Teores de mercúrio em mexilhões do mercado consumidor e influência do tratamento térmico / Mercury contents in mussels from the retail market and influence of thermal processing

A contaminação por mercúrio é um desafio para a saúde humana e animal. Os moluscos bivalves, especialmente os mexilhões, absorvem, retém e concentram o mercúrio. Este trabalho teve como objetivo determinar os teores de mercúrio em mexilhões do mercado varejista de Belo Horizonte, MG e investigar a influência do tratamento térmico. Foram analisadas 42 amostras de mexilhão marrom procedentes de cultivo marinho. Os teores de mercúrio foram determinados por espectrometria de absorção atômica de combustão após amalgamação em ouro. Todas amostras tinham mercúrio em teores que variaram de 0,020 a 0,076 mg/kg. Nenhuma amostra apresentou teor de mercúrio superior ao limite estabelecido pela legislação brasileira (0,05 mg/kg para crustáceos, moluscos e cefalópodes). O cozimento do mexilhão por 3 e 6 min não foi eficaz na eliminação do Hg.

Variación estacional de la composición proximal en tres especies de importancia comercial del Golfo de Nicoya, Puntarenas, Costa Rica / Seasonal variation of proximate composition in three commercially important species in the Gulf of Nicoya, Puntarenas, Costa Rica

Nutritional value of seafood for human consumption is worldwide recognized. Some information have been generated in other countries, nevertheless, there is limited information describing the chemical composition of some fishery important species caught in the Gulf of Nicoya. For this reason, we studied the levels of proximal components of the edible parts (fresh) of three commercially important species. The meat samples of snook Centropomus unionesis, the shrimp Trachypenaeus byrdi and the bivalve Polymesoda radiata, were collected from the Puntarenas local fish market during the fishing season of February 2009 to January 2010. Proximate composition analysis was determined according to AOAC methodology, and evaluated the moisture content, and protein and lipid composition of shellfish meats. The results indicated that the moisture content ranged from 74.6-80.6g/100g for snook 76.9-80.0g/100g for shrimp and 77.9-89.5g/100g for green mussel. After the moisture, the protein was the most abundant chemical fraction (6.8 to 21g/100g) showing the highest values in February for the shrimp and green mussel, and December for snook. The largest fluctuations in the lipid content were found in the snook, ranging from 0.7g/100g to 5.6g/100g; the highest values in this fraction were found in shrimp, green mussel and snook, for July, February and April samples respectively. Considering these results, we concluded that fish and shrimp species studied are a good alternative for human consumption as a source of protein and low lipid content.

La información disponible sobre la composición química de algunos recursos pesqueros que se capturan en el Golfo de Nicoya es muy limitada. Por tal razón se determinaron los niveles de los componentes proximales de las partes comestibles (fresco) de tres especies de importancia comercial. Las muestras fueron adquiridas en el Mercado de Puntarenas entre febrero 2009 y enero 2001 durante la temporada de pesca. Los análisis de la composición proximal se determinaron según la metodología de AOAC. Los resultados indicaron que el contenido de humedad varió entre 74.6-80.6g/100g en robalo (Centropomus unionesis), 76.9-80.0g/100g en camarón (Trachypenaeus byrdi) y 77.9-89.5g/100g en almeja verde (Poymesoda radiata). Después de la humedad la fracción química más abundante fue la proteína presentando los valores más altos en diciembre para el robalo y febrero para el camarón y la almeja verde. Las mayores fluctuaciones en el contenido de lípidos se presentaron en el robalo, variando desde 0.7g/100g hasta 5.6g/100g. Los valores más altos en esta fracción fueron encontrados en julio, febrero y abril en camarones, almeja y robalo respectivamente. Se concluye que la especie de pescado y camarón estudiados son una buena alternativa para el consumo humano por ser una fuente importante de proteínas y por su bajo contenido en lípidos.

Variación estacional de la composición proximal del mejillón Tagelus peruvianus (Bivalvia: Solecurtidae) del Golfo de Nicoya, Puntarenas, Costa Rica

Seasonal variation in proximate composition of mussels Tagelus peruvianus (Bivalvia: Solecurtidae) from the Gulf of Nicoya, Puntarenas, Costa Rica. Marine bivalves are a very important food source for human consumption, and species that has not been of traditional use as a fishery resource are gaining interest. Seasonal variation in proximate composition, condition index and energy or caloric content of the mussel Tagelus peruvianus were studied in the Gulf of Nicoya, Puntarenas, Costa Rica. From November 2007 to October 2008, a total of 35 to 40 specimens per month were collected. The proximate composition using the AOAC methods was determined. Results showed that the condition index during December, January and May decreased, indicative of two spawning periods and one gonadal resting phase. Soft tissues were respectively characterized by protein (61.9±4.3%), carbohydrates (15.7±2.4%), ash (14.0±1.9%) and lipids (8.5±1.7%). The average caloric content was 5.0±0.1kcal/g. The results showed that the decrease in protein and fat percentage, and calories content, occurred during the spawning seasons. We suggest that T. peruvianus has an optimal nutritional value for human consumption because of the low-fat and moderate protein content. Rev. Biol. Trop. 59 (4): 1517-1523. Epub 2011 December 01.

La extracción del mejillón Tagelus peruvianus representa una actividad económica complementaria de los pescadores artesanales, es una de las especies de mayor pesca y consumo ya que son una fuente importante de proteína, minerales y vitaminas esenciales para la población humana. Por lo tanto, se estudió la variación estacional de su composición proximal, índice de condición y contenido energético. Mensualmente, entre noviembre de 2007 y octubre de 2008, se recolectaron de 35 a 40 especímenes. La composición proximal se determinó siguiendo la metodología recomendada por la AOAC. Los resultados mostraron que el índice de condición disminuyó en los meses de diciembre, enero y mayo, lo que indica que hay dos periodos de desove y una fase de reposo gonadal. El componente principal del mejillón es la proteína (61.9±4.3%), seguido de carbohidratos (15.7±2.4%), cenizas (14.0±1.9%) y lípidos (8.5±1.7%). El contenido calórico promedio fue de 5.0±0.1kcal/g. La disminución en los valores de proteínas, lípidos y calorías coinciden con los periodos de desove. Se puede concluir que T. peruvianus presenta valores nutricionales óptimos para el consumo humano, por su bajo contenido de grasa y su aceptable contenido proteico.

A new occurrence of Anodontites tenebricosus (Bivalvia: Mycetopodidae) in the Sapucaí river basin, São Paulo, Brazil: environmental and conchological aspects / Nova ocorrência de Anodontites tenebricosus (Bivalvia: Mycetopodidae) na bacia do rio Sapucaí, São Paulo, Brasil: aspectos ambientais e conquiliológicos

The aim of this work was to register the occurrence of Anodontites tenebricosus (Bivalvia: Mycetopodidae) in the Sapucaí river basin, municipality of São Joaquim da Barra, São Paulo state, Brazil, associating its occurrence to the environment in which they are found, besides providing conchological data to contribute to the identification of the species. Fifty one specimens of Anodontites tenebricosus were studied regarding their conchological and morphometrical aspects. Strong correlations were found between the morphometric variables, the correlation between 'length and height of the shell' being the most significant. The characteristics of the shells of A. tenebricosus found in the Sapucaí river basin resemble the descriptions of the species found in the literature; therefore, we are able to expand the area of occurrence of the species for the state of São Paulo.

Os objetivos deste trabalho foram registrar a ocorrência de Anodontites tenebricosus (Bivalvia: Mycetopodidae) na bacia do rio Sapucaí, no município de São Joaquim da Barra, estado de São Paulo, Brasil, associando sua ocorrência ao ambiente em que são encontrados, além de fornecer dados conquiliológicos que contribuem para a identificação da espécie. Cinquenta e um espécimes de Anodontites tenebricosus foram estudados sob aspectos conquiliológicos e morfométricos. Foram encontradas fortes correlações entre as variáveis, sendo a correlação entre "comprimento e altura da concha" a mais significativa. As características das conchas de A. tenebricosus encontradas na bacia do rio Sapucaí assemelham-se às descrições da espécie na literatura; podemos, assim, ampliar a área de ocorrência da espécie para o estado de São Paulo.

Estudio de la concentración de arsénico, mercurio, plomo y fenantreno en la macha (Mesodesma donacium): implicancias alimentarias y toxicológicas / Study on arsenic, mercury, lead and phenanthrene concentration in surf clam (Mesodesma donacium): food and toxicological implications

The coastal environment around the Maipo river outlet in the proximity of San Antonio bay (5th Region, Chile) it is one of the most contaminated zone of the country due to discharges of industrial wastes on the river that affect the marine environment. The surf clam (Mesodesma donacium, Lamarck 1818) a benthic organism that provides an important source of seafood for human consumption is caught in this area. The total arsenic and mercury, lead and phenanthrene concentrations in the soft body of the surf clam were measured. Their concentration in the marine organism fluctuated between 1,23-1,33 µg/g As , 0,26-0,39 µg/g Hg, and 0,23-0,33 µg/g Pb (dry basis). Phenanthrene was not detected in the samples. In spite of the high concentration of the elements detected in the surf clam, only in the case of Hg their intake could imply a certain grade of risk for human health, especially for young humans. Chronic effects, such as personality changes, neurological damage and others, could exhibit in the medium term. Therefore, it is important to carry out regular food surveillance studies, especially oriented to the specie specific aspect of toxic elements and monitoring of polyaromatic hydrocarbons (PAH) in several marine food.

La zona costera de la bahía de San Antonio en las proximidades a la desembocadura del río Maipo (Quinta Región, Chile), es una de las áreas más contaminadas del país, debido a residuos industriales vertidos al río, los cuales afectan el ambiente marino. La macha (Mesodesma donacium, Lamarck 1818), organismo bentónico que constituye una importante fuente de alimento humano, es capturada en esta área. Se midió la concentración de arsénico total, mercurio total, plomo y fenantreno en el cuerpo blando de la macha, con el fin de determinar su ingesta y el riesgo toxicológico para el consumidor. Las concentraciones de los elementos en el organismo marino, fluctuaron entre 1,23_1,33 µg As g-1, 0,26_0,39 µg Hg g-1 y 0,23_0,33 µg Pb g-1, valores expresados en base seca. El fenantreno no fue detectado en las muestras. A pesar de las altas concentraciones de los elementos detectadas en la macha, sólo para el caso del Hg su ingesta puede significar un cierto grado de riesgo para la salud humana, especialmente en el consumidor joven. Efectos crónicos tales como cambios en la personalidad, daño neurológico y otros, pudieran manifestarse a mediano plazo. Por lo tanto, es importante realizar estudios regulares de vigilancia alimentaria, especialmente dirigidos a la especiación de los elementos tóxicos y el monitoreo de hidrocarburos poliaromático (HPA), en variados alimentos marinos.

Avaliação da concentração de metais pesados em tecido de ostras Crassostrea gigas (Molusca, bivalve) cultivadas na baía da Barbitonga, literoal norte de Santa Catarina / Evaluation of heavy metal concentration in tissue of Crassostrea gigas (Molusca, bivalve) oysters cultivated in Babitonga Bay, north coast of Santa Catarina state, Brazil

Este trabalho objetivou avaliar a concentração de metais pesados em tecidos de ostras Crassostrea gigas cultivadas em 4 pontos da Baía da Babitonga, litoral norte do estado de Santa Catarina. Para tanto, foram instaladas estruturas de cultivo em cada ponto no sistema longline. Durante um anos foram medidos os parâmetros físico-químicos da águas, quinzenalmente, e realizadas análises químicas bimensais dos metais pesados arsênio, cádmio, cobre, níquel e zinco no sedimento, na águas e no tecido de ostras. Os resultados da concentração de metais pesados mostraram teores acima do permitido pela legislação brasileira para arsênio, níquel, cobre, cádmio e zinco durante o período do verão. Entretanto, foi observada a presença de concentrações significativas de zinco para todos os pontos ao longo do ano. Constatou-se que as ostras apresentaram assimilação de contaminantes, indicando a biodisponibilidade no ambiente, no entanto, também foi observada a capacidade de autodepuração por parte dos organismos

Gill tissues of the mussel Mytilus edulis chilensis: a new source for antimicrobial peptides

Antimicrobial peptides are small-sized, cationic and amphipathic molecules able to neutralize pathogenic microorganisms. Their antimicrobial effects tie them to mechanisms of immune defense, which is why they have been normally purified from immune cells. We describe an apparently new group of antimicrobial peptides from gill tissues of the mussel Mytilus edulis chilensis. 20 specimens yielded 40 g of gills which produced 16 mg of an enriched fraction with antimicrobial activity as low as 0.045 µg/µl over reference strains. Considering the chemical nature of these molecules we used an acid extraction procedure followed by consecutive cationic exchange and hydrophobic interaction chromatography steps for peptide enrichment. The resulting post Sep-pak C-18® 20 percent acetonitrile (ACN) eluate was fractionated by reverse phase HPLC and all resulting fractions were the source for in vitro antimicrobial activity evaluation. Active fractions were characterized by SDS-containing protein gel electrophoresis. All fractions were particularly enriched with low molecular weight peptides displaying neutralizing growth activity against Gram positive and Gram negative bacteria and 10 times more efficient over fungal pathogens. Active fractions resulted to be thermostable and non cytotoxic to eukaryotic cells. Considering these results, industrial waste gills of bivalves arise as a new source for antimicrobial molecules.

Heavy metals in sediments, mussels and oysters from Trinidad and Venezuela

Abstract: The Gulf of Paria is bordered by both Trinidad and Venezuela,from which various metallic pollutants and other contaminants can originate.The Gulf is still a significant source of fish,crabs and shellfish for human consumption to both countries,where concerns over the quality of this marine environment have been long expressed but never properly addressed.In addition,the circulatory current patterns in the Gulf ensure that contaminants originating from either country are likely to affect both countries eventually.Heavy metals were determined in oysters (Crassostrea rhizophorae and C.virginica ),green mussels (Perna viridis )and sediments from the Gulf of Paria.Samples were obtained at four sites in Trinidad and three sites in Venezuela in the Gulf of Paria,in addition to comparative samples collected from three sites on the north coast of Venezuela.Edible tissues of twelve shellfish from each location were blended and aliquots digested with concentrated nitric acid, for extraction of cadmium,chromium,copper,lead,nickel and zinc.The solutions were analysed by flame atomic absorption spectroscopy.Mercury was extracted with a mixture of nitric,hydrochloric and sulphuric acids and determined by cold vapour atomic absorption.Sediments were oven-dried at 60°C, before being similarly extracted.Results showed that mercury in sediments at all sites in Trinidad and Venezuela exceeded NOAA and Canadian sediment quality guidelines,while cadmium, copper, nickel, lead and zinc also exceeded these guidelines at several sites.Heavy metal levels in oysters and green mussels varied widely with location. However,oysters from the Gulf of Paria contained significantly higher mean levels of cadmium,copper,nickel and zinc than those from the north coast of Venezuela, but this difference was not apparent in mussels.Cadmium, mercury and zinc in sediments were significantly correlated with those of mussels,but not of oysters,in which copper and zinc at several sites in the Gulf of Paria exceeded local maximum permissible levels (Cu =20 µg g-1 wet wt; Zn =50 µg g-1 wet wt)for human consumption. These findings indicate that while mussels may be better biological indicators of heavy metal pollution in sediments than oysters,the latter may provide copper and zinc contamination.Further research is needed to determine the most appropriate biological indicators of heavy metal and other pollutants in the local marine environment and to develop protocols for their use

Paralytic Shellfish Poisoning (PSP) in Margarita Island, Venezuela

A severe outbreak of Paralytic Shellfish Poisoning (PSP) occurred in Manzanillo and Guayacán, northwestern coast of Margarita Island, Venezuela, between August and October 1991. A bloom of dinoflagellates including Prorocentrum gracile, Gymnodinium catenatum and Alexandrium tamarense seemed to be responsible for this outbreak. Levels of PSP toxins in mussels (Perna perna) exceeded the international safety limit of saxitoxin, 80 µg STX/100 g meat. PSP toxin values varied between 2 548 and 115 µg STX/100 g meat in Manzanillo, and between 1 422 and 86 µg STX/100 g meat in Guayacán. At both locations, the highest levels were detected in August, when 24 patients exhibited typical symptoms of PSP toxicity after consuming cooked mussels (16 required hospitalization). A high pressure liquid chromatographic (HPLC) procedure was recently used on the 1991 samples. The major toxin detected in samples of both locations was decarbamoyl saxitoxin (dcSTX), but low concentrations of saxitoxin were also found in Manzanillo samples. Gonyautoxins GTX1, GTX2 and GTX3 were detected only at Guayacán, while in both locations, decarbamoylgonyatouxin (dcGTX2,3) toxins were detected. These findings represent the first time that causative toxins of PSP in Venezuela have been chemically identified, and confirm the presence of dcSTX and dcGTX in mussels from the Caribbean Sea. The presence of dcSTX and dcGTX in shellfish is indicative that Gymnodinium catenatum was a causative organism for outbreak of PSP

Un severo brote de intoxicación paralizante por moluscos (PSP en inglés) ocurrió en Manzanillo y Guayacán en la costa noroeste de la Isla de Margarita, Venezuela entre agosto y octubre de 1991. Una proliferación de Prorocentrum gracile, Gymnodinium catenatum y Alexandrium tamarense causó el brote. Los niveles de PSP en mejillón (Perna perna) superaron los niveles máximos permisibles de saxitoxina, 80 µg STX/100g carne. Los niveles de toxinas variaron entre 2 548 y 115 µg STX/100 g carne en Manzanillo y entre 1 422 y 86 µg STX/100g carne en Guayacán. En ambas localidades, los máximos niveles se detectaron en agosto, cuando 24 personas presentaron síntomas típicos de PSP después de consumir mejillones cocidos (16 fueron hospitalizados). Se aplicó recientemente cromatografía líquida de alta presión (HPLC) a muestras del año 1991 y la toxina más detectada fue decarbamoyl saxitoxina (dcSTX), pero también se encontró saxitoxinas en muestras de Manzanillo. Las gonyautoxinas GTX1, GTX2 y GTX3 solo se encontraron en Guayacán; en ambas localidades se detectó decarbamoylgonyatouxin (dcGTX2,3). Estos hallazgos representan la primera vez que las toxinas causantes de un brote de PSP en Venezuela han sido químicamente identificadas, confirmando la presencia de dcSTX y dcGTX en mejillones del mar Caribe. La presencia de dcSTX y dcGTX en moluscos, indica que G. catenatum fue el organismo responsable de la intoxicación

Paralytic shellfish toxins in the chocolata clam, Megapitaria squalida (Bivalvia: Veneridae), in Bahia de La Paz, Gulf of California

Occurrence and toxic profiles of paralytic shellfish toxins (PST) in the chocolata clam Megapitaria squalida were investigated. From December 2001 to December 2002, 25 clams were obtained monthly from Bahía de La Paz, Gulf of California. Additionally, net (20 µm) and bottle phytoplankton samples were also collected to identify toxic species. Toxins were analyzed by HPLC with post-column oxidation and fluorescence detection. Toxicity in the clam was low and varied from 0.14 to 5.46 µg/STXeq/100 g. Toxicity was detected in December, March, April, June, and August. Toxin profile was composed mainly by STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX and B1. Gymnodinium catenatum was the only PST-producing dinoflagellate identified in the phytoplankton samples throughout the study period. G. catenatum was observed mainly in net samples from December 2001 to December 2002; however, in bottle samples, G. catenatum was only observed in five months. Highest abundance (2 600 cells l-1 ) was observed in March and the lowest (160 cells l-1 ) in June. G. catenatum mainly formed two-cell chains and rarely four or eight. The presence of PST in net phytoplankton samples support the fact that G. catenatum is the main source of PST in the clams. This study represents the first report of PST toxins in the chocolata clam from Bahía de La Paz

Se investigó la ocurrencia así como los perfiles de toxinas paralíticas (PST) en la almeja chocolata Megapitaria squalida (Sowerby, 1835), de la cual se recolectaron mensualmente 25 ejemplares de diciembre del 2001 a diciembre del 2000 en La Bahía de La Paz, Golfo de California. Simultáneamente, se obtuvieron muestras de fitoplancton de botella y de red (20 µM) para identificar especies tóxicas, así como para detectar la presencia de toxinas paralíticas. Las toxinas se analizaron por HPLC con una oxidación post-columna y detección fluorescente. La toxicidad en las almejas fue baja y varió de 0.14 a 5.46 µg/STXeq/100 g y se detectó en diciembre, marzo, abril, junio y agosto. El perfil de toxinas estuvo compuesto principalmente por STX, GTX2, GTX3, dcGTX2, dcGTX3, C2, dcSTX y B1, siendo similar al perfil observado en las muestras de red. Gymnodinium catenatum fue la única especie productora de toxinas paralíticas identificada en las muestras de fitoplancton a través de todo el período del estudio. G. catenatum se observó principalmente en muestras de red correspondientes a diciembre 2001-diciembre 2002; sin embargo, en muestras de botella, G. Catenatum solo fue observado en cinco meses. La abundancia más alta (2 600 céls l-1 ) se encontró en marzo y la más baja (160 céls l-1 ) en junio. G. catenatum se presentó formando cadenas de dos células y raramente de cuatro u ocho. La presencia de toxinas en las muestras de red donde esta especie es frecuente, apoya la idea de que G. catenatum sea la fuente principal de PST en las almejas. Este estudio representa el primer reporte de toxinas paralíticas en la almeja chocolata de Bahía de La Paz

Simultaneous presence of Paralytic and Diarrheic Shellfish Poisoning toxins in Mytilus chilensis samples collected in the Chiloe Island, Austral Chilean Fjords

The study shown here provides the first indisputable evidence that shellfish can be contaminated with Paralytic Shellfish Poisoning (PSP) and Diarrheic Shellfish Poisoning (DSP) toxins during the summer season in the Southern Chilean fjords. Quantitative analysis of the simultaneous presence of PSP and DSP toxins in Mytilus chilensis samples collected in the Chiloe Island are shown. The High Performance Liquid Chromatography (HPLC) analysis with pre-column derivatization method for DSP toxins and the post-column derivatization methods for PSP toxins, both with fluorescent on-line detections, showed that both type of toxins were concentrated by the filter bivalve Mytilus chilensis in amounts above the international safe limits. The phytoplankton analysis showed the presence of both Alexandrium catenella and Dinophysis acuta in the water column. The data shows stratification of the toxic dinoflagellates in the water column, since the lowest amount of both DSP and PSP toxins were measured in the superficial and deeper levels of the water column. Moreover, the highest toxicities of both types of toxins were shown by the shellfish samples collected at a depth of 6 meters with 190 nanograms of DTX-1 / gram of digestive gland and 709.8 mg of PSP toxins / 100 grams of mussel meat.

Just a diarrhea? Evidence of diarrhetic shellfish poisoning in Santa Catarina, Brazil

The occurrence of phycotoxins from the diarrhetic shellfish poisoning group has been detected in mussels from Santa Catarina by two independent assays. This finding can help to elucidade several official and unofficial reported cases of human intoxication in the region. The issue becomes very important once the mussel culture activity is growing rapidly in the state which is already the largest mussel producer in the Country.

Biological monitoring of organochlorides using the limnic bisalves anodontites trapesialis: (Lam., 1819)

The mussel Anodontites trapesialis (Lam, 1819) was used as an indicator of organochloride pollutans in the Canoas River, located in the municpality of Mococa (21-25'08"S and 47W), State of Säo Paulo, Brazil. Biological monitoring was performed for one year at the site of an orange grove on the left bank of the river. Forty-five animals were placed in aluminum enclosures on the river bottom at this site and 4 animals were sacrificed for pesticide analysis at 3-month intevals, each corrsponding to one season of the year. Pesticides were extracted by the method of Bedford et al., (1968), modified, and the analyses were performed bay gas phase chromatography equipped with an elelctron capture detector. The aninals were found to have been exposed to DDT. Lindane and Heptachlor. Variation in Aldrin and Dieldrin levels was not significant enough to permit inferences. Endrin was not detected in any of the analyses

Bioadhesives: a biotechnological opportunity

Marine mussels secrete the byssus in order to attach to solid surfaces and to servive under the turbulent effects of waves. The adhesive responsable for this atachment is the polyphenolic protein secreted by the phenol gland in the foot of the animal To purify this adhesive protein form the chilean mussel Mylilus chilensis, a modification of previous procedures has been developed. Accordingly, the protein is differentially precipitated with acetone in the presence of 0.25 N HCl. The purified protein is rich in the amino acids lysine, 3,4-dihydroxyphenylalanine, serine, threonine, proline and hydrozyproline. The protein exhibited strong adhesion to glass and other solid supports. Moreover, its has been found that the adhesive protein can mediate the immobilization of ß-galactosidase to glass. About 75% of the enzyme activity was immobilized under the experimental conditions described. This is the first study reporting the use of the polyphenolic protein to immobilize enzymes