Pigment complex of frozen broccoli

Abstract

Background. The stable demand for fresh fruits and vegetables and products of their processing is due to not only their high biological, nutritional value, but also to an extremely wide palette of colors and shades, which for consumers are one of the defining criteria of their choice. Pigment complex of fruit and vegetables is represented by carotenoids, chlorophyll, flavonoids, anthocyanins, which are responsible for a color variety of fresh fruits and vegetables. Medicinal properties of chloroplatinic vegetables with the content of a- and b-chlorophyll, which is structurally similar to hemoglobin and have antitumor properties, increase immunity, normalization of metabolism and is due to the combined action of chlorophylls, ascorbic acid and β-carotene, which are in a considerable amount in green vegetables.
Chlorophyll of fruits and vegetables is not resistant to the effects of various factors: under the influence of heat treatment, pH, oxygen, light it experiences significant loss of chlorophyll, accompanied by darkening or discoloring of the product. So, the problem of preservation of color of chloroplatinic products of processed fruit and vegetables is important because different species and varieties of fruits and vegetables vary greatly in chemical composition.
The aim of this study is research of the pigment complex of cabbage and broccoli, which grow in Ukraine and its changes during processing and freezing.
Material and methods. The object of research is fresh, soaked in a solution of salt, blanched and frozen broccoli variety Partenon, Monaco F1, Belstar F1, Quinta F1. Samples of cabbage are soaked in the salt solution concentration of 3 % for 20 min, blanching occurred at the temperature of 85 оC for 3 min. The study was conducted according to the following criteria: content of a- and b-chlorophyll and β-carotene.
Results. Conducted research of fresh broccoli confirmed that the varieties have no significant difference in the content of chlorophyll, the amount of which depending on the varieties ranged from 49.0 to 53.7 mg/100 g. During the blanching of the cabbage a-chlorophyll reduced on average by 10 % and b-chlorophyll on the average by 16 %. Soaking in salt solution induces an increase of the concentration of a-chlorophyll on average by 12 % and b-chlorophyll on average by 18 % due to a compensatory reaction, because in the given conditions the efficiency of solar energy decreases. During freezing of broccoli a-chlorophyll decreased by 12–18 %, b-chlorophyll by 4–19 % depending on the species and its content in fresh cabbage. The results of studies of β-carotene confirm its negligible content in cabbage from 3.1 to 4.6 mg/100 g.
Conclusion. It has been established that the pigment complex of the studied broccoli variety is characterized by a rather high content of a- and b-chlorophyll and low content of β-carotene.
It has been identified that soaking broccoli in a solution of salt increases concen­trations of a- and b-chlorophyll by 7–11 % depending on the variety, which confirms the additional benefits of this method of pretratment before freezing. It provides frozen broccoli, pigment complex of which will undergo minimal modifications.