality. J. Food Sci., 2008, 73 (1), 78 - 82.
  • [6] Bruce H. L., Beilken S. L., Leppard P.: Textural descriptions of cooked steaks from bovine m. longissimus thoracis et lumborum from different production and aging regimes. J. Food Sci., 2005, 70, 309 - 316.
  • [7] Calkins C. R., Hodgen J. M.: A fresh look at meat flavor. Meat Sci., 2007, 77, 63 - 80.
  • [8] Campbell R. E., Hunt M. C., Levis P., Chambers IV E.: Dry-aging effects on palatability of beef longissimus muscle. J. Food Sci., 2001, 66, 196 - 199.
  • [9] Chan J. T. Y., Omana D. A., Betti M.: Effect of ultimate pH and freezing on the biochemical properties of proteins in turkey breast meat. Food Chem., 2011, 127, 109 - 117.
  • [10] Christensen M., Ertbjerg P., Failla S., Sañudo C., Richardson R. I., Nute G. R., Olleta J. L., Panea B., Albertí P., Juárez M., Hocquette J. F., Williams J. L.: Relationship between collagen characteristics, lipid content and raw and cooked texture of meat from young bulls of fifteen European breeds. Meat Sci., 2011, 87, 61 - 65.
  • [11] Claus J. R., Du C.: Nitrite-embedded packaging film effects on fresh and frozen beef color development and stability as influenced by meat age and muscle type. Meat Sci., 2013, 95, 526 – 535.
  • [12] Clausen I., Jakobsen M., Ertbjerg P., Madsen N. T.: Modified atmosphere packaging affects lipid oxidation, myofibrillar fragmentation index and eating quality of beef. Packag. Technol. Sci., 2009, 22, 85 - 96.
  • [13] Dai Y., Lua Y., Wua W., Lu X., Han Z., Liua Y., Li X., Dai R.: Changes in oxidation, color and texture deteriorations during refrigerated storage of ohmically and water bath-cooked pork meat. Innov. Food Sci. Emerg., 2014, 26, 341 - 346.
  • [14] DeGeer S. L., Hunt M. C., Bratcher L. C., Crozier-Dodson B. A., Johnson D. E., Stika J. F.: Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times. Meat Sci., 2009, 83, 768 - 774.
  • [15] Descalzo A. M., Sancho A. M.: A review of natural antioxidants and their effects on oxidative status, odor and quality of fresh beef produced in Argentina. Meat Sci., 2008, 79, 423 - 436.
  • [16] Dikeman M. E., Obuz E., Gök V., Akkaya L., Stroda S.: Effects of dry, vacuum, and special bag aging; USDA quality grade; and end-point temperature on yields and eating quality of beef Longissimus lumborum steaks. Meat Sci., 2013, 94, 228 - 233.
  • [17] Dolatowski Z. J., Twarda J., Dudek M.: Zmiany uwodnienia mięsa podczas dojrzewania. Ann. UMCS, Sect. E, 2004, 5 (94), 1595 - 1606.
  • [18] Domaradzki P., Skałecki P., Florek M., Litwińczuk A.: Wpływ przechowywania zamrażalniczego na właściwości fizykochemiczne mięsa wołowego pakowanego próżniowo. Żywność. Nauka. Technologia. Jakość, 2011, 4 (77), 117 - 126.
  • [19] Epley R. J.: Aging beef. Minnesota Extension Service. University of Minnesota, St. Paul, MN, 1992, pp. 1 - 2.
  • [20] Esterbauer H.: Cytotoxicity and genotoxicity of lipid-oxidation products. Am. J. Clin. Nutr., 1993, 57 (5 Suppl.), 779S - 785S.
  • [21] Estévez M.: Protein carbonyls in meat systems: A review. Meat Sci., 2011, 89, 259 - 279.
  • [22] Falowo A. B., Fayemi P. O., Muchenje V.: Natural antioxidants against lipid-protein oxidative deterioration in meat and meat products: A review. Food Res. Int., 2014, 64, 171 - 181.
  • [23] Farouk M. M., Mustafa N. M., Wu G., Krsinic G.: The “sponge effect” hypothesis: An alternative explanation of the improvement in the waterholding capacity of meat with ageing. Meat Sci., 2012, 90, 670 - 677.
  • [24] Faustman C., Liebler D. C., McClure T. D., Sun Q. R.: α, β-Unsaturated aldehydes accelerate oxymyoglobin oxidation. J. Agric. Food Chem., 1999, 47, 3140 - 3144.
  • [25] Frederiksen A. M., Lund M. N., Andersen M. L., Skibsted L. H.: Oxidation of porcine myosin by hypervalent myoglobin: The role of thiol groups. J. Agric. Food Chem., 2008, 56, 3297 - 3304.
  • [26] Gorraiz C., Beriain M. J., Chasco J., Insausti K.: Effect of aging time on volatile compounds, odor, and flavor of cooked beef from Pirenaica and Friesian bulls and heifers. J. Food Sci., 2002, 67, 916 - 922.
  • [27] Hęś M., Korczak J.: Wpływ różnych czynników na szybkość utleniania się lipidów mięsa. Nauka Przyr. Technol., 2007, 1 (1), 1-11.
  • [28] Howard A., Lee C. A., Webster H. L.: C. S. I. R. O. Div. Food Pres. Tech., 1960, 21, 3.
  • [29] Hughes J. M., Oiseth S. K., Purslow P. P., Warner R. D.: A structural approach to understanding the interactions between colour, water-holding capacity and tenderness. Meat Sci., 2014, 98, 520 - 532.
  • [30] Insausti K., Beriain M. J., Gorraiz C., Purroy A.: Volatile compounds of raw beef from 5 local Spanish cattle breeds stored under modified atmosphere. J. Food Sci., 2002, 67 (4), 1580 - 1589.
  • [31] Insausti K., Beriain M. J., Purroy A., Alberti P., Lizaso L., Hernandez B.: Colour stability of beef from different Spanish native cattle breeds stored under vacuum and modified atmosphere. Meat Sci., 1999, 53, 241 - 249.
  • [32] Jeremiah L. E., Gibson L. L.: The effects of postmortem product handling and aging time on beef palatability. Food Res. Int., 2003, 36, 929 - 941.
  • [33] Juárez M., Larsen I. L., Gibson L. L., Robertson W. M., Dugan M. E. R., Aldai N., Aalhus J. L.: Extended ageing time and temperature effects on quality of sub-primal cuts of boxed beef. Can. J. Anim. Sci., 2010, 90 (3), 361 - 370.
  • [34] Karwowska M., Dolatowski Z.J.: The effect of natural antioxidant on the oxidative processes in beef. Acta Sci. Pol. Technol. Aliment., 2007, 6 (1), 17 - 25.
  • [35] Kołczak T., Krzysztoforski K., Palka K.: Effect of post-mortem ageing, method of heating and reheating on collage solubility, shear force and texture parameters of bovine muscles. Pol. J. Food Nutr. Sci., 2008, 58 (1), 27 - 32.
  • [36] Kołczak T.: Jakość wołowiny. Żywność. Nauka. Technologia. Jakość, 2008, 1 (56), 5 - 22.
  • [37] Koutsidis G., Elmore J. S., Oruna-Concha M. J., Campo M. M., Wood J. D., Mottram D. S.: Watersoluble precursors of beef flavour. Part II: Effect of post-mortem conditioning. Meat Sci., 2008, 79, 270 - 277.
  • [38] Kristensen L., Purslow P. P.: The effect of ageing on the water-holding capacity of pork: Role of cytoskeletal proteins. Meat Sci., 2001, 58, 17 - 23.
  • [39] Lagerstedt A., Lundström K., Lindahl G.: Influence of vacuum or high-oxygen modified atmosphere packaging on quality of beef m. longissimus dorsi steaks after different ageing times. Meat Sci., 2011, 87, 101 - 106.
  • [40] Laster M. A., Smith R. D., Nicholson K. L., Nicholson J. D. W., Miller R. K., Griffin D. B., Harris K. B., Savell J. W.: Dry versus wet aging of beef: Retail cutting yields and consumer sensory at-tribute evaluations of steaks from ribeyes, strip loins, and top sirloins from two quality grade groups. Meat Sci., 2008, 80, 795 - 804.
  • [41] Li Y., Liu R., Zhang W., Fu Q., Liu N., Zhou G.: Effect of nitric oxide on μ-calpain activation, protein proteolysis, and protein oxidation of pork during post-mortem aging. J. Agric. Food Chem., 2014, 62, 5972 - 5977.
  • [42] Lindahl G., Lagerstedt A., Ertbjerg P., Sampels S., Lundström K.: Ageing of large cuts of beef loin in vacuum or high oxygen modified atmosphere-effect on shear force, calpain activity, desmin degradation and protein oxidation. Meat Sci., 2010, 85, 160 - 166.
  • [43] Lindahl G.: Colour stability of steaks from large beef cuts aged under vacuum or high oxygen modified atmosphere. Meat Sci., 2011, 87, 428 - 435.
  • [44] Litwińczuk Z., Barłowska J., Florek M., Tabała K.: Slaughter value of heifers, cows and young bulls from commercial beef production in the central-eastern region of Poland. Anim. Sci. Pap. Rep., 2006, 24 (2 Suppl.), 187 - 194.
  • [45] Lorenzo J. M., Gómez M.: Shelf life of fresh foal meat under MAP, over wrap and vacuum packaging conditions. Meat Sci., 2012, 92, 610 - 618.
  • [46] Lund M. N., Heinonen M., Baron C. P., Estévez M.: Protein oxidation in muscle foods: A review. Mol. Nutr. Food Res., 2011, 55, 83 - 95.
  • [47] Lund M. N., Lametsch R., Hviid M. S., Jensen O. N., Skibste L. H.: High-oxygen packaging atmosphere influences protein oxidation and tenderness of porcine longissimus dorsi during chill storage. Meat Sci. 2007, 77, 295 - 303.
  • [48] Lundesjö Ahnström M., Seyfert M., Hunt M. C., Johnson D. E.: Dry aging of beef in a bag highly permeable to water vapour. Meat Sci., 2006, 73, 674 - 679.
  • [49] Lynch M. P., Faustman C.: Effect of aldehyde lipid oxidation products on myoglobin. J. Agric. Food Chem., 2000, 48, 600 - 604.
  • [50] Martínez J., Nieto G., Ros G.: Total antioxidant capacity of meat and meat products consumed in a reference ‘Spanish standard diet’. Int. J. Food Sci. Technol., 2014, 49, 2610 - 2618.
  • [51] Maughan C., Tansawat R., Cornforth D., Ward R., Martini S.: Development of a beef flavor lexicon and its application to compare the flavor profile and consumer acceptance of rib steaks from grassor grain-fed cattle. Meat Sci., 2012, 90, 116 - 21.
  • [52] McKenna D. R., Mies P. D., Baird B. E., Pfeiffer K. D., Ellebracht J. W., Savell J. W.: Biochemical and physical factors affecting discoloration characteristics of 19 bovine muscles. Meat Sci., 2005, 70, 665 - 682.
  • [53] McMillin K. W.: Where is MAP going? A review and future potential of modified atmosphere packaging for meat. Meat Sci., 2008, 80, 43 - 65.
  • [54] Mercier Y., Gatellier Ph., Viau M., Remignon H., Renerre M.: Effect of dietary fat and vitamin E on colour stability and lipid and protein oxidation in turkey meat during storage. Meat Sci., 1998, 48, 301 - 318.
  • [55] Min B., Ahn D. U.: Mechanism of lipid peroxidation in meat and meat products: A review. Food Sci. Biotechnol., 2005, 14, 152 - 163.
  • [56] Min B., Nam K. C., Cordray J., Ahn D. U.: Endogenous factors affecting oxidative stability of beef loin, pork loin, and chicken breast and thigh meats. J. Food Sci., 2008, 73, 439 - 446.
  • [57] Monsón F., Sañudo C., Sierra I.: Influence of breed and ageing time on the sensory meat quality and consumer acceptability in intensively reared beef. Meat Sci., 2005, 71, 471 - 479.
  • [58] Mottram D. S.: Flavor formation in meat and meat products: A review. Food Chem., 1998, 62, 415 - 424.
  • [59] Myers A. J., Scramlin S. M., Dilger A. C., Souza C. M., McKeith F. K., Killefer J.: Contribution of lean, fat, muscle color and degree of doneness to pork and beef species flavor. Meat Sci., 2009, 82, 59 - 63.
  • [60] Ngapo T. M., Berge P., Culioli J., Dransfield E., De Smet S., Claeys E.: Perimysial collagen crosslinking and meat tenderness in Belgian Blue double-muscled cattle. Meat Sci., 2002, 61, 91 - 102.
  • [61] Novakofski J., Brewer M. S.: The paradox of toughening during the aging of tender steaks. J. Food Sci., 2006, 71, 473 - 479.
  • [62] Oliete B., Carballo J. A., Varela A., Moreno T., Monserrat L., Sanchez L.: Effect of weaning status and storage time under vacuum upon physical characteristics of meat of the Rubia Gallega breed. Meat Sci., 2006, 73, 102 - 108.
  • [63] Oliete B., Moreno T., Carballo J. A., Varela A., Monserrat L., Sánchez L.: Influence of ageing time on the quality of yearling calf meat under vacuum. Eur. Food Res. Technol., 2005, 220, 489 - 493.
  • [64] Palka K.: The influence of post-mortem ageing and roasting on the microstructure, texture and collagen solubility of bovine semitendinosus muscle. Meat Sci., 2003, 64, 191 - 198.
  • [65] Pastsart U., De Boever M., Claeys E., De Smet S.: Effect of muscle and post-mortem rate of pH and temperature fall on antioxidant enzyme activities in beef. Meat Sci., 2013, 93, 681 - 686.
  • [66] Petron M. J., Raes K., Claeys E., Lourenço M., Fremaut D., De Smet S.: Effect of grazing pastures of different botanical composition on antioxidant enzyme activities and oxidative stability of lamb meat. Meat Sci., 2007, 75, 737 - 745.
  • [67] Popova T., Marinova P., Vasileva V., Gorinov Y., Lidji K.: Oxidative changes in lipids and proteins in beef during storage. Arch. Zoot., 2009, 12 (3), 30 - 38.
  • [68] Purslow P. P., Archile-Contreras A. C., Cha M. C.: Meat science and muscle biology symposium: Manipulating meat tenderness by increasing the turnover of intramuscular connective tissue. J. Anim. Sci., 2012, 90, 950 - 959.
  • [69] Santé-Lhoutellier V., Engel E., Aubry L., Gatellier P.: Effect of animal (lamb) diet and meat storage on myofibrillar protein oxidation and in vitro digestibility. Meat Sci., 2008, 79, 777 - 783.
  • [70] Savell J. W.: Dry-aging of beef. Center for Research and Knowledge Management, National Cattlemen’s Beef Association, Centennial, CO, 2008, pp. 1 - 12.
  • [71] Schäfer A., Rosenvold K., Purslow P.P., Andersen H. J., Henckel P.: Physiological and structural events post mortem of importance for drip loss in pork. Meat Sci., 2002, 61, 355 - 366.
  • [72] Shahidi F.: Lipid-derived flavours in meat products. In: Meat Processing: Improving Quality. Eds. J. Kerry, J. Kerry, D. Ledward. Woodhead Publishing Ltd, Cambridge 2002, pp. 105 - 121.
  • [73] Shanks B. C., Wulf D. M., Maddock R. J.: Technical note: The effect of freezing on Warner-Bratzler shear force values of beef longissimus steaks across several postmortem aging periods. J. Anim. Sci., 2002, 80, 2122 - 2125.
  • [74] Sierra V., Guerrero L., Fernández-Suárez V., Martínez A., Castro P., Osoro K., Rodríguez-Colunga M. J., Coto-Montes A., Oliván M.: Eating quality of beef from biotypes included in the PGI “Ternera Asturiana” showing distinct physicochemical characteristics and tenderization pattern. Meat Sci., 2010, 86, 343 - 351.
  • [75] Sitz B. M., Calkins C. R., Feuz D. M., Umberger W. J., Eskridge K. M.: Consumer sensory acceptance and value wet-aged and dry-aged beef steaks. J. Anim. Sci., 2006, 84, 1221 - 1226.
  • [76] Stenström H., Li X., Hunt M. C., Lundström K.: Consumer preference and effect of correct or misleading information after ageing beef longissimus muscle using vacuum, dry ageing, or a dry ageing bag. Meat Sci., 2014, 96, 661 - 666.
  • [77] Takahashi K.: Structural weakening of skeletal muscle tissue during post-mortem ageing of meat: The non-enzymatic mechanism of meat tenderization. Meat Sci., 1996, 43 (S), 67 - 80.
  • [78] Ventanas S., Estévez M., Tejeda J. F., Ruiz J.: Protein and lipid oxidation in Longissimus dorsi and dry cured loin from Iberian pigs as affected by crossbreeding and diet. Meat Sci., 2006, 72, 647 - 655.
  • [79] Wajda S.: Możliwości wzrostu produkcji i poprawy jakości wołowiny. Gosp. Mięs., 2006, 12, 26 - 29.
  • [80] Warren K. E., Kastner C. L.: A comparison of dry-aged and vacuum-aged beef strip loins. J. Muscle Foods, 1992, 3, 151 - 157.
  • [81] Xiao S., Zhang W. G., Lee E. J., Ma C. W, Ahn D. U.: Effects of diet, packaging, and irradiation on protein oxidation, lipid oxidation, and color of raw broiler thigh meat during refrigerated storage. Poult. Sci., 2011, 90, 1348 - 1357.
  • [82] Yancey E. J., Dikeman M. E., Hachmeister K. A., Chambers IV E. C., Milliken G. A.: Flavor characterization of top blade, top sirloin, and tenderloin steaks as affected by pH, maturity, and marbling. J. Anim. Sci., 2005, 831, 2618 - 2623.
  • [83] Yancey E. J., Grobbel J. P., Dikeman M. E., Smith J. S., Hachmeister K. A., Chambers IV E. C.: Effects of total iron, myoglobin, hemoglobin, and lipid oxidation of uncooked muscles on livery flavor development and volatiles of cooked beef steaks. Meat Sci., 2006, 73 (4), 680 - 686.
  • [84] Yim D., Jo C., Kim H., Cha J., Kim H. C., Nam K.: Combined effect of irradiation and ageing condition on physicochemical and microbial quality of Hanwoo eye of round. Korean J. Food Sci. An., 2015, 35 (3), 406 - 412.
  • [85] Zakrys P. I., Hogan S. A., O'Sullivan M. G., Allen P., Kerry J. P.: Effects of oxygen concentration on the sensory evaluation and quality indicators of beef muscle packed under modified atmosphere. Meat Sci., 2008, 79, 648 - 655.
  • [86] Zakrys-Waliwander P. I., O’Sullivan M. G., Allen P., O’Neill E. E., Kerry J. P.: Investigation of the effects of commercial carcass suspension (24 and 48 h) on meat quality in high oxygen modified atmosphere packed beef steaks during chill storage. Food Res. Int., 2010, 43, 277 - 284.
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.agro-3ab48500-9bfd-47ac-853a-59f5d925ee5e
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.