Effect of Vacuum Impregnation with Apple-Pear Juice on Content of Bioactive Compounds and Antioxidant Activity of Dried Chokeberry Fruit

Abstract

Food technology seeks ways to preserve products while maintaining high bioactive properties. Therefore, an attempt was made to assess the effect of the process of impregnation with apple-pear juice and the drying process on the content of bioactive compounds in chokeberry fruit. Chokeberry fruits were subjected to impregnation with apple-pear juice at three levels of vacuum pressure, 4, 6, and 8 kPa; then, they were dried using microwave-vacuum technology. The water activity of the obtained products, the content of fructose, glucose, sorbitol, and polyphenolic compounds, and antioxidant activity were determined. A total of 20 polyphenolic compounds were identified in the fruits and the obtained products (seven anthocyanins, six flavonols, four phenolic acids, and three flavan-3-ols). Preliminary processing, which consisted of introducing the juice ingredients into tissue of the chokeberry fruit, resulted in increased content of bioactive compounds. Moreover, a positive effect of impregnation on the antioxidant stability of the fruit after drying was noted. Water activity in the obtained products showed their microbiological safety. Impregnation at 4 kPa vacuum pressure proved to be the most desirable; in such conditions, the best product in terms of the content of bioactive compounds was obtained.

Analysis of Selected Properties of Fruits of Black Chokeberry (Aronia melanocarpa L.) from Organic and Conventional Cultivation

“…In the above studies, the highest concentration was sorbitol (6.55-12.99 g/100 g FW), while the content of fructose and glucose was at a similar level (glucose 1.53-3.02 g/100 g FW and fructose 2.2-369 g/100 g FW). A similar analogy was obtained in the studies by Nawirska-Olszańska et al [27]. In the cited studies, the content of total sugars was significantly higher (10.26-19.70 g/100 g FW) than in the study below (5.01-7.96 g/100 g FW).…”

“…Three sugars were determined in the tested samples-fructose, sorbitol, and glucose (Table 3). Studies by other authors confirm the presence of fructose, glucose, and sorbitol in fresh chokeberry fruits [27,31]. In these studies, the main sugar in chokeberry fruit is glucose and there are slightly less sorbitol and the least fructose were determined.…”

“…Similarly, slight differences in the ash content were found (Table 1), which was affected by the same factors as in the case of dry matter. In the fruit studied by Nawirska-Olszańska et al [27], the ash content in fresh chokeberry fruits was higher (by 2.93%), which may result from testing another variety. Chokeberry fruits are among the fruits moderately rich in pectin, literature sources state that their content in fresh fruits ranges from 0.30-0.75% [3]; in this study, the pectin content ranged from 0.35-0.54%, on average-0.47%.…”

“…The extracts from black chokeberry fruits contained selected 27 compounds, including 11 flavonols, 7 anthocyanins, 5 phenolic acids, 3 flavan-3-ols, and 1 flavanone. Identification of polyphenolic compounds was conducted on a comparison of their MS, MS/MS data, retention times, UV spectra of standards, and data available in the literature [27][28][29][30]33]. Compounds identified in the negative ion mode belonged to the group of flavonols, hydroxycinnamic acids, flavanone, and flavan-3-ols.…”

The Effect of Plant Additives on the Stability of Polyphenols in Dried Black Chokeberry (Aronia melanocarpa) Fruit

“…The expected influence of cinnamon or cloves on the content of polyphenols, particularly anthocyanins in chokeberry fruit was not observed. Nawirska-Olszańska, Pasławska, Stępień et al [ 34 ] achieved a much higher level of preservation of anthocyanins, phenolic acids, flavonols, and procyanidins in chokeberry fruit impregnated with apple and pear juice, dried by the microwave-vacuum method. A relevant factor that influenced the obtained effect was the impregnation under pressure (4, 6, or 8 kPa).…”