Antioxidant activity of red beet juices obtained after microwave and thermal pretreatments

Abstract

Slavov A., Karagyozov V., Denev P., Kratchanova M., Kratchanov C. (2013): Antioxidant activity of red beet juices obtained after microwave and thermal pretreatments. Czech J. Food Sci., 31: 139-147.Pressed juices and water extracts from untreated, microwave pretreated, and thermally treated red beet were obtained. The highest total betalain content -606.34 mg/100 g dry matter (DM) was found in pressed juice obtained after microwave pretreatment. The individual betalains in the pressed juice from untreated red beet were tentatively determined by HPLC. The most abundant betalain pigments were betanin (312.47 mg/100 g DM), vulgaxanthin I (104.08 mg/100 g DM), and isobetanin (71.28 mg/100 g DM). The antioxidant activity of the pressed juices and extracts was determined. The highest antioxidant activity -10832.4 µmol ТЕ/l was found in the pressed juice obtained from microwave pretreated red beet. The possibility of obtaining mixed fruit-vegetable juices on the basis of red beet juice was investigated. Different variants of mixed beverages using chokeberry, blackberry, blueberry, and black currant were obtained in which the concentration of the red beet pressed juice was 25, 50, and 75%. Their polyphenol contents and antioxidant activity were determined. The highest antioxidant activity revealed mixed pressed juice from red beet and chokeberry.

Using Red Beet (Beta vulgaris L.) Extract to Improve Silk Production of Mulberry Silkworm (Bombyx mori l.)

“…The beetroot was used as extraction material, 250 gm of beetroot was cut into slices, 1000 ml of water was added then the mixture was heated at 100°С for 5 minutes (Slavov, et al 2013). After cooling the juice was extracted through a cheese cloth and collected in a bottles and then used as a standard juice to make a different concentrations.…”

Usage of betalain extracts in food

“…80 °C gibi yüksek sıcaklıklar ve 20 °C gibi oda sıcaklıkları pigment hidrolizine neden olurken, buzdolabı sıcaklığında (4 °C) renk değişiminin azalmakta, stabilitenin ise artmakta olduğu gözlemlenmiştir [5], [40]. Aynı zamanda betalainin, mikrodalga uygulaması ile 60 °C üzerindeki sıcaklıklarda degradasyona uğradığı bildirilmiştir [5], [41].…”

Characteristics of Kamaboko from Catfish (Clarias Gariepinus) Surimi Processed with Carrot and Beet Root as Filler and Natural Food Colorants

“…Beet root contains betalain pigmen which has purplish red colour. This pigment is very easily and radically altered during most cooking processes (Slavov et al, 2013). Kamaboko processed with beet root before steaming had red purple colour, but after steaming the purple colour changed to be reddish-yellow colour.…”

“…Meanwhile, beet root have long been used as medical purposes, primarily to prevent the risk of obesity, diabetic, heart disease and promotes a healthy complexion and hair, increased energy (Megan, 2015). It was recently discovered that natural food pigments of beet root can inhibit the cell proliferation of a variety of human tumor cells (Slavov et al, 2013). Beet root also contains high concentration of sugar, about 15-20% (Nottingham, 2004), while total sugar in carrots is 5,6% and has three major types of sugars namely glucose, fructose and their polymer (Sharma et al, 2012).…”