-Research Note-

Chemical and Microbiological Studies on "Crottin de Chavignol" , a Soft Goat's Milk

Akiyoshi HosoNo and Satoru SHIROTA

Department of Crop and Animal Science, Faculty of Agriculture, Shinshu University, Minamiminowa-mura, Nagano-ken, 399-45

(Received August 16, 1993)

Key words: goat's milk cheese, "Crottin de Chavignol", chemical composition, microbiological composition

Annual world production of goat's milk has Materials and Methods risen progressively by about 6.5% in recent years, though at a level far below that of cow's A total of 12 samples of "Crottin de Cha- milk4,13). is renowned for its produc- vignol" which was manufactured in France on tion of regional goat's milk cheese along with a a farm were kindly donated by Mr. Hiroshi notable ewe's milk cheese; namely HATTORI of the Cheese & Wine Academy cheese. The production of goat's cheese in Tokyo. The samples were sent from a manu- France is still farm-based despite progressive facturer to our laboratory via the Cheese & industrialization. Wine Academy Tokyo, under refrigeration "Crottin de Chavignol" is produced in the (below 5℃)within 2 weeks after manufacture, province of Berry in the central region of held at 4℃ and analyzed within 24h. The France, and one of the most important goat's weight of each cheese was around 60g with a in France. HATTORI and SHIRAISHI11) diameter of 6-7 cm and a height of 4-3.5cm. defined it as "a quickly ripening cheese, home- Standard analytical methods for cheese were made with whole raw goat milk. Having a pre- used to analyze moisture, fat, carbohydrate dominantly lactic curdling, a brownish-yellow and ash content16). Protein breakdown was rough rind, a white and compact interior with measured as N content as a percentage of little holes throughout the mass, a slightly water soluble N (WSN) to total N (TN) of the salty and acid flavor and a gelatinous texture cheese using KJELDAHL methods16). Total which could become layered." amino acid analysis was performed with a high This work aims to assess the chemical and performance liquid chromatograph (HPLC) microbiological qualities of "Crottin de (Model JLC-300, JEOL Ltd., Tokyo, Japan), Chavignol", which have not previously been after hydrolysis of the cheese sample in 6N studied. HCl at 110℃ for 20h18). Free amino acids were

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Anim. Sci. Technol. (Jpn.) 65 (6):551-555 551 1994 HOSONO and SHIROTA analyzed with HPLC after treatment of cheese Results and Discussion samples with metaphosphate18). All analyses were carried out in duplicate, and their average The cheese samples used in this experiment values are presented. were just ready for consumption. Table 1 On the other hand, one gram of cheese shows the values for protein, fat, carbohydrate sample was ground in a mortar and mixed with and ash content in the "Crottin de Chavignol" 99ml of physiological saline (PS). Suitable ripened for 2 weeks, and the ripening rate decimal dilutions were prepared with PS, then (WSN/TN) value was 26.36%. The average 0.1ml portions of the diluted samples were values for protein, fat, carbohydrate and ash spread on Brom Cresol Purple Plate Count content are 15.23% 22.80%, 0.72% and 2.60%, Agar, "Nissui" (BCP) for total bacterial count, and percentages of protein (PDB%), fat (FDB and on Desoxycholate Agar, "Nissui" for coli- %), carbohydrate (CDB%) and ash (ADB%) on a form count. BCP plate and desoxycholate dry basis are calculated as 37.31, 55.85, 1.76 and agar plates were incubated at 30℃, and 37℃, 6.36, respectively. respectively. After counting colonies on BCP, "Crottin de Chavignol" is a soft cheese that the colonies on the plate agar were purified by undergoes lactic fermentation and bears sur- streaking on BCP and finally kept in 10% skim face flora for consumption within 15 to 20 days. milk supplemented with 1% glucose and 0.02% Therefore, compared with the total solid values yeast extract. Yeasts and molds were counted in artisanal goat cheeses like "Majorero" and "Bablia on a ZAPECK-Dox plate and an Acidified Potato -Laciana" cheeses1) , the solid value in "Crottin de Chavignol" is fairly low Dextrose Agar (PDA) plate. Colonies on the . Further, plates were purified and kept on PDA slants. the presence of residual carbohydrate (mainly Taxonomic properties of all isolates were ex- lactose) was observed in almost all samples amined, and identification was performed ac- analyzed. cording to Bergy's Manual of Systematic Bac- As seen from Table 1, the total amino acid teriology, Vol. II3), and Laboratory Methods in composition is characterized by a high mol % Food and Dairy Microbiology10). The identi- of glutamic acid (17.9), proline (13.8), leucine fication tests included: gram staining, motility (10.7), valine (8.1). These values are quite close test using soft agar, reduction of nitrate, spore to the amino acid composition reported for formation test10), catalase production10), gas goat's milk, viz. MEHAIA and AL-KAHNALI4) production from glucose and gluconate, carbo- reported that the relative abundance of various hydrate fermentation10), growth at several tem- amino acids in goat's milk was found to be: peratures, salt tolerance, growth initiation at glutamic acid, 17.88; proline, 10.61; leucine, various pH values10), hydrolysis of esculin, hy- 9.27; valine, 7.81 and lysine, 7.21g/100g pro- drolysis of arginine10), acetoin formation from tein. The mol % of free amino acids such as glucose10), citrate utilization10), dextran forma- glycine, alanine, phenylanine and histidine are tion from glucose10), reduction of 0.1% methyl- comparable to those in the total amino acid ene blue, reduction of litmus milk10), growth in pattern.

40% bile10), and optical isomer of lactate10. Bacterial levels of 2.46×107 organisms/g The identification of yeast included mor- (BCP agar plate), and yeast and mold levels of phological characteristics, colony morphology, 8.25×106 organisms/g (acidified PDA plate) and growth characteristics in YM medium12), car- of 5.8×103 organisms/g(ZAPECK-Dox plate) on bohydrate fermentation, and utilization of eth- average, were obtained in the "Crottin de anol as a sole carbon source. Chavignol" samples. Lactic acid bacteria, which were found to be the dominant flora

552 Studies on "Crottin de Chavignol"

Table 1. Chemical and bacterial composition of "Crottin de Chavignol"*

*Ripening rate [(Water soluble N/Total N)×100]=26 .36% were revealed to the order of 107 organisms/g. trehalose, maltose, but not melezitose and

Lactobacillus casei subsp. casei, Lb. casei subsp. glycerol. However, these two strains hydro- pseudoplantarum, Lb. maltaromicus and Lb. lyzed arginine, which differed from those P. plantarum, Lactococcus lactis subsp. lactis urinaeequi. biovar diacetilactis, Lc. lactis subsp. lactis, and The genuses of yeasts and molds isolated Leuconostoc mesenteroides subsp. cremoris were from the "Crottin de Chavignol" samples were isolated as lactic acid bacteria (Table 1). Two identified as Endomyces, Kluyveromyces, Deba- isolates were close to Pediococcus urinaeequi, as ryomyces, Saccharomyces and Pichia. Of these they produced L (+) lactate, fermented ribose, isolates, the strains belonging to the genus of

553 HOSONO and SHIROTA

Endomyces were most representative, about sample was ca. 8.25×106 organism/g, which 23% of all isolates (data not shown). confirms the similarity in counts for yeasts and Regarding microbial flora in goat's milk molds to those of other goat's milk cheeses. cheeses, several studies have been report- Acknowledgement ed6,8,9,15,17),but little is known about the micro- biology of French goat's milk cheese. In gen- Authors thank Mr. Hiroshi HATTORI, Cheese eral, the microbiological qualities of goat's milk & Wine Academy Tokyo, Senior Lecturer, for cheeses are quite different among cheese the cheese samples used in the above work. varieties, because most goat's milk cheeses are References manufactured on farms using goat's milk with and without thermal treatment. The "Crottin 1) ARGUNOSA,O. G., J. CARBALLO,A. BERNARDOand de Chavignol" samples used in the present R. NARTIN, Chemical characterization of a Spanish artisanal (Babia-Laciana study were from goat's milk without thermal Variety). Microbiologie-Aliments-Nutri., 10: treatment. However, no coliforms or Salmo- 69-76. 1992. nella, which were detected in goat's milk 2) ASHENAFI,M., Microbiological quality of Ayib, cheeses manufactured on farms15), were found. a traditional Ethiopian cottage cheese. Interna- In addition, the incidence of fecal microorgan- tional J. Food Microbiol., 10: 263-268. 1990. 3) Bergey's Manual of Systematic Bacteriology, isms was low in these samples. These facts Vol. II (KRIEG, N. R. ed.). The Williams & indicate that handling during milking collec- Wilkins. Baltimore, Hong Kong, London, tion and processing were not so unsanitary. Sydney. 1984. The lactic acid bacterial counts were made in 4) BISS, K., Sheep and goat cheese. J. Soc. Dairy BCP medium described for the isolation of Lac- Technol., 44: 104-106. 1991. tobacillus, Lactococcus and Leuconostoc. The 5) CHVARRS,F. J., J. A. NEZ, L. BAUTISTAand M. NEZ, Factors affecting the microbiological quality most common species identified was Lb. casei of Burgos and Villaln cheese at the retail level. subsp. pseudoplantarum, Leu. mesenteroides J. Food Protection, 48: 865-869. 1985. subsp. cremoris, Lb. casei subsp. casei, Lb. 6) FONTECHA,J., C. PELEZ,M. LUREZ,T. REQUENA,C. plantarum, Lc. lactis subsp. cremoris and Lc. GMEZ and M. RAMOS,Biochemical and micro- lactis subsp. lactis. Extremely high levels of biological characteristics of artisanal hard goat's cheese. J. Dairy Sci., 73: 1150-1157. 1990. these strains closely coincide with the cases in 7) GARCA, M. C., A. OTERO, M. L. GARCA and B. other varieties of goat's milk cheeses8,9,17). In MORENO,Microbiological quality and composi- most goat's cheeses, these microbes are known tion of two types of Spanish sheep's milk to contribute to the formation of aroma compo- cheeses (Manchego and Burgos varieties). J. nents by the degradation of milk components. Dairy Res., 54: 551-557. 1987. 8) GMEZ, R., C. PELEZ and C. MARTN-HERNANDEZ, Therefore, the lactic acid bacteria found in the "Crottin de Chavignol" samples may contribute Enzyme activity in Spanish goat's cheese. Food Chem., 28: 159-165. 1988. to the fermentation of this cheese. Some spe- 9) GMEZ, R., C. PELEZ and E. DELATORRE, cies of the microorganisms isolated are consid- Microbiological study of semi-hard goat's ered to be wild types, because "Crottin de milk cheese. International J. Food Sci. and Chavignol" is a product native to a very closed Technol., 24: 147-151. 1989. 10) HARRIGAN,W. F. and M.E. McCANE, Laboratory area in France, and made from raw goat's milk methods in Food and Dairy Microbiology. Ac- with no starter. ademic Press. New York. 1976. Higher counts of yeasts and molds are usual- 11) HATTORI,H. and T. SHIRAISHI,"The Encyclope- ly described in goat's milk cheeses manu- dia of Cheese", D-2, Cheese & Wine Academy factured on farms2,5,7,9,15). The average count of Tokyo. Tokyo. 1989. 12) IZUKA, H. and S. GOTO, Kobo no Bunri.Dotei- yeasts and molds in the "Crottin de Chavignol"

554 Studies on "Crottin de Chavignol"

Hou. 138-139. Univ. Tokyo Press. Tokyo. 1973. 16) O'KEEFE,R. B., P.F. Fox and C. DALY,Proteolysis 13) MARTIN-HERNANDEZ,M. C., M. JUAREZ and O. in Cheddar cheese: Influence of the rate of RAMOS,Biochemical characteristics of three acid production during manufacture. J. Dairy types of goat cheese. J. Dairy Sci., 75: 1747- Res., 42: 111-122. 1975. 1752. 1992. 17) REQUENA,T., C. PELEZ and M. J. DESMAZEAUD, 14) MEHAJA,M. A. and M.A. AL-KAHNAL,Studies on Characterization of lactococci and lactobacilli camel and goat milk proteins; Nitrogen dis- isolated from semi hard goat's cheese. J. Dairy tribution and amino acid composition. Nutri. Res., 58: 137-145. 1991. Reports International, 39: 351-357. 1989. 18) SAITO,T., T. YOSHIDAand T. ITOH,Composition 15) MOR-MUR, M., C. CARRETERO,R. PLA and B. of free form glycopeptide isolated from bovine GUAMIS,A survey on the microbiological qual- colostrum. International Dairy J., 3: 129-139. ity of a semi-soft manufactured goat cheese. 1993. Food Microbiol., 10: 263-268. 1990.

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