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The purpose of the study has been to determine the stability, microbiological quality, and antioxidant properties of extracts from the berry fruits of black chokeberry, American blueberry, and bilberry. In addition, the content of polyphenolic compounds in the extracts was analysed and the ratio of the content of anthocyanins to total phenols (the ACY/TP ratio) was determined. Extracts from the fruits of black chokeberry, American blueberry, and bilberry had different stability, microbiological quality, content of polyphenols, and ACY/TP ratio. The highest stability of anthocyanins and the highest ACY/TP ratio were determined in the extracts from bilberry, and the lowest ones appeared in the extracts from American blueberry. The stability of anthocyanins tended to decline during storage, either cooled or frozen. No bacteria were found in the berry fruit extracts although small contamination with microorganisms (yeast, mould) was detected. The highest content of polyphenolic compounds was determined in the extracts from black chokeberry and the lowest one in the extracts from American blueberry. The antioxidant activity of the extracts ranged from 1.99 to 2.41 TEAC mmol TR/100 g, and the antiradical activity varied from 84.91% to 86.30%. The applied extraction method with citric acid had a positive influence on the stability, microbiological quality, and antioxidant properties of the fruit extracts.
Dalmadi , I., Polyák-Fehér , K. & Farkas , J. (2007): Effects of pressure- and thermal-pasteurization on volatiles of some berry fruits. High Pressure Res. , 27 (1), 169–172. Farkas J
For prevention of non-infectious diseases such as cancer, and cardiovascular disorders consumption of more and more fruits and vegetables is highly advised. Fruits of Ribes and Rubus species are very popular in Hungary. Antioxidant properties of these fruits are well known, but the values of the characteristics depend on several factors including species, cultivars, soil and climate conditions, water and nutrition supply, and so on. Phenolics in several cultivars of raspberry, blackberry and currants grown in Hungary were measured. Total polyphenols and anthocyanins were detected by spectrophotometric methods while flavonoids including apigenin, luteolin, kaempferol, myricetin, quercetin and also ellagic acid were quantified by RP-HPLC technique. Total polyphenol contents of raspberry (yellow and red cultivars), blackberry and currants (white, red and black cultivars) were 219, 244, 379, 333, 192 and 533 mg/100 g, respectively. The concentrations of anthocyanins in the same order were 1.0, 41.9, 145, 0.2, 46 and 354 mg/100 g. Apigenin, luteolin and kaempferol could not been detected in any of the samples. Ellagic acid (2.0 to 23.7 mg/100 g) could be measured in white and red raspberries, in blackberries, and in some red and white currant cultivars. Quercetin could be detected in all berry species ranging from 0.1 to 14.4 mg/100 g. Measurable amount of myricetin was observed only in black currant cultivars between 1.5 and 7.7 mg/100 g. Polyphenols including flavonoids and anthocyanins in berry fruits are important forms of natural antioxidants. These molecules play essential role in the prevention of diseases in the pathomechanism of which free radicals are involved. Berry fruits are good sources of antioxidants consumed either in fresh or in processed forms because of great susceptibility of polyphenols to heat and other physicochemical processes.
The content of potentially antioxidant, anticarcinogenic and antiallergic flavonoid aglycons, quercetin, kaempferol, myricetin, apigenin and luteolin of 45 fruits were determined by RP-HPLC with UV detection. Fresh and dried fruits were purchased in the local markets in Budapest at a period of their most frequent consumption. Total flavonoid content of fruits varied between 0–1000 mg kg –1, the average concentration was about 30 mg kg –1 fresh weight. Quercetin could be detected in most fruits, namely in apples, pear, plums, sweet and sour cherry and berries between 10–53 mg kg –1. Luteolin at a concentration of 20 mg kg –1 was found in melons, apples, kiwi and lemon. Myricetin was in detectable amount in redcurrant, and at very high concentration in some berry fruits (mulberry 453 mg kg –1, raspberry 540 mg kg –1, blackberry 636 mg kg –1, strawberry 994 mg kg –1), and in walnut (4565 mg kg –1). Kaempferol and apigenin were not found in the fruits investigated. None of the five flavonoids was found in some variety of grapes, in peach, pear, banana, orange, grapefruit and tangerine, in nuts such as almond, pistachio, nuts, and in dried fruits such as raisin, date, fig and prunes. These data provide a basis for the evaluation of the average daily intake of Hungarian population and for an epidemiological evaluation of health-promoting effects of flavonoids. __
small trees with simple or pinnate compound leaves, racemose, paniculate or umbellate inflorescence, bisexual or andromonoecious flowers, and berry fruits ( Boissier 1879 , Schonebeck-Temesy 1972 ). Solanum is considered of
Dalmadi, I., Polyák-Fehér, K., Farkas, J. (2007a) Effects of pressure- and thermalpasteurization on volatiles of some berry fruits. High Pressure Research , 27(1): 169–172. Farkas J
.11.004 Mattila , P. , Hellström , J. , and Törrönen , R. ( 2006 ). Phenolic acids in berries, fruits, and beverages . Journal of Agricultural and Food Chemistry , 54 ( 19 ): 7193 – 7199 . 10.1021/jf0615247 Miles , A.A. , Misra , S.S. , and Irwin
-Uzelac , V. , Delonga , K. , Ganić , K.K. , Banović , M. , and Kovačević , D. B. ( 2010 ). Polyphenols and volatiles in fruits of two sour cherry cultivars, some berry fruits and their jams . Food Technology and Biotechnology , 48 ( 4 ): 538
