Tracking antioxidant properties and color changes in low-sugar bilberry jam as effect of processing, storage and pectin concentration

<p>Abstract</p> <p>Background</p> <p>Recently, an increased interest in the identification of valuable possibilities for preserving the antioxidant properties of products obtained by thermal processing of fruits rich in bioactive compounds can be noticed. In this regard, an extensive analysis is necessary in terms of thermal processed products behavior in relation to various factors. The purpose of the present study was to assess the effect which processing and storage at 20°C has on the antioxidant properties and color quality of low-sugar bilberry jam with different low-methoxyl pectin (LMP) concentrations.</p> <p>Results</p> <p>For all measured parameters, it should be noted that thermal processing induced significant alterations reported to the values registered for fresh fruit. Most important losses due to thermal processing were recorded for total monomeric anthocyanins (TMA) (81-84%), followed by L-ascorbic acid (L-AsAc) content (53-58%), total phenolics (TP) content (42-51%) and FRAP (ferric reducing antioxidant power) values (36-47%). Moreover, depreciation of the investigated compounds occurred during storage at 20°C. Jam storage for 7 months resulted in severe losses in TMA content in the range 58-72% from the value recorded one day after processing. This coincided with marked increases in polymeric color percent of these products after 7 months of storage. Also, bilberry jam storage for 7 months resulted in a decrease in L-AsAc content of 40-53% from the value recorded one day after processing, 41-57% in TP content and 33-46% from the value recorded one day after processing for FRAP values. By decreasing of LMP concentration in the jam recipe from 1 to 0.3% there has been an increase in losses of investigated compounds.</p> <p>Conclusion</p> <p>Overall, the results indicated that bilberry jams can also represent a good source of antioxidant compounds, although compared to the fruit, important losses seem to occur. Practical application of this work is that this kind of information will be very useful in optimizing the jam processing technology and storage conditions, in order to improve the quality of these products.</p

Antioxidant properties of plant-based food products

W pracy omówiono właściwości przeciwutleniające żywności roślinnej. Podkreślono jej znaczenie w profilaktyce wielu chorób. Bliżej scharakteryzowano owoce, warzywa, nasiona oleiste, zboża, zioła, przyprawy i herbatę. Zwrócono też uwagę na wybrane produkty przetworzone wykazujące dużą pojemność przeciwutleniającą, jak: soki i napoje, wina, tłuszcze roślinne, produkty warzywne i zbożowe. Scharakteryzowano substancje bioaktywne o właściwościach przeciwutleniających obecne w żywności roślinnej, przede wszystkim polifenole, witaminę C, E i karotenoidy. Omówiono take mechanizm działania tych związków, wskazując jednocześnie na zależności między ich koncentracją i składem jakościowym a wielokierunkowym oddziaływaniem in vitro i in vivo. Podkreślono także aktualne trendy w produkcji żywności, ukierunkowane na zastępowanie przeciwutleniaczy syntetycznych – naturalnymi. Stwarza to duże możliwości wykorzystania surowców roślinnych jako ich źródła.The paper focuses on the antioxidant properties of plant food products, which are very important for the prevention of many diseases. Fruits, vegetables, oil seeds, cereals, herbs, spices, and tea are characterized more precisely. Some processed food products were selected and described owing to their high antioxidant capacity: juices, drinks, wines, plant fats, vegetable and cereal products. Furthermore, there were characterized bioactive substances in plant-based foods that have antioxidant properties; first of all such as polyphenols, vitamins C and E, and carotenoids. The paper also discusses mechanisms of their action on the basis of available references, and correlations between their concentration & qualitative composition, as well as their multidirectional in vitro and in vivo effects. Those current trends in the food production are highlighted which suggest that synthetic antioxidants can be substituted for natural antioxidants provided from raw plants as their source. In this way, the potential of applying raw plants may be essentially increased

Fruit mousses as the source of natural antioxidants

Celem pracy było scharakteryzowanie handlowych musów: jabłkowego, jabłkowo-brzoskwiniowego, jabłkowo-gruszkowego, jabłkowo-truskawkowego, jabłkowo-wiśniowego i jabłkowo-porzeczkowego pod względem zawartości związków fenolowych ogółem, aktywności wygaszania rodników DPPH˙ i OH˙. oraz podstawowych wyróżników chemicznych, jak: sucha masa, ekstrakt i kwasowość. Uzyskane wyniki poddano analizie statystycznej. Do oceny istotności różnic pomiędzy wartościami średnimi zastosowano test Duncana. Wykazano statystycznie istotne (p < 0,05) zróżnicowanie badanych musów pod względem zawartości związków fenolowych ogółem oraz aktywności wygaszania rodników DPPH˙ i OH˙, uzależnione od gatunku owoców. Najwięcej związków fenolowych ogółem (216,97 mg/100 g) zawierał mus jabłkowo-porzeczkowy. Jednocześnie wykazywał on najsilniejszą aktywność neutralizacji rodników DPPH˙ (EC50 = 2,83 mg musu). Najniższą natomiast aktywnością (EC50 = 17,10 mg musu) charakteryzował się mus jabłkowo-gruszkowy, o najmniejszej zawartości związków fenolowych ogółem, wynoszącej 54,20 mg/100 g. Mus jabłkowo-porzeczkowy wyróżniał się największą „efektywnością antyrodnikową” (AE) w odniesieniu do rodników DPPH˙. W odniesieniu do rodników OH˙ najbardziej aktywny okazał się mus jabłkowo-gruszkowy. Wykazane różnice zawartości związków fenolowych ogółem, aktywności wygaszania rodników DPPH˙ i OH˙, a także „efektywności antyrodnikowej”, zależne od komponentów owocowych badanych musów, mogą być podstawą do projektowania składu recepturowego, w celu otrzymania produktu o określonych właściwościach przeciwutleniających.The objective of the paper was to characterize the trade mousses made of apple, apple-pear, apple-peach, apple-strawberry, apple-cherry, and apple-currant with regard to their: total content of phenolic compounds, DPPH˙ and OH˙ radical scavenging activity, and to such major chemical characteristics as dry matter, extract, and acidity. The results obtained were statistically analyzed. To evaluate the significance of differences among the means, a Duncan’s test was applied. It was proved that the analyzed mousses differed statistically significantly (p<0.05) with regard to the content of total phenolic compounds and DPPH˙ & OH˙ radical scavenging activity depending on the fruit species. The apple-currant mousse had the highest content of total phenolic compounds (216.97 mg/100 g) and, at the same time, it showed the highest DPPH˙ radical scavenging activity (EC50 = 2.83 mg of mousse). But this activity was the lowest (EC50 = 17.10 mg of mousse) in the apple-pear mousse that also had the lowest concentration of total phenolic compounds (54.20 mg/100 g). The apple-currant mousse was characterized by the highest antiradical efficiency (AE) with respect to DPPH˙. As for the OH˙ radicals, the apple-pear mousse was found to be the most active. The differences found in the contents of total phenolic compounds, in the DPPH˙ and OH˙ radical scavenging activity, and in the antiradical efficiency, depending on the fruit components contained in the analyzed mousses, may provide a basis for designing special composition formulas for the purpose of manufacturing products showing specific, necessary antioxidant properties

Effect of bilberry mash treatment on the content of some biologically active compounds and the antioxidant activity of juices

The aim of the present study was to determine the effect of different bilberry mash treatment methods, i.e. heat treatment, enzymatic treatment and combined treatment (enzymatic maceration preceded by heat treatment) on total phenolics, anthocyanin profile and ascorbic acid as well as on DPPH’ and OH’ radical scavenging activity of juices. Three fractions of juice containing different groups of phenolic compounds were evaluated. Enzymatic maceration of fruit mash was carried out using three enzymatic preparations: Pektopol PT-400, Pectinex BE Colour and Gammapect LC Color. Juices obtained by combined treatment of fruit mash (enzymatic maceration preceded by heat treatment) were the richest source of total phenolics, the concentration of which ranged from 2304 to 4418 mg l−1 in these juices. These juices showed also the strongest DPPH’ and OH’ radical scavenging activity. Juices produced from fruit mash subjected to enzymatic maceration contained the highest amount of anthocyanins. The juices differed considerably with regard to their anthocyanin profile, determined by HPLC. Ascorbic acid content was at a comparable level in all juices, and varied between 13.5 and 16.9 mg/100 g. Fraction I, containing mostly anthocyanins, showed the highest DPPH⤙ and OH⤙ radical scavenging activity, while fraction III, dominated by phenolic acids, was found to be the least active