JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2007
S. VALCHEVA-KUZMANOVA
ABSTRACT Aronia melanocarpa fruit juice (AMFJ) is very rich in phenolic antioxidants, mainly flavonoids from the subclass anthocyanins. The aim of this study was to assess the influence of AMFJ on body and liver mass, plasma lipids and lipoprotein profiles, and the histopathology of liver and aorta in rats fed with cholesterol diets. AMFJ was applied orally for 30 days at doses of 5, 10 and 20 mL/kg. In rats fed the cholesterol-containing diets, AMFJ significantly hindered an increase in plasma lipids (total cholesterol, low-density lipoprotein cholesterol and triglycerides) because of cholesterol feeding. Body weight gains, liver weights, and liver and aorta histopathology were not influenced either by high-cholesterol diets or by AMFJ treatment. In conclusion, AMFJ showed lipid-lowering effects in rats with experimentally induced hyperlipidemia, and could be valuable in reducing lipidemia as a factor of cardiovascular risk. PRACTICAL APPLICATIONS Hyperlipidemia characterized by an increase in low-density lipoprotein (LDL) cholesterol and a decrease in high-density lipoprotein cholesterol is one of the major risk factors for atherosclerosis and cardiovascular disease. Plant foods with high contents of phenolic phytochemicals are reported to be inversely correlated with plasma total cholesterol (TC) and LDL cholesterol. Aronia melanocarpa fruits are remarkably rich in phenolic substances. They are used for human consumption as juice, syrup, jam and wine. Our research demonstrated that A. melanocarpa fruit juice hindered the dietary-induced elevation of plasma TC, LDL cholesterol and triglycerides in rats. In view of the results from our experiment, we can suppose that the juice may be further tested for reducing hyperlipidemia in humans and possibly approved a valuable dietary supplement. [source]

HIGH PRESSURE INACTIVATION OF PECTIN METHYL ESTERASE IN ORANGE JUICE USING COMBINATION TREATMENTS

JOURNAL OF FOOD BIOCHEMISTRY, Issue 6 2001
S. BASAK
ABSTRACT The contribution of several high pressure (HP) processing related factors (pressure level, 300-400 MPa; pressure cycle, 1-3, and pressure-hold time, 30,120 min) on the inactivation of pectin methyl esterase (PME) in single strength (pH 3.7 and 11.4 °Brix) and concentrated (pH 3.5 and 42 °Brix) orange juice was evaluated. A response surface methodology was employed to model the combined effects of factors on the enzyme inactivation. The main effects were described by linear or quadratic functions. For both single strength and concentrated orange juices, the effects of all three main factors and some interactions (pressure level, cycle and holding time) were statistically significant (p<0.05). The dual nature of pressure inactivation of PME (with an instantaneous inactivation due to a pressure pulse, instantaneous pressure fall, and first order rate of inactivation during the pressure hold, yielding D and z values) reported in earlier studies was confirmed. Combination models were developed to predict the residual enzyme activity as influenced by the pressure level, number of pressure cycles and pressure hold time. [source]

THERMORESISTANCE OF PECTIN METHYLESTERASE IN SANGUINELLO ORANGE JUICE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2001
FRANCESCO DE SIO
ABSTRACT The behavior of pectin methylesterase (EC 3.1.1.11) activity as a function of temperature was investigated in Sanguinello orange juice. The thermal inactivation of this enzyme was evaluated in the range of 75,95C and was found to be nonlinear. Due to very low activity content, after the thermal treatment at temperatures above 80C, the active enzyme was concentrated by affinity chromatography. The logarithmic values of decimal reduction times, plotted against temperature, showed a nonlinear pattern featuring a sudden change in slope at temperatures exceeding 85C. The z value determined in the range 85,95C was much higher than that calculated in the range 75,85 C. The decimal reduction times were used to estimate the times of treatment for the enzyme inactivation during a HTST process. [source]

CLARIFICATION OF WATERMELON (CITRULLUS LANATUS) JUICE BY MICROFILTRATION

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2008
Ch. CHHAYA
ABSTRACT Microfiltration of watermelon juice was conducted using stirred membrane cell in continuous mode. The experiments were conducted at operating pressures of 136.5, 204.7 and 276 kPa, and stirring speeds 1,200 rpm (Re = 1.40 × 105), 1,400 rpm (Re = 1.63 × 105) and 1,600 rpm (Re = 1.87 × 105). Permeate flux decline was analyzed using a first-order kinetic model, and correlations were developed for the steady-state polarized layer resistance with the operating conditions, e.g., transmembrane pressure difference, Reynolds number and membrane resistance. The permeate flux was calculated based on the developed correlation, and found to be in good agreement with the actual experimental flux. The change in quality parameters of clarified juice was marginal compared to that of original juice. PRACTICAL APPLICATIONS The application of membrane technology is one of the emerging areas in food industry. The major application includes fruit juice clarification and concentration. Because of the nonthermal nature of membrane separation, the juice can be clarified at room temperature and packed aseptically for a longer shelf life without the loss of its initial quality parameters. The major problem during clarification is decline in permeate flux of fruit juice with time. Identification of causes for flux decline is essential for designing of membrane modules to make the clarification process commercially viable. The quality of juice during storage is vital, and therefore, determination of variation of its physicochemical properties during storage is also important. [source]

THE EFFECT OF ENZYMATIC MASH TREATMENT, PRESSING, CENTRIFUGATION, HOMOGENIZATION, DEAERATION, STERILIZATION AND STORAGE ON CARROT JUICE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2007
HONGMEI LIAO
ABSTRACT The enzyme preparation Pectinex Smash XXL was employed to macerate the carrot pulp, the effect of enzymatic mash treatment (EMT), pressing, centrifugation, homogenization, deaeration, sterilization and storage on carrot juice was investigated. As compared with the control sample, an increase of juice yield, total soluble solid (TSS) and carotenoids in carrot juice was close to 20%, 1% and 26 mg/kg, respectively, after EMT. The EMT also increased the color parameters CIEL*, a*and C*values in carrot juice. However, it significantly decreased the viscosity from 2.54 to 2.09 mPa·s. The centrifugation resulted in a significant decline in turbidity from 240.33 to 187.33 NTU and a significant increase in the color parameters in carrot juice. After homogenization, the turbidity and the carotenoids in carrot juice were significantly reduced from 187.33 to 161.67 NTU and from 61.87 to 58.76 mg/kg, respectively. The turbidity and carotenoids in carrot juice decreased during storage, and all the color parameters had a closer relationship with storage temperature and time; higher storage temperature and longer storage time caused greater loss of color. [source]

QUANTIFICATION OF FLUX DECLINE OF DEPECTINIZED MOSAMBI (CITRUS SINENSIS[L.] OSBECK) JUICE USING UNSTIRRED BATCH ULTRAFILTRATION

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2005
P. RAI
ABSTRACT Ultrafiltration of enzymatically treated mosambi (Citrus sinensis [L.] Osbeck) juice was performed in a batch, unstirred membrane cell. Thin film composite polyamide membrane of molecular weight cut-off 50,000 was used. The flux-decline mechanism was identified by the growth of a gel-type layer over the membrane surface. The flux decline, the gel resistance, the gel-layer thickness and various domains of resistances were calculated at a constant pressure difference in the range of 276,552 kPa. The conventional gel-filtration theory was employed to analyze the flux-decline behavior. The calculated permeate flux and gel-layer resistances were consistent with the experimental results. The calculated gel-layer thickness varied from 4.12 to 74.1 µm for different operating condition (pressure) and time. The time at which the gel resistance becomes equal to the membrane-hydraulic resistance ranged from 13 to 31 s for the pressure range studied herein. Thus, the deposited layer resistance to permeate flow was substantial, throughout the whole operation, except in the first few seconds. [source]

EFFECTS OF CO-IMMOBILIZATION OF PECTINASE AND AMYLASE ON ULTRAFILTRATION OF APPLE JUICE SIMULATE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2001
MARÍA E. CARRÍN
ABSTRACT In view of its possible application in apple juice clarification, the potential of co-immobilized pectinase/amylase by physical adsorption on a polysulfone ultrafiltration hollow fiber was examined. Solutions containing different concentrations of pectin and starch were used. The effect of various operational parameters on the production of reducing compounds, mainly galacturonic acid and maltose, was investigated. Results indicated that relative permeate flux, during ultrafiltration of starch-pectin solutions, was up to 35% higher when commercial pectinase and amylase were co-immobilized on a hollow fiber membrane. Although the concentration of reaction products increased up to 50% with the pectin concentration, the same was not verified when the starch content changed from 3.85 to 5.00 mg/mL. However, the reference permeate flux was improved when starch was added to substrate, independently of its concentration. Considering the size of an average starch granule, this increase in permeate flux was attributed to the removal of pectin gel by dragging. Permeate fluxes were comparable for both batch and permeate recycling operations. [source]

PARTICLE SIZE DETERMINATION OF FOOD SUSPENSIONS: APPLICATION TO CLOUDY APPLE JUICE

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 6 2000
D.B. GENOVESE
ABSTRACT Three different techniques were applied to determine particle size distribution (PSD) of cloudy apple juice: sedimentation-photometry (S-F), scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS). All the three techniques found particles in a range from about 0.05 to 3 micrometers (,m = 10,6m). While calculation of PSD by SEM was based on particle number, calculation of PSD by PCS and S-F were based on intensity of scattered light, and both weight (or volume) and projected area (or absorbed light), respectively. In order to compare results from these techniques, appropriate equations were used to convert distributions from one base to another. Three characteristic diameters were also obtained from each distribution: mean, median and modal. Characteristic diameters range from 0.88 to 2.50 ,m in weight basis, 0.77 to 2.50 ,m in projected area basis and 0.08 to 0.23 ,m in number basis. Differences between these diameters were due to asymmetry in the distributions. [source]

BIOCHEMICAL AND SENSORY QUALITY OF PHYSALIS (PHYSALIS PUBESCENS L.) JUICE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2010
ALY F. EL SHEIKHA
ABSTRACT Ground cherry (Physalis pubescens L.) is one of the most promising exotic fruits and some interesting functional products could be developed from these berries. The fresh juice was yellowish or orangey and had a light, sweet taste with acidic nature (pH 3.5). The titratable acidity was 1.43, polyphenols 76.6 mg/100 mL and vitamin C 38.8 mg/100 mL. Physalis juice was rich in carotenoids (70 µg/mL). The juice had a high level in minerals such as phosphorus (578 mg/100 mL), potassium (1,196 mg/100 mL), zinc (2.4 mg/100 mL) and boron (1 mg/100 mL). The essential amino acids in the juice such as isoleucine, valine and tryptophan (42.97, 39.92 and 39.83 mg/100 mL) were higher than those recommended by Food and Agriculture Organization/World Health Organization/United Nations Union (FAO/WHO/UNU). PRACTICAL APPLICATIONS Tropical pulpy juices play an important role in nutrition as an excellent base for low-calorie and dietetic products. Physalis fruit and juice are nutritious, containing particularly high levels of niacin, carotenoids and minerals. There are very little available data in the literature regarding physicochemical and sensory properties. As part of the first steps toward developing Physalis as commercial crop, the present study aimed to evaluate the nutritional and sensorial properties of fresh juice as a new product from Physalis. [source]

THE EFFECT OF REFRIGERATED STORAGE ON SENSORY PROFILE AND PHYSICAL-CHEMICAL CHARACTERISTICS OF MINIMALLY PASTEURIZED ORANGE JUICE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2009
TATIANA BEATRIS TRIBESS
ABSTRACT Minimal pasteurization of orange juice (OJ) consists of using minimum holding time and temperature to ensure partial inactivation of pectin methylesterase (PME). This process produces juice with preserved sensory attributes and has a better acceptance by consumers when compared with commercially pasteurized OJ. Sensory profile and physical-chemical characteristics of minimally processed OJ was determined, during refrigerated storage, for two OJ blends with different pH values and the same level of PME thermal inactivation. A selected and trained sensorial panel (n = 16) performed sensory analysis, based on a quantitative descriptive analysis, twice a week for 30 days, evaluating the attributes of appearance (suspended particles and color intensity), odor (natural orange and fermented orange) and flavor (orange characteristic, fermented orange, acid and bitter taste). Storage presented great effect on OJ sensory profile; however, it was not noticeable on physical-chemical characteristics. PRACTICAL APPLICATIONS Minimal pasteurization of orange juice (OJ) consists of using minimum holding time and temperature to ensure partial inactivation of pectin methylesterase. This process produces juice with longer shelf life than fresh squeezed orange juice, preserved sensory attributes and better acceptance by consumers when compared with commercially pasteurized OJ. This study can contribute for quality evaluation of minimally pasteurized OJ under refrigeration. [source]

ESSENTIAL OIL AND OLEORESINS OF CINNAMOMUM TAMALA (TEJPAT) AS NATURAL FOOD PRESERVATIVES FOR PINEAPPLE FRUIT JUICE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2008
I.P.S. KAPOOR
ABSTRACT The essential oil and oleoresins (methanol, ethanol, isooctane and CCl4) from tejpat have been used as a natural food preservative for pineapple juice. The stored samples were studied for pH, total and reducing sugars, ascorbic acid, peroxide value, titrable acidity and microbiological count at fixed time intervals of 7 days. Significant changes were observed during the storage period. The essential oil showed better preservative effect than the oleoresins did. PRACTICAL APPLICATIONS Essential oils and oleoresins derived from spices are considered luxurious items because of their uses in aromatherapy, confectionary, beverages and pharmaceutical industries. Moreover, they also possess antioxidant and antimicrobial efficiency. Essential oil and oleoresins extracted from tejpat are used in the preservation of pineapple juice, which is better and safer than synthetic conservers. This characteristic is of great interest for the food industries. [source]

STUDIES ON THE FERMENTATION OF TOMATO JUICE BY USING ,-CARRAGEENAN IMMOBILIZED LACTOBACILLUS ACIDOPHILUS

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2008
JEN-HORNG TSEN
ABSTRACT Lactobacillus acidophilus was entrapped in ,-carrageenan and used to perform tomato juice fermentation in order to raise the survival of the bacteria in the product. Gel beads with diameters approximately 3.0 mm for cell immobilization were obtained, fresh raw tomatoes were used to make the juice and both free and immobilized cells were applied to carry out the fermentation for 80 h. Cell leakage from the gel beads and proliferation in the juice during the fermentation of immobilized cells were observed. The final viable cell number was attained with 107 cfu/mL in the juice, over 1010 cfu/mL-gel in gel beads for the fermentation of immobilized cell, and ca. 109 cfu/mL for the free cell. Immobilized cells could withstand the unfavorable low pH environment in tomato juice and better growth was achieved compared with free cells. The viable cell counts of immobilized L. acidophilus in the fermented tomato juice could maintain the level of 106 cfu/mL-gel after 10 weeks of cold storage at 4C, in comparison with 104 cfu/mL for free cells. The immobilized cell fermented tomato juice also showed better overall palatability than that of free cells in cold storage at 4C. PRACTICAL APPLICATIONS This study demonstrates the applicability of ,-carrageenan immobilized Lactobacillus acidophilus in the fermentation of tomato juice. The unfavorable low pH condition in tomato juice could be overcome and certain benefits were provided by cell immobilization. [source]

STORAGE STABILITY OF STRAWBERRY JAM COLOR ENHANCED WITH BLACK CARROT JUICE CONCENTRATE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2007
EGÜL KIRCA
ABSTRACT Black carrot juice concentrate was added to enhance the color of strawberry jams prepared from two locally grown cultivars, Osmanl, and Kara. Compared to other cultivars processed to jams, these two cultivars are lightly colored but very aromatic. Color and pigment stability of colored and noncolored (control) strawberry jams were studied during storage. The use of black carrot concentrate as a source of natural colorant stabilized the color of strawberry jam. The stabilization was more noticeable for jams prepared from Osmanl, cultivar. Monomeric anthocyanin degradation was fitted to a first-order reaction model. Storage temperature had a strong influence on anthocyanin degradation. As the storage temperature increased, the stability of anthocyanins decreased significantly in both colored and noncolored jams. Parallel to decrease in monomeric anthocyanins, hue (h°) values of all jam samples increased throughout the storage. However, increase in h° values was much smaller in colored samples than in noncolored samples. High correlation was found between h° value and anthocyanin concentration at 22C (r = 0.910,0.978) and 37C (r = 0.931,0.981). [source]

NUTRITIONAL QUALITY OF IRRADIATED ORANGE JUICE,

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2002
XUETONG FAN
Single-strength orange juice was exposed to 0, 0.89, 2.24, 4.23 and 8.71 kGy gamma radiation at 5C, and then stored at 23C for 6 days and 7C for 21 days. Conversion of ascorbic acid (AA) to dehydroascorbic acid (DHA), and loss of AA, total AA (TAA = AA plus DHA) and total antioxidants increased with radiation dose. Rate of TAA loss due to irradiation was much less than that of AA loss. Compared to nonirradiated juice (0 kGy), juice irradiated at 2.24 kGy or less had similar rates of AA and TAA loss during storage while juice irradiated at 4.23 and 8.71 kGy had higher rates of AA and TAA loss. Loss of total antioxidants in irradiated orange juice appeared to result from loss of AA. [source]

OPTIMIZATION OF GUAVA JUICE AND POWDER PRODUCTION

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2001
CHETAN A. CHOPDA
Enzyme treatment of guava puree was optimized for yield and clarity by first determining the most effective concentration, then varying both incubation time and temperature. Application of Pectinex Ultra SP-L® was optimal using 700 ppm enzyme for 1.5 h at 50C. Clarified guava juice was clearer (89.6%) when prepared using ultrafiltration (MW cut-off 40,60 kDa) rather than plate and frame filtration (82.8%); however, the latter was higher in both soluble solids and ascorbic acid. Clarified guava juice powders were made using freeze-drying, spray drying and tunnel drying. The freeze-dried product had superior quality; however, the spray-dried product was stable and may be more economical. Sensory panelists ranked the cloudy juice prepared from aseptic guava puree highest, and there were no significant differences between the juices from pasteurized, clear nectar, freeze-dried puree powder or juice powder. [source]

COMPARISON OF VOLATILE COMPOUNDS AND CHEMICAL AND PHYSICAL PROPERTIES IN ORANGE JUICE FROM DIFFERENT PARTS OF JINCHEN FRUIT

JOURNAL OF FOOD QUALITY, Issue 2 2010
YU QIAO
ABSTRACT Jinchen is a native sweet cultivar of Citrus sinensis and one of the most important varieties used in orange juice processing in China. The study of flavor components of Jinchen orange juice has not been carried out before. In this paper, the color characteristics, pH value, total soluble solids, total acids, as well as organic acids and sugars were determined in Jinchen orange juice from different parts of fruit (peeled juice, pulp juice, whole fruit juice). The color characteristics were significantly different among three types of Jinchen orange juice. The level of vitamin C and total soluble solids/total acids ratio (TSS/TA) is higher in whole fruit juice. The organic acids and sugars also changed. Pulp juice is rich in the highest amounts of organic acids and sugars. Volatiles from three juices were studied using the solid phase microextraction (SPME) combined with gas chromatography/mass spectrometry. The whole fruit juice has the highest amount of volatile compounds (53.07 mg/L) followed by peeled juice (51.044 mg/L) and pulp juice (27.107 mg/L). Some differences in the constituents of the volatile compounds of three type juices were observed. These results indicated that volatile compounds and quality properties differed in Jinchen orange juice from different parts of fruit. PRACTICAL APPLICATIONS The peeled orange fruits are usually used for juice processing. Great amounts of aroma components with intensive odor are located in the peel of orange. The aroma of pulp possessing weak fresh citrus odor is different from peel. The different parts of the orange utilized in processing have direct impact on juice quality. It is very essential to obtain the data of chemical and physical properties in juice from different parts of orange fruit. The quality information could be used to modify the orange aroma. [source]

EFFECTS OF ACIDIFICATION ON PE ACTIVITY, COLOR AND ANTIOXIDANT PROPERTIES OF COLD BREAK TOMATO JUICE

JOURNAL OF FOOD QUALITY, Issue 1 2008
FALLOU SARR
ABSTRACT Turbidity maintenance, high antioxidant activity and attractive red color are important attributes of good tomato juice. Acidification was found effective in pectin esterase (PE) inactivation and turbidity maintenance. However, no information related to the changes of antioxidant properties after enzyme inactivation by acidification has been reported. In this article, acidification of cold break tomato juice to pH 2 or 3 was conducted after extraction. The changes of antioxidant properties (content and activity) and their correlation with PE activity and color in the juice were studied. Results indicated that acidification enhanced the viscosity of tomato juice by decreasing its PE activity. Significant increases of the main antioxidant contents (lycopene, polyphenols and vitamin C) and antioxidant activities (1,1-diphenyl-2-picrylhydrazyl scavenging, ferrous ion chelating ability [FICA] and reducing power), as well as red color, were also found. In addition, the acidified cold break tomato juice exhibited better FICA and reducing power than butylated hydroxyanisole and, -tocopherol. This finding reveals the possibility of producing tomato juice with high antioxidant capacities by acidification. PRACTICAL APPLICATIONS The consumers' demand for healthy products with high quality toward fresh and health has increased remarkably these years. Tomato is one of the most popular vegetable juices, and its important quality aspects are color, stability and antioxidant capacity. Pectin esterase is the principal agent responsible for tomato juice stability. In addition, the goal of tomato juice processors is to optimize processing conditions by prevention of heat and oxidative damages on antioxidant components. Our results indicated that acidification may stabilize tomato juice and improve its color characteristics and main nutritional factors. Therefore, the acidification treatment could be used as a tool for providing the attractive color and enhancing the nutritional value and health-promoting properties of cold break tomato juice. [source]

VISCOSITY AND QUALITY OF TOMATO JUICE AS AFFECTED BY PROCESSING METHODS

JOURNAL OF FOOD QUALITY, Issue 6 2007
CHARANJIT KAUR
ABSTRACT Quality and viscosity of tomato juice is strongly governed by mechanical and thermal abuse during processing. The effect of processing and storage duration on the viscosity and quality parameters of tomato juice was evaluated in the present work. Tomato juice was obtained by two different methods, normal method (NM) and variable method (VM), and was heated by both conventional and microwave hot break treatments. Tomato juice was evaluated for various quality characteristics including precipitate weight ratio, degree of serum separation (DOSS), Brookfield viscosity, lycopene levels, vitamin C, phenols and antioxidant activity. Changes observed in several quality parameters during storage were statistically insignificant. The methods and processing had the greatest contribution toward viscosity, whereas storage duration had no significant effects. Viscosity parameters viz precipitate weight, DOSS and Bostwick consistency revealed that juice processed by VM was more viscous than that of NM, irrespective of the hot break processing used. Ascorbic acid and lycopene content varied significantly with mechanical methods and processing conditions. However, phenolic content and antioxidant activity remained stable. The variable process represents an improvement over the conventional by enabling tomato processors to improve the consistency of the tomato product. PRACTICAL APPLICATIONS Quartering or slicing tomatoes followed by hot break processing techniques can significantly improve the quality of tomato juice in terms of reduced degree of serum separation and precipitate weight ratio. The modified technology could be considered as a viable and economical method for small- and medium-scale tomato processors with limited resources and facilities at their disposal. [source]

ORGANIC ACIDS PROFILE IN TOMATO JUICE BY HPLC WITH UV DETECTION

JOURNAL OF FOOD QUALITY, Issue 1 2007
OMBRETTA MARCONI
ABSTRACT A simple method was developed to determine 10 organic acids simultaneously in tomato products using reverse-phase high performance liquid chromatography (HPLC) column with the diode array detector set at 210 nm. After centrifugation and filtration, the samples were passed through to an anion exchange resin and the organic acids were released using 0.1 N HCl. The chromatographic separation was achieved with isocratic analysis in a 20-min run. The method was reliable and sensitive. The coefficient of determination of the standard calibration curve is 0.9925 , r2 , 0.9999 and the limit of detection ranged from 0.08 to 6.00 mg/kg for trans -aconitic acid and acetic acid, respectively. The limit of quantification ranged from 0.19 to 15.18 mg/kg for trans-aconitic and acetic acid, respectively. To establish the efficiency of the anion resin the procedure was applied to a standard solution of a mixture of organic acids. The organic acids recovery ranged from 87.0% ± 1.9 for citramalic acid to 109.9% ± 5.2 for fumaric acid. [source]

USE OF CLARIFYING AGENTS AND ULTRA FILTER TO DECREASE FUMARIC ACID, HMF AND INCREASE CLARITY OF APPLE JUICE

JOURNAL OF FOOD QUALITY, Issue 3 2006
YAHYA TULEK
ABSTRACT In this study, the effects of eight different processing treatments of apple juice (AJ) production (Process 1: Ultra filtration [UF], Process 2: Activated charcoal [AC], Process 3: polyvinylpolypyrolidone [PVPP], Process 4: Gelatine [G] + Bentonite [B], Process 5: [G + B] + UF, Process 6: [G + B] + AC, Process 7: [G + B] + PVPP and Process 8: [G + B] + Kieselguhr [K]) on the fumaric acid (FA), hydroxymethylfurfural (HMF), color and clearness values of AJ were investigated. With the exception of Processes 1 and 5, AC, K, PVPP, G and B were used at various doses in other processes. FA, HMF, color and clearness values of control sample were determined as 3.24 mg/L, 3.84 mg/L, 48.5 (%T) and 94.1 (%T), respectively. The highest proportional decrement in FA and HMF values of the samples were observed with Process 6 at the level of 5. The fifth level of Process 6 resulted in 35.8% (3.24,2.08 mg/L) and 35.9% (3.84 to 2.46 mg/L) reductions in FA and HMF values, respectively. On the other hand, the best improvement in clearness of AJ was obtained with Process 6 at the fourth level and obtained as 98.9 (%T). [source]

QUALITY AND STABILITY OF BLUEBERRY JUICE BLENDED WITH APPLE, GRAPE AND CRANBERRY JUICE,

JOURNAL OF FOOD QUALITY, Issue 2 2001
GARY MAIN
ABSTRACT Sensory quality and storage stability of blueberry juice blends were investigated with the goal of maintaining dominant blueberry flavor, aroma and color. Apple juice, Concord and Venus grape juices and cranberry juice cocktail were blended at 75, 50 and 25% with blueberry juice. As the percent of blueberry juice decreased, the intensity of blueberry-related sensory attributes decreased. The 25% Concord and Venus blends were the only blends that resulted in blueberry flavor similar to the reference. Apple and cranberry juice cocktail blended with blueberry juice produced several blends with good flavor and aroma, but they were not readily characterized as blueberry juice. All blends at the 25% level produced blueberry color equal to or greater than the reference. The juice samples were evaluated initially and after three months of storage at 37C. After storage, all blends had decreased red color. [source]

REDUCTION OF PATULIN IN APPLE JUICE CONCENTRATES DURING STORAGE

JOURNAL OF FOOD SAFETY, Issue 1 2005
NURAY KOCA
ABSTRACT In this study, the reduction of patulin content in apple juice concentrates during 6 months of storage at 22 and 30C was investigated. Results demonstrated that reduction in patulin content was dependent on the storage temperature and time. Patulin reductions after 1 month of storage at 22 and 30C were in the ranges of 45,64% and 66,86%, respectively. Levels of patulin were below detectable limits after 4 months of storage at 22 and 30C. [source]

THE CONSUMER SENSORY PERCEPTION OF PASSION-FRUIT JUICE USING FREE-CHOICE PROFILING

JOURNAL OF SENSORY STUDIES, Issue 1 2005
ROSIRES DELIZA
ABSTRACT Free-choice profiling (FCP) was carried out in order to investigate how naive consumers (who had never tried the product before) described and perceived passion-fruit juice. This method allows participants to use their own attributes to describe and quantify food products and beverages. The study used four different samples of passion-fruit juice, analyzed by 10 consumers in three replicates. The data were analyzed by using generalized Procrustes analysis. The first and second dimension accounted for 78.7% of the variance. The product consensus configuration revealed that assessors were able to reproduce samples' description, and also to differentiate samples. Free-choice profiling is a useful method for describing consumer perception of passion-fruit juice. [source]

STEVIOSIDE AS A REPLACEMENT OF SUCROSE IN PEACH JUICE: SENSORY EVALUATION

JOURNAL OF SENSORY STUDIES, Issue 5 2001
GIUSEPPINA PAOLA PARPINELLO
ABSTRACT The suitability of stevioside as a sweetener in peach juice was investigated. Comparison between stevioside and sucrose in terms of sweetness, sweet and bitter aftertastes were determined both in water and peach juice. The results demonstrated that 160 mg/L of stevioside may replace 34 g/L of sucrose in juice, with a 25% decrease in calories, without affecting the sensory characteristics of the product. Synergistic and inhibitory effects between sucrose and stevioside were also monitored at different stevioside concentration. A new juice formulation sweetened with a binary mixture of stevioside (160 mg/L) and sucrose (56 g/L) was not significantly different in terms of desirability from a reference product sweetened with 9% sucrose. [source]

RHEOLOGICAL BEHAVIOR OF POMEGRANATE (PUNICA GRANATUM L.) JUICE AND CONCENTRATE

JOURNAL OF TEXTURE STUDIES, Issue 1 2005
N ALTAN
ABSTRACT The rheological behavior of pomegranate juice (Punica granatum L.), prepared from fresh pomegranates, was studied as a function of solids concentration in the range 17.5,75°Brix at 10,55C, using a controlled stress rheometer. Concentration methods did not influence flow behavior. There were no significant differences (P > 0.05) between viscosity and activation energy values for the pomegranate juices concentrated by different methods. The juices exhibited Newtonian behavior regardless of the concentration method. The effect of temperature was described by an Arrhenius-type equation with an activation energy in the range 5.34,32.2 kJ/mol depending on concentration. An exponential model described better the effect of the soluble solids on the viscosity and Eavalues. A simple equation was proposed for describing the combined effect of temperature and soluble solids content on the juice viscosity. [source]

RHEOLOGICAL BEHAVIOUR OF CLARIFIED MANGO JUICE CONCENTRATES

JOURNAL OF TEXTURE STUDIES, Issue 3 2000
NGASEPPAM IBOYAIMA SINGH
ABSTRACT The rheological behaviour of clarified mango juice was measured at temperatures 15,85C and concentrations 15,66 °Brix, using a rotoviscometer. Mango juice free of pectin and pulp behaves as a Newtonian fluid. The effect of temperature can be described by an Arrhenius-type equation. The activation energy for viscous flow was in the range of 1.64,8.44 kcal/g-mol, depending on the concentration. The effect of concentration was modelled better by an exponential relationship than a power-law relationship. Simple equations are proposed for describing the combined effect of temperature and soluble solids content on the juice viscosity. [source]

ANTIOXIDANT ACTIVITY OF FERMENTED BERRY JUICES AND THEIR EFFECTS ON NITRIC OXIDE AND TUMOR NECROSIS FACTOR-ALPHA PRODUCTION IN MACROPHAGES 264.7 GAMMA NO(,) CELL LINE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006
TRI VUONG
ABSTRACT Serratia vaccinii, a novel bacterium isolated from blueberry microflora, increased the phenolic content of berry juices, and thus increased antioxidant activities. The fermentation capacity of Serratia was investigated with Saskatoon berries, cranberries, strawberries and grapes in both aerobic and anaerobic conditions. It was shown to be compatible with wine yeast in anaerobic fermentations, producing wine with high antioxidant activity. The effects of fermented berry juices were tested on lipopolysaccharide/inferon-gamma-activated macrophages 264.7 NO(,). Data indicated that fermented berry juices strongly inhibited activated-macrophage NO production but induced tumor necrosis factor-alpha production. [source]

FUNGI AND PATULIN IN APPLES AND THE ROLE OF PROCESSING ON PATULIN LEVELS IN JUICES: A STUDY ON NATURALLY CONTAMINATED APPLES

JOURNAL OF FOOD SAFETY, Issue 2 2010
JULIANE ELISA WELKE
ABSTRACT The purpose of this study was to determine the predominant fungal species, including toxigenic strains, patulin levels in apples used for juice production and in produced juices. The possibility of use of apple highly contaminated with patulin to produce juice with lower patulin levels than the limit permitted by Codex Alimentarius was also checked. Sixteen lots of apples and juices were analyzed. The most prevalent fungal population was Penicillium spp. (93%) followed by the Aspergillus spp. (3.5%) and the Rhizopus spp. (3.5%). The mycoflora of apples was composed mainly of species that produce patulin. P. expansum was identified as the most frequently isolated species (66%). Species able to produce patulin were P. expansum and P. griseofulvum. Patulin levels in apples from cold storage ranged from 254.6 to 653.4 µg/kg. Apple juice processing caused average reduction of 95% in patulin levels. Patulin levels ranged from 14.3 to 46.7 µg/L in apple juices. In all samples were found patulin levels lower than the limit of 50 µg/L considered acceptable by the Codex Alimentarius Commission. PRACTICAL APPLICATIONS This study was performed to define the mycoflora of apples and patulin levels in apples that were used for juice production. This approach is useful to evaluate the quality of apples and the effect of processing on patulin to determine if the toxin level can be managed through postharvest procedures. Besides, information about patulin levels in juices is important to contribute for establishing national regulation. [source]

A Study of Heavy Metal Complexation in Grape Juice

ELECTROANALYSIS, Issue 5-6 2005
Íñigo Salinas
Abstract Differential pulse anodic stripping voltammetry, DPASV, has been used to monitor the initial stages of grape juice fermentation, focusing on Zn interactions with natural occurring ligands. Langmuir and Scatchard linearization methods have been employed. A 1,:,1 ratio has been found by either method; from Langmuir data analysis only one ligand population was found, while Scatchard approach gave rise to the detection of two ligand types. Both data analysis procedures led to the same total ligand concentration. When catechin was used as model ligand, a 1,:,1 ratio was found for Zn and also for Cu. [source]

Evaluation of Clarithromycin Resistance in Helicobacter pylori Obtained from Culture Isolates, Gastric Juice, and Feces

HELICOBACTER, Issue 2 2009
Emiko Rimbara
No abstract is available for this article. [source]