Application of gaseous ozone to control populations of Escherichia coli, Bacillus cereus and Bacillus cereus spores in dried figs

The effect of ozonation as a method to reduce Escherichia coli, Bacillus cereus and Bacillus cereus spores in dried figs was investigated. Dried figs were sprinkle inoculated with E. coli, B. cereus and B. cereus spores in sterile bags at a level of 10(7)microorganism g(-1), mixed and allowed to dry for 1h at 25 degrees C prior to ozonation. Inoculated samples were exposed to gaseous ozone in a chamber at 20 degrees C and 70% relative humidity. Ozone concentrations of 0.1, 0.5 and 1.0 ppm up to 360 min were used to inactivate E. coli and B. cereus while 1.0, 5.0, 7.0 and 9.0 ppm ozone concentrations for 360 min were used to treat B. cereus spores. E. coli and B. cereus counts were decreased by 3.5 log numbers at 1.0 ppm ozone concentration for 360 min ozone treatment. Up to 2 log reductions in the number of B. cereus spores were observed above 1.0 ppm ozone concentration at the end of 360 min of ozonation. No significant changes in color, pH and moisture content values of dried figs were observed after the ozonation treatments. No significant changes were found between sweetness, rancidity, flavor, appearance and overall palatability of ozonated and non-ozonated dried figs. Ozonation was found to be effective especially in reduction of vegetative cells in dried figs and a promising method for the decontamination of dried figs.     

Effect of different ozone treatments on aflatoxin degradation and physicochemical properties of pistachios

This study evaluated the efficiency of ozone for the degradation of aflatoxins in pistachio kernels and ground pistachios. Pistachios were contaminated with known concentrations of aflatoxin (AF) B₁, B₂, G₁ and G₂. Pistachio samples were exposed to gaseous ozone in a chamber at 5.0, 7.0 and 9.0 mg L^?1 ozone concentrations for 140 and 420 min at 20 °C and 70% RH. Aflatoxin degradation was determined by high performance liquid chromatography (HPLC). The efficiency of ozone for aflatoxin degradation in pistachios increased with increasing exposure time and ozone concentration. The results indicated that AFB₁ and total aflatoxins could be reduced by 23 and 24%, respectively, when pistachio kernels were ozonated at 9.0 mg L^?1 ozone concentration for 420 min. Only a 5% reduction in AFB₁ and total aflatoxin levels could be achieved for ground pistachios under the same conditions. No significant changes occurred in pH, color, moisture content and free fatty acid values of pistachio kernels and ground pistachios. Fatty acid compositions of pistachios did not change significantly after the ozonation treatments. No significant changes were found between sweetness, rancidity, flavor, appearance and overall palatability of ozonated and non‐ozonated pistachio kernels. Significant changes were observed in the organoleptic properties of ground pistachios, except rancidity, after 5.0 mg L^?1 ozone treatment for 140 min. Ozonation was found to be more effective for degrading aflatoxins in pistachio kernels than ground pistachios. Copyright © 2006 Society of Chemical Industry     

Efficacy of ozone for Callosobruchus maculatus and Callosobruchus chinensis control in cowpea seeds and its impact on seed quality

The insecticidal efficacy of ozone was evaluated against the adults of Callosobruchus maculatus (F.) and C. chinensis L. on stored cowpea seeds under laboratory conditions. Ozone was assessed at concentrations of 0.25, 0.5, 1.0, 1.5, and 2.0 g/m³. The effect of ozone treatments on the adult mortality after 1, 3, 5 and 7 days of treatment, progeny production after 45 days, cowpea seed weight loss, seed germination and chemical constituents of cowpea seeds were determined. Adult mortality of C. maculatus and C. chinensis was improved with the increase in ozone concentration. Thus, all tested concentrations caused complete adult mortality of C. chinensis after 7 days of treatment, while the concentrations of 1.0, 1.5, and 2.0 g/m³ caused complete adult mortality of C. maculatus after the same periods. Progeny of both species was significantly decreased in all ozone concentrations after 45 days of treatment. Nevertheless, strong suppression in progeny production was achieved at the highest concentration of ozone (2.0 g/m³). Also, the ozone treatment at the highest concentration protected the cowpea seeds from damage caused by C. maculatus and C. chinensis for 45 days. In addition, there was no significant effect of ozone treatments on the cowpea seed germination compared with untreated seeds. Moreover, the chemical analysis of treated cowpea seeds showed a slight decrease in protein, fat, carbohydrate, moisture, total phenolics, total flavonoids and tannins contents, and a slight increase in fiber and ash contents compared with untreated cowpea seeds. Our findings suggest the ozone can be effectively used for the control C. maculatus and C. chinensis and can provide sufficient protection of stored cowpea seeds.     

臭氧对橙皮果脯品质及抗氧化活性的作用

本研究探讨了不同浓度臭氧水前处理对橙皮果脯营养价值和抗氧化能力的影响。经低、中和高三个浓度的臭氧水清洗处理15 min后,新鲜橙皮被制备成橙皮果脯。以未处理组与臭氧水处理组做对比,测定了橙皮果脯的还原性Vc、黄酮、总色差与抗氧化值。结果显示：还原性Vc、黄酮、总色差以及还原力、DPPH?清除率、?OH清除率、O2-?清除率和ABTS+?清除率从高到低均依次为：中浓度（9.10 mg/L）处理组>低浓度（13.78 mg/L）处理组>高浓度（22.23 mg/L）处理组>未处理组。中浓度臭氧水处理组橙皮果脯与未处理组的对比,Vc含量从1.25 mg/g提升到1.40 mg/g,黄酮含量从0.57 mg RE/g提升到0.68 mg RE/g,总色差从34.88下降到28.80。臭氧水处理对橙皮果脯的营养价值和颜色都有显著的保护作用（p<0.05）,对其抗氧化活性也有显著的提高（p<0.05）。其中,橙皮果脯的抗氧化能力与加工过程中橙皮里Vc和黄酮含量变化存在着极显著的正相关。可见,短期的臭氧水处理对橙皮果脯的品质及抗氧化活性均有良好的作用。     

Effectiveness of ozone in combination with controlled atmosphere on quality characteristics including lignification of carrot sticks

Fresh-cut carrots were ozonized in water (1:2 w/v; @ 200 mg O₃/h) for 10 min and stored under controlled atmosphere (CA) conditions (2% O₂, 5% CO₂ and 93% N₂) at 6 ± 1 °C and 85% RH for up to 30 d. Ozonation was found to reduce lignification and maintaining the keeping quality of fresh-cut carrots during CA storage. The maximum decrease in respiration and ethylene emission rates were obtained by the combination of CA with ozone followed by CA alone and ozonation compared with the control samples kept under low temperature (6 ± 1 °C). Significant (p < 0.05) reduction in ascorbic acid, carotenoids and oxidative enzymes such as polyphenol oxidase (PPO) and peroxidase (POD) were observed due to ozonation and CA storage. The control of lignification by ozone in synergy with CA was characterized by decrease in L∗ values. The results highlighted the positive role of ozonation in combination with CA storage in controlling lignification and microbial spoilage of carrot sticks.     

Anthocyanin and colour degradation in ozone treated blackberry juice

Response surface methodology (RSM) was used to investigate the effects of ozone concentration (%w/w) and treatment time (min) on the anthocyanin content and colour of fresh blackberry juice. RSM methodology based on a two factor five level central composite design was employed with control variables of ozone concentration (0 to 7.8%w/w) and treatment time (0 to 10 min) at a constant gas flow rate. Predicted models were found to be significant (p < 0.001) with regression coefficients (R²) of 0.89, 0.82, 0.95, 0.86 and 0.97 for L, a, b, TCD and anthocyanin content respectively. Ozone concentration and treatment time were found to be critical factors influencing both anthocyanin and colour degradation. This study demonstrated that response surface methodology can be employed to model colour and anthocyanin degradation of ozonated blackberry juice while minimising the number of experiments required.Industrial relevanceIn the United States (US) legislation requires fruit juice processors to achieve a 5-log reduction in the numbers of the most resistant pathogens in their finished products. Consequently a number of commercial fruit juice processors in the US started to employ ozone for fruit juice pasteurisation. Ozonation was approved by the FDA in 2001 as a direct additive to food. The FDA issued industry guidelines for fruit juice processing with ozone [FDA, (2004). FDA Guidance to Industry, 2004: Recommendations to Processors of Apple Juice or Cider on the Use of Ozone for Pathogen Reduction Purposes. Available online http://www.cfsan.fda.gov/~dms/juicgu13.html.], however this report concludes that these guidelines are based upon limited scientific data. This paper investigates the effect of ozone processing on the anthocyanin content and colour of blackberry juice. The results presented demonstrate that the effect of ozonation on the nutritional properties of blackberry juice or juice products containing blackberry should be considered by processors prior to its adoption as a preservation technique.     

Influence of roasting pretreatment on high‐oleic rapeseed oil quality evaluated by analytical and sensory approaches

Qualitative and quantitative effects on the contents of minor components of cold‐pressed high‐oleic rapeseed oil (HORO) were evaluated in a function of different roasting temperatures (80, 100, 120 and 140 °C). Along with roasting temperature elevation, a significant increase in the content of total tocopherols up to 32% (mainly γ‐T homologue) and a slight increase of total sterols concentration (up to 5%) were observed, whereas no significant changes in the fatty acid composition occurred during seeds thermal pretreatment. Additionally, an increased degree of hydrolysis and lipid oxidation was reported; however, obtained results were within codex limits. The peroxide value of the oil ranged from 1.30 to 2.34 mEq O₂ kg^?1, while the acid value did not exceed 0.46 mg/KOH g. Principal component analysis was capable of differentiating between rapeseed oils acquired from seeds pretreated with different roasting temperatures.     

Use of gaseous ozone to reduce aflatoxin B1 and microorganisms in poultry feed

This study was undertaken to evaluate the efficacy of gaseous ozone for the degradation of aflatoxin B₁ (AFB₁) and inactivation of indigenous microflora in poultry feed. Feed samples were treated with continuous stream of two different constant concentrations (2.8 and 5.3 mg/L) of ozone at room temperature up to 240 min. The initial AFB₁ level in artificially contaminated feed samples, determined as 32.8 μg/kg, decreased by 74.3 and 86.4% after 240 min of exposure at 2.8 and 5.3 mg/L, respectively. At the both ozone concentrations, 240 min exposure was reduced the aerobic plate and yeast and mold counts below the detection limit (<10 CFU/g) with a reduction more than 3.2 and 2.7 log, respectively. The thiobarbituric acid reactive substances (TBARS) assay indicated that no significant (P ≥ 0.05) increase occurred in the level of lipid oxidation in feed samples during 120 min ozonation at 2.8 mg/L. At the end of the 240 min of exposure at 2.8 and 5.3 mg/L, initial TBARS concentration, determined as 2.4 mg/kg, reached to 4.4 and 5.3 mg/kg with a significant (P < 0.05) increases, respectively. The results presented in this study suggested that significant (P < 0.05) reductions in the AFB₁ level and microbial population can be achieved in poultry feed by ozonation with an acceptable changes in lipid oxidation.     

Effect of ozone processing on the colour,rheological properties and phenolic content of apple juice

Apple juice samples were ozonated with processing variables of ozone concentration (1–4.8% w/w) and processing time (0–10 min). Effects of processing variables on colour values (L, a and b), rheological properties and phenolic content were studied. Significant reductions in these parameters were observed during ozonation. Second order polynomial regression modelling was used to investigate the main effects of ozone concentration and processing time on the changes in the selected quality parameters of ozonated apple juice. Predicted models were found to be significant (p < 0.05) with low standard error and high coefficients of determination (R²).     

Removal of endocrine-disrupting chemicals during ozonation of municipal sewage with brominated byproducts control

The decomposition of endocrine-disrupting chemicals (EDCs) including estrone (E1), 17beta-estradiol (E2), estriol (E3), nonylphenol (NP), and bisphenol A (BPA) during ozonation of municipal sewage grabbed from the outlets of primary sedimentation tanks was studied through laboratory-scale experiments. A newly developed in vitro bioassay called nuclear receptor-ligand assay and GC-MS were both utilized to respectively determine the estrogenicity and individual EDCs in the wastewater samples. The original estrogenicity, expressed as the E2 equivalent concentration (EEQC), in the primary effluents was 315-1018 ng/L. Results indicate that the EEQC can be reduced rapidly to below 10 ng/L after ozonation. The appearance of 0.1 mg/L dissolved ozone (DO3), which corresponds to a consumed ozone amount of 0.4 mg per initial TOC (total organic carbon) of wastewater samples, was an appropriate operational parameter to simultaneously achieve efficient EDC removal and control of BrO3- and total organic bromine (TOBr). The presence of suspended solids in the range of 38-67 mg/L exhibited no obvious impact on the removal of nonsorbed estrogenicity. A complete decomposition of E2, E3 and BPA was achieved once 0.1 mg/L DO3 appeared in the primary effluent. The oxidative decomposition of NP was relatively less efficient with a residual concentration of 100 ng/L. This work investigates the feasibility of EDC removal and brominated byproduct control during ozonation of original municipal sewage prior to biological treatment.     

Chemical,Technological, and Sensory Properties of Wheat Grains (Triticum aestivum L) as Affected by Gaseous Ozonation

Gaseous ozonation, an emerging technology, is applied to microbiological decontamination and to the degradation of residues and contaminants in wheat grains. However, due to its high oxidizing capacity, ozone may cause undesirable effects on the quality of grains or in their derivatives. This study aimed to evaluate the influence of ozone gas on wheat grain quality when exposed to different levels of ozone concentration, exposure time, and grain mass, using a full 2³ factorial design. After the milling of ozonized grains, two fractions were evaluated: flour (A) and bran plus germ (B). In fraction A, the quality of the wheat flour was analyzed by both alveography and farinography. The flour extraction rate, falling number and gluten contents were also measured. The chemical and mineral profiles were determined in both fractions. A sensory evaluation, using the difference-from-control test, was applied to investigate the possible differences in aroma or in overall appearance of the flour obtained from the ozonized grains. The results showed that ozone concentration (60 mg/L) positively affected (p < 0.05) the toughness and the falling number of the flour. The other parameters of alveography, as well as farinography, gluten content, chemical composition, mineral, and sensory profiles were not affected (p > 0.05) by ozonation. This study demonstrated that gaseous ozonation, when applied under the conditions of 10 to 60 mg/L, from 2 to 5 h of exposure, grain mass from 2 to 5 kg, does not cause any negative impact on the wheat quality.     

Effectiveness of ozonation treatment in eliminating toxicity of oil sands process-affected water to Chironomus dilutus

Water soluble organic compounds (OCs), including naphthenic acids (NAs), are potentially toxic constituents of oil sands process-affected water (OSPW) that is generated during extraction of bitumen from Alberta oil sands. Ozonation can decrease concentrations of OCs in OSPW. However, effects of ozonated-OSPW on multicellular organisms are unknown. A 10-day and a chronic exposure of Chironomus dilutus to OSPW were conducted to assess effects on survival, growth, development, and behavior. Two separate batches of OSPW were treated with 30 or 80 mg ozone (O(3))/L. Wet body masses of larvae exposed to OSPW were 64 to 77% less than their respective controls (p < 0.001). However, both levels of ozonation significantly attenuated effects of OSPW on growth. Similarly, chronic exposure to untreated OSPW resulted in significantly less pupation than in the controls, with 31% and 71% less pupation of larvae exposed to the two batches of OSPW (p < 0.05). Emergence was significantly less for larvae exposed to OSPW, with 13% and 8% of larvae emerging, compared to 81% in controls (p < 0.0001). Both levels of ozonation of OSPW attenuated effects on emergence. These results suggest that OCs degraded by ozonation causes toxicity of OSPW toward C. dilutus, and that ozonation attenuates toxicity of OSPW.     

Optimization of supercritical CO2 extraction of phytosterol-enriched oil from Kalahari melon seeds

Supercritical carbon dioxide (SC-CO₂) extraction of oil from Kalahari melon seeds was investigated in this study. Response surface methodology was applied to model and optimize the extraction, namely pressure (200–400 bar), temperature (40–80 °C), and supercritical fluid flow rate (10–20 mL/min). Well-fitting models were successfully established for oil recovery (R ² = 0.9672) and phytosterol concentration (milligrams per 100 g; R ² = 0.8150) through multiple linear regressions with backward elimination. The effect of supercritical fluid flow rate was the most significant (P < 0.05) factor that affected oil recovery but this factor had no significant (P > 0.05) effect on phytosterol concentration. The optimal processing conditions for oil recovery and phytosterol concentration were pressure of 300 bar, temperature at 40 °C, and supercritical fluid flow rate of 12 mL/min. These optimal conditions yielded a 76.3% oil recovery and 836.5 mg/100 g of phytosterol concentration. The oil content in the Kalahari melon seeds as estimated by Soxhlet extraction was around 30.5/100 g. The phytosterol concentration in the oil extracted with SC-CO₂ extraction was 94% higher than that obtained with solvent extraction.     

Potential of nanofiltration for the concentration of bioactive compounds from watermelon juice

The aim of this study was to evaluate the potential of nanofiltration for the concentration of bioactive compounds of watermelon juice. Lipophilic and hydrophilic antioxidant activities were determined through two assays, ferric reducing antioxidant power and DPPH. The content of lycopene, flavonoids and total phenolic in the concentrate samples increased with the increase in the volume reduction factor. Volume reduction factor of three showed the best performance of concentration, generating the highest values for lycopene, flavonoid and total phenolic contents. Average permeation flux was 2.3 L h^?1 m^?2, with continuous extraction of the concentrate at a volumetric reduction ratio of three. Lycopene showed the highest rejection coefficient (0.99), followed by flavonoids (0.96) and total phenolic content (0.65). The hydrophilic antioxidant activity values in both assays were higher than the lipophilic antioxidant activity values. A highly significant correlation was noted between the contents of flavonoids, phenolic compounds, ascorbic acid, and lycopene and their antioxidant potential in both lipophilic and hydrophilic fractions.     

Optimisation of supercritical CO2 extraction of grape seed oil using response surface methodology

The aim of this study was to use waste from the wine production process with special accent on grape seeds and new green technology. Supercritical CO₂ was considered as a green solvent in extraction of grape seed oil. The effects of different extraction process parameters on oil yield and antioxidant activity were investigated. Extraction optimisation was conducted using response surface methodology (RSM). Extraction pressure has proven to be the most significant factor influencing oil yield and antioxidant activity (P < 0.0001). The optimal conditions for obtaining the highest oil yield and antioxidant activity within the experimental range of the variables studied were at extraction pressure of 400 bar and temperature of 41 °C. Under these optimal conditions, the predicted extraction oil yield was 14.49% and DPPH 37.07%. Applying this green extraction method, the oil from grape seeds was totally extracted. The produced oil was of satisfactory quality, and the content of α‐tocopherol in obtained grape seed oil at optimal extraction conditions was 36.05 mg kg^?1.     

Polyphenolic and phytochemical content of Cucumis sativus seeds and study on mechanism of preservation of nutritional and quality outcomes in enriched mayonnaise

Oxidative rancidity in food emulsions leads to a reduction in shelf life. Synthetic antioxidants are widely used in food industry to prevent the development of rancidity. The present study was focussed on investigating the antioxidant potential of Cucumis sativus seeds (CSS) and correlates these findings with mayonnaise enrichment and extends its shelf life. CSS exhibited the highest abundance in phenolic compounds (93.5 ± 0.1 mgGAE g^?1), flavonoids (57.4 ± 0.1 mgQE g^?1), β‐carotene (19.46 ± 0.4 mg carotenoids per 100 g) and high free radical scavenging activity. CSS (200 ppm) and butylated hydroxyanisole (200 ppm) were incorporated in mayonnaise and the oxidative stability was evaluated by peroxide, p‐anisidine and TBARS values during storage at different temperatures. Organoleptic evaluations indicated that CSS enriched sample was recorded the highest overall acceptability. The results from our study will provide scientific basis for CSS as natural preservative against lipid oxidation or food enrichment while developing functional foods.     

Inactivation kinetics of peroxidase and polyphenol oxidase in peach juice treated with gaseous ozone

The effectiveness of gaseous ozone for inactivating peroxidase (POD) and polyphenoloxidase (PPO) in peach juice was investigated. The suitability of first‐order and Weibull models to describe inactivation kinetics was also analysed. Peach juice was exposed to ozone (0.11 and 0.20 mg O₃ min^?1 mL^?1) in a bubble column up to 12 min at 20 ± 1 °C. Enzyme activities were reduced due to treatments. The magnitude of the inactivation increased with ozone level and exposure time. Reductions in activity after 12 min of treatment ranged between 99.5% and 99.8% for POD and between 93.9% and 97.3% for PPO, depending on ozone concentration. Inactivation curves were successfully fitted with the first‐order and Weibull models; although, based on the root‐mean‐square error, the corrected Akaike and the Bayesian Schwarz criterion, the Weibull model showed stronger capability in all cases.     

Degradation kinetics of pirimiphos-methyl residues in maize grains exposed to ozone gas

This work investigates the kinetics of degradation of pirimiphos-methyl residues in maize grains exposed to ozone gas and evaluates the effect of ozonation on grain quality. The assays employed maize grains treated with the insecticide, namely Actellic 500 CE^® (pirimiphos-methyl), which were exposed for different periods to ozone gas at a concentration of 0.86 mg L⁻¹, provided at a continuous flow rate of 1.0 L min⁻¹. The insecticide residues were extracted from the grains using solid-liquid extraction with low temperature partitioning. The extracts were analyzed by gas chromatography with electron capture detection. Ozone effectively degraded more than 91% of the pirimiphos-methyl residues, with the degradation efficiency increasing in direct proportion to the duration of exposure to the gas. A first order kinetic model provided the best fit to the degradation data. The use of ozone gas did not alter the qualitative characteristics of the maize.     

Ozonation of corn and potato starch in aqueous solution: effects on the thermal,pasting and structural properties

Starch–water suspensions were exposed to ozone gas for 1 h at 5 °C. The concentration of dissolved ozone gas in the suspension was kept at 4.2 mg ozone/L^?1 water. Polarised light and scanning electron microscope (SEM) were used to examine the birefringence and surface characteristics of the samples, respectively. A differential scanning calorimeter (DSC) was used to measure the gelatinisation properties, while a rapid visco analyser (RVA) was used to examine pasting properties. The structure of corn and potato starch showed very little change after treatment with ozonated water. The DSC gelatinisation temperatures (i.e. onset, peak and conclusion) of starch samples increased as a result of ozonation. However, a decrease in gelatinisation enthalpies was observed for ozonated starch samples. A dramatic decrease in the RVA viscosities of ozonated starch samples was observed after ozonation, which are explained by the partial cleavage of the glycosidic linkages in the starch granules during ozonation.     

Response surface optimisation of germination conditions to improve the accumulation of bioactive compounds and the antioxidant activity in quinoa

Germination has been proposed as an economic approach to improve the content of bioactive compounds in pseudocereals. In this work, response surface methodology (RSM) was employed to investigate the impact of germination conditions on the phytochemical content and antioxidant activity of quinoa. The use of desirability methodology showed that the optimum conditions to maximise the content of total phenolic content (TPC) and antioxidant activity in sprouted quinoa were 20 °C for 42 h. Sprouts produced under these conditions exhibited increases of 80% and 30% in TPC and antioxidant activity, respectively, compared to un‐germinated seeds, and contained high γ‐aminobutyric acid (GABA) concentration. The nonsignificant lack‐of‐fit and high determination coefficients obtained confirmed the suitability of the predictive models developed for TPC and antioxidant activity, whilst the one obtained for GABA was not significant (R² < 0.75) within the conditions studied. Sprouting under optimum conditions enhanced the content of both flavonoid and nonflavonoid compounds, being the increase in flavonoids more pronounced. Kaempferol‐O‐dirhamnosyl‐galactopyranose and quercetin‐O‐glucuronide were the compounds that experienced the most noticeable increase in quinoa after germination. In conclusion, this study provides useful information on the optimum germination conditions to improve the levels of health‐promoting compounds in quinoa.