Interrelationships among microbiological, physicochemical, and biochemical properties of Terrincho cheese, with emphasis on biogenic amines

• Published in: Journal of food protection 2004-12, Vol.67 (12), p.2779-2785
• Main Authors: Pinho, O, Pintado, A.I.E, Gomes, A.M.P, Pintado, M.M.E, Malcata, F.X, Ferreira, I.M.P.L.V.O
• Format: Article
• Language: English
• Subjects: acidity; aerobes; Amino Acids - analysis; Animals; Bacteria - isolation & purification; biochemical compounds; biogenic amines; Biogenic Amines - analysis; Biological and medical sciences; Cheese - analysis; Cheese - microbiology; cheese ripening; cheesemaking; cheeses; Chromatography, High Pressure Liquid; Colony Count, Microbial - methods; Enterococcus; ewe milk; Fermentation; food contamination; Food Handling - methods; Food industries; Food Microbiology; free amino acids; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; lactic acid bacteria; Lactobacillus; Lactococcus; microbial activity; microbial contamination; microbial load; Milk - chemistry; Milk - microbiology; Milk and cheese industries. Ice creams; molds (fungi); nitrogen content; physicochemical properties; plate count; Pseudomonas; raw milk; salt concentration; Sheep; sodium chloride; Solubility; Staphylococcus; Time Factors; traditional technology; viability; water activity; water content; yeasts
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028x-67.12.2779

Changes in the microbiological, physicochemical, and biochemical characteristics of Terrincho cheese as represented by native microflora, pH, water activity, soluble nitrogen fractions, free amino acids, and biogenic amines (e.g., ethylamine, dimethylamine, tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, cystamine, and spermine) during ripening were monitored. Terrincho is a traditional Portuguese cheese manufactured from raw ewe's milk. The main groups of microorganisms (lactococci, lactobacilli, enterococci, pseudomonads, staphylococci, coliforms, yeasts, and molds) were determined following conventional microbiological procedures. Free amino acids and biogenic amines were determined by reverse-phase high-performance liquid chromatography, following extraction from the cheese matrix and derivatization with dabsyl chloride. The total content of free amino acids ranged from 1,730 mg/kg of dry matter at the beginning of the ripening stage to 5,180 mg/kg of dry matter by day 60 of ripening; such an increase was highly correlated with the increase of water-soluble nitrogen in total nitrogen, 12% trichloroacetic acid-soluble nitrogen in total nitrogen, and 5% phosphotungstic acid-soluble nitrogen in total nitrogen throughout ripening. Histamine was consistently present at very low levels, whereas putrescine, cadaverine, and tryptamine were the dominant biogenic amines and increased in concentration during ripening. Ethylamine, tryptamine, phenylethylamine, and cystamine reached maxima by 30 days of ripening and decreased thereafter. Significant correlations between amino acid precursors and corresponding biogenic amines, as well as between biogenic amines and microbial viable numbers, were observed.