Changes in Soluble Nitrogen, Ph and Lactic Acid During Ripening of Chabichou-Type Cheese

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Changes in Soluble Nitrogen, pH and Lactic Acid During Ripening of Chabichou-type Cheese

A. F. WOLFSCHOONl. and M. MANSUR FURTADO Instituto de Laticinios Candido Tastes. Departamento de Tecnologia de Alimentos. Empresa de Pesquisa Agropecuaria de Minas Gerais, 36/00Juiz de Fora, Minas Gerais, Brazil

(Received for publication November 29, 1978) Downloaded from http://meridian.allenpress.com/jfp/article-pdf/42/8/666/1649519/0362-028x-42_8_666.pdf by guest on 29 September 2021

ABSTRACT EXPERIMESTALPROCEDLRES Twenty-eight samples of Chabichou-type cheese made from goat's Cheese were manufactured on different dates from goat's milk milk in Juiz de Fora. Brazil. were tested for soluble and total nitrogen. according to the previously described technique (4). Cheese samples titratable acidity (expressed as percent lactic acid), and pH during a were taken from the ripening chamber 1.4 (n = 14). 7 (n 3). 30-day period. Soluble N amounted to 4S".{,oftotal N after 30 days. and 14 (n 4). 2 I (n = 3) and 30 (n 4! days after production and were pH and laetic acid were increa:.ed and decreased. respectively. from analysed for total and soluble N. lactic acid and pH. Between the tirst 5.20 to h.H2 and from O.HJ to ().05%. The composition of 14 cheese and fourth day (after production) 14 cheeses were analysed to samples was determined between the tirst and fourth dav alter determine the fat. protein. moisture and :,alt content. as well as the production. The minimal and maximal values were as follows: l0-25% above-mentioned parameters. Each time a cheese not previously fat, 16-20% protein, 1.6-2.3% soluble protein, 51-53% moisture, investigated was used; the samples analysed were not always from the 1.4-2.2"1, NaCl. (J.7-0.9 ".\,lactic acid and 5.2-5.3 pH. same batch of cheese. All determinations were made in duplicate. Total and soluble N were determined according to the method described by Kosikowski (6) but using I g of cheese and only 50 mg of During cheesemaking and cheese ripening a gradual the diluted sample to perform the Kjeldahl determination with a protein breakdown takes place; this is a complex process micro-Kjeldahl kit (AOAC 47.021; 1975). Fat was determined using 3 g in which the enzymes from rennet, from starter bacteria of cheese. a Van-Gulik butyrometer, 10 ml of H2SO, (d 1.820), 5 ml and from milk itself play an important role (2.9). In of warm water and 1 ml of amyl alcohol (d = 0.815) for each determination. Determination of moisture and sodium chloride content mold-ripened cheese. the phenomena occurring during was according to the method described by Kosikowski (6). The cheese ripening, partially caused by the proteolytic titratable acidity was meawred (using 0.1 N NaOH) and the titration enzymes from specific molds, contribute to development value of the sample was assumed to be lactic acid (8). The pH was of the organoleptic characteristics of the cheese. determined according to Kosikowski (6) using a Radiometer In ripened cheeses with surface mold of the potentiometer Model THM 26 (Denmark). Penicillium roquejortitype, the proteolytic activity of this RESULTS AND DISCUSSION microorganism causes a breakdown of as 1- and (3-casein (3) and an increase in pH 4.6-soluble N to about 50o/o of Liberation ofsoluble nitrogen the total N (5). Formation of amino acids and other Liberation of soluble N proceeded continuously nitrogenated compounds also results in an increase in pH throughout the ripening of the cheese. Soluble N during cheese ripening; the relation between pH and increased from about 10 cr;o (first days) to about 26 o/o of ripening days has been studied for Camembert cheese by total N after 2 weeks (normal ripening period for this Lenoir (7). cheese), and up to 36o/o of total N at the end of 3 weeks. The Chabichou cheese has been produced in the After 30 days, such N amounted to 45% of total N. High Departments Vienne and Deux-Sevres as well as in values for pH 4.6-soluble N were reported for Danish Poitiers, in France for many years. Experiments were cheese (5). Levels of about 55% were found in inoculated conducted at the Dairy Institute Candido Tostes (4) to cheeses produced aseptically and with P. roqueforti adapt the French technique ofChabichou cheese-making and Penicillium caseicolum (3). Proteolysis was evident to the conditions in Brazil. This cheese was produced on the surface of the Chabichou-type cheese and from goat's milk and the Penicillium glaucum (or proceeded progressively to the center during ripening; roquef'ortl) was used as the lipolytic and proteolytic agent this occurred because the P. glaucum was sprayed on the during the ripening. An active proteolysis that lead to cheese surface where it grew. Due to its endo- and appearance of significant amounts of soluble N during exopeptidase activity, an increase in soluble N was ripening of the cheese was observed. Changes in pH and brought about and in a centripetal way. The changes in in lactic acid content were followed as long as the concentrations of soluble N with time of ripening of the ripening took place. The composition (minimal and Chabichou type cheese are shown in Fig. 1. maximal values) of cheese was also determined. The pH. lactic acid content and cheese ripening present paper reports the results of such determinations. Changes in pH paralleled the proteolytic activity in the 'Present address: Institut fur Milchwissenschaft der Technischen cheese because the amino acids, peptides, peptones and Universitat Miinchen. 8050 Freising· Weihenstephan. W. Germany. amines formed during the protein breakdown contribute CHANGES IN CHABICHOU-TYPECHEESE DURING RIPENING 667

breakdown of sugars during Camembert ripening was studied by Berner (J). He showed that sugar breakdown proceeded more slowly in the interior of the c_heese than in the rind, the velocity of breakdown depending on the number of microorganisms in the internal and external parts of the cheese. The decrease of lactic acid during ripening of Chabichou-type cheese probably reflects the amount metabolized by the mold. It was also observed ~ that pH increased more rapidly in cheese rind than in the 20 center; however, not enough data were obtained to report a mean value. Finally, Table 1 gives the minimal and maximal values

0 10 30 experimentally determined (n = 14) for the composition Downloaded from http://meridian.allenpress.com/jfp/article-pdf/42/8/666/1649519/0362-028x-42_8_666.pdf by guest on 29 September 2021 Rl PE~fNG DAYS Figure 1. Changes in concentrations of soluble nitrogen with time of of the cheese. ripening. TABLE 1. Composition cheese. a to changes in basicity of the cheese. One day after the Minimal Maximal cheese was produced, the pH of the cheese was near 5.20, Fat (%) 25.0 and after 7 days it increased by 0.4 pH-unit (for the same Total protein (o/o) 16.0 20.0 period soluble N increased approximately 4 %). After Soluble protein (%) 1.6 2.3 14 days, the pH was about 5.81, and after 21 days, it was Moisture(%) 51.0 53.0 Fat in dry matter (o/o) 42.0 51.2 slightly over 6, whereas at the end of 30 days it reached Salt (NaCl) (%) 1.4 2.2 6.82. This is shown in Fig. 2. Desmazeaud and coworkers Lactic acid (%) 0.7 0.9 (3) reported that in cheeses containing Penicillium molds 5.2 5.3 the pH increased after 12 days of ripening, and after 27 cheese samples analysed within 1 and 4 days after days the pH stayed constant at about 7. REFERENCES l.or------············------, 7 1. Berner, G. 1971. Milchsiiureabbau wiihrend der Camembert Reifung. Milchwissenschaft 26:685. 2. Desmazeaud. M. J.. and J. C. Gripon. 1977. General mechanism of pH protein breakdown during cheese ripening. Milchwissenschaft Cl ~ 32:7.11. -(..) 3. Desmazeaud. M. J ., J. C. Gripon, D. Le Bars, and .1. L. Bergere. ""{ 1976. Etude du role des microorganismes et des enzymes au cours (..) 0,5 de Ia maturation des fromages. Ill. Influence des microorganismes. 5 Le Lait 56:379. ""{ 4. Mansur Furtado, M. and A. F. Wolfschoon. 1979. Fabricacao de -.1 queijo tipo Chabichou. II. Adaptacao da tecnologia. Rev. lnst. Lat. Candido Tostes (In press). 5. Ismail. A. A .. and K. Hansen. 1972. Accumulation of free amino 0o~------~1~0------2~0~------7305,/ ------·-~--- acids during cheese ripening of some types of Danish cheese. RIPENING DAYS Milchwissenschaft 27:556. b. Kosikowski. F. 1977. Cheese and fermented milk foods. 2nd ed. Figure 2. Changes in pH and percent lactic acid during ripening of Edwards Bros. Inc .. Ann Arbor. Michigan. USA. the Chabichou type cheese. 7. Lenoir. J. 1963. Note sur ]a degradation des protides au cours de Ia On the other hand, the pH increased in the same way maturation du Camembert. Le Lait 43:154. as the lactic acid content decreased. After cheesemaking, 8. Ramos. Cordova, M. 1976. Manual de am\lisis de leche y lactidnios. 2nd ed. Bern. despacho 201, Mexico, D.F. the percentage oflactic acid in the Chabichou cheese was CJ. Visser. F. M. W .. and A. E. A. Groot-Mostert. 1977. Contribution about 0.85o/Q, and after 4 days it decreased to 0.55%. of enzymes from rennet. starter bacteria and milk to proteolysis and After 1 week, the value decreased to about 0.10%, and at tlavor development in Gouda cheese. 4. Protein breakdown. the end of 30 days it was less than 0.05%(See Fig. 2). The Netherlands Milk Dairy J. 31 :24 7.