FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

BARBARA WÓJCIK-STOPCZYŃSKA, PAWEŁ KIEDOS

Title

Effect of pre-treatments on content of some selected constituents in frozen ‘Geant d’hiver’ (Spinacia oleracea L.) spinach cultivar

Abstract

In the paper, the content was assessed of some selected components in the spinach stored under refrigerated conditions depending on blanching and cutting processes prior to freezing. In the research study, a ‘Geant d’hiver’ spinach cultivar was utilized; it was derived from the autumn harvest and purchased at a vegetable producer. Four variants of spinach were frozen and then stored under the refrigerated conditions (six months, at -25 ºC): whole and cut (slices 3 cm of width) raw leaves and whole and cut blanched leaves (95 – 96 ºC; 120 s). The raw and blanched spinach and the spinach stored 6 months under the refrigerated conditions were analyzed for the content of dry matter, crude fibre, vitamin C, total polyphenols, total chlorophyll, carotenoids and nitrates. It was proved that, compared to the raw spinach, the blanching process significantly decreased the content of dry matter (8.4 %), carotenoids (11.2 %), chlorophyll (17.0 %), vitamin C (29.2 %) and nitrates(V) (46.0 %). The content of the  components in the spinach assessed 6 months after the refrigerated storage depended mostly on the blanching  process whereas the way of cutting the spinach generally did not significantly impact their concentration.  Compared to the nonblanched frozen spinach, in the frozen spinach made from the blanched spinach (whole and  cut) significantly more bioactive components were reported: vitamin C, carotenoids, chlorophyll and more  polyphenols. On the other hand, the frozen non-blanched spinach was characterized by a significantly higher content of potentially harmful nitrates(V). In relation to the composition of the raw spinach, the average losses of components in the frozen blanched spinach ranged from 5.9 % (raw fibre) to 50.4 % (nitrates(V)) and in the frozen non-blanched spinach those losses ranged from 3.5 % (nitrates(V)) to 72.3 % (vitamin C).

Keywords

spinach, processing, bioactive components, nitrates(V)

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