Search

Pasteurized orange juice is one of the most consumed juices. Although very popular, pasteurization changes the aroma of the juice and produces some off-flavor compounds. This study investigated the effects of cold plasma processing on the aroma and off-flavors of pasteurized orange juice, evaluating if the dielectric barrier discharge (DBD) plasma could improve the aroma and reduce the pasteurized juice off-flavors. Orange juice was subjected to DBD plasma processing operating at several excitation frequencies (50 to 600 Hz). Twenty-four compounds were identified using GC–MS analysis, consisting mainly of terpenoids, alcohols, aldehydes, and esters. DBD plasma induced several chemical reactions changing the volatile profile of the juice. The chemical pathway induced by DBD plasma was discussed and correlated to the changes in aroma and formation of off-flavor compounds. DBD plasma increased the terpenoid and aldehyde compounds that give orange juice its fresh-like characteristics while controlling off-flavors formation. [ABSTRACT FROM AUTHOR]

Studies based on the effect of cold plasma excitation frequency on the physicochemical properties of unconventional starches, such as Goeppertia allouia (popularly known as aria in Brazil), have not been extensively found in the scientific literature. Treatments using 5 different excitation frequencies from 50 to 550 Hz were performed on a dielectric barrier cold plasma equipment operated at 20 kV for 15 min. The morphological and physicochemical changes in starches were investigated by scanning electronic microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The content of amylose, reducing sugars, carbonyl, and carboxyl groups, as well as the starch digestibility, gel hydration, pasting, and thermal properties of native and treated starches were investigated. The native starch presented C-type polymorphism; however, the starch treated at 200 Hz presented higher proportion of A-type/B-type crystals and crystallinity. These changes in the phase composition and crystallinity directly affected the physicochemical properties of the aria starch, increasing its hydration properties and content of resistant starch. In general, the excitation frequency of cold plasma can be used to modulate the physicochemical behavior of starches, being considered a green and non-destructive technique. Thus, the application of cold plasma showed to be an important tool to obtain tunable polysaccharides from aria for a wide range of industrial purposes, such as in food, chemical, or pharmaceutical fields. [ABSTRACT FROM AUTHOR]

Atmospheric and vacuum cold plasma technologies were applied to the Amazonian sapota-do-Solimões juice (Quararibea cordata Vischer) to evaluate its effects on several physicochemical and nutritional characteristics. The study was carried out applying atmospheric cold plasma using the dielectric barrier discharge (DBD) system operating at different frequencies (50 to 960 Hz) and processing times (5 to 15 min); and vacuum plasma operating at different synthetic air flow rates (10 to 30 mL/min) and processing times (10 to 30 min). The results from 1H NMR coupled with chemometrics showed a decrease in the amount of sucrose, glucose, fructose, and alanine in sapota-dos-Solimões juice. The increase in frequency and processing time increased the concentration of phenolic when applying atmospheric cold plasma, while a decrease in concentration was observed when vacuum plasma was applied. Atmospheric cold plasma processing increased the antioxidant activity of sapota-dos-Solimões more than vacuum plasma. The juice pH and total soluble solids content were not significantly affected by plasma processing. Plasma treated did not significantly change the perceived color (DE < 3), maintaining the yellow characteristic color (h° ~ 70). [ABSTRACT FROM AUTHOR]

The present study evaluated the influence of non-thermal technologies (ultrasound and ozone) on the content of the bioactive compounds, in vitro antioxidant capacity, and deteriorative enzymes (peroxidase and polyphenoloxidase) in fruit juices. Multivariate statistical analysis revealed that guava juice was more susceptible to ozone and ultrasound processing due to the increase of phenolics, vitamin C, and antioxidant capacity (ABTS). The ozone processing was deleterious in orange juice, reducing the content of bioactive compounds. Ultrasound processing enhanced the bioactive compounds in tangerine and guava juice. Higher amounts of phenolics in orange juice presented good correlation to the ozone processing, which was followed by more elevated amounts of vitamin C in guava, orange, and mostly tangerine. The softer ultrasound processing contributed to raise the vitamin C content (mainly in guava and orange). The results highlighted that the food matrix influences the non-thermal processing due to their different compositions. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) is a powerful technique to characterization of taste profile based on organic compounds from foods. Likely, gas chromatography coupled to mass spectrometry (GC-MS) enables the detection of aroma profile of foodstuff. Therefore, the present study aimed to evaluate the influence of two different cold plasma processes (dielectric barrier discharge atmospheric plasma (ACP) and glow discharge plasma (GP)), as well as the effect of different processing conditions on taste and aroma profiles from camu-camu juice. Both ACP and GP processing resulted in modifications on taste and aroma, which were strongly dependent of the frequency of plasma generation, flow rate, and treatment duration. The GP processing resulted in higher influence on camu-camu composition than ACP, which decreased the contents of important flavor compounds while increasing vitamin C and ethanol contents. Moreover, GP during 10 min at 10 mL/min and 20 min at 20 mL/min of plasma flow rate did not present significant effect on the juices composition as a whole (taste and aroma related compounds). The ACP processing presented significant influence on the juices composition at 420 and 530 Hz, while 200 and 960 Hz maintained the overall organic composition. Therefore, the use of NMR and GC-MS coupled to advanced chemometric analysis (data fusion) allowed a deep understand the camu-camu chemical variability submitted to plasma technologies based on taste and aroma compounds. This information indicates that appropriate treatment conditions are important for decontamination while preserving and improving the food characteristics in order to match the consumer demands. [ABSTRACT FROM AUTHOR]

Coconut water is widely consumed and appreciated due its sensory, nutritional, and functional characteristics. Despite being widely consumed, this beverage has a short shelf life that can be improved through processing technologies including non-thermal technologies. Although this processing is promising, it also can generate toxic bioactive compounds of natural and synthetic origin. Their safety has been long discussed, and concern for human food security is now clearly manifested by warnings added on products labels. The aim of this work was to evaluate the toxic and the protective effect of natural and processed coconut water by non-thermal technologies against oxidative stress in brine shrimp (Artemia salina). For acute toxicity test, A. salina nauplii instar II were exposed to different concentrations and ozone-processed (OTCW), plasma-processed (PTCW), and ultrasound-processed (UTCW) coconut water. The non-processed sample was the negative control. By the end of experiment (48 h), dead nauplii were counted and investigated under optical and electron microscopy. The protective effect was evaluated against H2O2 and morphological changes were also investigated. Coconut water treated with plasma and ultrasound was not toxic to Artemia salina nauplii at 10, 100, or 1000 μg mL−1; however, ozone-treated artificial seawater caused a mild toxicity to nauplii exposed to 1000 μg mL−1. All coconut water samples, included untreated samples, presented protective effect against oxidative stress caused by H2O2 reaching levels of 87.5% protection compared to control (24 h of experiment). [ABSTRACT FROM AUTHOR]

The potential use of alternative culture media towards the development of a sustainable bioprocess to produce lipases by Diutina rugosa is clearly demonstrated. First, a synthetic medium containing glucose, peptone, yeast extract, oleic acid, and ammonium sulfate was proposed, with lipase activity of 143 U/L. Then, alternative culture media formulated with agro-industrial residues, such as molasses, corn steep liquor (CSL), and olive mill waste (OMW), were investigated. An experimental design was conducted, and only CSL concentration was found to have a positive effect in lipase production. The highest lipase activity (561 U/L) was produced on a mixture of molasses (5 g/L), CSL (6 g/L), OMW (0.5% v/v), 0.5 g/L of ammonium sulfate, and 3 g/L of peptone at 24 h of cultivation. Lipase production was also carried out in a 1-L bioreactor leading to a slightly higher lipase activity at 24 h of cultivation. The semi-purified enzyme exhibits an optimum temperature and pH of 40 °C and 7.0, respectively. Finally, the media cost per unit of lipase produced (UPC) was influenced by the medium components, specially by the inducer used. The lowest UPC was obtained when the agro-industrial residues were combined and used at the improved concentrations. [ABSTRACT FROM AUTHOR]

Jabuticaba (Myrciaria cauliflora) is a dark berry, endemic to the south and central regions of South America, rich in anthocyanins and polyphenols. This study evaluated the ultrasound-assisted extraction of bioactive compounds from jabuticaba peel, developed a new mathematical model for the process, and estimated the model parameters. Extraction was carried out using water as solvent aiming its direct use in food formulations. The main anthocyanin (cyanidin-3-O-glucoside) and the main polyphenol (ellagic acid) from jabuticaba peel were extracted and quantified by LC–MS and HPLC. The results indicate that lowering the pH increased the extraction of the anthocyanin and had only slight effect on the extraction of ellagic acid. The application of ultrasound at 25 kHz favored the extraction of both compounds. Processing time of 20 min increased the yield of both compounds, while over processing (> 20 min) let to the sonochemical-induced hydrolysis of cyanidin-3-O-glucoside and ellagic acid. The highest yield of bioactive compounds was attained at 25 kHz, 20 min of extraction and pH 1.5 (8.9 mg/g dry peel of gallic acid equivalent, 0.9 mg/g dry peel of ellagic acid, and 7.9 mg/g dry peel of cyanidin-3-O-glucoside). The new mathematical model considered the mass transfer between the powder and the liquid media, and the sonochemical-induced hydrolysis of the compound. The model was able to predict satisfactorily the extraction process and the hydrolysis effect. [ABSTRACT FROM AUTHOR]

The effects of processing time (10, 20 and 30 min) and plasma flow rate (10, 20 and 30 mL min−1 of synthetic air) on the bioactive compounds of camu-camu juice (Myrciaria dubia) treated using glow plasma were evaluated herein. Plasma technology promoted the increase of the bioactive compounds' concentration (antioxidant compounds, ascorbic acid and total monomeric anthocyanins) in the juice serum. Peroxidase and polyphenol oxidase presented the higher reduction of the enzymatic activity for treatments using plasma flow rate of 20 mL min−1. The treatments with higher air flow rate presented great color change (ΔE* > 2). Furthermore, the bioavailability of ascorbic acid was increased after using plasma technology. Therefore, the cold plasma technology may represent a useful technique to improve the bioavailability of bioactive compounds in processed fruit juices. [ABSTRACT FROM AUTHOR]

This work evaluated the production of dehydrated mangoes (Mangifera indica L.) and the effectiveness of ultrasonic-assisted osmotic dehydration on the drying kinetics of mangoes. Cube shaped mango samples were pretreated using ultrasound-assisted osmotic dehydration (UAOD) and dried in a circulating drying oven. An experimental design was created to evaluate the effect of pretreatment time and osmotic solution concentration on the water loss and sugar gain in the osmotic dehydration and on the drying time. The ultrasonic pretreatment was carried out in a bath ultrasound operating at 25 kHz and outputting 55 W/m3 of power. Osmotic solution ranging from 0 to 500 kg sucrose/m3 was applied in the treatments, and air drying was carried out at 60 °C. A mathematical model was developed for the osmotic pretreatment, and Fick's law was used to model the air-drying process. The mass transfer coefficients were estimated for the ultrasonic-assisted osmotic dehydration, and the apparent water diffusivity was estimated for the air-drying process. The mass transfer coefficient ranged from 0.017 to 0.109 m2/s and the resistance to mass transfer at the surface ranged from 0.26 × 10−6 to 1.22 × 10−6 m2/s on the UAOD, while the apparent water diffusivity during air drying ranged from 5.94 × 10−9 to 8.41 × 10−9 m2/s. Mangoes presented a different behavior when compared to other fruits. The ultrasonic pretreatment was effective only when associated with an osmotic solution at 500 kg sucrose/m3. [ABSTRACT FROM AUTHOR]

The effects of glow discharge plasma on siriguela (purple mombin) juice quality were investigated through an experimental design changing the processing time (5-15 min) and the nitrogen gas flow rate (10-30 mL/min). Selected physicochemical properties and bioactive compounds were evaluated pre- and post-processing. No significant changes were found for vitamin C, and the processing did not affect the color of the product. Pigments, total phenolics, antioxidant activity, and B vitamins were increased due to the plasma processing. An increase in antioxidant activity was also observed. Polyphenol oxidase activity showed a decrease of about 20% (20 mL/min of N2/15 min), whereas peroxidase presented a slight activation (6%) in some processing conditions. The plasma processing imparted a positive or an adverse effect on the bioactive compounds in siriguela juice showing the importance of the optimization of food processing by cold plasma for real application. This behavior is related to the time intensity of the treatment, which can promote the extraction of the bioactive compound from the juice pulp followed by degradation at higher times or processing intensity. Due to the low pH of siriguela juice, no microbial contamination was found in the processed juices. [ABSTRACT FROM AUTHOR]

Potato peels are rich in α-solanine and α-chaconine, which are glycoalkaloids with known pharmacological activity but that have high cytotoxicity. Their aglycones (β-solanine and β-chaconine) have the same pharmacological activity but with a much lower cytotoxicity. In this work, we applied ultrasound technology to extract α-solanine and α-chaconine from potato peel and at the same time convert these molecules into β-solanine and β-chaconine, in a single-stage process without resorting to organic solvents. The extraction was studied varying ultrasonic power density (20, 35, and 50 W/L) and processing time (5, 10, 20, and 40 min) using an ultrasonic bath operating at 25 kHz. The chemical analysis was done by UHPLC-qTOF-MS and the results were evaluated by HCA, PCA, and PLS-DA chemometric analysis. The analysis of the single-stage procedure pointed to the viability of concomitant extraction and chemical conversion of α-solanine and α-chaconine into β-solanine and β-chaconine when operating at an ultrasonic power density of 35 and 50 W/L and subjecting the potato peel power to 20 and 40 min of ultrasound. [ABSTRACT FROM AUTHOR]

The effect of freeze- and spray-drying on physico-chemical characteristics, phenolics compounds and antioxidant activity of papaya pulp was investigated. The frozen pulp was freeze dried at − 62 °C during 48 h. Papaya pulp with 14% DE maltodextrin was also dried in a spray dryer. The organic acids, sugars, color, total soluble solids, pH, carotenoids, phenolic and flavonoid compounds, and antioxidant capacity values were determined. The changes in color, pH and lycopene were negligible. However, lower retention (86.5%) of vitamin C and sugars (glucose—79.7% and fructose—66.1%) was observed in spray dried products. Phenolic and flavonoid compounds were identified and quantified in dried papaya products by UHPLC-QqQ-MS/MS. Spray dried products presented a higher retention of phenolic and flavonoid compounds compared to the freeze dried products. Despite some variations in the parameters studied, the use of freeze- and spray-drying has proven viable options for the drying of papaya pulp. [ABSTRACT FROM AUTHOR]

The ongoing demand for high-quality processed foods which would preserve their natural and fresh-like characteristics has awakened a growing interest in non-thermal technologies. Thanks to their ability to inactivate microorganisms under mild conditions, these technologies avoid drawbacks usually attributed to the use of thermal treatments, such as nutrient loss, offflavors, and changes in the food's physical and chemical properties. Saccharomyces cerevisiae (S. cerevisiae) mainly causes spoilage in liquid foods with high sugar content and low pH values. Thus, it is one of the most undesirable microorganisms in the food industry since its presence may lead to important economic losses. This review offers an exhaustive compilation and critical revision of research conducted in the field of S. cerevisiae inactivation in liquid media, emphasizing the use of non-thermal technologies, such as high pressure processing, high-power ultrasound, supercritical carbon dioxide, pulsed electric fields, and others. Likewise, using these technologies in combination (the hurdle approach) may enhance their individual effect and significantly reduce the treatment time needed to obtain a given level of S. cerevisiae inactivation. In general, non-thermal technologies are proving to be able to successfully inactivate S. cerevisiae in liquid media. However, the need for further investigation and complete industrial implementation is made evident throughout this review. [ABSTRACT FROM AUTHOR]

Dextransucrase from Leuconostoc mesenteroides NRRL B-512F was subjected to immobilization and co-immobilization with dextranase from Chaetomium erraticum. Immobilization has enhanced the operational and storage stability of dextransucrase. Two hundred milligrammes (2.4 IU/mg) of alginate beads (immobilized and co-immobilized) were found to be optimum for the production of gluco-oligosaccharides (GOS) in orange juice with a high degree of polymerization. The pulp of the orange juice did not interfere in the reaction. In the batch process, co-immobilized dextransucrase (41 g/L) produced a significantly higher amount of GOS than immobilized dextransucrase (37 g/L). Alginate entrapment enhanced the thermal stability of dextransucrase for up to 3 days in orange juice at 30 °C. The production of GOS in semi-continuous process was 39 g/L in co-immobilized dextransucrase and 33 g/L in immobilized dextransucrase. Thus, immobilization technology offers a great scope in terms of reusability and efficient production of a value added functional health drink. [ABSTRACT FROM AUTHOR]

This study describes some effects of high-power ultrasound on cashew apple bagasse. The main objective was to develop an optimized process for sonication of cashew apple bagasse, evaluating the effect of ultrasound on antioxidant compounds. To define the best conditions for sonication, a 2 factorial central composite design was used changing the independent variables: bagasse/water ratio, ultrasonic power intensity (W/cm), and processing time (min). Antioxidant compounds such as vitamin C, β-carotene, and total phenolic compounds were determined. The total antioxidant capacity (ABTS(2,2 AZINO BIS (3-ethylbenzo thiazoline 6 sulfonic acid) diammoninum salt and DPPH (2,2-Diphenyl-1-picryl-hidrazil)) was also evaluated. A thermal treatment was carried at the highest temperature reached after sonication (51 °C) to evaluate the heat effect due to a temperature increase during processing. Sonication changed the bagasse aspect from a fibrous residue to a pleasant yellow puree. The maximal concentration of vitamin C, phenolics, and β-carotene was obtained when the processing conditions were as follows: bagasse/water ratio of 1:4 ( w/w), ultrasound power intensity of 226 W/cm, and 6 min of processing. The high total phenolic content (2186 mg of gallic acid/100 g DW), vitamin C (148 mg/100 g DW), and β-carotene (12 mg/100 g) obtained proved the sonication efficiency. The antioxidant activity determined by the DPPH and ABTS assays confirmed the suitability of ultrasound for the preparation of antioxidant-rich cashew apple bagasse puree. [ABSTRACT FROM AUTHOR]

In the present work pineapple, cantaloupe melon and orange juice were evaluated as substrate for oligosaccharide synthesis by dextransucrase acceptor reaction. Dextransucrase is a bacterial enzyme industrially applied for dextran synthesis using sucrose as carbon source. The acceptor reaction takes place only when a sufficient amount of another carbohydrate (acceptor) is also present in the reaction medium. The reducing sugars naturally present in fruit juices (fructose and glucose) were the acceptors for the oligosaccharides synthesis. High conversion was found for the evaluated juices and the residual sugars after the synthesis was very low (<1 %) due to the sugar consumption for oligosaccharide formation. The oligosaccharides obtained were evaluated regarding their resistance to the stomach acidity, digestive enzymes and stimulation of bifidobacterium growth. The results showed that the evaluated juices were suitable to produce ready to drink low caloric prebiotic juices by modulating the initial sugar concentration. [ABSTRACT FROM AUTHOR]

Oligosaccharides can be synthesized using the sugars present in the fruit juices through the dextransucrase acceptor reaction. In the present work, the effect of reducing sugar and sucrose concentration on oligosaccharide formation in lemon juice was evaluated through response surface methodology. The oligosaccharide formation in lemon juice was favored at high concentrations of sucrose (75 g/L) and reducing sugar (75 g/L). At this synthesis conditions, an oligosaccharide concentration of 94.81 g/L was obtained with a conversion of 63.21% of the initial sugars into the target product. Oligosaccharides with degree of polymerization up to 11 were obtained. The lemon juice was dehydrated in spouted bed using maltodextrin as drying adjuvant. The powder obtained at 60°C with 20 % maltodextrin presented low moisture (2.24 %), low water activity (Aw = 0.18) and the lowest reconstitution time (~46 s). The results showed that lemon juice is suitable for oligosaccharides enzyme synthesis and can be dehydrated in spouted bed. [ABSTRACT FROM AUTHOR]

This work has examined the influence of ultrasonic-assisted air-drying on the dehydration of apple ( Malus domestica L. var Royal Gala) and its influence in the availability of vitamins A, B, B, B, B, B, and E of the dried product. This study also has estimated the effective water diffusivity in air-drying process subjected to ultrasonic waves. The water effective diffusivity increased by up to 79 % by ultrasound application, which caused a reduction of about 35 % in the total drying time compared to the air-drying without sonication. The application of ultrasound increased the availability of vitamins B, B, B, and B in the dried product. A loss of vitamins B and E were observed for all studied drying conditions. [ABSTRACT FROM AUTHOR]

Yellow mombin ( Spondias mombin, L.) is a tropical fruit that presents exotic taste and aroma, being source of carotenoids and phenolics compounds. It presents a good potential for processing, despite some restriction related with the presence of high amounts of peroxidase (POD) and pectinmethylesterase (PME) which can cause sensory changes in the product. This work addresses the evaluation of changes in POD and PME enzyme activity during the traditional industrial processing used to produce tropical juices in Brazil. The enzyme activity was determined after the main steps of the processing: fruit pulping, homogenization and pasteurization. Although both enzymes presented significant activity loss during processing, the final product showed residual activity for PME (25 %) and POD (2.5 %). PME showed to be more thermal resistant than POD in yellow mombin juice. Considering the compounds with antioxidant activity, yellow mombin presented high amounts of carotenoids and phenolics when compared to other tropical fruits such as passion fruit and pineapple. Although the processing of the fruit resulted in significative phenolic loss, the carotenoids content was not affected significantly by the processing. [ABSTRACT FROM AUTHOR]

The aim of this work was to determine the best operating condition for spray drying prebiotic pineapple, melon, and orange drinks. Maltodextrin and Arabic gum were evaluated as drying adjuvant at two different drying temperatures (160 and 180 °C). The best operating condition was inlet air temperature of 180 °C, atomizer nozzle flow rate at 30 L/min, inlet air-drying flow rate at 3.5 m/min and feed flow rate at 0.3 L/h with 20 % (m/m) of maltodextrin. The powders presented low water activity ( a ≤ 0.200) and low moisture (0.267-0.733 %). The rehydration time ranged from 90 to 144 s, the powder hygroscopicity from 5.17 to 7.48 % in dry basis, and the degree of caking from 24 to 67 %. The instrumental color difference was below the threshold for the human eye perception for all drinks. [ABSTRACT FROM AUTHOR]

Data on spray-drying of fruit juices containing probiotic bacteria are scarce. The main challenge is to avoid the viability losses of the microorganism during drying and storage. In the presented study, the dehydration by spray-drying of cashew apple juice containing Lactobacillus casei NRRL B-442, and the influence of the storage temperature (25 and 4 °C) on the viability of L. casei NRRL B-442 and on the physical properties of the powder during 35 days of storage were evaluated. Probiotic cashew apple juice was dehydrated according to the following conditions: inlet temperature of the drying air (120 °C), feed flow rate of juice (0.3 L/h), hot air flow (3.0 m/min), and pressurized air flow (30 L/min). The outlet temperature was 75 °C. The carriers used were 20 % ( w/ v) maltodextrin or 10 % ( w/ v) maltodextrin + 10 % ( w/ v) gum arabic. Microbial survival rates higher than 90 % were obtained for the powder stored at 4 °C for 35 days (both carriers) and higher than 70 % up to 21 days for the powder obtained using only maltodextrin at 25 °C. Higher yields were obtained only by maltodextrin which was used as carrier (72 %) compared to the yield obtained when the mixture of maltodextrin and gum arabic was applied (60 %). The water activity was kept low (Aw < 0.30) during the storage, and the characteristic color of the product was maintained. [ABSTRACT FROM AUTHOR]

The enzyme dextransucrase in a medium containing sucrose and an acceptor as substrate synthesizes prebiotics oligosaccharides. The cashew apple juice works as a source of acceptors because it is rich in glucose and fructose (enzyme acceptors). The use of cashew apple juice becomes interesting because it aims at harnessing the peduncle of the cashew that is wasted during the nut processing, which is the product of greater economic expression. The production of dextransucrase enzyme was done by fermentative process by inoculating the bacterium Leuconostoc mesenteroides NRRL B512F into a culture medium containing sucrose as the only carbon source. Thus, the aim of this work was the production of prebiotic oligosaccharides by enzymatic process with addition of the dextransucrase enzyme to the clarified cashew apple juice. Dextran yield was favored by the combination of low concentrations of sucrose and reducing sugars. The formation of oligosaccharides was favored by increasing the concentration of reducing sugars and by the combination of high concentrations of sucrose and reducing sugars, the highest concentration of oligosaccharides obtained was 104.73 g/L and the qualitative analysis showed that at concentrations of 25 g/L and 75 g/L of sucrose and reducing sugar, respectively, it is possible to obtain oligosaccharides of degree of polymerization up to 12. The juice containing prebiotic oligosaccharide is a potential new functional beverage. [ABSTRACT FROM AUTHOR]

The effect of pre-treatments on the colour of freeze-dried strawberries was studied. Strawberries were subjected to different ultrasound and osmotic dehydration conditions followed by freeze-drying. Two concentration levels of sucrose solution (25 and 50 % w/w) and four levels of processing time (from 10 min to 45 min) were studied. Also, ultrasound application without using an osmotic solution was studied. Colour was quantified with a colorimetric analysis (CIE LCh). Sonicated strawberries presented higher lightness (L) and lower hue (h) than fresh and non-treated strawberries (control samples). The sonicated and osmo-sonicated strawberries have presented a more reddish and vivid colour then the control samples. [ABSTRACT FROM AUTHOR]

The stability of nonfermented cashew apple juice (control) and the fermented juice with Lactobacillus casei NRRL B-442 (sweetened and nonsweetened samples) was investigated along the storage at 4 °C for 42 days. The viability of the probiotic bacteria, sugars, lactic acid, and vitamin C content besides color, antioxidant activity, enzyme activity, and sensory characteristics of probiotic cashew apple juice was evaluated. It was observed that viable cell counts increased in the probiotic cashew apple containing sucrose (8 % w/ v) along the storage period. Viable cell counts were always higher than 8.00 Log CFU/ml throughout the storage period. Ascorbic acid loss was higher in the nonfermented juice (40 %) compared to the fermented juice (23 %). The same behavior was observed for antioxidant activity and total polyphenolic compounds content, conferring nutritional benefits to this functional food. Browning reactions and nutritional breakdown caused by enzymes were minimized in the fermented samples during storage. In the fermented sample, higher reduction (>70 %) in the polyphenol oxidase enzyme activity was observed. During storage, the increase in the chroma values from 3.2 to 5.0 indicated that the yellow color became more vivid. Sensory analysis of the fermented cashew apple juice revealed that the product was well-accepted, with acceptance percentages above 80 % for the sweetened juice at the end of the storage period. [ABSTRACT FROM AUTHOR]

The use of sonicated melon juice as substrate for Lactobacillus casei growth in cantaloupe melon juice and its effect on product quality were investigated. The survival of L. casei in the fermented juice, the product color, the post-acidification and other quality parameters were evaluated in the refrigerated product (4 °C) for a period of 42 days. Storage pH, color, sugar content, lactic acid concentration, biomass and viable cells count were determined. The caloric value of the product was also evaluated. During the refrigerated storage period, acidification and a slight reduction in the number of viable cells were observed. However, a sufficient number of viable cells were observed to guarantee the beneficial properties from probiotic consumption (>8 log CFU ml) throughout the storage period, for both stocked samples (with and without sugar addition). The product color was also preserved during storage. The developed product resulted in a low caloric product. The caloric value was reduced during the storage period due to sugar consumption by the remaining microorganisms. [ABSTRACT FROM AUTHOR]

The influence of ultrasound processing on the physicochemical characteristics of pineapple juice was investigated through an experimental design changing ultrasound time and intensity. After processing, the polyphenoloxidase (PPO) activity in the pineapple juice was reduced by 20% as result of the treatment with longer exposure and higher intensity (376 W/cm and 10 min). The effect on phenolic compounds compared to the fresh pineapple juice (non-sonicated) was not statistically significant. Ultrasound processing reduced juice viscosity by 75% of the initial value (non-sonicated juice). The higher the ultrasound intensity and the juice exposure (processing time), the higher the final temperature of the juice, reaching a maximum of 54 °C. Ultrasound processing enhanced the juice color and its stabilization along 42 days of storage compared to the non-sonicated juice. Thermal treatment at the highest temperature reached due to juice sonication (54 °C) showed no effect on PPO inactivation. [ABSTRACT FROM AUTHOR]

The production of lactic acid by Lactobacillus casei B-442 was studied and modeled. Sugar feedstock was provided using cashew apple juice, an alternative glucose and fructose feedstock that proved to yield high concentrations of lactic acid. The fermentations were carried out in a 1-L fermenter under constant agitation (150 rpm) and controlled pH (6.5). Lactic acid production was evaluated through a dynamic study, varying the initial concentration of sugar in the range of 20 to 60 g/L. Biomass, reducing sugars, and lactic acid concentration were measured throughout the experiments. The highest production of lactic acid (59.3 g/L) was obtained operating the fermentation with 60 g/L of reducing sugar from the cashew apple juice. A rigorous kinetic model was developed for batch fermentation of cashew apple juice for lactic acid production by L. casei B-442. The growth of biomass and lactic acid production were affected by substrate limitation, substrate inhibition and lactic acid inhibition. The model assumed growth- and non-growth-associated lactic acid production and a term for microorganism death was also included in the model. Parameters of the kinetic model were determined based on experimental data by using the least mean squares method and Levenberg-Marquardt algorithm. The model validation was performed and the model was statistically able to fit the profiles for growth of biomass, sugar consumption and lactic acid production. The optimization of the process, using the model, was carried out and the optimum operating conditions aiming highest productivity, lowest production cost and highest gross profit are presented. [ABSTRACT FROM AUTHOR]

This study was carried out to optimize the fermentation pH and temperature and also the fermentation time for development of a new probiotic fermented drink with cantaloupe juice. The fermented juice was subjected to a storage study during 42 days at 4 °C. The initial pH and temperature influenced the growth of Lactobacillus casei in cantaloupe juice. However, on the microbial viability only the effect of temperature was significant. Optimum conditions for a satisfactory growth and viability of L. casei in cantaloupe juice were as follows: pH = 6.1 and temperature = 31 °C. The fermentation time of 8 hours was selected as the optimal fermentation time to prepare the probiotic cantaloupe juice. The cell viability was 8.3 log CFU mL at the end of the fermentation. This level was kept over the 42 days of refrigerated storage. The consistent growth and viability of the probiotic microorganism in cantaloupe juice during fermentation and storage suggested that melon is a suitable vehicle for L. casei delivering. The fermented juice arises as a good alternative to the traditional dairy based products. [ABSTRACT FROM AUTHOR]

This study aimed at the optimization of the production of chitosanase in solid culture. Trichoderma koningii sp., an entomopathogenic fungus, was used to produce chitosanase under solid-state fermentation using a mixture of wheat bran and chitosan. The incubation period; addition of moistening water and culture medium composition were optimized. The protocol to extract the enzyme was also optimized. The optimal conditions for chitosanase production by T. koningii were obtained using a mixture of 3.0 g of wheat bran and 1.5 g of chitosan, with the addition of 2.5 mL of moistening water (pH 5.5) and of 2.5 mL of saline solution (pH 5.5) containing NaNO (1.0 g/L), (NH)HPO (1.0 g/L), MgSO.7HO (1.0 g/L), and NaCl (1.0 g/L). Optimal enzyme extraction was carried out adding 20 mL of sodium acetate buffer (200 mM, pH 5.5) at 30 °C under orbital agitation at 150 rpm for 6 min. The optimized production yielded 4.84 IU/gds. [ABSTRACT FROM AUTHOR]

Trichoderma strains were extensively studied as biocontrol agents due to their ability of producing hydrolytic enzymes, which are considered key enzymes because they attack the insect exoskeleton allowing the fungi infection. The present work aimed to evaluate the ability of chitosanase production by four Trichoderma strains ( T. harzianum, T. koningii, T. viride and T. polysporum) under solid stated fermentation and to evaluate the effect of pH and temperature on enzyme activity. pH strongly affected the enzyme activity from all tested strains. Chitosanase from T. harzianum and T. viride presented optimum activity at pH 5.0 and chitosanase from T. koningii and T. polysporum presented optimum activity at pH 5.5. Temperature in the range of 40-50°C did not affect enzyme activity. T. polysporum was found as the most promising strain to produce chitosanase with maximal enzyme activity of about 1.4 IU/gds, followed by T. viride (~1.2 IU/gds) and T. harzianum (1.06 IU/gds). [ABSTRACT FROM AUTHOR]

The aim of the present work was to investigate the use of cashew apple juice as a low cost substrate for Lactobacillus casei B-442 cultivation and lactic acid production. Ammonium sulfate was employed as the only exogenous nitrogen source. The effect of cashew apple juice reducing sugars and ammonium sulfate concentration and the fermentation pH and temperature on biomass formation, lactic acid production, and productivity were evaluated. The highest productivity (2.36 g/L.h) was obtained applying 50 g/L of reducing sugar from the cashew apple juice supplemented with 6 g/L of ammonium sulfate. The process yield was about 95% when fermentation was carried out at 37 °C with pH controlled at pH 6.5 using NaOH (120 g/L). [ABSTRACT FROM AUTHOR]

This work examined the influence of the ultrasonic pre-treatment prior to air drying on dehydration of jambo ( Syzygium malaccense L.) also known as Malay apple. This study allowed the estimation of water loss and sugar gain during the pre-treatment and the effective water diffusivity in the air-drying process for jambo subjected to ultrasonic pre-treatment. Results showed that during the ultrasonic treatment, in distilled water, the Malay apples lost sugar, so such a pre-treatment stage can be a practical process to produce dried fruits with lower sugar content. The water effective diffusivity increased by 28.1% (best result) after application of ultrasound, which caused a reduction of about 27.3% in the total drying time. [ABSTRACT FROM AUTHOR]

In the present work, the stability of crude dextransucrase from Leuconostoc citreum B-742 was evaluated in synthetic and in cashew apple juice culture broth. Optimum stability conditions for dextransucrase from L. citreum B-742 were different from the reported for its parental industrial strain enzyme ( L. mesenteroides B-512F). Crude dextransucrase, from L. citreum B-742, produced using cashew apple juice as substrate, presented higher stability than the crude enzyme produced using synthetic culture medium, showing the same behavior previously reported for dextransucrase from L. mesenteroides B-512F. The crude enzyme presented good stability in cashew apple juice for 48 h at 25°C and pH 6.5. [ABSTRACT FROM AUTHOR]

This paper provides a capsule overview of recent experimental studies dealing with the drying of a large assortment of tropical and subtropical fruits, also called 'exotic' fruits. The term exotic includes a number of tropical fruits that are not yet commonly found in global markets but do have the potential to do so in view of their appearance, taste, and textural and nutritional quality parameters. As the consumer is seeking diverse tastes and flavors without compromising on quality, it is logical to expect the market for dried exotic fruits to increase over the next decade. This review covers diverse drying techniques, drying kinetics, and key quality parameters of dried fruits. [ABSTRACT FROM AUTHOR]

The use of agriculture waste as substrate for biotechnological process became an interesting alternative to reduce production costs and the negative impact of agricultural wastes disposal in the environment. In Brazil, cashew tree cultivation is done aiming the cashew nut production, and tons of cashew apples are wasted in the field after the nut removal. Thus, cashew apple juice can be used as low cost substrate for biotechnological process. In this study, the stability of dextransucrase produced in a fermentation medium using cashew apple juice as substrate was evaluated. The crude enzyme was stable at 30 °C for 30 h at pH ranging from 4.5 to 5.5. The partially purified enzyme was stable in non-fermented cashew apple juice at pH 5.0 for 96 h at 30 °C. The high stability of the enzyme in cashew apple juice at room temperature allows its industrial use without needing the enzyme purification, consequently reducing process costs. [ABSTRACT FROM AUTHOR]

This work evaluated the production of dehydrated papayas (Carica papaya L.) with low sugar content. The product was obtained applying ultrasonic waves to enhance the loss of sugar from the fruit. To achieve this goal, this paper examined the influence of the ultrasonic pre-treatment before air-drying on dehydration of papaya. Ultrasonic pre-treatment for air-drying of fruits was studied and compared with osmotic dehydration. This study allowed estimate of the effective diffusivity water in the air-drying process for papayas submitted to ultrasonic pretreatment. Results show that the water effective diffusivity increases after application of ultrasound causing a reduction of about 16% in the drying time. During ultrasonic treatment the papayas lost sugar (13.8% in 30 min), so such a pre-treatment stage can be a practical process to produce dried fruits with lower sugar content. [ABSTRACT FROM AUTHOR]

To test whether African ancestry is protective for severe dengue, we genotyped 49 hospitalized cases of dengue hemorrhagic fever (DHF) as well as 293 neighborhood cases of dengue fever and 294 asymptomatic controls in Salvador, Bahia, Brazil. Ancestry-informative markers and 282 unlinked SNPs not associated with the clinical presentation of dengue were used to estimate ancestry. After controlling for income, both self-defined Afro-Brazilian ethnicity and African ancestry were protective for DHF (P=0.02, OR=0.28 and P=0.02, OR=0.13, respectively). Income or an index of income indicators, however, was also independently associated with the diagnosis of DHF.European Journal of Human Genetics (2008) 16, 762–765; doi:10.1038/ejhg.2008.4; published online 13 February 2008 [ABSTRACT FROM AUTHOR]

In the present work, the use of low-cost substrates to produce Trichoderma spores was evaluated. Rice, corn bran, and wheat bran were used as solid substrate to grow Trichoderma harzanium sp., Trichoderma viride sp., Trichoderma koningii sp., and Trichoderma polysporum sp. No external nutrient sources were added to the solid substrate that was only moisturized with deonized water, sterilized, inoculated, and cultivated at 30 °C for 7 days. Wheat bran showed to be the most suitable substrate to produce Trichoderma spores for all strains that were evaluated. High spore counts were obtained for T. harzianum sp. (28.30x108/gds) and T. viride sp. (24.10x108 spores/gds). [ABSTRACT FROM AUTHOR]