Alfredo Tenuta-Filho

ESTABILIDADE QUÍMICA E MICROBIOLÓGICA DE "MINCED FISH" DE PEIXES AMAZÔNICOS DURANTE O CONGELAMENTO

This work intended to study the stability of some minced freshwater fish species, available in the Amazon region: aracu-comum (Schizodon fasciatus), branquinha-comum (Potamorhina latior), branquinha-de-cabeca-lisa (P. altamazonica), curimata (Prochilodus nigricans), jaraqui-de-escama-fina (Semaprochilodus taeniurus), jaraqui-de-escama-grossa (S. insignis), mapara (Hypophthalmus edentatus), pacu-comum (Metynnis hypsauchen), pacu-manteiga (Mylossoma duriventre) and pirapitinga (Piaractus brachypomum), produced under industrial conditions and frozen stored. During a 150 day period, chemical and microbiological stability of the minced fish, under frozen temperatures of -18±1°C and -36±1°C, were monthly determined by evaluation of pH, nitrogen of total volatile bases (N-BVT), thiobarbituric acid reactant substances (TBARS) and mesophile and psycrotrophic aerobic counts at 35°C and 7°C, respectively, and total and fecal coliforms (MPN). The results were compared, and we could conclude that the different species under study have important technological characteristics. Minced fish prepared with the seven species under study were fit for consumption, from a chemical and microbiological point of view, during the 150-day period of storage at -18 and -36°C.

Óxidos de colesterol: ocorrência em alimentos, formação e efeitos biológicos

Important points involving the occurrence of cholesterol oxides -COs- in foods, formation mechanisms and biological activities of these compounds associated to cytotoxic, angiotoxic, atherogenic, mutagenic and carcinogenic processes were reviewed. The individual and/or total COs levels detected in foods were considered of potential risk for health. It was also considered necessary to determine the implication of COs from dietary sources in relation to endogenous COs formed metabolically. Inhibition of the cholesterol oxidation in foods to prevent the ingestion of these oxides was emphasized.

Avaliação de condições de consumo da sardinha Sardinella brasiliensis

Since there is not enough information about the quality of sardine (Sardinella brasiliensis) commercialized in the city of Sao Paulo-SP, Brazil, samples of fresh, defrosted (traded during the species-catching prohibition period) and processed sardines were analyzed for thiobarbituric acid reacting substances (TBARS) and total volatile base nitrogen (TVB-N). The fresh sardine traded at CEAGESP (Companhia de Entrepostos e Armazens Gerais do Estado de Sao Paulo) showed acceptable condition for consumption. Considering literature data, TBARS concentrations were adequate (<0,43 mg MA/kg), and TVB-N levels were below the legal limit of 30 mg/100 g. But this was not true for TBARS in the fresh and defrosted sardines collected from the open-air markets. Brined sardine and sardinha anchovada presented TVB-N above the legal limit, and so were not in acceptable condition for consumption. The results showed that sardine may arrive at CEAGESP (wholesale) in good condition, but its quality is lost while on sale at the open-air markets. This work emphasizes the need for better examining sardine freezing and storage carried out long before its commerce during the species-catching prohibition period.

Mercúrio total em cação comercializado em São Paulo - SP, Brasil

Total mercury contents in shark species - anjo, cacao-azul, cambeva, cacoa, machote and anequim - commercialized in Sao Paulo-SP, Brazil. Were determined. The levels ranged from 0.04 to 4.71 mg Hg/kg being 54% above the Brazilian acceptable legal limit of 1 mg Hg/kg (predator fishes) for consumption purposes. The results show that sharks have been commercialized in disagreement with the legislation exposing consumers to a high risk of mercury toxicity. Considerations were made in relation to the observed high levels of mercury and to the corresponding consumption based upon the Provisional Tolerable Weekly Intake to a total mercury of 0.3 mg Hg/person, of which no more than 0.2 mg should be present as methylmercury (FAO/WHO). Considerations were also made regarding the need of inspection and monitoring of the shark species locally used as food.

Colesterol, 7-cetocolesterol e 25-hidroxicolesterol em maionese

SUMMARY CHOLESREROL, 7-KETOCHOLESTEROL AND 25-HYDROXYCHOLESTEROL IN MAYONNAISE. The antioxidant system used in mayonnaise production is efficient mainly in relation to oxidation of unsaturated fatty acids. Consequently the shelf-life of the product is large (six months). However very little is known about the stability of cholesterol present in mayonnaise introduced with the eggs (raw material). The oxidation of cholesterol in mayonnaise was confirmed quantifying 7-Ketocholesterol (7-Keto) and 25Hydroycholesterol (25-OH) using HPLC. The following occurrences were observed: 7-Keto,1.99±0.59 g/g, in recently manufactured mayonnaise (approximately 15 days), 7-Keto, 8.30±4.03 to 22.86±3.06 g/g, and 25-OH, 2.21±1.94 to 13.98±2.72 g/g, in mayonnaise samples (A,B,C,D and E) with 30 to 210 days after production, and 7-Keto, 8.44±6.78 g/g, in mayonnaise samples collected at domiciles (products in use stored under refrigeration). The sum between 7-Keto and 25-OH from A/E samples amounted to 2.07-4.94% in relation to cholesterol (50.66±3.08-73.36±3.53mg/100g). Results here obtained are relevant in relation to deleterious biological activity attributed to cholesterol oxides and also by the technological aspects involved in mayonnaise manufacture. cholesterol; cholesterol oxides; 7-ketocholesterol; 25-hidroxycholesterol; mayonnaise. µ µ µ µ