103 resultados para Juice processing

em Scielo Saúde Pública - SP


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Passion fruit is widely consumed due to its pleasant flavour and aroma acidity, and it is considered very important a source of minerals and vitamins. It is used in many products such as ice-cream, mousses and, especially, juices. However, the processing of passion fruit juice may modify the composition and biodisponibility of the bioactive compounds. Investigations of the effects of processing on nutritional components in tropical juices are scarce. Frequently, only losses of vitamin C are evaluated. The objective of this paper is to investigate how some operations of passion fruit juice processing (formulation/homogeneization/thermal treatment) affect this product's chemical and physicochemical characteristics. The results showed that the chemical and physicochemical characteristics are little affected by the processing although a reduction in vitamin C contents and anthocyanin, large quantities of carotenoids was verified even after the pasteurization stage.

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The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%), followed by ketones (26%), alcohols (18%), aldehydes (9%), acids (3%) and other compounds (9%). Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.

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In the present study, the effect of pectinases on the production of pulp and juice of araçá and the presence of bioactive compounds were evaluated. An enzyme extract (EE) produced by Aspergillus niger LB-02-SF in solid state fermentation and the commercial enzyme Ultrazym®AFP-L were used in this study. After enzyme treatment with the EE preparation, the extraction yield increased by 23.1% and viscosity decreased by 42.8%, during pulp maceration. During juice processing, there was an increase of 70.6% in clarification and a decrease of 72.87% in turbidity. Higher values of these parameters, 47.7, 69.0, 80.7, and 79.7%, respectively, were obtained using the Ultrazym®AFP-L, which also led to a significant increase in the polyphenol content, both in the pulp (24%) and in the juice (28%), with a less pronounced effect when the EE was applied (10 and 21%, respectively). The anthocyanins content in the araçá pulp increased after treatment with the commercial preparation (23%), and there was no significant increase with the use of EE. The use of Ultrazym®AFP-L increased the β-carotene content by 29.4% in the fruit pulp, while the treatment with EE did not result in significant changes compared with those of the juice and pulp controls.

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Penicillium citrinum grown in orange juice processing wastes medium under continuous agitation was studied in order to establish optimal conditions (incubation period, incubation temperature, initial pH and nitrogen addition) for biomass and ribonuclease production, as well as, biological depuration of the wastes. Nitrogen addition to wastes medium increased the biomass and ribonuclease production and provides COD reduction. The soy meal shows to be the best nitrogen source. The conditions for a more favorable enzyme and biomass production and COD reduction were initial pH 6.0 and temperature of 27°C. The maximum value obtained for these parameters on optimal conditions of cultivation was 11 U/mL of enzyme, 4 mg/mL of biomass (dry matter) and 55% of COD reduction, in 96 hours of incubation.

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Sugarcane juice with passion fruit pulp was clarified using microfiltration under different T (temperature), P (pressure), and V (tangential velocity). The effects of these processing parameters were evaluated applying a rotational central composite experimental design (RCCD) and response surface methodology (RSM). The tests were performed at a filtration pilot plant using a polyamide hollow-fiber membrane with an average pore diameter of 0.4 µm and filtration area of 0.723 m². In addition, the resistances to the permeate flux during the microfiltration were investigated according to the series resistance. The final permeate flux ranged from 7.05 to 17.84 L·h- 1·m- 2. There was a rapid decline in flux (50%) in the initial stages of microfiltration. T and V were the major variables responsible for the flux increase. The concentration polarization showed the greatest influence on the flux decline, and highest values for the flux decline rate (λ) were found when low pressures were used. In the clarified juice there was a reduction in the contents of total solids, proteins, vitamin C, and acidity, while the soluble solids, pH, and ash contents did not change. Finally, membrane process could produce high quality filtered sugarcane juice with substantial flux and increased luminosity improving organoleptical properties.

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Brazil is the world's largest producer of oranges and uses more than 70% of the harvested fruits in the production of juices. The amount of processed orange is growing about 10% per year, confirming the trend of the Brazilian citrus for juice production. This research aimed to investigate the Brazilian orange juice production chain from 2005 to 2009. Data from the amount of frozen juice produced and exported, international price of orange juice, and intermediate transactions were assessed in order to make possible selection of all interveners involved in the chain. The study using the Social Network Analysis (SNA) showed that the densest relationships in the network are from exporters to importers and from orange growers to the orange processing industry. No difference was found in the values of the network geodesic distance or the clustering coefficients from 2005 to 2009. The degree of centrality increased steadily throughout the years indicating that the processing industry attempts to minimize the risks by centralizing the actions. A decrease in export of orange juice from 2007 (2.07 10(6) t) to 2008 (2.05 10(6) t) was found, probably due to the world's financial crisis with recovery in 2009. Since 2004, there has been an increase of nearly 10% per year in the market preference of concentrate juice (OFCJ) when compared to the "not from concentrated" juice (NFC). Nowadays the NFC market represents nearly 50% of all Brazilian export which impacted in the logistic distribution and transportation issues.

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Cashew (Anacardium occidentale L.) apples from Pacajus, Ceará State, Brazil, were processed into high pulp content juice. The juice was packed either by hot fill or an aseptic process and evaluated for physical, physical-chemical, and sensorial changes during a 12-month storage period at room temperature. The results indicated that pH, soluble solids, total acidity, total sugar content and color did not change significantly during storage nor were affected by the type of filling. The sensorial analysis showed that juice acceptance remained high throughout the storage period regardless of the filling system. Differences in juice viscosity persisted between both processes.

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In this work, a protocol for the formulation of an enzyme concentrated product to be applied in fruit juice treatment is described. Downstream processing conditions for the recovery and concentration of pectinases produced by the new strain Aspergillus niger LB-02-SF in solid state cultivation were assessed. The solid-liquid ratio in the extraction step of pectinases recovery from the cultivated media was evaluated and the highest activity was obtained with a solid-liquid ratio of 1:10. The crude extract was concentrated by ultrafiltration and the total pectinase (TP) activity was 73.6-fold concentrated in relation to the crude extract, and a final TP titer of 663 U mL–1 was obtained with 73.7% of recovery yield. KCl and different glycerol concentrations were added to the concentrated extract and the stability of pectinases during the storage at 5°C for 59 weeks was tested. The formulation with 50% w/w glycerol was applied to the treatment of apple and grape juices and the results of these tests were statistically comparable to those obtained with two high-quality commercial preparations.

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The purpose of the present study is to compare the tomato juice agar, a well known medium employed to observe ascospore formation, with niger seed agar, casein agar and sunflower seed agar, applied to a differentiation between C. dubliniensis and C. albicans. After 48 hours of incubation at 30 ºC all 26 (100%) C. dubliniensis isolates tested produced chlamydospores on tomato juice agar as well as in the other three media evaluated. However, when we inoculated all media with C. albicans, the absence of chlamydospores became resulting in the following percents: tomato juice agar (92.47%), niger seed agar (96.7%), casein agar (91.39%), and sunflower seed agar (96.7%). These results indicate that tomato juice agar is another medium which can also be used in the first phenotypic differentiation between C. dubliniensis and C. albicans.

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Chagas disease can be transmitted to man by many different means, including contact with infected triatomine feces, blood transfusion, laboratory accidents, organ transplants, and congenital or oral routes. The latter mode has received considerable attention recently. In this assay, we evaluate the survival of Trypanosoma cruzi contaminating sugar cane used to prepare juice, as well as the viability and capacity for infection by the parasite after recovery. Thirty triatomines were contaminated with T. cruzi Y strain and 45 days later pieces of sugar cane were contaminated with the intestinal contents of the insects. The pieces were ground at different intervals after contamination (time = 0, 1, 4, 6, 12 and 24 hours) and the juice extracted and analyzed. Different methods were used to show T. cruzi in the juice: direct analysis, hematocrit tube centrifugation and QBC, and experimental inoculation in 47 female BALB/c mice (five control mice and seven mice for each interval examined (five inoculated orally and two intraperitoneally). Positive results were found using the direct analysis and QBC methods for juice prepared up to 12 hours after initial contamination. However, by the centrifugation technique, positivity was found only up to four hours after contamination of the sugar cane. Inoculated animals showed parasitemia during a 14 day observation period, demonstrating the high survival rate of T. cruzi in sugar cane.

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Development and standardization of reliable methods for detection of Mycobacterium tuberculosis in clinical samples is an important goal in laboratories throughout the world. In this work, lung and spleen fragments from a patient who died with the diagnosis of miliary tuberculosis were used to evaluate the influence of the type of fixative as well as the fixation and paraffin inclusion protocols on PCR performance in paraffin embedded specimens. Tissue fragments were fixed for four h to 48 h, using either 10% non-buffered or 10% buffered formalin, and embedded in pure paraffin or paraffin mixed with bee wax. Specimens were submitted to PCR for amplification of the human beta-actin gene and separately for amplification of the insertion sequence IS6110, specific from the M. tuberculosis complex. Amplification of the beta-actin gene was positive in all samples. No amplicons were generated by PCR-IS6110 when lung tissue fragments were fixed using 10% non-buffered formalin and were embedded in paraffin containing bee wax. In conclusion, combined inhibitory factors interfere in the detection of M. tuberculosis in stored material. It is important to control these inhibitory factors in order to implement molecular diagnosis in pathology laboratories.

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Vibrio cholerae represents a significant threat to human health in developing countries. This pathogen forms biofilms which favors its attachment to surfaces and its survival and transmission by water or food. This work evaluated the in vitro biofilm formation of V. cholerae isolated from clinical and environmental sources on stainless steel of the type used in food processing by using the environmental scanning electron microscopy (ESEM). Results showed no cell adhesion at 4 h and scarce surface colonization at 24 h. Biofilms from the environmental strain were observed at 48 h with high cellular aggregations embedded in Vibrio exopolysaccharide (VPS), while less confluence and VPS production with microcolonies of elongated cells were observed in biofilms produced by the clinical strain. At 96 h the biofilms of the environmental strain were released from the surface leaving coccoid cells and residual structures, whereas biofilms of the clinical strain formed highly organized structures such as channels, mushroom-like and pillars. This is the first study that has shown the in vitro ability of V. cholerae to colonize and form biofilms on stainless steel used in food processing.

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Abstract: INTRODUCTION: Before 2004, the occurrence of acute Chagas disease (ACD) by oral transmission associated with food was scarcely known or investigated. Originally sporadic and circumstantial, ACD occurrences have now become frequent in the Amazon region, with recently related outbreaks spreading to several Brazilian states. These cases are associated with the consumption of açai juice by waste reservoir animals or insect vectors infected with Trypanosoma cruzi in endemic areas. Although guidelines for processing the fruit to minimize contamination through microorganisms and parasites exist, açai-based products must be assessed for quality, for which the demand for appropriate methodologies must be met. METHODS: Dilutions ranging from 5 to 1,000 T. cruzi CL Brener cells were mixed with 2mL of acai juice. Four Extraction of T. cruzi DNA methods were used on the fruit, and the cetyltrimethyl ammonium bromide (CTAB) method was selected according to JRC, 2005. RESULTS: DNA extraction by the CTAB method yielded satisfactory results with regard to purity and concentration for use in PCR. Overall, the methods employed proved that not only extraction efficiency but also high sensitivity in amplification was important. CONCLUSIONS: The method for T. cruzi detection in food is a powerful tool in the epidemiological investigation of outbreaks as it turns epidemiological evidence into supporting data that serve to confirm T. cruzi infection in the foods. It also facilitates food quality control and assessment of good manufacturing practices involving acai-based products.