Sensory and mass spectrometric analysis of the peptidic fraction lower than one thousand daltons in Manchego cheese.

A total of 107 different peptides, all derived from alphaS1-, alphaS2-, and beta-casein, were identified in different fractions of artisan or industrial Manchego cheese at 4 and 8 mo of ripening, and their sequences were examined. Most of these peptides are described for the first time in Manchego cheese. Taste characteristics (umami and bitter) were assigned based on their AA sequence and the position of these AA within the sequence. The umami taste was predominant in all fractions analyzed by the panelists, and the peptides EQEEL, QEEL, and EINEL, containing a high number of glutamic residues, were found within the fractions. However, in several fractions described as having umami characteristics, no peptides responsible for this taste were detected. Therefore, compounds other than peptides seem to be involved in the umami properties of water-soluble extracts lower than 1,000 Da of Manchego cheese.

Short communication: Identification of the aroma compounds responsible for the floral/rose flavor in water-soluble fractions of Manchego cheese.

Water-soluble fractions from Protected Denomination of Origin Manchego cheese, with molecular weight <1,000 Da, were fractionated using gel permeation chromatography and studied using both instrumental and sensorial analysis. In 2 of the fractions, panelists detected a floral, rose-like flavor. Analysis of these fractions by gas chromatography-mass spectrometry after simultaneous distillation extraction with dichloromethane identified 2-phenylethanol and phenylacetaldehyde as the compounds responsible for this flavor.

Lactobacillus casei and Lactobacillus plantarum initiate catabolism of methionine by transamination.

AIMS: To study the ability of Lactobacillus casei and Lact. plantarum strains to convert methonine to cheese flavour compounds. METHODS AND RESULTS: Strains were assayed for methionine aminotransferase and lyase activities, and amino acid decarboxylase activity. About 25% of the strains assayed showed methionine aminotransferase activity. The presence of glucose in the reaction mixture increased conversion of methionine to 4-methylthio-2-ketobutanoate (KMBA) and 4-methylthio-2-hydroxybutanoate (HMBA) in all strains. The methionine aminotransferase activity in Lact. plantarum and Lact. casei showed variable specificity for the amino group acceptors glyoxylate, ketoglutarate, oxaloacetate and pyruvate. None of the strains showed methionine lyase or glutamate and methionine decarboxylase activities. CONCLUSION: The presence of amino acid converting enzymes in lactobacilli is strain specific. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of this work suggest that lactobacilli can be used as adjuncts for flavour formation in cheese manufacture.

Endoscopic excision of the submandibular gland by an intraoral approach.

The recent advent of endoscopic procedures has compelled both plastic and neck and head surgeons to reconsider the conventional methods by which the excision of submandibular gland is classically achieved. An endoscopic intraoral approach for excision of the submandibular gland is described. This procedure is anatomically safe and can be made with minimal morbidity; a transcervical incision is avoided. Both specific instruments and solid anatomical knowledge are necessary to perform a safe and efficient glandular endoscopic excision. The essential surgical steps are as follows: 1) Careful identification of the Wharton duct and lingual nerve; 2) Retraction of the mylohyoid muscle; 3) Protection of the sublingual gland and lingual nerve; 4) Extraoral manipulation of the submandibular gland obtaining intraoral protrusion; and 5) Careful dissection of the posterior third of gland, avoiding injury on the facial artery and vein. Two patients were operated on with this technique and were very pleased with their results. No complications were registered. With advanced endoscopic instruments, new surgical technique, and surgeon experience, endoscopic intraoral excision of the submandibular gland can be the method of choice in benign neoplasia, sialolith, sialoadenitis and plunging ranula.

Pure red cell aplasia in a patient with systemic lupus erythematosus.

Pure red cell aplasia developed in a female patient with systemic lupus erythematosus (SLE). Erythroid colony growth was assessed in semisolid medium culture of bone marrow obtained from a normal donor and cultured in the presence of normal and patient sera. Colony forming units of erythropoiesis and burst forming units of erythropoiesis obtained from a normal donor were inhibited in the presence of patient sera. Our findings support the concept that circulating inhibitors might influence the proliferation of erythroid progenitor cells and erythroid aplasia may be an immunologically mediated syndrome.