Sensory acceptability of raw and extruded bovine rumen protein in processed meat products

The use of bovine rumen protein (raw and extruded) as a replacement for extruded soy protein concentrate in three meat products (pork sausage, chicken hamburger, and kibbe) was investigated. Similarity between rumen and soy protein meat products was assessed using triangle tests and sensory acceptability evaluated by consumer panelists using a nine-point hedonic scale. The addition of raw rumen protein was detected in all meat product types tested, while extruded rumen protein was only detected in kibbe. The addition of raw rumen protein decreased the acceptability of pork sausage aroma and flavor, but improved kibbe appearance, texture and overall acceptability. The addition of extruded rumen protein reduced the acceptability of chicken hamburger texture, but improved pork sausage flavor. Replacement of soy protein by bovine rumen protein is feasible based upon sensory results, but depended upon its form and the type of meat product to which it was added. (C) 2011 Elsevier Ltd. All rights reserved.

Behavior and viability of spontaneous oxidative stress-resistant Lactococcus lactis mutants in experimental fermented milk processing

Previously, we isolated two strains of spontaneous oxidative (SpOx2 and SpOx3) stress mutants of Lactococcus lactis subsp cremoris. Herein, we compared these mutants to a parental wild- type strain (J60011) and a commercial starter in experimental fermented milk production. Total solid contents of milk and fermentation temperature both affected the acidification profile of the spontaneous oxidative stress- resistant L. lactis mutants during fermented milk production. Fermentation times to pH 4.7 ranged from 6.40 h (J60011) to 9.36 h (SpOx2); V(max) values were inversely proportional to fermentation time. Bacterial counts increased to above 8.50 log(10) cfu/mL. The counts of viable SpOx3 mutants were higher than those of the parental wild strain in all treatments. All fermented milk products showed post-fermentation acidification after 24 h of storage at 4 degrees C; they remained stable after one week of storage.

Sensory evaluation of precooked chicken meat with mate (Ilex paraguariensis) added as antioxidant

Dried mate leaves or aqueous extract of dried mate leaves added to chicken meat balls prior to cooking for antioxidant protection was found not to affect taste or smell of the product significantly for addition corresponding to 0.050% of dried mate leaves, while 0.10% changed the smell but not the taste and more significantly for dried leaves. Addition of aqueous mate extract corresponding to 0.050% of mate is recommended as an alternative to more strongly flavoured herbs for oxidative protection of meat products.

Effect of natural pigments on the oxidative stability of sausages stored under refrigeration

The objective was to use natural pigments to replace sodium erythorbate (NaEry), a synthetic compound used as an antioxidant in sausage formulations, and to evaluate the oxidative stability of the samples. Six assays were prepared in which sodium erythorbate (ERY) at 0.05 g/100 g was substituted by norbixin (NOR), lycopene (LYC), zeaxanthin (ZEA), beta-carotene (CAR) or dextrose (used as a control (CON)). Physical, chemical, color, texture and sensory parameters were measured on the first day and after 45 days of storage at 4 degrees C. All pigments used in the sausage formulations were able to maintain the oxidative stability of the sausages (MDA equivalents <038 mg/kg). Zeaxanthin and norbixin were the most efficient antioxidants of those tested. This antioxidant effect might be associated with the intermediate polarities of these two compounds, which would allow them to concentrate in the membrane lipids or emulsion interface, where lipid oxidation is most prevalent. Other volatile secondary products of oxidation besides MDA should be evaluated in further studies involving natural pigments and sensory oxidative stability. (C) 2009 Elsevier Ltd. All rights reserved.

Nuclear and mitochondrial DNA markers in traceability of retail beef samples

Several characteristics are important in a traceability system of animal products, such as age at slaughter, breed composition, besides information of the productive chain. In general, the certification agent records information about the animals and the system which it came from, although cannot guarantee that the slaughtering, meat processing and distribution are error proof. Besides, there is a differential price, at least at the international market, based on sex and breed composition of the animals. Genetic markers allow identification of characteristics controlled in the beef cattle traceability program, as sex and breed composition, in order to correctly identify and appraise the final product for the consumer. The hypothesis of this study was that the majority beef samples retailed in the local market originate from female with a great participation of zebu breeds. Therefore, the objective of this work was to characterize retail beef samples with DNA markers that identify cattle sex and breed composition. Within 10 beef shops localized in Pirassununga, SP, Brazil, 61 samples were collected, all were genotyped as harboring Bos taurus mitochondrial DNA and 18 were positive for the Y chromosome amplification (male). For the marker sat1711b-Msp I the frequency of the allele A was 0.278 and for the marker Lhr-Hha I the frequency of the allele T was 0.417. The results of sat1711b-Msp I and Lhr-Hha I allelic frequencies are suggestive that the proportion of indicus genome compared with the taurine genome in the market meat is smaller than the observed in the Nellore breed. The procedure described in this study identified sex and subspecies characteristics of beef meat samples, with potential application in meat products certification in special as an auxiliary tool in beef cattle traceability programs.

Condições socioeconômicas e padrões alimentares de crianças de 4 a 11 anos: estudo SCAALA - Salvador/ Bahia

OBJETIVOS: identificar os padrões alimentares de crianças e sua associação com o nível socioeconômico das famílias. MÉTODOS: estudo transversal com 1260 crianças de 4 a 11 anos, residentes em Salvador-Bahia que incluiu aplicação de um Questionário de Frequência Alimentar semi-quantitativo. Os padrões alimentares foram identificados, empregando-se análise fatorial por componentes principais. O nível socioeconômico foi avaliado por meio de um indicador socioeconômico composto. Regressão logística multivariada foi empregada. RESULTADOS: identificaram-se quatro padrões que explicaram 45,9% da variabilidade dos dados de frequência alimentar. Crianças que pertencem ao nível socioeconômico mais alto têm 1,60 vezes mais chance (p<0,001) de apresentarem maior frequência de consumo de alimentos do padrão 1 (frutas, verduras, leguminosas, cereais e pescados) e 3,09 vezes mais chance (p<0,001) de apresentarem maior frequência de consumo dos alimentos do padrão 2 (leite/ derivados, catchup/ maionese/ mostarda e frango), quando se compara com aquele de crianças de nível socioeconômico mais baixo. Resultado inverso foi observado no padrão 4 (embutidos, ovos e carnes vermelhas); isto é, quanto maior o nível socioeconômico menor a chance da adoção desse padrão. Tendência similar foi notada para o padrão 3 (frituras, doces, salgadinhos, refrigerante/ suco artificial). CONCLUSÕES: padrões alimentares de crianças são dependentes das condições socioeconômicas das famílias e a adoção de itens alimentares mais saudáveis associa-se aos grupos de mais altos níveis socioeconômicos.

Effects of natural antioxidants on the lipid profile of electron beam-irradiated beef burgers

The purpose of this study was to assess the efficacy of rosemary and oregano extracts in avoiding oxidative changes in beef burgers, and to evaluate the fatty acid profile of these products after electron beam exposition. Extracts, individually or in combination, were added to beef burgers and compared to synthetic antioxidants commonly used in food (butylated hydroxytoluene, butylated hydroxyanisole). The ground beef were submitted to electron beam irradiation at doses of 0, 3.5 and 7 kGy, and stored for 90 days. At regular time intervals, lipid oxidation and fatty acid composition were evaluated through measurement of thiobarbituric acid-reactive substances (TBARS) and gas chromatography, respectively. The results indicate that, although the irradiation process triggers an increase in the lipid oxidation ratio expressed by TBARS values, great changes in the fatty acid profiles were not observed; instead, they continued to present characteristics very similar to that of non-irradiated beef. Thus, as irradiation doses of up to 7 kGy for frozen meat can make foods safe from foodborne pathogens, natural antioxidants derived from spices are able to reduce and avoid lipid changes that may cause a deterioration of the sensory quality of these foods, and these natural extracts offer a good choice for replacing synthetic additives.

The viability of three probiotic organisms grown with yoghurt starter cultures during storage for 21 days at 4 degrees C

This study investigated the viability of probiotic (Lactobacillus acidophilus LA5, Lactobacillus rhamnosus LBA and Bifidobacterium animalis subsp. lactis BL-04) in milk fermented with Lactobacillus delbrueckii subsp. bulgaricus LB340 and Streptococcus thermophilus TAO (yoghurt - Y). Each probiotic strain was grown separately in co-culture with Y and in blends of different combinations. Blends affected fermentation time(s), pH and firmness during storage at 4 degrees C. The product made with Y plus B. animalis subsp. lactis and L. rhamnosus had counts of viable cells at the end of shelf life that met the minimum required to achieve probiotic effect. However, L. acidophilus and L. delbrueckii subsp. bulgaricus were inhibited.

Evaluation of culture media for enumeration of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium animalis in the presence of Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus

The study compared the growth capability of probiotic (Lactobacillus acidophilus La05, Lactobacillus casei Lc01 and Bifidobacterium animalis Bb12) and non-probiotic (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus) cultures on twenty-one culture media grouped according to selectivity: nonselective agars, selective agars without antibiotics and MRS agars containing different combinations of lithium chloride, cystein, bile salts and antibiotics. Four of these media were selected for quantitative enumeration of L acidophilus La05, L casei Lc01, and B. animalis Bb12. The best culture media and incubation conditions for enumeration of the probiotic cultures were: B. animalis: MRS agar with dicloxacillin, 37 degrees C or 42 degrees C, anaerobiosis; L acidophilus: MRS agar with bile salts, 37 degrees C or 42 degrees C, aerobiosis; L casei: MRS agar with lithium chloride and sodium propionate, 37 degrees C or 42 degrees C, aerobiosis or anaerobiosis. Plating on MRS with glucose replaced by maltose, 37 degrees C or 42 degrees C, anaerobiosis, will distinguish probiotic from non-probiotic cultures. For enumeration of each probiotic in a mixed culture, the following media and incubation conditions were recommended: B. animalis: 4ABC-MRS, 42 degrees C, anaerobiosis, L acidophilus: LC medium, 42 degrees C, aerobiosis or anaerobiosis and L casei: LP-MRS, 42 degrees C, aerobiosis or anaerobiosis. In all experiments, differences in counts using pour plating or surface plating were not significant (P <= 0.05). (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

Lactobacillus sakei 1 and its bacteriocin influence adhesion of Listeria monocytogenes on stainless steel surface

Listeria monocytogenes is of particular concern for the food industry due to its psychrotolerant and ubiquitous nature. In this work, the ability of L monocytogenes culturable cells to adhere to stainless steel coupons was studied in co-culture with the bacteriocin-producing food isolate Lactobacillus sakei 1 as well as in the presence of the cell-free neutralized supernatant of L sakei 1 (CFSN-S1) containing sakacin 1. Results were compared with counts obtained using a non bacteriocin-producing strain (L sakei ATCC 15521) and its bacteriocin free supernatant (CFSN-SA). Culturable adherent L monocytogenes and lactobacilli cells were enumerated respectively on PALCAM and MRS agars at 3-h intervals for up to 12 h and after 24 and 48 h of incubation. Bacteriocin activity was evaluated by critical dilution method. After 6 h of incubation, the number of adhered L monocytogenes cells in pure culture increased from 3.8 to 5.3 log CFU/cm(2) (48h). Co-culture with L sakei 1 decreased the number of adhered L monocytogenes cells (P < 0.001) during all sampling times with counts lower than 3.0 log CFU/cm(2). The CFNS-S1 also led to a significant and similar reduction in culturable adhered L. monocytogenes counts for up to 24 h of incubation, however after 48 h of incubation, re-growth of L monocytogenes number of adhered cells was observed, likely due to lack of competition for nutrients. L sakei ATCC 15521 or its supernatant (CFNS-SA) did not reduce the number of adhered L monocytogenes cells on stainless steel surface and from 6 h of incubation, listerial counts were between 4.3 and 4.5 log CFU/cm(2). These results indicate that L sakei 1 and its bacteriocin sakacin 1 may be useful to inhibit early stages of L monocytogenes adherence to abiotic surface. (C) 2011 Elsevier Ltd. All rights reserved.

Prevalence and characterization of Enterococcus spp. isolated from Brazilian foods

Enterococci can be used in the food industry as starter or probiotic cultures. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, the prevalence of enterococci in selected Brazilian foodstuffs (raw and pasteurized milk, meat products, cheeses and vegetables) was evaluated. Phenotypic and PCR protocols were used for species identification. Tests for production of gelatinase, haemolysin, bacteriocin and bile salt hydrolysis were done with all enterococci isolates, whereas molecular determination of virulence markers (genes esp, gel, ace, as, efaA, hyl and cylA) and antibiotic resistance was checked only for Enterococcus faecium and Enterococcus faecalis isolates. The antibiotic-resistant isolates were assayed for biofilm formation and adhesion to mammalian cells. From the 120 food samples analyzed, 52.5% were positive for enterococci, meat and cheese being the most contaminated. E. faecium was the predominant species, followed by E. faecalis, E. casseliflavus and Enterococcus gallinarum. Phenotypic tests indicated that 67.7% of isolates hydrolyzed bile salts, 15.2% produced bacteriocin, 12.0% were beta-hemolytic and 18.2% produced gelatinase. Antibiotic resistance (gentamicin, tetracycline and erythromycin) and genes encoding for virulence traits were more frequent in E. faecalis than in E. faecium. Three E. faecium isolates were resistant to vancomycin. Among antibiotic-resistant isolates, 72.4% of E. faecalis were able to form biofilm and 13.8% to adhere to Caco-2 cells. Antibiotic-resistant E. faecalis and E. faecium isolates were grouped by RAPD-PCR and a scattered distribution was noted, indicating that resistance was not related to a particular clone. The spread of virulence/resistance traits in isolates of the two species and different RAPD-types suggest the pathogenic potential of both species. By contrast, the recovery of bacteriocinogenic E. faecium isolates with no virulence traits suggests their potential for biotechnological applications. In conclusion, our results showed that enterococci from Brazilian foods present important dualist aspects for food safety. (C) 2008 Elsevier Ltd. All rights reserved.

Use of Carnobacterium maltaromaticum cultures and hydroalcoholic extract of Lippia sidoides Cham. against Listeria monocytogenes in fish model systems

Minimally processed refrigerated ready-to-eat fishes may offer health risk of severe infection to susceptible individuals due to contamination by the psychrotolerant bacterium L monocytogenes. In this work, inhibition of L monocytogenes by a plant extract and lactic acid bacteria (IAB) was studied in model fish systems kept at 5 degrees C for 35 days. For that, fillets of tropical fish ""surubim"" (Pseudoplatystoma sp.) and hydroalcoholic extract of the plant Lippia sidoides Cham. (""alecrim pimenta"") were used. Fish peptone broth (FPB), ""surubim"" broth and ""surubim"" homogenate were inoculated with combinations of L monocytogenes and bacteriocin-producing Carnobacterium maltaromaticum (C2 and A9b(+)) and non bacteriocin-producing C. maltaromaticum (A9b(-)), in the presence or absence of extract of ""alecrim pimenta"" (EAP). In all model systems, monocultures of L monocytogenes and carnobacteria reached final populations >= 10(8) CFU/ml after 35 days, except for L monocytogenes in ""surubim"" homogenate (10(4) CFU/ml). In FPB, EAP alone and combined with cultures of LAB inhibited L monocytogenes but carnobacteria without EAP were only weakly antilisterial. In ""surubim"" broth, EAP alone did not prevent L monocytogenes growth but cultures of carnobacteria combined or not with EAP inhibited L monocytogenes, with more pronounced effect being observed for C maltaromaticum C2, which produced bacteriocin. In ""surubim"" homogenate, EAP alone and combined with cultures of C. maltaromaticum A9b(-) and A9b(+) were strongly inhibitory to L monocytogenes, while C maltaromaticum C2 with EAP caused transient inhibition of L monocytogenes. No significant inhibition of L monocytogenes was observed for carnobacteria in ""surubim"" homogenate without EAP. In conclusion, it was observed that the use of EAP and cultures of carnobacteria have potential to inhibit L monocytogenes in fish systems and the applications should be carefully studied, considering the influence of food matrix. (c) 2011 Elsevier B.V. All rights reserved.

Development of a synthetic 7-ketocholesterol- rich emulsion resembling chylomicrons

Lipid emulsions that mimic natural lipoproteins help to understand the metabolism and the constitutional organization of circulating lipids. Chylomicrons synthesised by enterocyte cells usually contain oxysterols such as 7-ketocholesterol (7-KC). Here we describe the development of a 7-KC-containing emulsion as a model for oxisterol-rich chylomicron. Different amounts of 7-KC were used. Emulsion characteristics as effective diameter, lipid saturation with radiolabeled lipids was evaluated. In conclusion, the production of a synthetic 7-KC-rich emulsion resembling hylomicrons was feasible, being a model for in vivo metabolism studies.

Performance of a chromogenic medium for the isolation of Listeria monocytogenes in food

According to the producers, CHROMagar (TM) Listeria medium comes to facilitate the detection, differentiating Listeria monocytogenes from the other species, directly on the isolation process, allowing final results in 72 h, while the traditional method takes up to 10 days. A total of 120 food samples of sliced cooked ham, ground beef and frankfurters was analyzed. From 151 colonies presenting typical L. monocytogenes characteristics on CHROMagar (TM) Listeria (bluish, surrounded by a white halo), only 95 (62.9%) were confirmed as L. monocytogenes. The medium was highly sensitive to detect L. monocytogenes in ground beef and frankfurter, but not in sliced ham. (c) 2007 Elsevier Ltd. All rights reserved.

Adding value to the meat of spent laying hens manufacturing sausages with a healthy appeal

The aim of this study was to evaluate the viability of the use of spent laying hens' meat in the manufacturing of mortadella-type sausages with healthy appeal by using vegetable oil instead of animal fat. 120 Hy-line® layer hens were distributed in a completely randomized design into two treatments of six replicates with ten birds each. The treatments were birds from light Hy-line® W36 and semi-heavy Hy-line® Brown lines. Cold carcass, wing, breast and leg fillets yields were determined. Dry matter, protein, and lipid contents were determined in breast and leg fillets. The breast and legg fillets of three replicates per treatment were used to manufacture mortadella. After processing, sausages were evaluated for proximal composition, objective color, microbiological parameters, fatty acid profile and sensory acceptance. The meat of light and semi-heavy spent hens presented good yield and composition, allowing it to be used as raw material for the manufacture of processed products. Mortadellas were safe from microbiological point of view, and those made with semi-heavy hens fillets were redder and better accepted by consumers. Values for all sensory attributes were evaluated over score 5 (neither liked nor disliked). Both products presented high polyunsaturated fatty acid contents and good polyunsaturated to saturated fatty acid ratio. The excellent potential for the use of meat from spent layer hens of both varieties in the manufacturing of healthier mortadella-type sausage was demonstrated.