Fruit Juice Extraction Research Articles

In vitro erythrocyte membrane stabilization properties of Carica papaya L. leaf extracts

Background:Carica papaya L. fruit juice and leaf extracts are known to have many beneficial medical properties. Recent reports have claimed possible beneficial effects of C. papaya L. leaf juice in treating patients with dengue viral infections. This study aims to evaluate the membrane stabilization potential of C. papaya L. leaf extracts using an in vitro hemolytic assay.Materials and Methods:The study was conducted in between June and August 2010. Two milliliters of blood from healthy volunteers and patients with serologically confirmed current dengue infection were freshly collected and used in the assays. Fresh papaya leaves at three different maturity stages (immature, partly matured, and matured) were cleaned with distilled water, crushed, and the juice was extracted with 10 ml of cold distilled water. Freshly prepared cold water extracts of papaya leaves (1 ml containing 30 μl of papaya leaf extracts, 20 μl from 40% erythrocytes suspension, and 950 μl of phosphate buffered saline) were used in the heat-induced and hypotonic-induced hemolytic assays. In dose response experiments, six different concentrations (9.375, 18.75, 37.5, 75, 150, and 300 μg/ml) of freeze dried extracts of the partly matured leaves were used. Membrane stabilization properties were investigated with heat-induced and hypotonicity-induced hemolysis assays.Results:Extracts of papaya leaves of all three maturity levels showed a significant reduction in heat-induced hemolysis compared to controls (P < 0.05). Papaya leaf extracts of all three maturity levels showed more than 25% inhibition at a concentration of 37.5 μg/ml. The highest inhibition of heat-induced hemolysis was observed at 37.5 μg/ml. Inhibition activity of different maturity levels was not significantly (P < 0.05) different from one another. Heat-induced hemolysis inhibition activity did not demonstrate a linear dose response relationship. At 37.5 μg/ml concentration of the extract, a marked inhibition of hypotonicity-induced hemolysis was observed.Conclusion:C. papaya L. leaf extracts showed a significant inhibition of hemolysis in vitro and could have a potential therapeutic effect on disease processes causing destabilization of biological membranes.

Extraction and clarification of apple juice with polygalacturonase obtained from apple (&lt;i&gt;Malus domestica&lt;/i&gt;) fruits deteriorated by &lt;i&gt;Aspergillus niger&lt;/i&gt;

Pectinase is used commercially in the clarification and extraction of fruit juice from different fruit s. Green apples and Red apples obtained from the fruits section of a supermarket, Idiroko road, Ota were s urface sterilized and inoculated with Aspergillus niger . The stock culture was subcultured on Sabouraud Dextrose agar plates and 72-hr-old culture of Aspergillus niger served as the inoculum. The fruits were incubated for twenty-five days at room temperature (25 °C). Control fruits were similarly treated except that sterile inoculum was used for the inoculation. Extracts from the ino culated fruits exhibited appreciable polygalacturon ase activity while those from the uninoculated fruits p ossessed only traces of the enzyme activity. The polygalacturonase obtained after enzyme extraction was applied to freshly ripe apple fruits under cont rolled experimental conditions to investigate the role of polygalacturonase in the production of apple juice. The juice in the cylinder to which polygalacturonase was adde d was visually clearer and more than that with dist illed water. The optimum temperature of incubation for th e clarification of apple fruits with polygalacturon ase obtained from apple fruits deteriorated by Aspergillus niger was 25 °C. © 2011 International Formulae Group. All rights res erved.

Effect of Hydro-Alcoholic Extract of Cucurbita Maxima, Fruit Juice and Glibenclamide on Blood Glucose in Diabetic Rats

Problem statement: Cucurbita maxima has been used traditionally in Mexico, China and India as antidiabetic agents. Approach: The present study was to evaluate the hypoglycemic activity of fruit juice and hydro-alcoholic extract of Cucurbita maxima for validation of its folkloric use. Results: Hypoglycemic activity was evaluated on streptozotocin induced diabetic rats at the doses of 100 and 200 mg kg-1 for 28 days. Blood glucose level was evaluated on 0, 7, 14, 21 and 28 days. Oral daily administration of both fruit juice and extract led to significant decrease in hyperglycemia as compared to unfed diabetic control. High dose of both the treatment is more effective than low dose. Extract show more hypoglycemic effect than fruit juice. Conclusion/Recommendations: The result of this study scientifically proved the folkloric use of Cucurbita maxima as hypoglycemic agent. Thus the plant can be key contributor in alternative remedy in the treatment of diabetes.

Antimicrobial Activity of Six Different Parts of the Plant Citrus medica Linn.

Introduction: Antimicrobial activity of fruit juice and ethanolic extracts of root, leaf, bark, peel and pulp of citron (Citrus medica Linn., Rutaceae) was examined against seven bacteria (Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus vulgaris), two fungi (Aspergillus flavus and A. niger) and a yeast Candida albicans of clinical origin. Methods: The level of antimicrobial effects was established using an in vitro disc diffusion method; minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined by standard agar dilution method. Results: All extracts and fruit juice showed varied level of antibacterial activity against one or more test bacteria. Antifungal activity was shown by only root extract and fruit juice while C. albicans was resistant to all tested plant samples. Broad spectrum antimicrobial activity was shown by fruit juice (MIC <1% to 3.5% and MBC 1% to 7% v/v) and fruit pulp (MIC 25 mg/ml and MBC 30 to 75 mg/ml). Root extract was found highly potent with MIC as small as 0.5 mg/ml and MBC 1 mg/ml against S. aureus. Among all tested plant samples leaf and peel extracts have shown less antimicrobial activity. Conclusion: It is concluded that fruit juice and juiceless fruit pulp extract have shown broad antimicrobial activity while root extract was very effective against some tested microorganisms.

An innovative process for extraction of fruit juice using microwave heating

The objectives of this study were to evaluate the possibility of extracting juice from selected fruits (plum, apricot, grape) using microwaves and gravity, and to characterize this process. The process uses microwaves for hydrodiffusion of juice from the inside to the exterior of fruit material and earth gravity to collect the fruit juice outside the microwave cavity. The extraction kinetics were fitted by a descriptive model and the corresponding parameters were correlated to the operating conditions. Best yields were obtained at optimized microwave power and from frozen fruits respectively 480 ml kg −1 for plums, 620 ml kg −1 for grapes, and 550 ml kg −1 for apricots. The obtained juices were brightly colored, as this method allows inactivation of endogenous enzymes such as polyphenol oxidase prior to fruit grinding. They were perceived as fairly acidic and for plum and grape presented detectable astringency. The present apparatus permitted fast and efficient extraction even from “hard to press” fruits such as plums and apricots, yielding an original, brightly coloured product.

PURIFICATION, CHARACTERIZATION AND APPLICATION OF THERMOSTABLE EXO-POLYGALACTURONASE FROM STREPTOMYCES ERUMPENS MTCC 7317

ABSTRACT Exo-polygalacturonase (exo-PG) has a wide range of applications in food processing, i.e., juice extraction, clarification of wine, bakery and distillery industries. Culture parameters for optimum production of extracellular exo-PG by thermostable Streptomyces erumpens Microbial Type Culture Collections 7317 were found to be incubation period (36 h), pH (7.0) and temperature (50C). Enzyme production was higher in beef extract (1%) as nitrogen source as compared with others (casein, peptone, yeast extract, ammonium nitrate, etc.). The purified enzyme (by ammonium sulfate precipitation) had a molecular mass of 63.0 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Crude PG from S. erumpens was compared with marketed pectinase (Pectinex, Novozyme, Bagsvaerd, Denmark) in extraction of juice from vegetables (beet roots, carrot and sweet potato) and fruits (guava and pineapple). A 15–20% increase in juice yield was observed from vegetables and fruits with application of S. erumpens PG over Pectinex. PRACTICAL APPLICATIONS The results showed that a moderately thermostable exo-polygalacturonase (exo-PG) was produced by the actinomycetes strain Streptomyces erumpens MTCC 7317 in submerged fermentation. This enzyme can be used in extraction, clarification and depectinization of vegetables and fruit juices whose pHs are around 7.0. Furthermore, the efficiency of the enzyme has been compared with that of standard pectinase (Pectinex, Novozyme, Bagsvaerd, Denmark) for extraction of juice from vegetables (i.e., beet root [Beta vulgaris L.], carrot [Daucus carota L.] and sweet potato [Ipomoea batatus L.]) and fruits (i.e., guava [Psidium guava L.] and pineapple [Ananas comosus L.]). There was 15–20% increase in juice yield from these vegetables and fruits with the application of crude S. erumpens exo-PG over Pectinex.

Efficient Dye-Sensitized Solar Cells Using Red Turnip and Purple Wild Sicilian Prickly Pear Fruits

Dye-sensitized solar cells (DSSCs) were assembled by using the bougainvillea flowers, red turnip and the purple wild Sicilian prickly pear fruit juice extracts as natural sensitizers of TiO2 films. The yellow orange indicaxanthin and the red purple betacyanins are the main components in the cocktail of natural dyes obtained from these natural products. The best overall solar energy conversion efficiency of 1.7% was obtained, under AM 1.5 irradiation, with the red turnip extract, that showed a remarkable current density (Jsc = 9.5 mA/cm2) and a high IPCE value (65% at λ = 470 nm). Also the purple extract of the wild Sicilian prickly pear fruit showed interesting performances, with a Jsc of 9.4 mA/cm2, corresponding to a solar to electrical power conversion of 1.26%.

Changes in permeability of moderate electric field (MEF) treated vegetable tissue over time

Abstract A microscopic examination of beet tissue given a moderate electric field treatment shows that some cells lose their membrane selectivity while others remain intact. Raw, thawed, or precooked potato cylinders were chilled, and then warmed to 25 °C by either allowing them to equilibrate or by MEF treatment. The conductivity from 100 Hz to 20 kHz and apparent dielectric constant from 100 Hz to 5 kHz was initially not significantly different between raw-untreated samples and raw-MEF treated samples, but over 24 h, that of the raw-MEF treated samples increased while that of the raw-untreated samples remained constant. No such distinct pattern emerged from the thawed or precooked samples. The apparent dielectric constant of raw-MEF treated potato above 5 kHz was not significantly different from raw-untreated potato and higher than thawed and precooked potato. None of the samples showed marked changes in dielectric constant at 5–20 kHz over the 24 hour period. Apparently, even mild electrical treatments permeabilize vegetable tissue, permitting enhanced diffusion. This work has implications in improving nonthermal permeabilization processes for eukaryotic cells, which can be used in fruit and vegetable drying and juice extraction operations.

PRODUCTION AND CHARACTERIZATION OF THE CASHEW APPLE (ANACARDIUM OCCIDENTALEL.) AND GUAVA (PSIDIUM GUAJAVAL.) FRUIT POWDERS

ABSTRACT Cashew apple and guava residues from fruit juice processing industry were prepared as dehydrated fruit powders. Differences in compositional and physicochemical characteristics between both fruit powders were significant at the 5% probability level, with exception to ash content. It is important to point out that despite the dehydration process, both samples can still be considered good sources of vitamin C. In addition, the results show that the guava and cashew apple powders may be useful in the food industry as high dietary “fiber ingredients.” Higher lipid (14.05%) content was observed in guava powder. The guava powder could be an alternative source of lipid. The data also indicated that these materials are good sources of ash. The results suggest further utilization of these residues as valuable food ingredients or as a resource for nutraceuticals. PRACTICAL APPLICATIONS Large quantity of agro-industrial residues formed by fruit juice extraction represents a major disposal problem. An alternative to recycling the fruit-industrial residue is to submit it to drying processes and transform into value-added products as dehydrated fruit powder. In this way, this process contributes to diminish the problem and to recover valuable biomass and nutrients. The purpose of this study was to develop a technology to obtain guava and cashew apple powders with the objective of finding alternatives to the exploitation of these residues as valuable sources of vitamin C, as ashes and lipid that should also be regarded as potential nutraceutical resources in future or functional ingredients.

Analysis of Chlorpyrifos in Water, Fruit Juice, and Honeybee Extract by Chemiluminescent Elisa

The suitability of competitive enzyme-linked immunosorbent assays (ELISAs) with chemiluminescent detection-based immobilized antigen (indirect assay) for rapid and accurate determination of chlorpyrifos in various food matrices was tested. The limit of detection (LOD) values were 1–1.75 ng mL−1, the standard curve midpoint (IC50) was 3.5 ng mL−1, and the assay duration was 1.5 h. Assay application to the analysis of honeybee extract resulted in chlorpyrifos recoveries varying between 62 and 83% in 5–15 ng mL−1 herbicide concentration range.

Purification, characterization of pectinase produced from apple pomace and its evaluation in the fruit juice extraction and clarification

Purification, characterization of pectinase produced from apple pomace and its evaluation in the fruit juice extraction and clarification

Determination of Postharvest Fungicides in Fruit Juices by Solid-Phase Extraction Followed by Liquid Chromatography Electrospray Time-of-Flight Mass Spectrometry

A multiresidue method using liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS) has been developed for the quantitative analysis of five widely used postharvest fungicides (carbendazim, thiabendazole, imazalil, prochloraz, and iprodione) and two of their transformation products (imazalil and prochloraz metabolites) in fruit juices. LC-TOFMS in positive electrospray ionization mode was used to quantify and confirm trace levels of these fungicides in fruit juices. The proposed method consists of a sample treatment step based on solid-phase extraction using hydrophilic-lipophilic-balanced polymer-based reverse-phase SPE cartridges (Oasis HLB) and methanol as an eluting solvent. Fruit-juice extracts spiked at different fortification levels (10 and 20 microg L(-1)) yielded average recoveries in the range of 71-109% with RSD (%) below 15%. Subsequent identification, confirmation, and quantitation were carried out by LC-TOFMS analysis. The confirmation of the target species was based on accurate mass measurements of protonated molecules ([M+H]+) and fragment ions, obtaining routine accuracy errors lower than 2 ppm in most cases. The obtained limits of detection (LODs) of the proposed method were in the range of 0.08-0.45 microg L(-1). Finally, the proposed method was successfully applied to the analysis of 23 fruit juice samples collected from different European countries and the United States, showing the potential applicability of the method in routine analysis. Over 50% of the samples tested contained pesticide residues, but relatively low concentration levels were found.

Comparison of Physico–Chemical and Sensory Characteristics of Pawpaw Juice Extracted with Locally Produced and Commercial Pectin Enzymes

Fruit juices are often extracted more efficiently (faster rate of extraction or higher yield) by the application of pectin enzymes which are commercially available. A survey of small scale juice processors in Ghana indicated low level of production due to inefficient methods of extraction. These processors could therefore benefit from use of pectin enzymes in their operation. Our laboratory has been investigating the activity of pectin enzymes produced locally from Saccharomyces cerevisiae (ATCC 52712) in fruit juice processing. In this report, pawpaw juice was extracted with the Saccharomyces cerevisiae enzyme as well as a commercial pectin enzyme, Rohapect D5L under previously determined optimum conditions. The characteristics of the juices were then compared in order to evaluate the usefulness of the locally produced yeast enzyme to the local fruit juice industry. Fixed quantities of the yeast and commercial enzymes were added to a known amount of papaya mash and the samples held at room temperature for 30 minutes after which the samples were filtered to obtain the juice. Sensory analysis as well as physical and chemical properties of the juices were then determined on each sample. Physico – chemical characteristics of pawpaw juice such as pH, titrable acidity and color were not different when compared to control or the commercial enzyme extracted juice. Similarly, important sensory characteristics of the juice such as aroma, color, taste, cloudiness and acceptability were also comparable to that of the control and those extracted with the commercial enzyme. The results indicate the possibility of using locally produced pectin enzymes for fruit juice extraction. The potential applicability of the method to the industry is being evaluated in a scale – up extraction process. Journal of Science and Technology Vol. 26 (3) 2003: pp. 56-63

Flacourside, a new 4-oxo-2-cyclopentenylmethyl glucoside from the fruit juice of Flacourtia indica

A new glucoside ester, named flacourside, has been isolated together with known methyl 6- O-( E)- p-coumaroyl glucopyranoside and 6- O-( E)- p-coumaroyl glucopyranose from the n-butanol extract of fruit juice of the Flacourtia indica. The structure of flacourside has been determined to be 4-oxo-2-cyclopentenylmethyl 6- O-( E)- p-coumaroyl-β- d-glucopyranoside on the basis of spectroscopic studies.

COMBINED EFFECTS OF ENZYME DOSAGE AND REACTION TIME ON PAPAYA JUICE EXTRACTION WITH THE AID OF PECTIC ENZYMES - A PRELIMINARY REPORT

Pectic enzymes are widely used in the food industry for fruit juice extraction as well as in the clarification of cloudy juices. Our laboratory has been using pectic enzymes produced from a strain of Saccharomyces cerevisiae (ATCC 52712) in different applications including fruit juice extraction. The enzyme was produced in the laboratory by culturing the yeast in papaya juice supplemented with 1% pectin for 6 days. Known amounts of enzyme preparation (0–40 mg protein) were added to a measured weight of papaya mash for varying reaction periods (30–90 min) and the amount of free-run juice obtained in each treatment compared with a control sample. Treatment of 200 g of papaya mash with different dosages of the pectic enzyme extract resulted in rapid increases in flow rate of free-run juice. Mash treated with 32 mg of total protein extract with a 30-min reaction time was the optimum for a maximum rate of juice flow (25 mL/min) when initial rates were measured. There was no significant difference (P > 0.05) between the red- and yellow-fleshed varieties of the papaya used. When juice flow was monitored over 6 min, the treated samples gave a flow rate that was more than twice those of the untreated samples. This biotechnological approach could be adopted to enhance papaya-juice production by local fruit juice processors when parameters for scale-up processes are established.

Ultrasensitive Magnetic Particle-Based Immunosupported Liquid Membrane Assay

A magnetic particle-based immuno-supported liquid membrane assay (m-ISLMA) based on chemiluminescence detection of a horseradish peroxidase-labeled hapten tracer that allows sample cleanup, analyte enrichment, and detection in a single analysis unit has been developed. Antibodies were immobilized on magnetic beads, and their position in the acceptor was controlled by two alternating opposing electromagnetic fields generated by a voltage applied to either of two electromagnets placed below and above the acceptor channel of the supported liquid membrane unit. The influence of antibody bead dilution in the acceptor was investigated and found to follow the ISLM theory, that is improved enrichment and sensitivity with increasing antibody concentration. Two different extraction procedures were investigated: procedure 1 (m-ISLMA-P1), which keeps the antibody beads trapped at the bottom of the acceptor during the entire analysis process; and procedure 2 (m-ISLMA-P2), which keeps the antibody beads dispersed and in motion in the acceptor phase during the extraction process. m-ISLMA-P2 resulted in 2000 times improved enrichment of simazine and a more than 3 orders of magnitude better limit of detection (LOD(10%)) (1.29 x 10(-5) microg L(-1)) than for m-ISLMA-P1 (2.00 x 10(-2) microg L(-1)) and corresponding microtiter plate magnetic particle-based ELISA (m-ELISA, LOD(10%) 1.30 x 10(-1) microg L(-1)). m-ISLMA-P2 and m-ELISA were further applied for the extraction and analysis of simazine-spiked surface water and fruit juice, finding no evidence for matrix influence for the former method; however, indications that trace amounts (nanograms per liter) of simazine or specific cross-reactants were present in both samples.

Physicochemical properties of fruit of 16 saskatoon (Amelanchier alnifolia Nutt.) cultivars

Physicochemical properties were assessed for the fruit of 16 saskatoon (Amelanchier alnifolia Nutt.) cultivars harvested in 1998–2000 from replicated trials at two sites (Saskatoon and Moonlake, SK). The cultivars included Bluff, Buffalo, Elizabeth (at Saskatoon only), Forestburg, Honeywood, JB30, Martin, Nelson, Northline, PAR 90, Parkhill, Pearson II, Pembina, Smoky, Success, and Thiessen. Fruit weight and total solids, soluble solids, pH, titratable acidity, anthocyanin content, and colour characteristics of the fruit juice extracts were measured. Fruit of Martin, Thiessen and PAR 90 had the highest fruit weights (mean = 1.63 g), and Success and Bluff the lowest (mean = 0.79 g). Total and soluble solids contents ranged among cultivars from 19.9% and 14.0 °Brix, respectively, for JB30, to 27.9% and 20.1 °Brix, respectively, for Pembina. Fruit pH ranged from 3.65 for Nelson to 4.18 for Parkhill and Smoky. Fruit of Nelson had a titratable acidity (0.63%) that was approximately twice that of Success, Pearson II, Forestburg, Honeywood, Smoky and Parkhill. The soluble solids to titratable acidity ratio (SS/TA) differed greatly among cultivars ranging from 27 for JB30 to 55 for Parkhill. The colour characteristics of the fruit juice extracts differed among cultivars in chroma and L values, but not in hue angle. Anthocyanin analysis by HPLC identified four peaks: cyanidin-3-galactoside, cyanidin-3- glucoside and two unknowns. Total fruit anthocyanin content ranged from 414 µg g-1 for Forestburg to 852 µg g-1 for Nelson. Correlations were found between anthocyanin content and fruit pH, titratable acidity, hue angle and L value. Key words: Amelanchier alnifolia, saskatoon, fruit composition, acidity, anthocyanin content

Physicochemical properties of fruit of chokecherry (Prunus virginiana L.), highbush cranberry (Viburnum trilobum Marsh.), and black currant (Ribes nigrum L.) cultivars grown in Saskatchewan

Physicochemical properties of the fruit of chokecherry (Prunus virginiana L.), highbush cranberry (Viburnum trilobum Marsh.), and black currant (Ribes nigrum L.) were assessed from fruit harvested from replicated cultivar trials at Saskatoon, SK, and at Yorkton, SK, in 1999 and 2000. Fruit weight, total solids, soluble solids, pH, titratable acidity, percent pit, estimated percent flesh, and Hunterlab colour characteristics were measured. Fruit of the chokecherry cultivars ranged in their 10-fruit weights from 6.6 to 9.2 g, percent pit from 9.4 to 16.0%, estimated percent flesh from 17.2 to 23.7%, and pH from 3.86 to 4.25. Mean total solids and soluble solids contents were 35.2% and 18.3°Brix, respectively, and did not differ among the cultivars. Hue angle, chroma and L values of chokecherry fruit juice extracts ranged from 34.6 to 88.2°, 15.3 to 23.9, and 23.3 to 51.1, respectively. Fruit of the highbush cranberry cultivars ranged in their 10-fruit weights from 4.1 to 7.3 g, percent pit from 4.6 to 9.0%, estimated percent flesh from 10.9 to 14.0%, soluble solids content from 10.2 to 13.3°Brix, and pH from 2.89 to 3.13. The hue angle and L values of the fruit juice extracts of the highbush cranberry cultivars ranged from 16.0 to 18.2°, and from 15.5 to 21.3, respectively. Mean total solids content and L values were 18.9% and 18.0, respectively; both measurements did not differ significantly among the cultivars. Fruit of the black currant cultivars differed only in their 10-fruit weight, pH and titratable acidity which ranged from 7.5 to 12.8 g, 2.85 to 3.04, and 3.04 to 4.03%, respectively. Mean total solids and soluble solids contents of black currant fruit were 22.3% and 15.8°Brix, respectively. Black currant fruit juice extracts had a mean hue angle, chroma and L values of 13.2°, 12.6 and 9.8, respectively. Key words: Chokecherry, Prunus virginiana, highbush cranberry, Viburnum trilobum, black currant, Ribes nigrum, native fruit

ELECTRONIC NOSE CHEMICAL SENSOR FEASIBILITY STUDY FOR THE DIFFERENTIATION OF APPLE CULTIVARS

The ability to analytically differentiate and match intact apple (Malus domestica, Borkh) fruit and fruit juice extracts from different apple cultivars is of interest to the food industry. This study tested the feasibility of detecting the difference among volatile gases evolved from intact ‘McIntosh (Buhr),’ ‘Delicious,’ and ‘Gala’ apples and their extracted juice using a prototype 32-array polymeric detector chemical sensor. All data were first processed to obtain principal components. PCA analysis clearly separated whole ‘McIntosh,’ ‘Gala,’ and ‘Delicious’ samples from juiced on day 1. PCA analysis of day 2 samples showed clustering of whole vs. juiced for all three cultivars, although there was some overlap between the clusters. A soft independent modeling of class analogy (SIMCA) class discrimination of the sensor principal component data sets was then performed to determine the degree of difference. SIMCA analysis of the same samples showed a pronounced difference (SIMCA value >3.00) for only the ‘McIntosh’ samples. SIMCA values between 2.00 and 3.00 were found for the other two cultivars on day 1. For day 2 samples, no SIMCA values greater than 2.00 were found for any cultivar whole vs. juiced. PCA analysis showed clear separation between cultivars for day 1 whole samples. SIMCA analysis showed that there was a difference between ‘Delicious’ and ‘McIntosh’ and between ‘Delicious’ and ‘Gala.’ Neither PCA nor SIMCA showed good separation between day 2 whole cultivars, nor between juiced cultivars on either day. As a reference, the same sample headspace volatile gases were analyzed with a mass spectrometer. A hierarchical cluster analysis (HCA) of the principal components from the mass spectrometer data sets revealed five clusters that discriminated differences among intact apple and apple juice samples but did not discriminate between samples from different apple cultivars.

Determination of food dyes in soft drinks containing natural pigments by liquid chromatography with minimal clean-up

The essential aim of this work was the optimisation and characterisation of a method for the determination of five synthetic food colours added to soft drinks with natural colours by liquid chromatography with minimal clean-up. The method is simple, rapid, inexpensive and broadly applicable to soft drinks. The results show that tartrazine (E-102), quinoline yellow (E-104), yellow orange (E-110), azo rubine (E-122) and ponceau (E-124) can be determined at low levels simultaneously. The method was evaluated by constructing calibration lines, measurement of recovery and precision, and the limits of quantification and detection. It involves direct injection of a beverage solution (homogenized and degassed) for reversed-phase HPLC analysis with visible detection at a single wavelength. Synthetic colours determination in soft drinks was not affected by the presence of other natural colours contained in drinks with fruit juice and flavour extracts. The results obtained with the samples confirm that the proposed method works well and is useful for serious control or screening of the addition of synthetic colours in soft drinks; the method is therefore recommended for use by the quality control departments of soft drink producers using synthetic food colours.