Changes in Elderberry (Sambucus nigra L.) Juice Concentrate Polyphenols during Storage

Elderberry (Sambucus nigra L.) juice concentrate is highly rich in polyphenols, particularly anthocyanins and flavonols, which have been associated with a wide range of health-promoting properties. Phenolic compounds, in particular anthocyanins, are unstable and may change during storage, which might influence the product color quality and its potential health effects. The aim of this study was to evaluate the changes in the polyphenols profile of elderberry juice concentrate produced at an industrial scale during seven months of storage at 5 °C and at room temperature. The total phenolic content, the total monomeric anthocyanins, the percent polymeric color, and the ABTS•+ scavenging activity were monitored over time. In addition, the profile and content of the main individual phenolic compounds were also assessed by HPLC-DAD. The results show that cyanidin-3-O-sambubioside, cyanidin-3-O-glucoside, cyanidin-3-O-sambubioside-5-O-glucoside, cyanidin-3,5-O-diglucoside, chlorogenic acid, rutin, and quercetin-3-O-glucoside were the main phenolic compounds identified. Storage at room temperature resulted in a strong reduction in total monomeric anthocyanin content accompanied by an increase in percent polymeric color values. Cyanidin-3-O-sambubioside and cyanidin-3-O-glucoside degraded faster than cyanidin-3,5-O-diglucoside and cyanidin-3-O-sambubioside-5-O-glucoside. Concentration of chlorogenic acid also decreased over storage, whereas rutin and quercetin-3-O-glucoside were quite stable. Storage at 5 °C caused a lower impact on the contents of anthocyanins and chlorogenic acid and the percent polymeric color was not affected. The total phenolic content and the in vitro antioxidant activity remained quite similar over the time, for both temperatures, suggesting that elderberry concentrates still preserve their health benefits of antioxidant capacity after seven months of storage.

Farklı Maviyemiş Çeşitlerinden (Vaccinum Sp.) Üretilen Reçel ve Marmelatın Bazı Özelliklerinin Belirlenmesi

In this study, seasonal fruits belonging to two different varieties of Blueberry (Brigitta and Darrow) grown in Turkey were processed into jam and marmalade in order to ensure their availability throughout the year. It is aimed to examine the changes in the phytochemical properties of the obtained products during the storage period, such as total phenolic substance, total anthocyanin and antioxidant capacity, which are extremely important in terms of nutrition and health. Total phenolics content (TPC), total antioxidant capacity (TEAC and FRAP), total anthocyanins (TA), polymeric color (PC) and hydroxymethylfurfural (HMF) analyses were performed in fresh currant fruits at the beginning of the storage. Also, the same analyses were carried out on jams and marmalades at the end of 6-month storage period. During storage, the amount of total phenolic compounds, TEAC value, FRAP value and amount of anthocyanin values for jam and marmelade samples varied between respectively are 178.68-518.45 μg GAE/g; 1.16-11.60 μmol TE/g; 1.83-10.33 μmol TE/g; 7.35-298.22 µg cy-3 glu/g. Darrow blueberry samples had the highest values in the all types of blueberry jam and marmelade during storage. At the end of 6 months of storage period, it was observed to jam and marmalade samples of Darrow variety had the highest increase (124% and 73%) in terms of polymeric color value, on the other hand jam and marmalade samples of Brigitta variety had the highest increase (65% and 87%) in terms of HMF value.

Enzymatic coloration and finishing of wool with laccase and polyethylenimine

Enzymes have been widely used in textile wet processing. The precise reaction specificity of an enzyme has been utilized for specific or targeted textile finishing without causing undesirable fiber damage. Laccases are important enzymes for application in textile processing due to their great versatility and capability of catalyzing the oxidation of a broad range of substrates. The investigation of laccase-catalyzed coloration towards either wool or polyethylenimine was carried out. It is understood that amino groups from wool and polyethylenimine are involved in the formation of polymeric color during laccase catalyzation of catechin and gallic acid. The color depth and shrink-resistance of wool can be improved significantly by incorporating a multi-primary amine compound, such as polyethylenimine, and a crosslinking agent, such as glycerol diglycidyl ether, in the enzymatic coloration process of wool. This demonstrated the potential to achieve combined coloration and shrink-resistant finishing for wool fabrics.