Inhibitory activity of phosphates on molds isolated from foods and food processing plants.

Six commercial phosphates were evaluated for inhibition of the growth of 17 molds isolated from food sources. The assays were performed at neutral and natural (without pH adjustment) pH values, and the molds were streaked on plate count agar with added phosphates. Phosphate concentrations of 0.1, 0.3, 0.5, 1.0, and 1.5% (wt/vol) were used, and the MIC was determined. The resistance of molds to phosphates depended on the species. At a neutral pH, Aspergillus ochraceus and Fusarium proliferatum were resistant to all phosphates at all concentrations assayed, and Byssochlamys nivea, Aureobasidium pullulans, and Penicillium glabrum were most sensitive. The most inhibitory phosphates were those with chain lengths greater than 15 phosphate units and the highest sequestering power. At natural pH values (resulting from dissolving the phosphate in the medium), inhibitory activity changed dramatically for phosphates that produced alkaline or acidic pH in the medium. Phosphates with alkaline pH values (sodium tripolyphosphate of high solubility, sodium tripolyphosphate, and sodium neutral pyrophosphate) were much more inhibitory than phosphates at a neutral pH, but sodium acid pyrophosphate (acidic pH) had decreased inhibitory activity. The results indicate that some phosphates could be used in the food industry to inhibit molds linked to food spoilage.

Inhibitory effects of some spice essential oils on Aspergillus ochraceus NRRL 3174 growth and ochratoxin A production.

Inhibitory effects of essential oils of oregano (Origanum vulgare), mint (Menta arvensis), basil (Ocimum basilicum), sage (Salvia officinalis) and coriander (Coriandrum sativum), on the mycelial growth and ochratoxin A production by Aspergillus ochraceus NRRL 3174 were studied. Cultures were incubated on yeast extract-sucrose (YES) broth, at concentrations of 0, 500, 750 and 1000 p.p.m. of essential oils during 7, 14 and 21 d at 25 degrees C. At 1000 p.p.m., oregano and mint completely inhibited the fungal growth and ochratoxin A production up to 21 d, while basil was only effective up to 7 d. At 750 p.p.m., oregano was completely effective up to 14 d, whereas mint allowed fungal growth but no ocratoxin A production up to 14 d. At 500 p.p.m., no evident inhibition could be in observed with any of the essential oils under analysis. Sage and coriander showed no important effect at any of the concentrations studied. These inhibitory effects are interesting in connection with the prevention of mycotoxin contamination in many foods and they could be used instead of synthetic antifungal products.

Estudio de la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química. Universidad Nacional del Litoral / Study the environmental fungi at the library of the Faculty of Chemical Engineering (UNL)

Se analizó la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química de la Universidad Nacional del Litoral, Santa Fe, a los fines de evaluar los posibles riesgos tantos para la salud de los asistentes como por el probable deterioro de las colecciones existentes. El muestreo se realizó con un equipo SAS (sistema de aire sólido) que aspira 100 litros de aire por minuto, a 1,5 m de altura durante un min., por duplicado, entre las 11,30 y 12,30 horas. Se utilizó MEA + antibiótico (agar extracto de malta, cloranfenicol 100 mg por ciento). Se llevaron a cabo dos muestreos en condiciones ambientales diferentes: Muestreo A: Temperatura 16,5 ºC, Humedad Relativa 75 por ciento, Presión 1015,4 hPa. El salón de publicaciones periódicas presentó una carga fúngica de 25 UFC/m3 y el archivo 95 UFC/m3. Los géneros fúngicos aislados fueron: Cladosporium spp, Penicillium sp, Trichoderma sp, Aspergillus spp, Alternaria sp y Acremonium sp. Muestreo B: Temperatura 20 ºC, Humedad Relativa 95 por ciento, Presión 1013,7 hPa. El salón de publicaciones periódicas presentó una carga fúngica de 290 UFC/m3 y el archivo 360 UFC/m3. Los géros fúngicos aislados fueron: Cladosporium spp, Humicola sp, Aspergillus spp, Alternaria sp y Acremonium sp. Si bien en ambos muestreos no se detectaron valores altos de contaminación, éstos resultaron significativamente superiores en condiciones de humedad relativa y temperatura mayores. Se destaca que alguno de los mohos aislados como: Trichoderma viride y Humicola sp poseen una lata capacidad celulolítica deteriorante y otros: Cladosporium spp, Aspergillus spp, Acremonium sp y Alternaria sp son agentes de reconocida participación en procesos clínicos patógenos y en afecciones alérgicas

Estudio de la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química. Universidad Nacional del Litoral / Study the environmental fungi at the library of the Faculty of Chemical Engineering (UNL)

Se analizó la flora fúngica ambiental de la biblioteca de la Facultad de Ingeniería Química de la Universidad Nacional del Litoral, Santa Fe, a los fines de evaluar los posibles riesgos tantos para la salud de los asistentes como por el probable deterioro de las colecciones existentes. El muestreo se realizó con un equipo SAS (sistema de aire sólido) que aspira 100 litros de aire por minuto, a 1,5 m de altura durante un min., por duplicado, entre las 11,30 y 12,30 horas. Se utilizó MEA + antibiótico (agar extracto de malta, cloranfenicol 100 mg por ciento). Se llevaron a cabo dos muestreos en condiciones ambientales diferentes: Muestreo A: Temperatura 16,5 ºC, Humedad Relativa 75 por ciento, Presión 1015,4 hPa. El salón de publicaciones periódicas presentó una carga fúngica de 25 UFC/m3 y el archivo 95 UFC/m3. Los géneros fúngicos aislados fueron: Cladosporium spp, Penicillium sp, Trichoderma sp, Aspergillus

Long-term hypertriglyceridemia and glucose intolerance in rats fed chronically an isocaloric sucrose-rich diet.

We have previously shown that short-term feeding [20 to 25 day induction period (IP)] normal rats a sucrose-rich diet (SRD) results in an increase of plasma (P), liver (L), and heart (H) triacylglycerol (TG) levels, accompanied by a drop in plasma postheparin total (T-TGL) and hepatic (H-TGL) triglyceride lipases activities, IV glucose intolerance (low Kg) and hyperinsulin responses both in vivo and in vitro, suggesting that a state of insulin resistance had developed. Since normalization of P-TG ensued in the medium term [40 to 55 day adaptation period (AP)] we decided to carry out a longitudinal, long-term (90 to 120 day) follow-up study to observe the dynamic behavior of the above metabolic and hormonal parameters as compared to the appropriate time course control rats were fed the standard chow (STD).(ABSTRACT TRUNCATED AT 250 WORDS)

[Toxicological effects induced by the chronic intake of brominated vegetable oils]. / Efectos toxicológicos producidos por la ingesta crónica de aceites vegetales bromados.

Several biochemical parameters of male Wistar rats fed during 15 weeks with standard laboratory chow, supplemented with 0.1 g of brominated vegetable oil (olive, sunflower) per 100 g of diet, were compared to those of a control group fed a normal diet during the same period of time. The former group showed a significant increase of triglyceride content in both heart and soleus muscle, as well as of total and sterified cholesterol in heart muscle. This increase was accompanied by decreased plasma levels of total and HDL-cholesterol. Some of these abnormalities were similar to those observed in rats fed the same standard laboratory chow, supplemented with 0.5 g of brominated oil per 100 g of diet. The hepatic levels of triglycerides, total proteins and glycogen, as well as the weight gain and caloric intake of the animals which were fed 0.1 g of brominated oil per 100 g diet, were similar to those of the control group. In summary, the toxicologic effects observed during the chronic intake of diets supplemented with relatively low doses of brominated oils, suggest the need to undertake wider and deeper biochemical studies. The authors consider that these are necessary in order to ascertain the maximum tolerance levels for the use of these compounds, to minimize the risk of inducing important biological alterations.

Diazoxide prevents the development of hormonal and metabolic abnormalities present in rats fed a sucrose rich diet.

We have previously reported that normal Wistar rats fed an isocaloric, sucrose-rich (63%) diet (SRD) developed glucose intolerance and elevated triglyceride levels in plasma (P) as well as in heart (H) and liver (L) tissue. This metabolic state was accompanied by hyperinsulinism both in vivo and in vitro, suggesting that a state of insulin resistance has developed. In order to gather information on the role of hyperinsulinemia and glucose intolerance in the development of the above lipid metabolism abnormalities, diazoxide, a known insulin release blocking agent was administered (120 mg/kg/day) together with the diet (SRD + DZX) for 22 days. Control groups fed a standard chow (STD) or the STD plus diazoxide (STD + DZX) were included in the study. Under the present experimental design, DZX was able to prevent the development of hyperinsulinism, glucose intolerance and elevated levels of triacylglycerol in plasma, heart and liver present in animals fed on a sucrose rich diet. Our results suggest that mechanisms involved in the development of this nutritionally induced syndrome may include an interaction of hyperinsulinemia, with a direct effect of sucrose on several steps of lipid metabolism.

Effect of brominated vegetable oils on heart lipid metabolism.

Normal rats fed for 105 days on an experimental diet made up of standard laboratory chow supplemented with 0.5% of a mixture of brominated sunflower-olive oil (BVO) developed a significant increase in the triacylglycerol content of the heart, liver and soleus muscle compared to controls. In addition, BVO-treated rats had a decrease in plasma levels of triacylglycerol and total and HDL cholesterol. Plasma fatty acid levels and plasma post-heparin lipolytic activities, such as H-TGL, LPL, T-TGL and MGH were similar to those of control animals fed the standard chow alone. Heart PDHa (active portion of pyruvate dehydrogenase) was dramatically decreased in the BVO-fed rats. A faster rate of spontaneous lipolysis was recorded in the isolated perfused preparation of hearts from the experimental animals. The addition of 10(-7) M of glucagon to the perfusate, however, revealed a lipolytic effect comparable to the one observed in the control rats. In summary, our findings of normal fatty acids and low triacylglycerol plasma levels associated with normal activities of the various PHLA (post-heparin lipolytic activity) enzymes suggest that accumulation of triacylglycerol in heart muscle may not be explained essentially in terms of an elevated uptake and/or increased delivery of plasma fatty acids or plasma triacylglycerol. A decreased in situ catabolism of tissue triacylglycerol also appears unlikely because the spontaneous as well as the glucagon induced lipolysis in the heart both were found to be unimpaired.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of tiadenol and clofibrate on plasma post heparin lipolytic hepatic, extrahepatic and monoglyceride hydrolase activities in rats with hypertriglyceridemia induced by a sucrose rich diet.

Normal rats fed an isocaloric sucrose-rich diet (SRD) for 3 weeks developed high levels of triacylglycerol in plasma (P) (mmol triacylglycerol I-1) heart (H) and liver (L) tissues (mumol triacylglycerol mg DNA-1) as compared to control rats fed the standard chow (STD) (X +/- SEM; P: SRD 1.32 +/- 0.06 vs STD 0.49 +/- 0.05, P less than 0.001; H: SRD 2.1 +/- 0.17 vs STD 0.94 +/- 0.01, P less than 0.001; L: SRD 8.48 +/- 1.47 vs STD 1.71 +/- 0.12, P less than 0.001). A simultaneous drop in the activities (mumol glycerol ml-1 hr-1) of several plasma post heparin lipolytic enzymes was observed; total triglyceride lipase (T-TGL): SRD 5.32 +/- 0.34 vs STD 7.48 +/- 0.64, P less than 0.01; lipoprotein lipase (LPL): SRD 1.61 +/- 0.26 vs STD 2.42 +/- 0.41, P less than 0.05; hepatictriglyceride lipase (H-TGL): SRD 3.71 +/- 0.28 vs STD 5.05 +/- 0.69, P less than 0.05 and monoglyceride hydrolase (MGH) (mumol glycerol I-1 min-1): SRD 558 +/- 108 vs STD 1165 +/- 45, P less than 0.001. Rats fed the SRD presented glucose intolerance after i.v. glucose (Kg X 10(-2); 1.06 +/- 0.09 vs 2.61 +/- 0.14 of STD, P less than 0.001) in spite of the presence of hyperinsulinism (sigma plasma IRI microU/ml from 0 to 30 min: 184.6 +/- 23.6 vs 100.5 +/- 9.7 of STD, P less than 0.01) suggesting that a state of insulin resistance had developed.(ABSTRACT TRUNCATED AT 250 WORDS)

Postheparin lipolytic activities in Zucker rats fed with sucrose- or cornstarch-rich diets.

In order to study the metabolic effect of dietary sucrose or cornstarch on plasma total triglyceride lipase (T-TGL), hepatic triglyceride lipase (H-TGL) and monoglyceride hydrolase (MGH) activities, young male Zucker fatty and lean rats were pair-fed or fed ad libitum for 4 weeks with diets containing 68% carbohydrate as either sucrose or cornstarch. Our results show that ad libitum feeding of fatty rats with both diets produced an intensification of plasma hypertriglyceridemia which was accompanied by high levels of all plasma postheparin lipolytic activities. These diets did not affect the enzyme activities of lean littermates. Pair-feeding the fatties with sucrose-rich diet produced an increase in T-TGL, H-TGL and MGH. If cornstarch was the carbohydrate included in the diet no difference in postheparin lipolytic activities was found between phenotypes.

Effect of carbohydrate diet type upon obesity and hyperlipemia in the Zucker fa/fa rat.

20 fa/fa Zucker rats were submitted to a normalization of their food-intake energy level by pair-feeding using control Fa/-rats, for 4 weeks. Two diets were tested. The first was a starch-based diet (A) (66% starch w/w) and the second a sucrose-based diet (S) (66% sucrose w/w). The food-intake levels and the efficiency of storage of energy were thus comparable for the two diets. Though the fa/fa hyperinsulinemia decreased for the 4 weeks of experiment and was comparable with the (S) and (A) diets, the hypertriglyceridemia was lower with the (S) diet than that for the (A) diet. This could be in relation to the increased post-heparin lipase activity in the (S) diet, compared to the (A) diet.

Post-heparin plasma hepatic triglyceride lipase and monoglyceride hydrolase activities in hyperlipemia induced by a sucrose rich diet.

We have previously reported that normal Wistar rats fed an isocaloric, sucrose-rich (63%) diet (SRD) developed glucose intolerance and elevated triglyceride levels in plasma as well as in heart and liver tissue. This metabolic state was accompanied by hyperinsulinism both in vivo and in vitro, suggesting that a state of insulin resistance has developed. The aim of this study was to gather information on the various plasma post-heparin lipolytic activities in rats fed a SRD. Hepatic triglyceride lipase (H-TGL) was evaluated by both, protamine sulfate inhibition (PSI) of extrahepatic lipoprotein lipase (LPL) and heparin-Sepharose affinity chromatography (H-SAC). Both methods rendered comparable results. Total triglyceride lipase (T-TGL) was measured after Krauss et al. and monoglyceride hydrolase (MGH) after Vogel et al. Our results have shown a significant decline of plasma T-TGL (5.32 +/- 0.34 means +/- SEM vs. 7.48 +/- 0.64 mumol glycerol ml-1 h-1; p less than 0.01), H-TGL (3.71 +/- 0.28 vs. 5.05 +/- 0.69; p less than 0.05), LPL (1.61 +/- 0.26 vs. 2.42 +/- 0.41; p less than 0.05) and MGH (558 +/- 108 mumol glycerol l-1 min-1 vs. 1,165 +/- 45; p less than 0.001) activities. Thus, feeding a sucrose-rich diet induced a state of hyperlipemia and insulin resistance in which not only plasma T-TGL but also H-TGL and MGH activities were significantly decreased. This suggests that the latter two enzymes are also under nutritional and/or hormonal control.

Glucagon action upon plasma post-heparin lipolytic and monoglyceride hydrolase activities. Studies involving administration of exogenous hormone during suppression of endogenous hormone secretion with somatostatin.

It has been previously demonstrated that glucagon increased plasma post-heparin lipolytic activity (PHLA) in normal rats, but this was not the case in alloxan diabetic rats. The present work was designed to determine if the administration of exogenous glucagon (0.2 mg i.v.) during suppression of endogenous hormone secretion with somatostatin modifies the plasma post-heparin lipolytic activity in normal rats and the action of such hormone upon monoglyceride hydrolase (MGH) activity. It was found that exogenous glucagon significatively increased PHLA and MGH activity in normal rats after 18-24 hours of starvation. However, both enzymatic activities were not influenced by exogenous glucagon when they were measured during somatostatin administration. Therefore it is believed that the enhancement of these activities observed when somatostatin was not simultaneously given was due to the insulin secretion that follows the glucagon injection.