Investigations on Sweet Cherry Phenolic Degradation During Thermal Treatment Based on Fluorescence Spectroscopy and Inactivation Kinetics

Abstract

Five anthocyanins were detected in the sweet cherry extract as follows: cyanidin 3-rutinoside, cyanidin 3-glucoside, peonidin 3-rutinoside, peonidin 3-glucoside, and pelargonidin 3-rutinoside, whereas the cyanidin 3-rutinoside was found to be in the highest amount. The effect of thermal treatment on the degradation of the polyphenolic compounds in sweet cherry extract was investigated in the range of 70-120°C by means of fluorescence spectroscopy and spectrophotometric techniques. The fluorescence spectra were dominated by emission bands with maximum ranging from 356 nm at 25°C to 350 nm at 110°C. The heating of sweet cherry extract resulted in structural changes that led to a significant decrease in fluorescence intensity when increasing temperature. Degradation rate constants were estimated using a fractional conversion kinetic model. The activation energy values revealed a higher-temperature dependence of antioxidant activity, followed by anthocyanins, total polyphenols, and total flavonoids.

Ripeness stage effects on quality characteristics of smoothies made up of sweet cherries (P. aviumL., cv. ‘Lapins’)

“…2), it is possible to observe no significant difference (p-level > 0.05) even if those of smoothies were always slightly lower than those of fresh fruits (466.74 vs 496.51 mg gallic acid per kg -1 ). This last is in accordance to what could have been expected after a double thermal treatment (blanching and pasteurization by microwaves) applied during processing of cherries (Turturică et al, 2016). (Figs.…”

“…These last two antioxidant categories are highly thermolabile, so they are degraded when submitted to thermal treatments (Boon et al, 2010;Poiana Kadian et al, 2013). Then, it is reasonable to suppose that the great part of the residual antioxidant activity is due to polyphenols, which are relatively more resistant to thermal treatments (Turturică et al, 2016;Picariello et al, 2017) and this could explain our results. Nevertheless, the decrease of antioxidant capacity in smoothies respect to fresh fruits was not so relevant respect what could be expected after the double thermal treatment (blanching and pasteurization by microwaves) applied during processing of cherries.…”

Effects of gamma radiation on the stability and degradation kinetics of phenolic compounds and antioxidant activity during storage of (Oryza sativa L.) black rice flour

“…All the negative ∆S # values (from -281.91 to -293.51 J mol -1 K -1 ) found in the present study showed a lower structural freedom than the reactants, which further confirmed that this is an irreversible process. The same behaviour for the evaluated thermodinamic parameter was reported by Turturicã et al [34]. The stability of anthocyanin pigments is affected by several factors such as heat treatment, storage temperature, light, pH value, chemical structure, oxygen, solvents, and the presence of enzymes, proteins, flavonoids, and metallic ions [31].…”

Investigations on thermal degradation of phytochemicals from lavender extract

“…The degradation kinetics of phytochemicals content in lavender extract was fitted to a first-order fractional conversion kinetic model as described by Turturică et al (2016). The degradation kinetics of antioxidant capacity was described by fitting the first order kinetic model (Eq.…”