TOTAL ANTHOCYANINS IN FRESH FRUIT AND COMPOTE OF "OBLACINSKA" SOUR CHERRY (PRUNUS CERASUS L.)

Anthocyanins are secondary metabolites of plants in the flavonoid family. Red and blue fruits are the main sources of anthocyanins, because cyanidin-3-glucoside is one of the most common and gives the red colour of the fruit. They are soluble in water and are 100 % absorbed by the human body. Anthocyanins are powerful antioxidants that protect our body from free radicals. They have a unique ability to resist ultraviolet light and reduce the risk of serious illness. Nutritionists recommend the use of anthocyanins in amounts of 10 to 15 mg per day. Sour cherry (Prunus cerasus L.) contains high levels of anthocyanins that have strong antioxidant and anti-inflammatory properties. In this paper, for the determination of the content of total anthocyanins, fresh fruits from the sour cherry "Oblacinska" variety and compotes of the same variety sweetened with sucrose and stevia are used. Anthocyanins are examined according to the following method: AOAC Official Method 2005.02, Total Monomeric Anthocyanin Pigment Content of Fruit Juices, Beverages, Natural Colorants, and Wines, pH Differential Method. The content of anthocyanins is in the following order: 32.00 mg cyanidin-3-glucoside equivalents / 100 g in fresh sour cherry fruits, 16.10 mg cyanidin-3-glucoside equivalents / 100 g in sour cherry compote with sucrose and 16.12 mg cyanidin-3-glucoside equivalents / 100 g in sour cherry compote with stevia

STORAGE IMPACT ON THE QUALITY OF RASPBERRY AND PEACH JAMS

Abstract The aim of this study is to evaluate the quality properties of raspberry and peach jams during storage. Jams were prepared with a reduced amount of sucrose, citric acid and low-estrified pectin with the addition of calcium ions in the form of calcium citrate. Physico-chemical parameters, such as total dry matter, soluble solids, sugars, total acids, pH, vitamin C, fats, proteins and ash after storage of 15 and 90 days were tested. The jams were exposed to microbiological analysis also. Results showed that the values of ash, fats and vitamin C were not changed regardless the storage period of the analysed raspberry and peach jams. The period of storage increased the values of total dry matter from 44.97% to 45.86%, soluble solids from 40.17 °Brix to 41.5 °Brix and total acids from 1.47% to 1.49% in raspberry jam. In peach jam these results changed from 42% to 44.1%, from 41.92 °Brix to 42.9 °Brix, and from 0.92% to 0.97% respectively. Microbiological examinations indicate that jams are microbiologically proper according to standards. From the overall results it can be concluded that the storage period has effect on the prepared raspberry and peach jams, but their quality remains good and has maximum consumer acceptance