Thermal degradation kinetics of monomeric anthocyanins, colour changes and storage effect in elderberry juices

Abstract

BACKGROUND: Elderberry (Sambucus nigra L.) is considered an interesting fruit as food ingredient, due to its high content of anthocyanins that give products an attractive red colour. OBJECTIVE: The aim of present study was to evaluate the kinetics of elderberry monomeric anthocyanin (MAcy) and colour degradation due to thermal processing and storage. METHODS: Anthocyanins content was measured with pH-differential method. CIELab parameters were obtained with a Minolta Spectrophotometer, total phenolics were determined by Folin-Ciocalteu method. MAcy degradation and evolution of colour parameter a * were fitted to a first-order model. RESULTS:The degradation rate of a * was about three times lower than MAcy degradation rate. Activation energy for degradation of a * and MAcy were 140.6 and 144.6 kJ mol −1 respectively. Degradation rates (k) obtained during storage were 0.025 d −1 for MAcy and 0.0064 d −1 for a * . During storage, 50% reduction of initial values was at 120 days for MAcy and at 432 days for colour parameter a * at 25ºC. However, a high retention of polyphenols and antioxidant was noted. CONCLUSIONS: Kinetic parameters calculated for elderberry juice can be used to design a thermal treatment to obtain a high retention of colour and bioactive compounds.

Effect of gum arabic (Acacia senegal) addition on physicochemical properties and sensory acceptability of roselle juice

“…The anthocyanin content of roselle juice was ranged from 63.04±2.19 to 83.74±2.17 mg/100 mL of the sample (Table 1). The amount of anthocyanin content in roselle juice without GA (83.74±2.17 mg/100 mL) was lower than reported in elderberry juice (96.4±4.8mg/100 mL) and mulberry concentrate (223.3mg/100 mL) as reported by Casati et al (2015) and Kara and Ercelebi (2013), respectively. Nevertheless, the value was higher than reported in blackcurrant juice, pomegranate juice and roselle juice in previous studies (Turfan et al, 2011;Ibrahim and Mazuki, 2013;Dobson et al, 2017).…”

Effect of Processing Methods and Storage Time on the Content of Bioactive Compounds in Blue Honeysuckle Berry Purees

“…This includes during the enzymatic processing of fruit before juice pressing, which in turn allows for the better extraction of anthocyanins responsible for the color of berry juices [37]. However, many scientific studies point to the negative effect of thermal treatment on the stability of anthocyanins, which can easily degrade at higher temperatures [38][39][40]. Nevertheless, Casati et al [38] obtained interesting results when they studied the effect of heat treatment times on elderberries at 90 • C, 80 • C, and 70 • C, on the kinetics of anthocyanin degradation.…”

“…However, many scientific studies point to the negative effect of thermal treatment on the stability of anthocyanins, which can easily degrade at higher temperatures [38][39][40]. Nevertheless, Casati et al [38] obtained interesting results when they studied the effect of heat treatment times on elderberries at 90 • C, 80 • C, and 70 • C, on the kinetics of anthocyanin degradation. It turned out that the higher the temperature, the greater the degree of anthocyanin degradation, but the duration of thermal treatment is also very important.…”

Optimization of Extraction of Bioactive Compounds from Black Carrot Using Response Surface Methodology (RSM)

“…Similarly, Assous et al (2014) reported that purple carrots contain 168.7 mg anthocyanins/100 g fresh weight, and the major constituents were found as cyanidin-3-xylosyl-glucosyl-galactoside Color of the extracts is related with total anthocyanin content as expected (Khandare et al 2011). On the other hand, color degradation might be slower than the anthocyanin degradation at the same temperature (Casati et al 2015). The percent polymeric color value for unstored fruit or vegetables is generally less than 10 % (Türkyılmaz et al 2012).…”