Effects of high hydrostatic pressure on the overall quality of Pêra-Rio orange juice during shelf life.

The effect of high hydrostatic pressure on antioxidant activity, total phenolic compounds, physicochemical characteristics, color, pectin methylesterase activity, and microbiological count were evaluated during the shelf life of Pêra-Rio orange juice. Pressurized (520 MPa, 60 ℃, for 360 s), non-processed and pasteurized (95 ℃/30 s) orange juice were compared at zero time of storage. Pressurized and pasteurized juices were studied during a refrigerated 90-day shelf life. Pressurization did not cause expressive change in physicochemical characteristics of Pêra-Rio orange juice along shelf life, but significantly reduced pectin methylesterase residual activity to 13% and microbiological counts below detection levels up to 68 days of storage, with small counts (30.0 × 10 CFU/mL mesophilic aerobic bacteria and 20.7 × 10 CFU/mL yeast and mold) at 90 days, capable of ensuring the juice's stability along shelf life. Lightness ( L*) and b* values were significantly reduced by high hydrostatic pressure during shelf life, while a* values were significantly higher. Ascorbic acid decreased around 80% during shelf life. Antioxidant activity remained stable after processing and during storage.

Capillary electrophoresis to approach sorbate usage in processed meat products in Brazil.

Sorbate is a highly used preservative in a wide range of processed foods, including meat products. In this work sorbate usage in commercial processed meat products from the Brazilian market was evaluated. A capillary electrophoresis method for sorbate analysis using ethanol:water extraction solution (1:2, v/v) and sodium tetraborate (20 mmol L-1) electrolyte solution was validated. Low limits of detection (0.4 mg L-1) and quantification (1.0 mg L-1), good precision (RSD = 3.6%) and suitable accuracy (70.2%, RSD = 1.8%) were attained. Linearity was observed from 1.0 to 15.8 mg L-1, with r ≥ 0.999. The proposed method was applied to Brazilian pork and hot dog sausages, salami, ham and mortadella. A peak of sorbate between 4 and 6 min was found in pork and hot dog sausages, poultry and pork mortadella, but not in ham and salami. The sorbate levels ranged from 54.0 to 976.4 mg kg-1. Sorbate concentration exceeded the 200 mg kg-1 limit of the Brazilian legislation in all sorts of products in the majority of the brands despite there being no information regarding sorbate on the label. These results indicated the widespread use of sorbate, turning this into food for thought.

HS-GC-MS-O analysis and sensory acceptance of passion fruit during maturation.

The odor-active compounds of the conventional yellow passion fruit influence the aroma during ripeness and the acceptance of the juice. HS-GC-MS and GC-OSME analysis and sensory acceptance of the conventional passion fruit from different stages of ripeness were studied to characterize the aroma of the fruit and, aroma and flavor of the juice. Ethyl butanoate, ethyl hexanoate and propyl acetate showed high odoriferous importance in the passion fruit from the 1/3 yellow skin color. Cis-3-hexen-1-ol and diethyl carbonate plus the odor-active compounds from the 1/3 yellow skin color showed high odoriferous importance in the 2/3 yellow skin color, and butyl acetate and alpha-terpineol plus the same odor-active compounds from 2/3 were the most important for the 3/3 yellow skin color. There was difference in the aroma and flavor of the juices, with higher acceptance means for the passion fruit from the 3/3 yellow skin color. The passion fruit volatile compounds peak area, odoriferous intensity and sensory acceptance of the juices increased during ripeness, indicating that the conventional passion fruit characteristic aroma is completely expressed when the fruit reaches the whole maturation, at the 3/3 yellow skin color.

Identification of odour-active compounds of pasteurised orange juice using multidimensional gas chromatography techniques.

Odour-active compounds present in pasteurised orange juice were identified by gas chromatography-olfactometry (GC-O) employing heart-cut multidimensional GC techniques with olfactometry (O) and mass spectrometry (H/C MDGC-O/MS) and comprehensive two-dimensional gas chromatography-accurate mass time-of-flight MS (GC×GC-accTOFMS). Headspace solid phase microextraction sampling proved to be qualitatively adequate for the analysis of pasteurised orange juice. The GC-O approach distinguished 13 potent odour regions (detection frequency≥3) in the orange juice extract, in which 7 regions were then subjected to detailed identification of the compounds that contribute to the odour, by using higher resolution H/C MDGC-O/MS. This analysis permitted the odour-active peaks to be better resolved on the 2D column, with removal from background matrix, for the seven regions. GC×GC-FID and GC×GC-accTOFMS reveal the overall complexity of the volatile compounds in the product and assisted in assignment of the isolated peaks of the odour-active compounds, confirming the identification in a number of cases. Four aldehydes (hexanal, heptanal, octanal, citral), 2 esters (ethyl butanoate, methyl hexanoate), and 4 monoterpenes (α-pinene, D-limonene, linalool, α-terpineol) were confirmed in accordance with olfactometry assessment in the processed juice. This multi-assessment instrument approach of GC-O, GC×GC, and H/C MDGC provided an effective insight into the processed orange juice aroma.

The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp.

BACKGROUND: This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin-Ciocalteu reaction, and TAA using the ABTS radical reaction. RESULTS: The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L⁻¹ (P ≤ 0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L⁻¹ (P ≤ 0.05) for the conventional pulp. CONCLUSION: TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level.

Antioxidant activity of commercial ready-to-drink orange juice and nectar.

Total antioxidant activity (TAA), total phenolic compounds (TPC), and physicochemical characteristics of ready-to-drink orange juice and nectar from the most consumed brands available in Brazil were evaluated. TPC ranged from 18.7 to 54.2 mg of gallic acid/100 mL, and TAA varied from 57.88 to 349.32 µmol TEAC/100 mL ready-to-drink orange juice and nectar. The ascorbic acid content was the only physicochemical parameter that showed strong variation among packages and brands. Correlation of TPC with TAA showed that the higher the level of TPC the higher the TAA. Correlation of ascorbic acid content with TAA is higher for ready-to-drink orange juice than nectar. The same was found for the correlation of ascorbic acid content with TPC. The results confirm the contribution of the TPC to TAA.

Ciclamato de sódio em refrigerantes de baixa caloria / Sodium cyclamate in low calorie soft drinks

O objetivo deste estudo foi determinar os teores de ciclamato de sódio nos refrigerantes de baixa caloria mais consumidos no país. Os refrigerantes de baixa caloria dos tipos cola, guaraná, laranja, limão e uva foram analisados seguindo-se a técnica descrita por Sjõberg e Alanko (1987), com algumas modificações. Os ensaios de recuperação da metodologia foram realizados em três níveis de fortificação, com recuperação média de 92,5 e 110,3, respectivamente, para cola e guaraná, e o desvio-padrão relativo foi de 3,7. Os teores médios de ciclamato de sódio variaram de 27,1 ± 1,1 (cola A) a 127,3 ± 1,5 mg.100 mL-1 (limão B), o que mostra que a ingestão diária aceitável do edulcorante pode ser facilmente excedida com o consumo de refrigerantes de baixa caloria. Todas as amostras de refrigerantes apresentaram teores de ciclamato de sódio superiores àqueles indicados no rótulo, com 12,9 (cola A) a 19,0 (limão B) acima do declarado. Dos 18 refrigerantes analisados, apenas quatro apresentaram teor médio de ciclamato de sódio de acordo com o limite máximo de 40 mg.100 mL-1 de bebida, permitido pela legislação brasileira; e os demais apresentaram variação de 74,8 (laranja) a 218,3 (limão B) acima do limite permitido.

A nonstaining and tasteless hydrophobic salt of chlorhexidine.

Chlorhexidine (CHX) remains one of the most effective and widely used antiplaque agents around the world, although its side effects still limit a long-term usage as the patient compliance for oral treatment with CHX. We hypothesize that a less water-soluble tetracation salt of CHX might be able to interact weakly with tooth enamel and oral taste cells, reducing those undesirable side effects of CHX. The chlorhexidine tetrapalmitate (CHXTP) was obtained and the antimicrobial activity was evaluated by hole-plate diffusion method and twofold tube dilution method; for measurement of its propensity to stain, we used the in vitro method of polymethylmethacrylate blocks in an infusion with black tea solution; the rate of its removal from oral cavity was studied by high-performance liquid chromatography measurement of CHX extracted from human saliva samples; and its effect on the human taste perception was evaluated by taste confusion matrix method. The results showed that CHXTP salt is very active against Streptococcus mutans, with no interference on taste perception and a low tendency to stain; however, chlorhexidine digluconate shows a better retention in saliva. The use of polyvinylpyrrolidone turned possible a nonstaining and tasteless CHXTP formulation to linger in mouth.

Avaliação crítica da legislação brasileira de sucos de fruta, com ênfase no suco de fruta pronto para beber / Critical assessment of the Brazilian regulations on fruit juices, with emphasis on ready-to-drink fruit juice

O objetivo deste trabalho foi realizar a avaliação crítica da legislação brasileira de sucos de fruta, com ênfase no suco de fruta pronto para beber. De acordo com a legislação brasileira, os sucos industrializados devem atender à legislação específica, estando de acordo com a definição e a designação que os identificam e com os parâmetros de qualidade estabelecidos, devendo também atender à legislação sobre rotulagem de alimentos embalados. Foi observado que existem lacunas na legislação brasileira de sucos que favorecem sua interpretação equivocada, além da inclusão de sucos não regulamentados no mercado. Mudanças freqüentes, e diferentes informações, nas legislações de rotulagem concomitantemente vigentes, além do uso indevido de expressões no rótulo, também podem levar à interpretação equivocada. Para que se possa conhecer e usar adequadamente a legislação é necessário torná-la clara e mantê-la constantemente atualizada. Adicionalmente, sua ampla divulgação também deverá contribuir para uma escolha consciente na hora da compra.

The aim of this work was to critically assess the Brazilian regulations on fruit juices, with emphasis on ready-to-drink fruit juice. According to the Brazilian regulations, bottled fruit juices must follow specific regulations. They should be in accordance with the definition and designation that identify them, with the quality parameters established, and especially, follow the Brazilian food labeling regulations. The Brazilian regulations on bottled fruit juices have some gaps that promote their misunderstanding and marketing of substandard juices. Frequent changes, divergent labeling regulations and inappropriate use of expressions on the label can also lead to misinterpretation. Food regulations need to be clear and updated frequently if they are to be known and followed. Additionally, their wide dissemination should contribute to informed choices when buying.

Effect of gamma irradiation on caprolactam migration from multilayer polyamide 6 films into food simulants: development and validation of a gas chromatographic method.

A GC method to determine caprolactam in water, 15% ethanol, and olive oil food simulants was developed and validated. Linear ranges varied from 0.96 to 642.82 microg/mL for water, 0.64 to 800.32 microg/mL for 15% ethanol, and 1.06 to 1062.34 microg/g for olive oil, with correlation coefficients higher than 0.999. Method precision studies showed RSD values lower than 5.45%, while method accuracy studies showed recovery from 72 to 111% for all simulants. The effect of gamma irradiation on caprolactam migration from multilayer polyamide 6 (PA-6) films intended for cheese into water, 15% ethanol, olive oil, and 3% acetic acid simulants was also studied. For migration assay, non-irradiated and irradiated (12 kGy) films were placed in contact with the simulant and exposed at 40 degrees C for 10 days. The validated method was used to quantify caprolactam migration from multilayer PA-6 films into the simulants, which ranged from 1.03 to 7.59 mg/kg for non-irradiated films, and from 4.82 to 11.32 mg/kg for irradiated films. Irradiation caused almost no changes in caprolactam levels, with the exception of olive oil, which showed an increase in the caprolactam level. All multilayer PA-6 films were in accordance with the requirements of the legislation for caprolactam migration.

Efeito de dois anti-sépticos sobre a formaçäo da placa bacteriana in vivo / Effect of 2 antibacterial solutions on the formation of bacterian plaque in vivo

O presente estudo compara o efeito antiplaca de soluçöes equimolares de CUSO4 e CH a 1,6 mM. Dois grupos de voluntários bochecharam alternadamente CuSO4, CH e placebo durante 3 períodos de 7 dias. Ao final de cada período, os índices de palaca foram medidos e observados os efeitos inibitórios. Ambas as substâncias reduziram de forma semelhante e significativa a placa formada quando comparada ao placebo