1183

Journal of Food Protection, Vol. 69, No. 5, 2006, Pages 1183±1189 Copyright ᮊ, International Association for Food Protection

Research Note Microbiological Pro®les, pH, and Titratable Acidity of and Salchicho n (Two Spanish Dry Fermented Sausages) Manufactured with Ostrich, Deer, or Pork

ROSA CAPITA,* SANDRA LLORENTE-MARIGOÂ MEZ, MIGUEL PRIETO, AND CARLOS ALONSO-CALLEJA Downloaded from http://meridian.allenpress.com/jfp/article-pdf/69/5/1183/1680534/0362-028x-69_5_1183.pdf by guest on 26 September 2021 Department of Food Hygiene and Food Technology, School of Agrarian Engineering, University of LeoÂn, Avenida de Astorga, s/n. 24400-Ponferrada, Spain

MS 05-352: Received 15 July 2005/Accepted 6 November 2005

ABSTRACT

Microbial counts, pH, and titratable acidity were determined in 102 Spanish dry fermented sausages (chorizo and sal- chichoÂn) made with ostrich, deer, or pork meat. Average microbial counts (log CFU per gram) varied from 5.46 Ϯ 0.24 to 8.25 Ϯ 0.80 (total viable counts), from 4.79 Ϯ 0.36 to 7.99 Ϯ 0.20 (psychrotrophs), from 0.00 Ϯ 0.00 to 0.99 Ϯ 1.10 (undetectable values were assumed to be zero) (Enterobacteriaceae), from 0.00 Ϯ 0.00 to 4.27 Ϯ 1.47 (enterococci), from 5.15 Ϯ 1.15 to 8.46 Ϯ 0.49 (lactic acid bacteria), from 3.08 Ϯ 0.44 to 6.59 Ϯ 1.76 (Micrococcaceae), from 2.27 Ϯ 1.53 to 5.11 Ϯ 1.81 (molds and yeasts), from 0.00 Ϯ 0.00 to 2.25 Ϯ 0.81 (pseudomonads), and from 0.00 Ϯ 0.00 to 2.78 Ϯ 0.46 (Brochothrix thermosphacta). Average pH and titratable acidity varied from 5.07 Ϯ 0.25 to 5.63 Ϯ 0.51 (pH units) and from 0.30 Ϯ 0.01 to 0.86 Ϯ 0.19 (% lactic acid). Both type of sausage (P Ͻ 0.05) and species of meat (P Ͻ 0.001) in¯uenced microbial counts. SalchichoÂn samples showed lower average values than chorizo samples for most microbial groups (signi®cant for Enterobacteriaceae, lactic acid bacteria, and B. thermosphacta) and titratable acidity. Sausages made from pork showed the highest microbial loads for total viable counts, psychrotrophs, Enterobacteriaceae, enterococci, lactic acid bacteria, and yeasts and molds. Higher counts were observed only for pseudomonads in ostrich sausages. B. thermosphacta levels were similar for all species of meat. The highest average pH value was observed in sausages made from ostrich meat, and the lowest titratable acidity level was found in pork sausages.

The purchasing habits of consumers in industrialized dry fermented sausages (Ͼ130,000 tons/year) with respect countries during the past few years have changed with re- to consumption, and more than 50 different varieties have spect to foods as a consequence of the continuous evolution been described (Catalog of Cured Sausages and Hams of of economic and social conditions. Growing consumer in- Spain) (24). Both chorizo and salchichoÂn sausages in Spain terest in healthy foodstuffs of high nutritional value has are generally made from minced pork, beef, or beef and prompted interest in alternative . When compared pork, along with pork fat, salt, paprika (chorizo), black pep- with beef, ostrich (Strutio camelus) meat has a low fat con- per (salchichoÂn), and other spices and additives (e.g., garlic tent and cholesterol level and a favorable fatty acid pro®le and oregano) that have been mixed and inserted into natural (high percentage of polyunsaturated fatty acid ␻3) (26, 29). or arti®cial casings, which then undergo a dry-ripening pro- Deer (Cervus elaphus) meat is also perceived and marketed cess (20). Cured (dry fermented) sausages made with os- as a high-quality product, with a lower fat content and high- trich and deer meats have recently appeared in the Spanish er polyunsaturated fatty acid ␻3 values relative to beef (27). market and are being sold alongside traditional pork and The use of ostrich and deer is also of interest for meat beef products. production in communities where the consumption of pork The microbiological characteristics of fermented dry or beef is prohibited (e.g., Muslim and Hindu communities) sausages have been extensively studied (9, 14, 16, 19, 23, or dangerous (allergic people). Both ostrich and deer meats 25, 30). However, these studies focus on sausages manu- occupy a specialized and localized niche in the Spanish factured with pork and beef meats. Research on the micro- market. The consumption of such meats, which is presently biological pro®les of ostrich- and deer-meat sausages is 6 g (ostrich) and 50 g (deer) per person per year, is increas- very limited and generally refers to starter cultures (6, 13, ing (7, 34), representing viable consumption alternatives 26). The goal of the present study was to determine and with respect to meat types. compare the microbiological pro®les, pH, and titratable Chorizo and salchichoÂn are the most popular Spanish acidity of two Spanish dry fermented sausages (chorizo and salchichoÂn) produced from ostrich, deer, and pork meat in * Author for correspondence. Tel: Int-34-987-442000; Fax: Int-34-987- order to extend the understanding of the microbiology of 442070; E-mail: [email protected]. these foodstuffs. 1184 CAPITA ET AL. J. Food Prot., Vol. 69, No. 5

TABLE 1. Culture media, incubation times, temperatures, and references for microbiological analysisa Incubation

Temp Microbial group Culture medium (ЊC) Time Reference

Total viable counts Plate count agar 30 72 h 18 Psychrotrophs Plate count agar 7 10 days 11 Enterobacteriaceae Violet red bile glucose agar 30 24 h 3 Enterococci Kanamycin esculin azide agar 43 24 h 3 Micrococcaceae Mannitol salt agar 35 48 h 2 Yeasts and molds Oxytetracycline glucose yeast extract agar 25 5 days 3 Lactic acid bacteria deMan Rogosa Sharpe agar 30 72 h 3 Pseudomonads Pseudomonas agar with CFC supplement 25 48 h 2 Downloaded from http://meridian.allenpress.com/jfp/article-pdf/69/5/1183/1680534/0362-028x-69_5_1183.pdf by guest on 26 September 2021 Brochothrix thermosphacta Streptomycin sulfate thallous acetate actidione agar 25 48 h 2 a CFC, cetrimid, fucidin, and cephaloridin.

MATERIALS AND METHODS For pH determination, 50-g samples were blended with 200 ml of distilled water for 2 min (masticator I.U.L.). The supernatant Samples. A total of 102 dry fermented sausages (approxi- was ®ltered, and a 50-ml portion of the ®ltrate was diluted with mately 500 g each, 30 to 40 mm in diameter) were used in this 50 ml of distilled water. The pH was measured with a pH meter study: chorizo (n ϭ 33) and salchichoÂn (n ϭ 22) made from after 10 min of mixing (model Crison MicropH 2001, Crison In- ostrich meat, chorizo (n ϭ 6) and salchichoÂn (n ϭ 8) made from struments, Barcelona, Spain). The titratable acidity was measured deer meat, and chorizo (n ϭ 18) and salchichoÂn (n ϭ 15) made by titration to neutrality (pH 7.0) with 0.1 M NaOH. The titratable from pork meat. Sausages were industrially produced, naturally acidity was calculated as a percentage of lactic acid (35). For fermented (without the addition of starter bacteria), not mold rip- physicochemical determinations, samples were analyzed in trip- ened, only lightly smoked, and not too acid in ¯avor. The ripening licate, and the means were calculated. period was about 60 days. All samples were purchased before the ``best-before date'' from different retail outlets in LeoÂn, Spain Statistical analysis. An analysis of variance was performed (between 6 and 8 months after manufacturing), transported under to determine the effects of the species of meat, the sausage type, refrigeration to the laboratory, and analyzed within the following and the microbial groups investigated and their interactions with 4h. each other. Analysis was also performed to determine what effects the species of meat and the sausage type had on microbial counts, Microbiological analysis and physicochemical determi- pH values, and titratable acidity. Duncan's multiple range test was nations. For microbiological analysis, the sausage core was re- used to determine mean separation. All statistical results were cal- moved aseptically. With the aid of a sterile scalpel, 25 g of sample culated with the ``Statistica 6.0'' software package (StatSoft Ltd., was removed from each sausage. Samples were added to 225 ml Tulsa, Okla.). of sterile 1% (wt/vol) Tween 80 (Oxoid Ltd., Hampshire, UK) plus 0.1% (wt/vol) peptone water (Oxoid) and blended in a mas- RESULTS AND DISCUSSION ticator (I.U.L., S.A., Barcelona, Spain) for 2 min. Serial decimal An analysis of variance of the three factors (species of dilutions were prepared in sterile 0.1% (wt/vol) peptone water. Then, 1- or 0.1-ml dilutions of samples were poured or spread, meat, type of sausage, and microbial group) showed sig- respectively, on agar plates. The culture media (all from Oxoid) ni®cant differences for all factors and their interactions, and the incubation parameters used are shown in Table 1. Dupli- with the exception of species of meat ϫ type of sausage cate plates were incubated under aerobic conditions. Two replicate (Table 2). trials were carried out for each sample. Higher (P Ͻ 0.05) average total viable counts (TVCs;

TABLE 2. Analysis of variance of log microbial colony counts of nine microbial groups (total viable counts, psychrotrophs, Entero- bacteriaceae, enterococci, Micrococcaceae, yeasts and molds, lactic acid bacteria, pseudomonads, and Brochothrix thermosphacta)in two fermented sausage types (chorizo and salchichoÂn) manufactured with meat from ostrich, deer, and porka Factor source df SS MS FP

Species (S) 2 796.169 398.085 51.301 0.000 Type of sausage (T) 1 38.385 38.385 4.413 0.036 Microbial group (G) 8 5,576.157 697.020 390.883 0.000 S ϫ T 2 28.473 14.236 1.842 0.160 S ϫ G 16 236.317 14.770 14.339 0.000 T ϫ G 8 36.377 4.547 2.643 0.007 S ϫ T ϫ G 16 80.465 5.029 5.738 0.000 Residual 747 654.681 0.876 Total 800 7,145.857 a df, degrees of freedom; SS, sum of squares; MS, mean square. J. Food Prot., Vol. 69, No. 5 COMPARISON OF OSTRICH, DEER, AND PORK FERMENTED SAUSAGES 1185 determined at 30ЊC) were found in chorizo (7.45 Ϯ 1.09) (antibiotic-like substances) excreted by LAB and the de- than in salchichoÂn (6.87 Ϯ 1.06). Differences in TVCs were crease in pH as a result of their high acidifying capability also found among species of meat (6.82 Ϯ 0.92, 5.93 Ϯ may partially explain the reduction and disappearance of 0.55, and 8.18 Ϯ 0.60 for ostrich, deer, and pork, respec- some microbial groups (Enterobacteriaceae, enterococci, tively). When considering average TVCs for each species and pseudomonads) in fermented meat products. The con- of meat and type of sausage separately (Table 3), values ditions of anaerobiosis and salinity that develop in sausages varied from 5.46 Ϯ 0.24 (deer chorizo) to 8.25 Ϯ 0.80 as ripening proceeds to the endpoint also contribute to the (pork chorizo). Differences in time, temperature, and rela- decrease in these bacteria (19, 25). This fact is important tive humidity during the fermentation of sausages could be because the presence of microorganisms from the Entero- partially responsible for the different characteristics be- bacteriaceae family indicates a public health problem in tween samples because, as indicated, no samples with start- fermented foods, given that enteropathogenic types are er cultures were incorporated into our study. Our data com- common in genera such as Salmonella, Shigella, Yersinia,

pare well with ®ndings from Mediterranean countries. Dro- and Escherichia. Moreover, the presence of microorganisms Downloaded from http://meridian.allenpress.com/jfp/article-pdf/69/5/1183/1680534/0362-028x-69_5_1183.pdf by guest on 26 September 2021 sinos et al. (14) found TVC levels from 6.48 Ϯ 0.14 to in this family serves as an indicator of hygienic problems 8.58 Ϯ 0.04 log CFU/g on Greek fermented sausages man- and has value in the assessment of the microbiological qual- ufactured with a mixture of pork and beef meat. TVCs ity of foods (1). found in pork sausages in the present study (ca. 8 log No substantial differences in the counts of enterococci CFU/g) were similar to those found by Samelis et al. (30, on kanamycin esculin azide agar were found among the 31) and Metaxopoulos et al. (23) in Greek fermented sau- various types of sausage (average counts were 1.42 Ϯ 1.89 sages. The sausages in the studies by Samelis et al. and log CFU/g and 0.97 Ϯ 1.77 log CFU/g for chorizo and Metaxopoulos et al. had been made with pork meat or with salchichoÂn, respectively). By contrast, the species of meat a mixture of beef and pork or beef, pork, and mutton meat. signi®cantly in¯uenced enterococci loads (log CFU per Similar TVCs were also found by Barbuti et al. (5), Caserio gram), with data as low as 0.42 Ϯ 0.73 and 0.23 Ϯ 0.59 et al. (8), and Moretti et al. (25) in Italian fermented sau- (levels below the detection limit were computed as zero) sages made from pork meat. TVC data for chorizo manu- on ostrich and deer, respectively. Signi®cantly higher factured with pork in Spain (16) are also similar to the data counts were observed in pork sausages (4.19 Ϯ 1.48). Data presented for pork sausages in the present study. for pork sausages were similar to the ®ndings of Drosinos TVCs on salchichoÂn made from ostrich and deer in our et al. (14) (4.50 Ϯ 0.07 to 5.25 Ϯ 0.09), Samelis et al. (30) study are similar to results for salchichoÂn made from pork (4.69 to 5.17), and Metaxopoulos et al. (23) (4.35 Ϯ 1.90 and beef meat in Spain (19), for Italian (10), and to 4.57 Ϯ 0.66). Also, Pipova et al. (28) observed counts for poultry salami in the Slovak Republic (28). in poultry salami that were similar to ours (3.96 log The psychrotrophic bacteria found in chorizo and sal- CFU/g). Slightly higher values (about 6 log CFU/g) were chichoÂn showed similar average values (5.99 Ϯ 1.14 and observed by Barbuti et al. (5) in Italian salami. 6.18 Ϯ 1.47, respectively). Data for pork sausages (7.88 Ϯ Enterococci occur and may compete well with other 0.26) were signi®cantly higher (P Ͻ 0.05) than for ostrich micro¯ora in fermented sausages (30). Opinions about their (5.82 Ϯ 1.22) and deer (5.66 Ϯ 0.86) sausages. Psychro- signi®cance vary, as enterococci may enhance sausage aro- trophic counts for each combination of species of meat and ma and taste by their proteolytic activities but may also type of sausage (Table 3) varied between 4.79 Ϯ 0.36 (cho- compromise safety if opportunistic pathogenic strains pro- rizo of deer) and 7.99 Ϯ 0.20 (salchichoÂn of pork). Values liferate (17). High levels of enterococci are considered in- for sausages made from ostrich and from deer meat are dicators of a lack of hygiene. similar to data from poultry salami in the Slovak Republic Two categories of bacteria that are commonly found in (6 log CFU/g) (28). fermented sausages and play a signi®cant role are LAB and Counts of Enterobacteriaceae on violet red bile glu- gram-positive, catalase-positive cocci. These microorgan- cose agar were lower than 1 log CFU/g on both chorizo isms are used as starter cultures, promoting meat fermen- and salchichoÂn (0.47 Ϯ 0.85 and 0.12 Ϯ 0.35, respectively; tation (13). LAB reduce pH and improve the safety and P Ͻ 0.05). For statistical calculation, levels below the de- stability of the product. Gram-positive, catalase-positive tection limit were considered equal to zero. Greater cocci are necessary for the reduction of nitrate to nitrite; amounts (P Ͻ 0.05) of presumptive Enterobacteriaceae they also enhance color stability and prevent rancidity by were found in pork sausages (0.77 Ϯ 1.00) than in ostrich consuming oxygen. By their catalase activity, they destroy (0.13 Ϯ 0.41) and deer (0.14 Ϯ 0.36) sausages. With re- peroxides, and they release various aromatic substances be- spect to the various combinations of species of meat and cause of their intense lipolytic and proteolytic activities (14, types of sausage (Table 3), counts ranged from 0.00 Ϯ 0.00 19, 23). Microbiological analysis showed that counts of (salchichoÂn from deer) to 0.99 Ϯ 1.10 (chorizo from pork). these bacteria in deMan Rogosa Sharpe (MRS) agar con- The low Enterobacteriaceae counts found in the pre- stituted the major micro¯ora of both chorizo and salchichoÂn sent study agree with ®ndings in Greek fermented sausages sausages (average, 7.10 Ϯ 1.64 and 6.53 Ϯ 1.24, respec- (14, 23, 30) and in Italian fermented salami at the end of tively; P Ͻ 0.05). Counts of these bacteria on plate count the ripening period (5, 19) and suggest the strong compet- agar (30ЊC) and in MRS agar were similar. The dominance itive effect that lactic acid bacteria (LAB) have on other of LAB on both chorizo and salchichoÂn samples agrees endogenous ¯ora (9, 16, 19, 25). The chemical compounds with data from other authors on fermented sausages (5, 8, 1186 CAPITA ET AL. J. Food Prot., Vol. 69, No. 5 Ͻ Ân), P c b ad a a c d b b Ân), and C B A B D C CD B C A C 0.19 0.20 0.42 0.68 1.05 0.00 0.48 1.76 0.01 0.98 1.47 Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ân). Samples with 8.09 7.99 0.25 7.50 4.61 0.00 5.28 6.59 0.30 0.83 4.27 a a b b a c d b b D A A A A B B B C A BD Ân), 8 (100%; deer salchicho Ân icho 0.44 1.53 0.00 0.00 0.09 0.44 0.04 0.50 0.00 0.00 0.45 Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Downloaded from http://meridian.allenpress.com/jfp/article-pdf/69/5/1183/1680534/0362-028x-69_5_1183.pdf by guest on 26 September 2021 Salchicho 6.28 2.27 0.00 0.00 5.14 3.08 0.65 6.23 0.00 0.00 6.26 a standard deviations. Means in the same row that are not d ab Ϯ a b c c b e c D A A A AB A AD A C B C 0.60 0.81 0.51 1.25 0.10 1.42 0.37 0.52 1.14 0.64 0.00 Ostrich Deer Pork Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ 6.09 2.25 5.63 5.14 0.37 5.39 0.11 0.27 5.61 3.90 0.00 c b a a b c a c b C B B B C A C B A A CD 0.80 0.14 1.10 1.54 0.49 1.15 1.38 1.24 0.25 1.81 0.25 Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ân). Samples with undetected levels of enterococci were as follows: 23 (69.7%; ostrich chorizo), 4 were as follows: 5 (15.2%; ostrich chorizo), 2 (11.1%; pork chorizo), 23 (100%; ostrich salchicho 8.25 7.60 0.99 4.14 8.46 0.67 1.19 5.43 0.53 5.11 5.07 Ân). Samples with undetected levels of molds and yeasts were 2 (25%; deer salchicho Ân samples manufactured with ostrich, deer, or pork meat c a b b a a a b c B A A A B A AB B B A AB 0.05). Means in the same column that are not followed by the same letter (lowercase) are signi®cantly different ( 0.36 0.46 0.17 0.30 0.04 0.24 0.00 0.52 0.85 1.15 1.13 Ͻ P Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Chorizo 4.79 2.78 5.21 4.95 0.82 5.46 0.00 0.33 0.54 5.15 2.91 Brochothrix thermosphacta were as follows: 30 (90.9% of tested samples; chorizo made from ostrich meat), 4 (66.7%; deer chorizo), 11 (61.1%; pork chorizo), Ân). Undetected levels were assumed to be zero to carry out the statistical analysis of data. Ân), and 7 (46.7%; pork salchicho Ân) and 8 (100%; deer salchicho a bc d d c b e f f A A A A A A A A A AB A 0.19 0.29 0.76 1.06 0.43 0.84 1.42 0.64 0.97 1.07 0.35 Ostrich Deer Pork Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Ϯ Enterobacteriaceae 0.86 5.69 7.30 6.06 0.13 0.51 6.23 3.27 1.90 1.51 5.39 Ân), 8 (100%; deer salchicho Ân), and 15 (100%; pork salchicho Ân). Samples with undetected levels of Microbial counts, pH, and titratable acidity on chorizo and salchicho Parameter Results are given in log CFU per gram for microbial counts and % lactic acid for titratable acidity and are reported as means followed by the same letter (uppercase) are signi®cantly different ( 0.05). Samples with undetected levels20 of (87.0%; ostrich salchicho undetected levels of pseudomonads were as follows: 3 (9.1%; ostrich chorizo), 6 (100%; deer chorizo), 2 (11.1%; pork chorizo), 1 (4.3%; ostrich salch (66.7%; deer chorizo), 17 (73.9%; ostrich salchicho 3 (20%; pork salchicho 8 (100%; deer salchicho Micrococcaceae Yeasts and molds Pseudomonads Brochothrix thermosphacta pH Titratable acidity TABLE 3. Total viable counts Psychotrophs Enterobacteriaceae Enterococci Lactic acid bacteria a J. Food Prot., Vol. 69, No. 5 COMPARISON OF OSTRICH, DEER, AND PORK FERMENTED SAUSAGES 1187

10, 14, 16, 19, 23, 25, 30, 31) and is related to the ability yeast extract agar were 4.01 Ϯ 1.60 in chorizo and 3.83 Ϯ of LAB to adapt to the meat environment. Their fast growth 1.25 in salchichoÂn (P Ͼ 0.05). Signi®cant differences (P rates are evident during the fermentation and ripening of Ͻ 0.05) were found among the various species of meat, sausages. with deer sausages having the lowest yeast and mold loads Similar loads of LAB were observed on sausages from (2.55 Ϯ 1.36) and pork sausages having the highest (4.94 ostrich (5.96 Ϯ 1.33) and deer (5.78 Ϯ 0.97). Higher (P Ͻ Ϯ 1.59). Ostrich sausages showed an intermediate average 0.05) LAB counts were found in sausages from pork (8.02 ®gure (3.53 Ϯ 0.71). Taking into account the various com- Ϯ 0.75). This last value is similar to those found by most binations of species of meat and types of sausage (Table 3), authors in sausages from pork and beef in Mediterranean counts varied between 2.27 Ϯ 1.53 (salchichoÂn made from countries (14, 19, 23, 25, 31). LAB levels found in ostrich deer meat) and 5.11 Ϯ 1.81 (chorizo made from pork meat). sausages are lower than the value of 7.2 log CFU/g found Our data compare well with most studies on fermented by BoÈhme et al. (6) in salami made from ostrich meat to sausages (15, 23, 25, 30). However, higher (31) and lower

which had been added strains of Lactobacillus spp. and (19) values than ours have been observed by other authors. Downloaded from http://meridian.allenpress.com/jfp/article-pdf/69/5/1183/1680534/0362-028x-69_5_1183.pdf by guest on 26 September 2021 Micrococcus spp. The presence of starter cultures could be These microorganisms have lipolytic activities, but they are responsible for the high LAB reached in the above-men- frequently found in low numbers when compared with the tioned research. other microbial groups; consequently, their lipolytic action On chorizo and salchichoÂn sausages, similar counts may have a secondary signi®cance in the manufacture of (log CFU per gram) were obtained for presumptive Micro- fermented sausages. coccaceae (5.51 Ϯ 0.88 and 5.46 Ϯ 1.86, respectively). Average counts of pseudomonads on cetrimid, fucidin, Data were similar for ostrich (5.47 Ϯ 0.86) and pork (5.91 and cephaloridin agar were 1.15 Ϯ 1.19 (chorizo) and 1.23 Ϯ 1.58) sausages. Lower (P Ͻ 0.05) values were obtained Ϯ 1.23 (salchichoÂn), without signi®cant differences among for deer (3.88 Ϯ 1.03) sausages. Average counts for each types of sausage. For numerical calculations, loads below batch considered separately (Table 3) ranged from 3.08 Ϯ the limit of detection were assumed to be zero. Signi®cant 0.44 (salchichoÂn of deer) to 6.59 Ϯ 1.76 (salchichoÂn of differences were observed among the various species of pork) log CFU/g. Our data are comparable with those of meat, with levels of 2.08 Ϯ 0.89 in ostrich, 00.00 Ϯ 0.00 Samelis et al. (30) on Greek salami (4.15 to 5.89 log CFU/ in deer, and 0.78 Ϯ 0.97 in pork. Our data agree with those g) and with those of GonzaÂlez and DõÂez (16) on Spanish of Samelis et al. (30), Metaxopoulos et al. (23), and Dro- chorizo (about 5 log CFU/g). Other authors have also found sinos et al. (14), who have reported less than 2 log CFU Micrococcaceae counts similar to ours in most batches: pseudomonads per g at the end of the ripening period for Metaxopoulos et al. (23) found counts from 4.24 Ϯ 1.13 fermented sausages. to 5.63 Ϯ 0.73, and Barbuti et al. (5) found counts of 5.79 Counts (log CFU per gram) of Brochothrix thermos- Ϯ 0.52. By contrast, our results are slightly lower than phacta on streptomycin sulfate thallous acetate actidione those obtained by Caserio et al. (8) and Comi et al. (10) in agar were higher (P Ͻ 0.05) in chorizo than in salchichoÂn Italian sausages (6 to 7 log CFU/g) and those obtained by samples (1.67 Ϯ 1.14 and 0.00 Ϯ 0.00, respectively). The Samelis et al. (31) in Greek salami (6.43 log CFU/g). Ac- low (nondetected) levels found in salchichoÂn samples sug- cording to these authors, the high Micrococcaceae counts gest that the spices in this foodstuff have an inhibitory ac- found are due to the high pH (5.2 to 5.6) in the sausages tion on this microbial group. Levels in ostrich, deer, and studied. pork sausages were 0.64 Ϯ 1.02, 1.11 Ϯ 1.46, and 0.53 Ϯ The counts of Micrococcaceae in the present study are 1.05, respectively, without signi®cant differences among higher than those found by Lizaso et al. (19) in Spanish them. Average values for the various combinations of spe- salchichoÂn (3 to 4 log CFU/g). The incorporation of starter cies of meat and types of sausage (Table 3) varied from bacteria into the sausage by the aforementioned authors im- 0.00 Ϯ 0.00 (salchichoÂn made from all species of meat) to plies a large and fast decrease in pH, which could contrib- 2.78 Ϯ 0.46 (chorizo made from deer meat). To our knowl- ute to the inhibition of Micrococcaceae, given that they are edge, no other authors have performed studies on this mi- sensitive to acid. Micrococcaceae may become more com- crobial group with fermented sausages. petitive if the ®nal pH is above 5.5, and the greater decline Average pH values were similar in chorizo (5.29 Ϯ in Micrococcaceae found by Lizaso et al. (19) may be the 0.34) and salchichoÂn (5.42 Ϯ 0.50) samples. A higher av- result of the faster and more extensive acidi®cation of their erage pH value was obtained for ostrich sausages (5.49 Ϯ media. Thus, when the pH values of sausages are greater 0.43) than for deer (5.17 Ϯ 0.13) and pork (5.18 Ϯ 0.40) than 6.0, counts of nearly 7 log CFU/g have been found at sausages. These last ®gures are similar to those obtained the end of the ripening period (25). by other researchers on fermented sausages both in Spain The high pH of sausages made with ostrich meat prob- (12, 32, 33) and outside Spain (8, 31). ably enabled the acid-sensitive Micrococcaceae to multiply Our pH values, especially those for ostrich sausages, before the pH decreased below an inhibitory level (about were slightly higher than those found by Samelis et al. (30) 5.3) (21). This may also have been the reason for the higher and Drosinos et al. (14) in Greek sausages (4.78 and 5.20, numbers of pseudomonads in ostrich sausages compared respectively) and by Lizaso et al. (19) in Spanish salchichoÂn with deer and pork sausages, as will be commented on in in a mixture of pork and beef meat (4.88). On the other paragraphs that follow. hand, our values are lower than those in Italian salami, in Counts of molds and yeasts on oxytetracycline glucose which pH values of 6.25 to 6.37 have been found (25). 1188 CAPITA ET AL. J. Food Prot., Vol. 69, No. 5

According to the pH values obtained in our study, the fer- 6. BoÈhme, H. M., F. D. Mellett, L. M. Dicks, and D. S. Basson. 1996. mented sausages could be classi®ed as a product of ``me- Productions of salami from ostrich meat with strains of Lactobacillus sake, Lactobacillus curvatus and Micrococcus sp. Meat Sci. 45:173± dium acidity,'' between the values in German raw sausages Ͻ Ͼ 180. (®nal pH, 5.0) and Italian salami (®nal pH, 6) (22). 7. Carbajo, E. 2000. SituacioÂn actual del avestruz y sus productos en However, the pH values of fermented sausages depend on EspanÄa [Current state of ostrich farming and ostrich products in numerous factors, such as their environment during ripen- Spain], p. 29.1.1.±29.1.5. In Libro de ponencias de las VI Jornadas ing (time, temperature, and relative humidity). Thus, Bal- Profesionales del Avestruz, Febrero-marzo de 2000. Real Escuela de dini et al. (4) found pH values ranging from 4.65 to 6.18 Avicultura, Arenys de Mar, Barcelona. 8. Caserio, G., P. Croce, and S. Caserio. 2002. Utilizzo de budelli tes- in various Italian, Spanish, and French sausages. suti per la stagionatura di salami tipici italiani. Ind. Alim. 41:529± The higher pH values observed for sausages made 534. from ostrich meat (Table 3) are probably related to the high 9. CastanÄo, A., M. C. GarcõÂa FontaÂn, J. M. Fresno, M. E. Tornadijo, pH of fresh ostrich meat. Thus, the most crucial factor that and J. Carballo. 2002. Survival of Enterobacteriaceae during pro- cessing of Chorizo de cebolla, a Spanish fermented sausage. Food in¯uences the ®nal pH of the sausages is the initial pH Downloaded from http://meridian.allenpress.com/jfp/article-pdf/69/5/1183/1680534/0362-028x-69_5_1183.pdf by guest on 26 September 2021 Control 13:107±115. values of the meat (23, 31). The pH found in ostrich sau- 10. Comi, G., G. Procida, D. Aggio, P. Pittia, C. Cantoni, and L. Cocolin. sages in the present study is slightly higher than the 5.2 2000. Valutazione di uno starter microbico per la produzione di sa- value found by BoÈhme et al. (6) in salami made from os- lame tradizionale friulano. Ingegneria alimentare. Valutazione di uno trich meat. However, the addition of starter bacteria (Lac- starter microbico per la produzione di salame tradizionale friulano. tobacillus spp. and Micrococcus spp.) by the above-men- Ing. Alim. 4:9±25. 11. Cousin, M. A., J. M. Jay, and P. C. Vasavada. 2001. Psychrotrophic tioned authors could be the reason for the low pH values microorganisms, p. 159±166. In F. P. Downes and K. Ito (ed.), Com- found. pendium of methods for the microbiological examination of foods, The titratable acidity (grams of lactic acid per 100 g 4th ed., American Public Health Association, Washington, D.C. of total solids) was higher (P Ͻ 0.05) for chorizo (0.78 Ϯ 12. Daporta, P. M. 1988. Microorganismos de intereÂs tecnoloÂgico, con 0.23) than for salchichoÂn (0.47 Ϯ 0.17). Substantial differ- especial referencia a Micrococcaceae, en de las variedades ences were also observed with respect to the species of ``Cantimpalos'' y ``Cerdo IbeÂrico'' (Guijuelo) [Microorganisms of Ϯ Ϯ technological relevance, with special reference to Micrococcaceae, meat, with ostrich (0.71 0.29) and deer (0.72 0.94) in chorizo of the varieties ``Cantimpalos'' and ``Iberian'' (Guijuelo)]. sausages having higher (P Ͻ 0.05) values than pork (0.46 Tesina de Licenciatura. Universidad de LeoÂn, LeoÂn, Spain. Ϯ 0.23) sausages. The observed values are similar to those 13. Dicks, L. M. T., F. D. Mellett, and L. D. Hoffman. 2004. Use of found in different varieties of chorizo from northwest bacteriocin-producing starter cultures of Lactobacillus plantarum Spain: ``chorizo de cebolla'' (0.36 to 0.90) (9), ``chorizo de and Lactobacillus curvatus in production of ostrich meat salami. Meat Sci. 66:703±708. LeoÂn'' (0.35 to 0.55) (33), and ``chorizo de Cantimpalos'' 14. Drosinos, E. H., M. Mataragas, N. Xiraphi, G. Moschonas, F. Gaitis, (0.39 to 0.48) (32). and J. Metaxopoulos. 2005. Characterization of the microbial ¯ora In summary, loads for most microbial groups, includ- from a traditional Greek fermented sausage. Meat Sci. 69:307±317. ing the indicator microorganisms (Enterobacteriaceae and 15. Encinas, J. P., T. M. LoÂpez-DõÂaz, M. L. GarcõÂa-LoÂpez, A. Otero, and enterococci), in ostrich and deer chorizo and salchichoÂn are B. Moreno. 2000. Yeast populations on Spanish fermented sausages. Meat Sci. 54:203±208. lower than those found in pork sausages. From a safety 16. GonzaÂlez, G., and V. DõÂez. 2002. The effect of nitrite and starter standpoint, these results may substantiate claims that the culture on microbiological quality of ``chorizo''Ða Spanish dry consumption of ostrich and deer meat sausages is better for cured sausage. Meat Sci. 60:295±298. the consumer than the consumption of pork sausages. 17. Holley, R. A., A. M. Lammerding, and F. Tittiger. 1988. 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