Biomedical subjects

C Pompei

Publications and source records attributed to C Pompei.

8 recordsLinked to original sources

PubMed2002

Influence of food processing on the allergenicity of celery: DBPCFC with celery spice and cooked celery in patients with celery allergy.

BACKGROUND: Celery root is often consumed in a processed form as a cooked vegetable or as a spice. So far, however, there has been no information about the allergenicity of processed celery in celery-allergic patients. METHODS: In 12 patients with a history of allergic reactions to raw or raw and cooked celery, double-blind placebo-controlled food challenges (DBPCFCs) with raw celery (n = 10), cooked celery (110 degrees C/15 min; n = 11), and celery spice (n = 5) were performed. Nine patients underwent an open mucosal challenge with four samples of canned celery retorted at Co-values (cooking effect) of 7.45-76.07 (corresponding to the time periods in minutes at a thermal influence of 100 degrees C). IgE immunoblot analysis of celery extract was performed with sera of all challenged patients. The thermal stability of celery allergen was investigated by enzyme allergosorbent test (EAST) inhibition. Furthermore, intraperitoneal immunization of mice followed by a rat basophil leukemia (RBL) cell mediator release assay was used as a biological in vitro model to assess the allergenicity of processed celery. RESULTS: Six out of 11 patients showed a positive DBPCFC to cooked celery and five out of five patients to celery spice. Allergenicity of celery was preserved in four patients with a positive DBPCFC to cooked celery even if celery was treated at a Co-value of 76.07. Patients with positive DBPCFC to cooked celery reacted to known celery allergens (Api g 1, Api g 4, cross-reactive carbohydrate determinants CCD). EAST inhibition showed that heat resistance of celery allergens decreases in the following order: CCD > Api g 4 > Api g 1. Accordingly, five of six patients with a positive DBPCFC to cooked celery were sensitized to profilin and/or CCD. The murine model reflected the reactivity of patients sensitized to the major allergen Api g 1. CONCLUSIONS: 1) In a subset of patients with a positive DBPCFC to cooked celery, celery remains allergenic even after extended thermal treatment (76.07 min/100 degrees C). 2) Celery spice is allergenic for patients with an allergy to raw celery. 3) RBL cells sensitized with mouse IgE to raw celery may serve as a useful tool for screening the potential allergenicity of heat-processed products containing celery.

Adult↗

PubMed2001

Reaction between albumen and 3,3',5,5'-tetramethylbenzidine as a method to evaluate egg freshness.

The 3,3',5,5'-tetramethylbenzidine colorimetric test is proposed as a method for the evaluation of shell egg freshness. A simplification of the original method was tested on albumen, and the modified method was used to study the development of albumen-tetramethylbenzidine reaction in eggs stored at three temperatures for different times. The stability of the reagent solution and the repeatability of the analytical method were also studied. The reaction mechanism showed the predominant role of iron ions on the colorimetric response, and the secondary role of copper ions added to the reaction mix in order to enhance the response. The response coefficient of variation, due to the natural variability in eggs laid by hens of two breeds and different ages, was 10.3%, which is similar to the value obtained for furosine, but lower than those previously observed for other egg freshness indices such as Haugh Unit and air-cell height.

Animals↗

PubMed2001

Lipid transfer proteins and 2S albumins as allergens.

Plant lipid transfer proteins, a widespread family of proteins, have been recently identified as important food allergens. Their common structural features, such as eight conserved cysteines forming disulfide bridges, basic isoelectric point and high similarity in amino acid sequence, are the basis of allergic clinical cross-reactivity. This has been demonstrated for the LTP allergens of the Prunoideae subfamily, whose similarity is about 95% as demonstrated for the purified allergens of peach, apricot, plum and apple. A relevant aspect is the existence of sequence homology of LTPs of botanically unrelated foods, as demonstrated for LTPs of maize and peach. A class of food allergens of well recognized clinical importance is that of seed storage 2S albumins. They have been identified in the most diffused edible seeds and nuts, such as mustard, sesame, Brazil nut, walnut and peanut. In particular, a strong correlation between IgE-binding to these proteins and food-induced anaphylaxis has been demonstrated for Brazil nut and sesame seeds.

Albumins↗

PubMed2000

Hydroxymethylfurfural and furosine reaction kinetics in tomato products.

The reaction kinetics of two heat damage indices, HMF and furosine, were examined in four tomato products with different dry matter contents (10.2, 25.5, 28.6, and 34.5%) over a temperature-time range of 80-120 degrees C and 0-255 min. The reactions followed pseudo-zero order kinetics. E(a) and z-value were, respectively, 139. 9 kJ/mol and 19.2 degrees C for HMF, and 93.9 kJ/mol and 28.4 degrees C for furosine. The analyses of both indices in several samples of commercial and industrial tomato products showed very low levels of HMF (from 1 to 42 ppm) and a lack of correlation between HMF and furosine mainly because of the different evolution of the two indices during storage. The HMF level of a tomato paste sample stored at 25 degrees C decreased from 609 to 17 ppm after 98 days, while furosine increased from 458 to 550 mg/100 g of protein.

Food Preservation↗

PubMed2000

Technological processes to decrease the allergenicity of peach juice and nectar.

Among vegetable foods peach (Prunus persica) has been recognized as a significant cause of allergy. The protein, which is considered to be the major peach allergen, has been named Pru p 1. Because peaches are consumed both as fresh fruits and after processing to obtain peach juice, nectar, jam, syrupy peach, etc., research was carried out to identify a technological process for production of hypo- or nonallergenic peach-based products. SDS-PAGE and immunoblotting analysis of extracts prepared from four commercial peach nectars showed that the Pru p 1 was not removed, and neither was its allergenic activity decreased by technological treatments carried out for nectar production. Some treatments oriented toward a removal of or, at least, a decrease in the allergenic power were assumed and verified at laboratory scale. A variable considered was heat treatment at 121 degrees C for 10 and 30 min: this treatment was not able to decrease the allergenicity of the Pru p 1 protein. Furthermore, the protein band was still present even after 60-min reaction with two different acidic proteases. The two technological treatments that were found to decrease the major allergen of peach were chemical lye peeling of fruits and ultrafiltration of juice through membranes with suitable cutoff. On the basis of the results obtained from this research, a processing flow sheet was defined to obtain hypoallergenic or probably nonallergenic limpid juices and nectars. These products may represent, besides finished foods, intermediates to obtain various products after addition of further ingredients such as pectins, sugars, and fiber.

Beverages↗

PubMed1995

Changes in some egg components and analytical values due to hen age.

The influence of hen age on some egg characteristics was studied. Two commercial breeds of brown hens, namely Warren and Hy-Line, were considered at seven different ages. The variables analyzed were the weights of yolk and thick and thin albumen, pH, and the concentration of glucose, uridine, and uric and pyroglutamic acids of separated yolk and albumen. Albumen and yolk average weights and the proportion of yolk in the edible part of egg increased with hen age, whereas the average ratio of thick to thin albumen was not influenced by the progress of the laying cycle. Glucose, uridine, and uric acid were also not influenced by hen age. Pyroglutamic acid, which is detectable in yolk and not in the albumen of a fresh egg, showed a characteristic trend in yolk. Its concentration dramatically increased in the middle of the laying cycle and then decreased to values close to those observed in eggs of the young layers.

Aging↗

PubMedDate not supplied

[Search of optimum survival conditions for lactic acid bacteria in powders obtained by spray drying of yoghurt].

The paper reports the results of two spray-drying tests carried out on yogurt as such or previously neutralized. The operating conditions of the drying operation were such that the temperature of the product didn't exceed 80 degrees C, and the residual moisture of the powder was about 10%, slightly higher than the B.E.T. monolayer value. The decrease of total counts was three and two decimal reductions respectively for the natural and neutralized product. This latter gave also much higher viability index as determined in a "fermenting activity" test. Also, the analyses, related to the quality of the protein fraction, strongly support the opportunity of neutralization before drying. In storage tests carried out during 8 months the survival data were higher at 5% relative humidity (corresponding to 7-8% humidity) and at 5 degrees C temperature. In all cases the better results were obtained from the powders of neutralized yogurt, even in comparison with a freeze-dried sample obtained from the natural product. The typical shape of the sorption isotherms of these products suggests that the optimum process as regard to microorganisms' survival consists in drying the neutralized product up to residual humidities of 8-10%, followed by storage, in humidity-proof containers, at temperatures of about 5 degrees C.

Dairy Products↗

PubMedDate not supplied

[Problems relative to food industries waste water and their available solutions (author's transl)].

In this paper some practical considerations concerning food industries waste water are reported with the view to reduce global pollution and obtain a better utilisation of water supply. General principles and particular options leading to the realisation of an optimal depuration proceeding are set forth, followed by the illustration of some problems connected to waste water issues as well as means actually used for depuration in some typical food industries.

Disinfection↗