Effect of activated charcoal on patulin, fumaric acid and some other properties of apple juice

In this study, 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 g/l amounts of activated charcoal (AC) were added into apple juice with a patulin content of 62.3 ppb obtained from a well-established manufacturing company. Apple juice samples were then mixed for 0, 5, 10, 20, and 30 min, respectively. Considerable reduction in the patulin and HMF values was found while there is a dramatic improvement in the colour and clearness of apple juice. However, AC did not cause a significant decrease in the fumaric acid level of apple juice. The best result was obtained at 3.0 g/l AC mixed for 5 min. In addition, a negligible reduction in brix and pH values of samples was observed.     

Presence and Stability of Patulin in Pasteurized Apple Cider

Pasteurized apple cider produced in Georgia was surveyed for patulin. Levels from 244-3993 μg patulin/L cider were found. Eight high temperature-short time (HTST) treatments (60°, 70°. 80°, and 90°C for 10 set; 90°C for 20, 40, 80, and 160 set) and one batch treatment (90°C for 10 min) were used to determine the stability of patulin in pasteurized cider. The 60°, 80°, and 90°C HTST treatments and the batch pasteurization significantly reduced the patulin level, but did not completely destroy the toxin. Storage of the cider had no effect on the patulin level.     

EFFECT OF COMMERCIAL PROCESSING STAGES OF APPLE JUICE ON PATULIN, FUMARIC ACID AND HYDROXYMETHYLFURFURAL (HMF) LEVELS

The effects of different stages of commercial apple juice production on the patulin, fumaric acid and hydroxymethylfurfural (HMF) contents of apple juice were investigated. Heat treatment and activated charcoal were effective for the reduction of patulin. The average reduction of patulin were 13.4% and 22.9% for heat treatment and activated charcoal, respectively. Statistical analysis showed no significant differences (P<0.05) in the presence of fumaric acid between different treatments. Filtration and heat treatment caused an apparent increase in the HMF content, while activated charcoal caused a decrease. The average increments of HMF were 40.4% and 38.0% for separation and heat treatment, respectively, while the average reduction of HMF was 23.7% for activated charcoal. Spiking of samples with known amounts of patulin and fumaric acid revealed respective recovery rates of 96.4% and 95.9%.     

Effects of dehydration temperatures on colour and polyphenoloxidase activity of Amasya and Golden Delicious apple cultivars

During dehydration at different temperatures (60, 70 and 80 °C) of Amasya and Golden Delicious apple cultivars, changes in colour, polyphenoloxidase activity (PPO), browning index and hydroxymethylfurfural (HMF) content were studied. Effects of dehydration time on the L* values of both cultivars were not significant. Only Amasya samples dehydrated at 80 °C were found to have significantly higher L* values than the remaining samples. In all cases, Golden Delicious samples had higher L* values than those of the Amasya cultivar. a* values of samples increased within the first hour of dehydration and then remained almost unchanged. The enzyme activity showed a rapid decrease in the first hour of dehydration and residual enzyme activities (%) reached 9.8%, 5.3% and 4.5% for Amasya, and 17.4%, 10.3% and 4.6% for the Golden Delicious cultivar at 60, 70 and 80 °C, respectively. In all final samples the residual enzyme activities were around 1%. The highest browning values were observed at the second hour of dehydration at 60 and 70 °C and the first hour of dehydration at 80 °C. In all conditions Amasya apples had a higher browning tendency. The presence of HMF was detected only at the 4th hour of dehydration at 80 °C for both cultivars. Effects of dehydration temperature on colour and PPO of the final product were insignificant. However, an important effect of temperature was determined on the browning index of Golden Delicious samples. The lowest browning tendency was measured on samples dehydrated at 80 °C. The results showed that cultivar and dehydration temperature had considerable effect on the browning of apple slices. Copyright © 2006 Society of Chemical Industry     

EFFECT OF APPLE DECAY PROPORTION ON THE PATULIN, FUMARIC ACID, HMF AND OTHER APPLE JUICE PROPERTIES

Starking apples, classified by the decay proportion on the fruit surface as sound, 30, 60 or 100% decayed were used in the production of apple juice. Then patulin, fumaric acid, HMF, pH, brix and Hunter L, a and b values of apple juice samples were determined. Patulin and fumaric acid analysis were done with HPLC. The patulin concentration in juice samples produced with Starking apples that are sound, 30, 60 and 100% decayed ranged between 0.0–15.9 μg/kg, 47.1–500.3 μg/kg, 156.4–2257.5 μg/kg, 54.9–2508.6 μg/kg, respectively. The fumaric acid concentration in the same juice samples ranged between 0.00–0.20 mg/kg, 0.23–0.69 mg/kg, 0.41–2.08 mg/kg and 1.40–4.14 mg/kg. In general, the color values (L, a, b) of the samples produced from 100% decayed apples measured by reflectance with a Hunter colorimeter were low when compared with the others.     

Biomass and Patulin Production by Byssochlamys nivea in Apple Juice as Affected by Sorbate, Benzoate, SO2 and Temperature

The effects of potassium sorbate, sodium benzoate, SO₂ and incubation temperature on biomass and patulin production by Byssochlamys nivea in apple juice were determined. Growth at 21, 30 and 37°C over a 25-day incubation period was significantly retarded by 75 ppm SO₂, 150 ppm potassium sorbate and 500 ppm sodium benzoate. Biomass accumulated to approximately 500 mg/100 ml in control samples of apple juice. Patulin was produced in the highest concentrations at 21°C after 20 days incubation. After reaching a maximum concentration at 30 and 37°C, a rapid decline in patulin content was observed. Patulin production was also observed at 12°C. On the basis of concentration, SO₂ had the most significant effect on the rate of biomass and patulin production by B. nivea followed by potassium sorbate and sodium benzoate, respectively.     

Changes in the odors of reconstituted apple juice during thermal processing

Influences of the thermal treatment on the odors of apple juice were investigated by sensory methodology. Reconstituted juice was treated at 80, 90, 100, 110 and 120 °C for 2.0∼320 s by a continuous-flow thermal treatment. Treated juices were subjected to a series of sensory evaluations. The odors of apple juice changed markedly with the treatment temperature and residence time. The quality optimum points were observed around 65 s for 80 °C, 25 s for 90 °C and 15 s for 100 °C. Points of subjective equality on the thermal degradation of apple juice odor were also estimated. Present data enabled the thermal treatment of reconstituted apple juice to be optimized.     

Efficacy of media for promoting ascospore formation by Neosartorya fischeri,and the influence of age and culture temperature on heat resistance of ascospores

Gorodkowa agar (GA), Fowell's acetate agar (FAA), Kleyn's acetate agar (KAA), McClary's acetate agar (MAA), grape juice agar (GJA), apple juice agar (AJA) and vegetable juice agar (VJA) were evaluated for their efficacy to promote ascospore formation by three strains of Neosartorya fischeri. All three strains produced abundant mature ascospores when grown on FAA, GJA and AJA, but not on the other test media. Ascospores produced on GJA developed greater heat resistance with time when suspended in commercial apple juice (AJ), grape juice (GJ) and 0·1 M potassium phosphate buffer (PB) during heat treatment. From 10 to 13 days of incubation at 30°C, decimal reduction times at 80°C (D_80°C values) for ascospores increased from 27·0 to 66·7 min in AJ, 28·5 to 33·3 min in GJ and 18·2 to 50·0 min in PB. The rate of development of heat resistance was dependent upon the incubation temperature at which ascospores were produced. After treatment at 70°C for 60 min, survival percentages for 21-day-old ascospores were 0·32, 8·13, 54·95 and 53·70% of ascospores produced at 18, 21, 25 and 30°C, respectively. At 42 days, 0·23 and 38·02% of ascospores produced at 18 and 21°C, respectively survived 85°C for 30 min; this treatment did not inactivate 42-day-old ascospores produced at 25 and 30°C. During a 114-day test period, ascospores produced at all incubation temperatures became dormant to some extent and required heat activation to facilitate germination.     

High hydrostatic pressure treatment and storage of carrot and tomato juices: Antioxidant activity and microbial safety

The application of high hydrostatic pressure (HHP) (250 MPa, 35 °C for 15 min) and thermal treatment (80 °C for 1 min) reduced the microbial load of carrot and tomato juices to undetectable levels. Different combinations of HHP did not cause a significant change in the ascorbic acid content of either juice (P > 0.05). Both heat treatments (60 °C for 5–15 min and 80 °C for 1 min) resulted in a significant loss (P < 0.05) in the free‐radical scavenging activity as compared to untreated samples. HHP‐treated juices showed a small loss of antioxidants (below 10%) during storage. The ascorbic acid content of pressurized tomato and carrot juices remained over 70 and 45% after 30 days of storage, respectively. However, heat treatment caused a rapid decrease to 16–20%. Colour changes were minor (ΔE = 10) for pressurised juices but for heat‐pasteurised samples it was more intense and higher as a result of insufficient antioxidant activity. HHP treatment (250 MPa, 35 °C for 15 min) led to a better product with regard to anti‐radical scavenging capacity, ascorbic acid content and sensory properties (colour, pH) of the tomato and carrot juices compared to conventional pasteurisation. Therefore, HHP can be recommended not only for industrial production but also for safe storage of fresh juices, such as tomato and carrot, even at elevated storage temperatures (25 °C). Copyright © 2007 Society of Chemical Industry     

Changes in Quality and Nutritional Parameters During Refrigerated Storage of an Orange Juice–Milk Beverage Treated by Equivalent Thermal and Non-thermal Processes for Mild Pasteurization

The effects of high-pressure (HP) treatment (400?MPa at 42 °C for 5 min) and pulsed electric field (PEF) processing (25 kV/cm at 57 °C for 280 μs) on ascorbic acid, total carotenoids, total phenolic compounds and total antioxidant capacity (TEAC and ORAC) of an orange juice–milk (OJ-M) beverage along the storage time at 4 °C were compared with a conventional heat preservation technology used in industry (90 °C for 15 s). During storage, ascorbic acid, total carotenoids and antioxidant capacity (TEAC) depleted with time regardless of the treatment applied. Instead, total phenolic content and antioxidant capacity measured by the ORAC method increased at the end of the storage. Non-thermal-treated beverage had less non-enzymatic browning than the thermally pasteurized one. There were no significant variations in the hidroxymethylfurfural (HMF) content of the HP- and PEF-treated OJ-M, whilst a significant increase was obtained after thermal treatment. During refrigerated storage, HMF was always below the maximum values established. The HP treatments reduced the L* value of the treated beverages immediately after processing and during refrigerated storage and induced an increase in total colour differences of beverages treated by HP compared with PEF and thermally processed orange juice–milk. Hence, alternative methods such as HP and PEF may give new opportunities to develop orange juice–milk with an equivalent shelf life to that of thermally treated orange juice mixed with milk in terms of microbial, physicochemical and nutritional characteristics.     

Clarified Natural Apple Juice: Production and Storage Stability of Juice and Concentrate

Thermal treatment (90°C, 20 sec) of Red Delicious apple mashes followed by Pectinase (0.02%;v/w), centrifugation, bentoniting and filtration resulted in a clear natural apple juice. Whole apple mash juice was faintly pink due to extracted skin anthocyanins and the 70° Brix concentrate prepared from the juice was ruby red. Pink juice browned extensively over 648 hr storage at 37°C and browning was associated with development of an absorption maximum at 446 nm. The ruby red concentrate stored at 37°C, turned orange (167 hr) darkening to brown (648 hr) and gave visible spectral scan typical of Maillard browning development.     

Original article: Effects of continuous dense‐phase CO2 system on antioxidant capacity and volatile compounds of apple juice

The effects of different operating conditions applied to a continuous dense‐phase carbon dioxide (DPCD) system on antioxidant capacity and volatile compounds of apple juice were compared with current heat pasteurisation method. Only the microbial tests required by Italian Regulation to assure microbiological safety to ‘fruit juices and vegetables’ were performed, and DPCD‐treated (15 MPa, 35 °C, 15 min; 25 MPa, 35 °C, 15 min), heat‐pasteurised (75 °C, 15 s) and untreated apple juice samples were considered. The DPCD processing carried out at 15 MPa resulted as effective as 25 MPa in reducing microbial cells. Trolox equivalent of DPCD treated at 25 MPa (0.41 mm ) resulted significantly (P < 0.05) lower than DPCD treated at 15 MPa (0.48 mm ). Head space analysis of volatile compounds indicated the lowest decrease in apple aroma compounds (59% esters and 59% aldehydes) in DPCD treated at 15 MPa.     

Determination of patulin in apple juice using magnetic solid-phase extraction coupled with high-performance liquid chromatography

ABSTRACT

An efficient magnetic sorbent consisting of benzofuran-2-carboxylic acid-loaded magnetic nanocomposite was successfully synthesised for pre-concentration of patulin from apple juice. The prepared magnetic nanocomposite was characterised by scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. Determination of enriched patulin was performed by high-performance liquid chromatography. The best adsorption conditions were 40 mg of sorbent, 50 ml of apple juice sample, pH 5, ambient temperature and 25 min; the elution conditions were 500 μl methanol, pH 5, ambient temperature, and 4 min. Under optimised conditions, pre-concentration factor was 100, linearity range was 1–400 μg l^–1 of patulin, limit of detection was 0.15 μg l^–1 and limit of quantification was 0.5 μg l^–1. When samples were determined 20 times, the recovery was 93.9–102.6% and the relative standard deviation was below 5.3%. In terms of proposed procedure, the developed method was successfully applied for patulin detection in apple juice samples.     

Combined high pressure and heat treatment effectively disintegrates spore membranes and inactivates Alicyclobacillus acidoterrestris spores in acidic fruit juice beverage

The commercial potential of high pressure and thermal processing (HPTP) was investigated against Alicyclobacillus acidoterrestris spores in commercial acidic apple juice beverage and in acidified and neutral potassium buffers. With starting spore counts prior to treatments being 6.5 and 7.2 log₁₀ respectively for strains AJA 66 (D_90°C 15.4 min) and ATCC 49025 (D_90°C 8.5 min), HPTP at 600 MPa at 80 °C for 3 min provided an optimal treatment with spore viability reduced below the detection limit for both strains. HPTP at 80 °C for 1 min and HPTP at 70 °C for 3 min achieved 4.1–4.5 log₁₀ CFU/mL reduction. HPTP at 70 °C for 1 min reduced the number of viable spores by 2.0–2.5-log₁₀ CFU/mL. Flow cytometry revealed the presence of membrane-compromised spores among culturable spores following HPTP and heat alone treatments at different temperatures. Electron microscopy clearly showed the efficiency of HPTP with crushed or hollow spores predominating after treatments. No correlation between HPTP susceptibility and genetic diversity was observed for two genotypes of A. acidoterrestris spores. The treatment combination provides a promising option for industrial utility since it requires lower heat and processing time.     

Inactivation of apple (Malus domestica Borkh) polyphenol oxidases by radio frequency combined with pulsed electric field treatment

Radio frequency (RF) preprocessing combined with pulsed electric field (PEF) processing was employed to inactivate polyphenol oxidase (PPO) in apple juice. PPO enzyme levels, loss of total phenolic content (TPC), colours and volatile components in the apple juice were subsequently determined and compared with conventional processing methods (60 °C for 10 min and 70 °C for 10 min). Results indicated that, when the apple tissue was preprocessed using RF for 10 min, the residual activity of PPO decreased to 13.57%; when the squeezed juice was processed by PEF, the residual activity decreased to about 5% at 15–35 kV cm^?1 for 400 μs. RF treatment caused no significant loss in TPC. Compared with the conventionally processed samples, the apple juice that was RF‐treated for 10 min and PEF‐treated at 15 kV cm^?1 for 400 μs increased its lightness and maintained its fresh‐like flavour.     

Investigation and kinetic evaluation of furan formation in tomato paste and pulp during heating

Due to its high ascorbic acid content and acidic environment, tomato is susceptible for furan formation during heat treatment. In this study, kinetics of furan formation was analyzed in order to have an understanding of the reactions taking place in tomato pulp during heating. Also several tomato paste samples were investigated in terms of their furan and hydroxymethylfurfural (HMF) concentrations, and the possible furan precursors. Paste samples were found to contain 3.3–13 ng/g furan and 0.9–39.4 μg/g HMF (dry weight basis). Freshly prepared tomato pulps were heated at 70, 80, and 90 °C for different times, and analyzed for ascorbic acid, dehydroascorbic acid, and furan concentrations. The formation rates of furan in the very first 5 min of heating at 70, 80, and 90 °C were 0.0071, 0.0130, and 0.0168 nmol/g·min, respectively. Rate constants related to reactions taking place during furan formation were estimated by multi-response kinetic modeling. The results revealed that ascorbic acid oxidation is the critical step in furan formation reaction mechanism during heating of tomato pulp, and prevention of oxidation during processing might help to limit furan formation.     

Combined treatment of high pressure and heat on killing spores of Alicyclobacillus acidoterrestris in apple juice concentrate

Alicyclobacillus acidoterrestris, a thermoacidophilic and spore-forming bacterium, has been isolated from spoiled acidic juices and is considered to be one of the important target microorganisms in quality control of acidic canned foods. Combined high pressure and heat treatment showed an effectiveness to control A. acidoterrestris spores. However, the effectiveness of the combined treatment may change upon the apple juice concentration. Therefore, the objective of this study was to evaluate different levels of apple juice concentrate for reduction of Alicyclobacillus spores by high pressure and heat. Spores of A. acidoterrestris were inoculated into three different concentrations of apple juice (17.5, 35, and 70 degrees Brix), and subjected to three high-pressure treatments (207, 414, and 621 MPa) at four different temperatures (22, 45, 71, and 90 degrees C). High-pressure treatment (207, 414, and 621 MPa) at 22degrees C did not reduce the level of spores regardless of the apple juice concentration (P > 0.05). In diluted apple juice (17.5 degrees Brix), the combined treatment of high pressure and heat resulted in spore reductions of about 2 log at 45 degrees C, and more than 5 log at higher temperatures (71 and 90 degrees C) in a high-pressure and temperature-dependent manner. For apple juice with a higher concentration (30 degrees Brix), high-pressure treatment showed no effect at 45 degrees C but resulted in about 2 and 4 log reduction at 71 and 90 degrees C, respectively. However, for apple juice concentrate (70 degrees Brix), treatment with heat or high pressure alone, or their combinations showed no inactivation against spores of A. acidoterrestris. It is likely that differences in the water availability explain the greater resistance of spores to high-pressure inactivation in the juice concentrates than in diluted juices. Our results demonstrate that the effect of high pressure combined with heat against spores of A. acidoterrestris was highly dependent on the apple juice concentration.     

Lipid oxidation and colour in pressure‐ and heat‐treated minced chicken thighs

Lipid oxidation and colour in pressurised and heated chicken samples were evaluated. In a preliminary test, raw and overcooked (100 °C/60 min) minced chicken thighs were pressurised (500 MPa/50 °C/30 min). Samples were stored at 4 °C in contact with air. Thiobarbituric acid reactive substances (TBARS) were quantified at 1, 6 and 9 days. Pressure induced oxidation in chicken, but overcooking generated many more secondary oxidation compounds. In a second experiment, raw minced chicken thighs were pressurised (500 MPa/?10, 5, 20 and 50 °C/30 and 60 min) or cooked (90 °C/15 min). Samples were vacuum stored at 4 °C. TBARS were measured at 1 and 9 days, whereas colour parameters (L, a, b and ΔE) were determined at 1 day. No differences in TBARS values were observed between untreated and pressurised samples, whereas cooked samples presented the highest values. Pressurisation for 30 and 60 min generated similar TBARS contents. At 9 days, oxidation values did not increase. Pressurisation and cooking induced marked colour changes. Pressurised samples were lighter and less red than untreated ones. Samples pressurised at 50 °C were the palest and, together with cooked samples, presented the lowest a values. Therefore pressurised chicken thigh cannot be marketed as a fresh product but can be incorporated as an ingredient in ready‐to‐eat meals. Copyright © 2004 Society of Chemical Industry     

Effect of thiamine hydrochloride,pyridoxine hydrochloride and calcium‐d‐pantothenate on the patulin content of apple juice concentrate

Thiamine hydrochloride, pyridoxine hydrochloride and calcium‐d‐pantothenate were applied apple juice concentrates (AJC) at various doses in order to reduce the patulin content. AJC samples containing high levels of patulin were stored at 22 ± 2°C and 4°C for 6 months after vitamins were added. Patulin was fully degraded at the end of a 6‐month period in samples stored at 22 ± 2°C, on the other hand, other quality parameters diminished significantly. Without any considerable reduction on other quality parameters, applications of 1000 and 2500 mg/kg calcium‐d‐pantothenate resulted in reduction of patulin of 73.6 and 94.3%, respectively, however, 42.1% of patulin reduction was observed in the control sample of AJC stored for 1 month at 22 ± 2°C. Addition of thiamine hydrochloride (1000 mg/kg( pyrodoxine hydrochloride (625 or 875 mg/kg) and calcium‐d‐pantothenate (1000 or 2500 mg/kg) into the samples and storage at 4°C for 6 months yielded 55.5 to 67.7% of patulin reduction which was only 35.8% for the control, while the other quality parameters were protected adequately.