Stability of Anthocyanins from Red Grape Skins under Pressurized Liquid Extraction and Ultrasound-Assisted Extraction Conditions

Abstract

Abstract:The stability of anthocyanins from grape skins after applying different extraction techniques has been determined. The following compounds, previously extracted from real samples, were assessed: delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, peonidin 3-glucoside, malvidin 3-glucoside, peonidin 3-acetylglucoside, malvidin 3-acetylglucoside, malvidin 3-caffeoylglucoside, petunidin 3-p-coumaroylglucoside and malvidin 3-p-coumaroylglucoside (trans). The techniques used were ultrasound-assisted extraction and pressurized liquid extraction. In ultrasound-assisted extraction, temperatures up to 75 °C can be applied without degradation of the aforementioned compounds. In pressurized liquid extraction the anthocyanins were found to be stable up to 100 °C. The relative stabilities of both the glycosidic and acylated forms were evaluated. Acylated derivatives were more stable than non-acylated forms. The differences between the two groups of compounds became more marked on working at higher temperatures and on using extraction techniques with higher levels of oxygen in the extraction media.

Phenolics in Foods: Extraction, Analysis and Measurements

“…By opposition, the main limitations often reported are the low selectivity towards the analytes during extraction, and many interferents may be extracted during the extraction process, an exaggerated dilution of the analytes, especially when a large number of cycles are used, and the high requirements in instrumentation, which increases their costs [103][104][105]. However, these limitations in PLE are a well-known extraction technique and have been used for the extraction of polyphenols from several diferent matrices [106][107][108][109][110][111].…”

Research of extraction of biologically active substances from grape pomace by the subcritical water

“…Comparison of the stability of anthocyanins extracted from the grape skin by the subcritical extraction together with ultrasound with the results obtained by microwave extraction showed that the effect of temperature and the resistance of anthocyanins are different [17].…”

Obtaining anthocyanin-rich extracts from frozen açai (Euterpe oleracea Mart.) pulp using pressurized liquid extraction

“…Additionally, anthocyanins are considered to be nontoxic and safe additives (Pina et al, 2012). However, there are some limitations for commercial uses of anthocyanins due to the availability of feedstocks (quantity and quality), difficulty in purifying the extracts, the high cost of raw materials and low stability during processing and storage (Del Pozo-Insfran et al, 2004;Liazid et al, 2014).…”

“…Anthocyanins are relatively unstable pigments, and temperature is the main factor that triggers the degradation of the anthocyanins. Dther factors, such as their chemical structure, pH, presence of light, ions, enzymes or oxygen, can trigger their degradation (Liazid et al, 2014;Sui et al, 2014). However, the color stability of the anthocyanins is increased under acid presence due to the antibrowning effects (Altunkaya & Gökmen, 2009).…”

“…The PLE process has become a feasible alternative for recovering bioactive compounds from vegetal feedstock (Liazid et al, 2014;Liu et al, 2014;Machado et al, 2014 solvent extraction (ASE), pressurized solvent extract ion (PSE) or enhanced solvent extraction (ESE). As the extraction process is performed using high pressures, the solvent remains in a liquid state, even when the temperatures are above the boiling point of the solvent (Richter et al, 1996).…”