Total Phenolic Content Of Juice Research Articles

Phenolic Content of Apple Juice for Cider Making as Influenced by Common Pre-Fermentation Processes Using Two Analytical Methods

Pre-fermentation methods can influence the cider produced from apple juice. This study analyses the influence of pre-fermentation methods; maceration and press fractioning, on the total phenolic content of juice from four apple varieties; ‘Red Delicious’, ‘Pink Lady’, ‘Sturmer’, and ‘Bulmer’s Norman’. The must was macerated for 0 or 2 h and juice was collected at free run or under 200 kpa. Base juice characteristics and total phenolic content was analysed using the Folin–Ciocalteu method and spectrophotometric absorbance at 280 nm (A280), a method used for the analysis of white wine. Both methods of analysing the total phenolic content were used, measuring the same samples to determine if the methods are comparable. No interaction was found between pre-fermentation technique and the results varied by variety and analytical method. High pressure improved the phenolic extraction for ‘Bulmer’s Norman’ juice compared to free run juice when analysed by A280. Non-macerated juice had higher total phenolic content than macerated juice for ‘Red Delicious’ and ‘Pink Lady’ juice when analysed using the Folin–Ciocalteu method. There was a moderate positive correlation between the analytical methods.

Phenolic Compounds Contained in Little-known Wild Fruits as Antiadhesive Agents Against the Beverage-Spoiling Bacteria Asaia spp.

The aim of the study was to evaluate antioxidant activity and total phenolic content of juice from three different types of fruits: elderberry (Sambucus nigra), lingonberry (Vaccinium vitis-idaea) and cornelian cherry (Cornus mas), and their action against adhesion of bacterial strains of Asaia lannensis and Asaia bogorensis isolated from spoiled soft drinks. The antioxidant profiles were determined by total antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl, DPPH), and ferric-reducing antioxidant power (FRAP). Additionally, total polyphenol content (TPC) was investigated. Chemical compositions of juices were tested using the chromatographic techniques: high-performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC-MS). Adhesion properties of Asaia spp. cells to various abiotic materials were evaluated by luminometry, plate count and fluorescence microscopy. Antioxidant activity of fruit juices expressed as inhibitory concentration (IC50) ranged from 0.042 ± 0.001 (cornelian cherry) to 0.021 ± 0.001 g/mL (elderberry). TPC ranged from 8.02 ± 0.027 (elderberry) to 2.33 ± 0.013 mg/mL (cornelian cherry). Cyanidin-3-sambubioside-5-glucoside, cyanidin-3-glucoside, and cyanidin-3-sambubioside were detected as the major anthocyanins and caffeic, cinnamic, gallic, protocatechuic, and p-coumaric acids as the major phenolic acids. A significant linear correlation was noted between TPC and antioxidant capacity. In the presence of fruit juices a significant decrease of bacterial adhesion from 74% (elderberry) to 67% (lingonberry) was observed. The high phenolic content indicated that these compounds may contribute to the reduction of Asaia spp. adhesion.

Comparison of Ascorbic Acid, Total Phenolic Content and Antioxidant Activities of Fresh Juices of Six Fruits Grown in Oman

Background: Regular consumption of fruits and their juices play a beneficial role in the prevention of many diseases owing to the presence of dietary antioxidants such as ascorbic acid, flavonoids and polyphenols. Aim: The aim of the study was to analyze and estimate total phenolics, ascorbic acid content and to investigate free radical scavenging activity of six locally grown and commonly eaten fruits in Oman. Methods: The fruits were thoroughly washed and mechanically squeezed to obtain the juices. The fruit juices after filtration were analyzed for total acidity, ascorbic acid, total phenolic content and in- vitro antioxidant activity by alkalimetery, iodimetric (volumetric), Folin Ciocalteu reagent (colorimetric) and 1,1, diphenyl picrylhyrazyl (DPPH) assay methods respectively. Key findings: Lime juice was found to be the most acidic while grapefruit juice had the maximum ascorbic acid content. Total phenolic content of the juices were observed in the following order of decreasing levels; pomegranate>grapefruit>lemon>lime>s weet melon>watermelon. The result of in- vitro antioxidant activity of all juices, barring watermelon and sweet melon, were quite significant, but the highest scavenging activity of DPPH radicals was exhibited by pomegranate juice closely followed by grapefruit and lemon juices respectively. Conclusion: The Results of this study indicated that these fruits are important to the consumer’s health and a potential source of dietary antioxidants due to their high phenolic and ascorbic acid contents.

Application of decolourized and partially purified polygalacturonase and α-amylase in apple juice clarification.

Polygalacturonase and α-amylase play vital role in fruit juice industry. In the present study, polygalacturonase was produced by Aspergillus awamori Nakazawa MTCC 6652 utilizing apple pomace and mosambi orange (Citrus sinensis var mosambi) peels as solid substrate whereas, α-amylase was produced from A. oryzae (IFO-30103) using wheat bran by solid state fermentation (SSF) process. These carbohydrases were decolourized and purified 8.6-fold, 34.8-fold and 3.5-fold, respectively by activated charcoal powder in a single step with 65.1%, 69.8% and 60% recoveries, respectively. Apple juice was clarified by these decolourized and partially purified enzymes. In presence of 1% polygalacturonase from mosambi peels (9.87 U/mL) and 0.4% α-amylase (899 U/mL), maximum clarity (%T(660 nm) = 97.0%) of juice was attained after 2 h of incubation at 50 °C in presence of 10 mM CaCl2. Total phenolic content of juice was reduced by 19.8% after clarification, yet with slightly higher %DPPH radical scavenging property.

Efficacy of ozone against Alicyclobacillus acidoterrestris spores in apple juice

Alicyclobacillus acidoterrestris survives during the typical pasteurization process and can cause the spoilage of fruit juices thanks to its spore forming and thermo-acidophilic nature. In recent years, A. acidoterrestris has become a major concern to the fruit juices industry worldwide. This study was undertaken to evaluate ozone for the reducing number of A. acidoterrestris spores in apple juice. Apple juice inoculated with A. acidoterrestris spores was bubbled with continuous stream of two different constant concentrations (2.8 and 5.3mg/L) of ozone at 4 and 22°C up to 40min. Level of A. acidoterrestris spores in juice decreased by 2.2 and 2.8 log after 40min of ozonation at 4°C with concentrations of 2.8 and 5.3mg/L, respectively. Treatments at 22°C for 40min with 2.8 and 5.3mg/L ozone resulted in 1.8 and 2.4 log reductions of spore viability, respectively. At the ozone concentration of 5.3mg/L, significant (P<0.05) reductions were observed in total phenolic content of juice at both temperature levels. However, treatments performed at 2.8mg/L were observed to have no significant (P>0.05) effect on total phenolic content. The results presented in this study indicate that over the 2 log reduction in the count of A. acidoterrestris spores in apple juice can be achieved by bubbling ozonation at 4°C without causing a significant decrease in total phenolic content of product. Therefore, it can be suggested that bubbling ozonation is a promising method for the control of A. acidoterrestris in fruit juices.