- Tytuł:
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Wpływ warunków przechowywania na wybrane właściwości liofilizowanych malin
The influence of storage conditionons on selected properties of freeze dried raspberry - Autorzy:
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Tryzno, E.
Sledz, M.
Witrowa-Rajchert, D. - Powiązania:
- https://bibliotekanauki.pl/articles/807185.pdf
- Data publikacji:
- 2015
- Wydawca:
- Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
- Opis:
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Celem pracy była analiza zmian barwy, zawartości antocyjanów i zdolności adsorpcji pary wodnej liofilizowanych malin w trakcie przechowywania. Owoce suszono sublimacyjnie, a następnie przechowywano (bez dostępu światła) w trzech temperaturach 25, 35 i 45°C przez 1, 2, 5 i 8 miesięcy. Zarówno temperatura, jak i czas przechowywania miały istotny wpływ na zmiany zawartości antocyjanów i barwy suszonych malin. Z kolei w przypadku właściwości higroskopijnych tylko temperatura przechowywania miała znaczący wpływ na zdolność adsorpcji pary wodnej przez susze. Wydłużenie czasu i wzrost temperatury przechowywania powodowały zmniejszenie zawartości antocyjanów oraz nasycenia barwy, jak również, w większości eksperymentów, pogorszenie właściwości higroskopijnych.
The purpose of this study was to determine the effect of time and temperature storage on properties of freeze-dried raspberries. Frozen raspberries from the Oerlemans company were placed in a shock freezer at the temperature of about -40°C for obtaining the fruit temperature of -38°C. Samples were then dried at the temperature of 20°C and pressure of 63 Pa for 24 hours, after which the fruit was packed in opaque PET/Met/PE plastic bags with removing 95% of air. Packaged samples were stored in incubators without light exposure at three different temperatures: 25, 35 and 45°C. Colour, adsorption capacity, dry matter content, and anthocyanin content analyses were made before storing the fruit, as well as after 1, 2, 5, and 8 months of storage. Anthocyanin content analysis was carried out according to Giusti and Wrolstad method. Adsorption capacity (hygroscopy) on the basis of changes in the water content in dried fruit kept over a saturated NaCl solution (aw = 0.75) for 72 hours was analysed. Weight changes were successively measured after 0.5, 1, 3, 5, 24, 48 and 72 hours. For measurement colour of dried fruit was use the reflection method. The analysis was performed using a colorimeter Konica Minolta CR-5. Dried pieces were laid in a glass Petri dish and set on the measuring head. Brightness L*, coefficient a* and b* were measured with the following settings: measuring diameter - 30 mm, the standard observer - 2°, and a light source - D65. Storing resulted in significant colour change of freeze-dried raspberries, particularly of those stored at higher temperatures. In most cases, dried fruits were lighter and had reduced a* values and chroma. Both temperature and storage time had a significant effect on the colour change of dried fruits. Anthocyanins are very unstable compounds at elevated temperatures. After 39 weeks of storage at 35 and 45°C virtually all of anthocyanins content in freeze-dried raspberries was degraded. Anthocyanins were most stable at 25°C, and their content did not decrease during the 8 weeks of storage. Both temperature and storage time had a significant impact on the content of pigments in the dried fruits. The storage temperature had a significant impact on fruit's water vapour adsorption. Adsorption was significantly reduced immediately after drying the fruits, except in the samples stored at the highest temperature for the longest period. The storage time did not significantly affect this value. - Źródło:
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Zeszyty Problemowe Postępów Nauk Rolniczych; 2015, 581
0084-5477 - Pojawia się w:
- Zeszyty Problemowe Postępów Nauk Rolniczych
- Dostawca treści:
- Biblioteka Nauki
Artykuł