Evaluation of black grape pomace, a fruit juice by-product, in shalgam juice production: Effect on phenolic compounds, anthocyanins, resveratrol, tannin, and in vitro antioxidant activity.

The aims of this research were to investigate the usability of black grape pomace in the production of shalgam juice, which is a traditional fermented Turkish beverage, to transform the pomace into the high value-added product and to enrich the shalgam juice with phenolic compounds. Black grape pomace and black carrot were used as the sources of polyphenols and five different formulations were obtained according to the amounts of black carrot and black grape pomace. During the fermentation, the samples were taken at different periods and analyzed for anthocyanins, phenolic compounds, antioxidant activity, and tannin content. Gentisic, caffeic, ferulic, coumaric, and chlorogenic acids, catechin, glucosides of kaemferol and isorhamnetin, resveratrol, rutin, cyanidin-3-xylosylglucosylgalactoside, cyanidin-3-xylosylgalactoside, cyanidin-3-xylosylglucosylgalactoside acylated with sinapic acid, ferulic acid, or coumaric acid, and glucosides of cyanidin, petunidin, and malvidin were identified in the shalgam juices that contained both black grape pomace and black carrot in their formulation. Some of these polyphenols were not detected detect in the shalgam juices that were produced from only the black carrot or black grape pomace. During the fermentation, a decrease in the amount of anthocyanins originated from black carrots and an increase in the amount of anthocyanins orginated from black grape pomace were determined. Black grape pomace addition to the formulation before the fermentation caused an increase in the amount of tannin in the shalgam juice samples. Consequently, it is thought that black grape pomace can be fruitfully evaluated in shalgam juice production and can be enhanced by polyphenolic profile of shalgam juice.

Evaluation of antioxidant activity, phenolic, mineral contents and some physicochemical properties of several pine honeys collected from Western Anatolia.

In this study, the qualities of 15 red pine honey samples from different parts of the Mugla province in Turkey were evaluated. Important chemical parameters such as degrees Brix, pH, moisture, ash, electrical conductivity, free acidity, proteins, diastase activity, hydroxymethylfurfurale, total reducing sugar, reducing sugar, sucrose, the five common physical parameters refractive index, density, water activity, dynamic viscosity and color index (L*, a* and b*), and mineral compositions, including potassium, sodium, magnesium, phosphorus, calcium, iron, copper, zinc, manganese, nickel, aluminum, boron, molybdenum, and chromium, were determined. Pine honey samples also were analyzed for total phenolic contents and antioxidant activity. The antioxidant activities were evaluated based on the ability of the pine honey extracts to scavenge 1,1-diphenyl-2-picrylhydrazyl. Significant correlations were obtained between the antioxidant activity and phenolic content (r = 0.887). All samples indicated proper maturity, considering the high soluble solids. The values for ash and electrical conductivity were high (0.24-0.60% and 878-1463 muS/cm, respectively). The concentration of 14 minerals of red pine honeys were determined by inductively coupled plasma-atomic emission spectrometry. All samples contained high amounts of potassium, calcium, phosphorus, sodium, iron, magnesium, aluminum, nickel, and zinc. Within the mineral contents, potassium was quantitatively the most important mineral, having an average content of 3,802 ppm, and accounted for 45% the minerals.