Mycological assessment of cooked beef products

Abstract

A total of 130 samples of ready-to- eat beef products comprised luncheon, fried sausage, fried burger, grilled kofta and fried liver (26 each) were randomly purchased embedded in their sandwiches ( with exception of luncheon's samples ) from different supermarkets and restaurants having various sanitation levels at Mansoura city, Egypt –were analysed mycologically. Laboratory findings exhibited presence of moulds contaminants in 23 ( 88.5 %) beef luncheon, 19 ( 73.1 % ) every of fried beef sausage and fried beef burger, 18 (69.2 %) of grilled beef kofta plus 25 ( 96.2 % ) fried beef liver samples. Whereas, the yeasts were detected in 25 (96.2%) luncheon, 21 (80.7%) sausage, 23 (88.5 %) burger, 22 (84.6%) kofta and 16 (61.5%) liver of the same samples. Enumeration plates of dichloran rose bengal chloramphenicol ( DRBC ) agar revealed the fungal populations in examined cooked beef products by maximum & mean ± standard error levels every of moulds and yeasts in 26 tissue samples of each product as 1.3×103 & 1.7 × 102 ± 0.48 × 102 and 6.5×103 & 1.6 ×103 ± 0.34 ×103 cfu / g in beef luncheon, 1.1×103 &1.6×102 ± 0.46×102 and 1.4×104 & 3 ×103 ± 0.67 × 103 cfu / g in fried beef sausage, 5×102 &1.1 × 102 ± 0.22 × 102 and 7.8 × 103 & 2.02 × 103 ± 0.48 × 103 cfu / g in fried beef burger, 1.2 × 103 & 2.4 × 102 ± 0.65 × 102 and 8.2 ×103 & 2.15 × 103 ± 0.51×103 cfu / g in grilled beef kofta plus 9.5 × 102 & 2.3 × 102 ± 0.48 × 102 and 6 × 103 & 8.92 × 102 ± 3.09 ×102 cfu / g in fried liver, respectively. Data revealed the isolation of a sum of 472 mould strains from a whole 130 tissue samples of cooked beef products ( 26 each of kind ) ; 88 (18.64 %) strains of them recovered from luncheon, 85 (18 % ) from fried sausage, 57 (12.08 %) from fried burger, 124 (26.27%) from grilled kofta, and 118 (25%) from fried liver samples. Generic level identification of the total mould strains categorized them as 170 (36.02 %) Aspergillus strains, 103 ( 21.82 %) Cladosporium, 76 (16.1%) Penicillium, 40 (8.47 %) Alternaria alternata and 22 (4.66 %) Fusarium strains which obtained from all kinds of tested beef products, in addition to 20 (4.24 %) Acremonium strictum strains (18 from fried sausage and 2 from grilled kofta), 16 ( 3.39 %) Geotrichum candidum (10 from fried sausage, 4 from fried burger and 2 from fried liver ), 5 (1.06 %) Mucor ( 2 from luncheon and 3 from grilled kofta ), 4 ( 0.85 % ) Rhizopus ( 1 from luncheon, 2 from grilled kofta and 1 from fried liver ), 3 ( 0.64 %) Rhizomucor ( from grilled kofta samples), 2 (0.42%) each of Curvularia lunata (from grilled kofta and fried liver ) and Trichothecium roseum ( from fried burger ), 1 ( 0.21 % ) each of Bipolaris ( from fried liver ), Cheatomium ( from fried burger ), Drechslera ( from one grilled kofta ), Endomyces fibuliger ( from fried burger ), Ulocladium botrytis ( from grilled kofta ), besides 4 (0.85%) unidentified mould strains ( 3 from luncheon and 1 from fried liver samples ). Data showed the identified groups of total obtained 170 Aspergillus strains as 73 (42.94 %) of them were belonged to Aspergillus niger which were distributed in all types of tested samples and represented by 5 ( 6.85 % ) strains in luncheon, 3 ( 4.11 % ) in fried sausage, 10 (13.69 % ) in fried burger, 30 (41.09 %) in grilled kofta and 25 (34.25 %) in liver samples; followed by 23 (13.52 %) strains of Aspergillus fumigatus group consisted of 2 ( 8.69 %) strains recovered from luncheon, 10 ( 43.48 % ) from every of fried sausage and grilled kofta, besides 1 ( 4.35 % ) from fried burger ; then 22 (12.94 % ) strains of Aspergillus flavus group, 3 ( 13.64 %) of them isolated from luncheon, 4 (18.18 %) from grilled kofta and 15 ( 68.18 %) strains from fried liver samples ; besides 17 (10 %) isolates of Aspergillus ochraceus group, categorized as 6 ( 35.29 %) strains determined in each of luncheon & grilled kofta, 1 ( 5.88 %) in fried burger and 4 (23.53 %) in liver ; 10 (5.88 %) strains of Aspergillus terreus group were found in grilled kofta, exclusively ; 9 (5.29 %) isolates of Eurotium chevalieri, composed of 1 (11.11%) strains from every of luncheon & fried sausage, 3 ( 33.33 %) from grilled kofta, and 4 (44.44 %) strains from fried liver samples ; 6 ( 3.52 % ) strains of Aspergillus parasiticus, distributed as 1 (16.67 % ) of them recovered from each of fried sausage & fried liver and 2 ( 33.33% ) from every of fried burger & grilled kofta samples ; 5 (2.94%) isolates of Aspergillus candidus, 3 (60 %) of them were found in grilled kofta and 2 (40 %) in fried liver ; 4 ( 2.35 % ) strains of Eurotium amstelodami, consisted of 1 ( 25 % ) strain recovered from every of luncheon & grilled kofta and 2 ( 50 % ) from fried sausage samples ; in addition to a sole strain of Aspergillus ustus ( 0.58 % ) was found in a grilled kofta sample..