Simultaneous allergen inactivation and detoxification of castor bean cake by treatment with calcium compounds

Ricinus communis L. is of great economic importance due to the oil extracted from its seeds. Castor oil has been used for pharmaceutical and industrial applications, as a lubricant or coating agent, as a component of plastic products, as a fungicide or in the synthesis of biodiesel fuels. After oil extraction, a castor cake with a large amount of protein is obtained. However, this by-product cannot be used as animal feed due to the presence of toxic (ricin) and allergenic (2S albumin) proteins. Here, we propose two processes for detoxification and allergen inactivation of the castor cake. In addition, we establish a biological test to detect ricin and validate these detoxification processes. In this test, Vero cells were treated with ricin, and cell death was assessed by cell counting and measurement of lactate dehydrogenase activity. The limit of detection of the Vero cell assay was 10 ng/mL using a concentration of 1.6 x 10(5) cells/well. Solid-state fermentation (SSF) and treatment with calcium compounds were used as cake detoxification processes. For SSF, Aspergillus niger was grown using a castor cake as a substrate, and this cake was analyzed after 24, 48, 72, and 96 h of SSF. Ricin was eliminated after 24 h of SSF treatment. The cake was treated with 4 or 8% Ca(OH)2 or CaO, and both the toxicity and the allergenic properties were entirely abolished. A by-product free of toxicity and allergens was obtained.

Ochratoxin A in Brazilian green coffee

Ochratoxin A is a nephrotoxic, teratogenic and imunotoxic compound produced by Aspergillus and Penicillium spp. It is a suspected carcinogen to humans and it is carcinogenic to rats. Recently it has drawn attention because it has been found in coffee and it has been the object of regulation by coffee importing countries. Brazil is the largest coffee producing country and its largest consumer. In order to conduct an initial assessment of the situation of the coffee produced in the country and offered to its population, one hundred and thirty two samples of Brazilian green coffee from 5 producing states (Minas Gerais, Paraná, São Paulo, Espírito Santo and Bahia) and destined for the home market, were collected at sales points at the cities of Londrina and Santos, Brazil, and analyzed for ochratoxin A. The toxin was isolated in immunoaffinity columns and quantified by HPLC with florescence detection. The limit of detection was 0.7ng/g and the average RSD for duplicates of the samples was 11%. Twenty seven samples were found contaminated with the toxin and the average concentration for the contaminated samples was 7.1ng/g ochratoxin A. Neither the total number of defects nor the number of specific defects according to the Brazilian coffee classification system (black, partly -- black, sour, stinkers-black, stinkers-green, pod beans) showed any relation to the contamination of the samples with ochratoxin A.

Effect of processing and roasting on the antioxidant activity of coffee brews

The aim of this work was to evaluate the effect of processing and roasting on the antioxidant activity of coffee brews. Brews prepared with light, medium and dark roasted coffees were analyzed. The pH, total solids content, polyphenols content, reducing substances and chlorogenic acids content were determined. The antioxidant activity of aqueous extracts, the guaicol decolorizing and the capacity to inhibit lipid peroxidation were also analyzed. The antioxidant activity of coffee brews were concentration-dependent. A progressive antioxidant activity and polyphenols content was observed decreasing with roasting. The light roasted coffee showed the highest antioxidant activity and dark roasted coffee showed the lowest antioxidant activity. The results indicate that the ingestion of coffee brews prepared with light and medium roasted coffees might protect cells from oxidative stress damages.

Brazilian roasted coffee oil obtained by mechanical expelling: compositional analysis by GC-MS

A preliminary analysis by GC-MS comparing the mass spectrum of the compounds with the Wiley 275 L mass spectral data base was used to identify the fatty acids and mainly, some volatile compounds responsible for the flavor of the roasted coffee oil. The oil was obtained by mechanical expelling of Brazilian beans (Coffea arabica) roasted at 238ºC for 10 minutes. Different sample preparation methodologies such as headspace, adsorbent suction trapping and esterification were used. It was possible to identify pyrazines, pyridines, furan derivatives and other compounds not reported in the literature.

Sensory evaluation of black instant coffee beverage with some volatile compounds present in aromatic oil from roasted coffee

The oil obtained from Brazilian roasted coffee by supercritical CO2 extraction shows considerable aromatic properties, mainly composed by five aromatic compounds, 2-methylpyrazine; 2-furfurylalcohol, 2,5-dimethylpyrazine; γ-butyrolactone and 2-furfurylacetate. Sensory analyses were used to verify the influence of a mixture of these important classes of aromatic coffee compounds (pyrazines, furans and lactones) and of the roasted coffee aromatic oil on the coffee aroma and flavour of black instant freeze and spray-dried coffee beverages. In the acceptance evaluation of the aroma, the samples prepared with freeze-dried instant coffee without the mixture of volatile compounds (sample 4) were not significantly different from the freeze-dried instant coffee in which the aromatic coffee oil was added (sample 5) and from the sample prepared with freeze-dried coffee in which the mixture of the five volatile was added (sample 3), coincidentally from the same drying process. Therefore, sample (3) did not differ from samples prepared with spray dried instant coffee without (sample 1) and to which (sample 2) the mixture of volatile was added. Therefore, with respect to this attribute, the addition of this mixture did not interfere in this drink acceptance. Taking into consideration the flavor, samples prepared with freeze-dried instant coffee in which the aromatic coffee oil was added (5) and the samples with (3) and without (4) the mixture of the five volatile was added did not differ significantly, however sample (4) did not differ from samples (1) and (2). Regarding this attribute, the addition of the aromatic oil of roasted coffee or a mixture of volatile in samples of freeze-dried instant coffee had a better acceptance than those dried by spray dryer (1) and (2). Thus, the enrichment of drinks with the aromatic oil of roasted coffee, or even with the mixture of the five components did not influence the consumer acceptance with respect to the aroma, but exerts influence with respect to flavour.

In vitro protein digestibility of enzymatically pre-treated bean (Phaseolus vulgaris L.) flour using commercial protease and Bacillus sp. protease

The common bean (Phaseolus vulgaris L.) is a staple food in the Brazilian diet and represents the major source of dietary protein and other micronutrients and minerals. Despite the considerable protein concentration in beans, the food is considered of low biological value when compared to animal proteins and other plant protein sources. To improve the availability of protein in beans, enzymatic treatments were performed in four cultivars (ON, OPNS, TAL and VC3). The approach was a completely randomized design with four replicates. We used a 4 × 3 factorial arrangement (four cultivars and three treatments: treatment 1-addition of commercial protease (Trypsin 250, Difco), treatment 2-addition of protease from Bacillus sp., and treatment 3:-control without enzyme addition). The enzyme: substrate ratio was 5% w/w (amount of enzyme per total protein in bean flour). The approach was a completely randomized design with four replicates. A 4 × 3 factorial arrangement (four cultivars and three treatments, the same as those mentioned above) was used. The concentration of total protein (g.100 g-1 of dry matter) in the samples ranged from 16.94 to 18.06%, while the concentration of total phenolics was between 0.78 and 1.12% (g Eq. tannic acid.100 g-1 dry matter). The in vitro protein digestibility of enzymatically untreated bean flour (control) ranged from 47.30 to 56.17% based on the digestibility of casein. Concentrations of P, K, Ca, Mg, and Zn observed in the four cultivars tested were within the average values available in the literature. Treatment 2 with protease from Bacillus sp. induced decreases in the levels of Cu and Mn. The average Fe content increased in all bean flour samples when treated with proteases, reaching a maximum increase of 102% in the TAL flour treated with protease from Bacillus sp. The digestibility of all beans tested was significantly increased (p < 0.05) after the enzyme treatment. The greatest change was observed in the OPNS cultivar treated with protease from Bacillus sp., which increased its digestibility from 54.4% (control treatment) to 81.6%.

Determination of thermobacteriological parameters and size of Bacillus stearothermophilus ATCC 7953 spores

In order to determine thermobacteriological parameters for B. stearothermophilus spores, they were diluted in a saline solution medium and in ground corn-soybean mix, distributed in TDT tube, and submitted to heat for a specific period of time. The D value (time to reduce 1 log cycle of microbial count under a certain temperature) and z value (variation of temperature to cause 10-fold change in D value) were estimated. To estimate their dimensions, the spores were visualized by using a scanning electron microscope. D121.1 ºC and z values for these spores, as determined in the saline solution, were 8.8 minutes and 12.8 ºC, respectively. D121,1 ºC and z values determined in the corn-soy mix were 14.2 minutes and 23.7 ºC, respectively. The micrographs indicated that the spores have homogeneous shape and size, with length and diameter of 2 and 1 µm, respectively. These results confirm that the spore is highly thermal-resistant, and it is a good biological indicator to evaluate the extrusion process as a feed sterilizer.

Detection of enterotoxins produced by B. cereus through PCR analysis of ground and roasted coffee samples in Rio de Janeiro, Brazil

Coffee is one of the most appreciated drinks in the world. Coffee ground is obtained from the fruit of a small plant that belongs to the genus Coffea. Coffea arabica and Coffea canephora robusta are the two most commercially important species. They are more commonly known as arabica and robusta, respectively. Two-thirds of Coffea arabica plants are grown in South and Central America, and Eastern Africa - the place of origin for this coffee species. Contamination by microorganisms has been a major matter affecting coffee quality in Brazil, mainly due to the harvesting method adopted. Brazilian harvests are based on fruits collected from the ground mixed with those that fall on collection cloths. As the Bacillus cereus bacterium frequently uses the soil as its environmental reservoir, it is easily capable of becoming a contaminant. This study aimed to evaluate the contamination and potential of B. cereus enterotoxin genes encoding the HBL and NHE complexes, which were observed in strains of ground and roasted coffee samples sold in Rio de Janeiro. The PCR (Polymerase Chain Reaction) results revealed high potential of enterotoxin production in the samples. The method described by Speck (1984) was used for the isolation of contaminants. The investigation of the potential production of enterotoxins through isolates of the microorganism was performed using the B. cereus enterotoxin Reverse Passive Latex Agglutination test-kit (BCET-RPLA, Oxoid), according to the manufacturer's instructions. The potential of enterotoxin production was investigated using polymerase chain reaction (PCR) methods for hblA, hblD and hblC genes (encoding hemolysin HBL) and for nheA, nheB and nheC genes (encoding non-hemolytic enterotoxin - NHE). Of all the 17 strains, 100% were positive for at least 1 enterotoxin gene; 52.9% (9/17) were positive for the 3 genes encoding the HBL complex; 35.3% (6/17) were positive for the three NHE encoding genes; and 29.4% (5/17) were positive for all enterotoxic genes.

Influence of the fungi population on the physicochemical and chemical composition of coffee (Coffea arabica L.)

The influence of fungi associated with coffee fruits was verified regarding the chemical and physicochemical composition of Coffea arabica L. raw grains. The fruits were harvested at EPAMIG Experimental farm in Lavras, State of Minas Gerais - making up the different samples here analyzed. After processing and drying, the grains were incubated in wet chamber for fungal exteriorization through the blotter test method and submitted to the following analyses: polyphenoloxidase, total reducing and non-reducing sugars, clorogenic acid, titrable acidity, potassium leaching, electric conductivity and caffeine. The occurrence of the P. variable, P. rugulosum, P. funiculosum, F. equiseti, F. semitectum, A.alutaceus, A. niger and C. cladosporioides fungi in the different samples was detected. From the analysis of the results obtained, it was observed that the presence of the Aspergillus alutaceus fungus reduces the activity of the enzyme polyphenoloxidase and increases the values of potassium leaching, electric conductivity and chlorogenic acid. The incidence of the Cladosporium cladosporioides fungus influenced the average values of potassium leaching and electric conductivity.

Form, size and volumetric expansion of Adzuki beans (Vigna angularis) during soaking

This study analyzed the variation in shape and size of Adzuki beans during soaking at different temperatures. In addition, different mathematical models were fitted to the experimental values of volumetric expansion, selecting the best one. Grains of Adzuki beans (Vigna angularis) with moisture content of approximately 0.25 (decimal d.b.) were manually harvested; they were, then, dried to 0.128 (decimal d.b.). The beans were subjected to soaking in distilled water at the temperatures 18 ± 1, 27 ± 1, 36 ± 1, and 45 ± 1 °C, in five repetitions. Recipients containing 80 mL of distilled water and 20 g of beans for each sample were used. The samples were periodically weighed in order to determine the water absorption. After that, the samples were removed from the recipients and placed on filter papers for two minutes to drain the surface water. Water absorption continued until the beans reached the saturation moisture content. It was concluded that, the form of the Adzuki beans was altered regularly, the orthogonal axes expanded differentially in the radial and axial directions, and that the linear model appropriately described the volumetric expansion of the Adzuki beans, among the series of models analyzed for the temperatures 18, 27, 36 and 45 °C.

Sensory evaluation of "dulce de leche" with coffee and whey using different affective data analysis methods

This study sought to evaluate the acceptance of "dulce de leche" with coffee and whey. The results were analyzed through response surface, ANOVA, test of averages, histograms, and preference map correlating the global impression data with results of physical, physiochemical and sensory analysis. The response surface methodology, by itself, was not enough to find the best formulation. For ANOVA, test of averages, and preference map it was observed that the consumers' favorite "dulce de leche" were those of formulation 1 (10% whey and 1% coffee) and 2 (30% whey and 1% coffee), followed by formulation 9 (20% whey and 1.25% coffee). The acceptance of samples 1 and 2 was influenced by the higher acceptability in relation to the flavor and for presenting higher pH, L*, and b* values. It was observed that samples 1 and 2 presented higher purchase approval score and higher percentages of responses for the 'ideal' category in terms of sweetness and coffee flavor. It was found that consumers preferred the samples with low concentrations of coffee independent of the concentration of whey thus enabling the use of whey and coffee in the manufacture of dulce de leche, obtaining a new product.

Use of colour parameters for roasted coffee assessment

Fast and non-destructive indicators were evaluated as tools to measure the technological quality of Arabica and Robusta coffee. Accordingly, considering the roasting intensity in highly valuable commercial samples, volume, mass, apparent density, moisture, total ash, ash insoluble in hydrochloric acid, and ether extract were characterized. The chromatic parameters L*, C*, Hº were measured using illuminants D65 and C. It was found that in roasted coffee beans, the parameters L*, C*, Hº, and coordinate b* had an antagonist interaction due to an increase in the roasting intensity, whereas after milling, only L* and Hº decreased progressively. Considering that the parameters L* and Hº followed similar patterns using both illuminants, D65 and C, it can be concluded that they are appropriate to evaluate coffee colour changes during roasting, enabling a relationship with coffee quality.

Processing and characterization of extruded breakfast meal formulated with broken rice and bean flour

The objective of this work was to develop an extruded breakfast product containing broken rice and split old beans and to verify the influence of the extrusion process on their physicochemical, technological, and sensory characteristic. The final product had a protein content of 9.9 g.100 g-1, and therefore it can be considered a good source of proteins for children and teenagers. The dietary fiber content of the final edible product was 3.71 g.100 g-1. Therefore, the breakfast meal may be considered as a source of dietary fiber according to Brazilian law . As for the technological properties, the extruded product presented an expansion index of 8.89 and apparent density of 0.25 g.cm-3. With regard to the sensory analysis, the acceptance average was ranked between 6.8 and 7.7, corresponding to the categories "liked slightly" and "liked very much". With regard to purchase intention, 79% of the panelists said they would certainly or possibly purchase the product. Broken rice and split old beans are interesting alternatives for the elaboration of extruded breakfast products presenting good nutritional, technological, and sensory qualities.

Development and validation of a method for detection and quantification of ochratoxin A in green coffee using liquid chromatography coupled to mass spectrometry

A method using Liquid Chromatography Tanden Mass Spectrometry (LC-MS/MS) with matrix-matched calibration curve was developed and validated for determining ochratoxin A (OTA) in green coffee. Linearity was found between 3.0 and 23.0 ng.g-1. Mean recoveries ranged between 90.45% and 108.81%; the relative standard deviation under repeatability and intermediate precision conditions ranged from 5.39% to 9.94% and from 2.20% to 14.34%, respectively. The limits of detection and quantification were 1.2 ng.g-1 and 3.0 ng.g-¹, respectively. The method developed was suitable and contributed to the field of mycotoxin analysis, and it will be used for future production of the Certified Reference Material (CRM) for OTA in coffee.

Technological properties of precooked flour containing coffee powder and rice by thermoplastic extrusion

Although Brazil is a country of tradition in both the production and consumption of coffee, the most of the coffee is consumed as a beverage, which reduces greatly the competitiveness on international market, for reducing the chances of supplying the product under other forms of consumption. Owing to that, the aim of this study was developing a precooked mixed flour containing coffee powder and rice for use in coffee flavored products. Mixtures of rice and coffee in the proportions of 900:100, 850:150 and 800:200 g, respectively, were processed in a single screw extruder (Brabender DS-20, Duisburg, German) and the effect of the extrusion process on the variables moisture content (16%, 18% and 20%) and temperature in the third extruding zone (140 °C, 160 °C and 180 °C) was studied. The results for expansion index ranged from 2.91 to 11.11 mm in diameter; the water absorption index from 4.59 to 6.33 g gel/g sample and the water solubility index varied from 4.05% to 8.57%. These results showed that, despite coffee powder influenced the variables studied, the expanded product after milling resulted in a extruded mixture with good absorption and water solubility indices, which favors the use of the precooked mixed flour for human consumption.