Use of phytic acid from rice bran combined with sodium erythorbate as antioxidants in chicken mortadella.

The antioxidant effect of purified phytic acid (PPA) from rice bran (rice polishing by-product) combined with sodium erythorbate (SE) was evaluated for the first time in mortadella (added with 60% mechanically separated meat), a cured product with high-fat content and highly prone to oxidation, characteristic in Brazil. PPA proved effective compared to standard analytical grade phytic acid (SPA). Two central composite rotational designs (CCRD) (A and B) were employed to investigate the influence of PPA and SE, and SPA and SE, respectively, on mortadella lipid oxidation evaluated by TBARS after 30 days at 30 °C. Due to the high phytic acid's potent antioxidant capacity, the combination of PPA and SE synergistically reduced mortadella lipid oxidation. Furthermore, PPA from rice bran effectively controlled lipid oxidation in mortadella when combined with SE in the range of 5.0 to 9.0 mmol/kg of SPA and 25.0 to 50.0 mmol/kg of SE.

Coffee Extract as a Natural Antioxidant in Fresh Pork Sausage-A Model Approach.

Consumers are increasingly looking for healthy foods without the addition of synthetic additives. The aim of this study was to evaluate the efficiency of coffee extracts as a natural antioxidant in fresh pork sausage. Firstly, the conditions for obtaining coffee green extracts were optimized (Central Composite Rotatable Design 23, variables: extraction time, ethanol-water ratio, and sample-solvent ratio) in an ultrasound bath (70 °C). The response variables were the bioactive compounds levels and antioxidant activity. Valid models were obtained (p ≤ 0.05, R2 > 0.751), with higher bioactive content and antioxidant activity in the central point region. Extracts of Robusta and Arabica coffee green (RG and AG) and medium roast (RR and AR) obtained, and central point (10 min, an ethanol concentration of 30%, and a sample-solvent ratio of 10 g/100 mL) and optimized (14.2 min, 34.2%, and 5.8 g/100 mL) parameters were characterized. The RG presented a significantly (p ≤ 0.05) higher content of caffeine (3114.8 ± 50.0 and 3148.1 ± 13.5 mg/100 g) and 5-CQA (6417.1 ± 22.0 and 6706.4 ± 23.5 mg/100 g) in both extraction conditions, respectively. The RG and RR coffee presented the highest antioxidant activity. Two concentrations of RG and RR coffee extracts were tested in fresh pork sausage. The Robusta coffee extract presented the highest antioxidant activity in both roasted and green states. However, when applied to a meat product, the extract prepared with RG coffee showed better results, with efficiency in replacing synthetic antioxidants (content of malonaldehyde/kg of sample below 0.696 ± 0.059 in 20 days of storage), without altering the sensory attributes of the product (average scores above 7.16 ± 1.43 for all attributes evaluated). Therefore, the RG coffee extract was a suitable alternative as a natural antioxidant applied to fresh pork sausage.

Chemical Composition and Biological Activity of Commelina erecta: An Edible Wild Plant Consumed in Brazil.

In recent years, the interest in products of natural origin has boosted the exploitation and use of plants as food and sources of bioactive compounds, especially wild plants widely used in different cultures for several purposes. Commelina erecta is a wild edible plant (WEP) traditionally used as food and medicine, about which few studies exist. Thus, this study aimed at enhancing the knowledge about its nutritional, chemical and bioactive profile, considering different plant parts and development stages, in order to increase its inclusion in the diet of South American communities. The nutritional profile was found to be similar to other WEP frequently consumed in Brazil. Thirteen phenolic compounds (HPLC-DAD-ESI/MS) were tentatively identified, with apigenin, luteolin and quercetin derivatives being the most abundant. Fructose and oxalic acid were the major sugar and organic acid, respectively, in the aerial parts of C. erecta, and four isoforms of tocopherols were also identified. Regarding the plant's antioxidant activity, the EC50 values varied between 18.4 and 1060 µg/mL in the inhibition of lipid peroxidation assay (TBARS) and between 53 and 115 µg/mL in the oxidative haemolysis inhibition (OxHLIA) assay. The hydroethanolic extract obtained from stems at the flowering stage also presented anti-inflammatory activity. In general, all the extracts evidenced promising antimicrobial activity. Altogether, these results reinforce the traditional use of this plant species as food and medicine to support the diet of needier populations and also promote food sovereignty and sustainability.

Antimicrobial curcumin-mediated photodynamic inactivation of bacteria in natural bovine casing.

BACKGROUND: Outbreaks related to food contamination by resistant microorganisms is a worldwide concern that, motivates industries and research institutions to search for affordable solutions. Among the solutions that have been proposed, Photodynamic Inactivation (PDI) of microorganisms has gained prominence, among other aspects, because it is easy to apply and does not generate microbial resistance. METHODS: In this study, we used the association between curcumin solubilized with Tween and light in the photodynamic inactivation process, using light-emitting diodes with a wavelength of 430 nm for decontamination S. Typhimurium and K. pneumoniae from bovine casings used as wrappers for meat products. The result was verified by counting and comparing the number of colony-forming units of the treatment concerning the negative control. RESULTS: The solubilizer, Tween 80, used does not change the optical absorption of curcumin. An optical fluence of 150J/cm2 induces a microbial log reduction of 3.8±0.2 and 2.7±0.1 for S. Typhimurium, and K. pneumoniae contaminated guts, respectively. For the 200µM concentration of curcumin, the PDI provided a microbial log reduction of 3.16±0.03 for S. Typhimurium. For K. pneumoniae, the minimal inhibitory concentration of curcumin occurs up to 12.5µM, causing an microbial log reduction of 2.08±0.03. CONCLUSION: Both curcumin and tween are already used as additives in food production and do not pose health risks at the concentrations used. Furthermore, in the case of the material studied, the addition of curcumin favors the organoleptic quality associated with the color of the food, unlike the green or blue photossensitizers. The results pave the way for possible application of curcumin in finished meat products.

Phytic Acid against Clostridium perfringens Type A: A Food Matrix Study.

This study evaluated the inhibitory effect of phytic acid (PA) on the spore germination and vegetative cells growth of Clostridium perfringens type A, as well as its effect in combination with maltodextrin (MD) in cooked sausages. The addition of 1% PA showed a satisfactory inhibition of spores' germination and vegetative cells growth of C. perfringens in BHI media. The inhibitory effect of 1% PA on vegetative cells was similar to the additive sodium sorbate (SS) at 10%. Subsequently, a mixture of PA-MD (1:1; w/w) was evaluated for the inhibition of C. perfringens spores in cooked sausages. The PA-MD 1.5% and 2.5% had a similar performance to SS 10% and a similar or higher performance than 0.015% NO2 (p < 0.05). In an unprecedented way, the present study demonstrated that PA inhibited spore germination and vegetative cells growth of C. perfringens, highlighting its potential use as an alternative and natural preservative for the meat industry.

Effect of ultrasound and chlorine dioxide on Salmonella Typhimurium and Escherichia coli inactivation in poultry chiller tank water.

This study evaluated the application of ultrasound alone or combined with chlorine dioxide (ClO2) for Salmonella Typhimurium and Escherichia coli inactivation in poultry processing chiller tank water. A Full Factorial Design (FFD) 22 was conducted for each microorganism to evaluate the effect of ultrasound exposure time (x1: 1 to 9 min; fixed: 37 kHz; 330 W; 25 °C) using a bath, and ClO2 concentration (x2: 1 to 17 mg L-1) on microorganism count expressed in log CFU mL-1 in distilled water. Variable x2 had a negative effect on Salmonella Typhimurium (-5.09) and Escherichia coli (-2.00) count, improving the inactivation; while a x1 increase present no inactivation improvement, explaining the use of x1 lower level (1 min) and x2 higher level (17 mg L-1). The best condition for microorganism inactivation based on FFD was evaluated in chiller tank water (with organic matter) at 25, 16, and 4 °C; x1 was kept (1 min), however x2 was adjusted to obtain the same residual free chlorine (2.38 mg L-1) considering the ClO2 consumption by organic matter, achieving the value of 30 mg L-1. An inactivation of 49% and 31% were observed for Salmonella Typhimurium and Escherichia coli. When ultrasound was replaced by a simple agitation in the presence of ClO2, there was no inactivation for both microorganisms. Moreover, at poultry carcass pre-chilling (16 °C) and chilling (4 °C) conditions, the synergism of ultrasound combined with ClO2 was more pronounced, with microorganisms' reductions up to 100%.

Cochineal carmine adsorbed on layered zinc hydroxide salt applied on mortadella to improve color stability.

The pink/reddish color meat products characteristic of cured meat without the curing salts is a meat industry demand to serve consumers who are looking for healthy foods with the usual sensory characteristics. This study aimed to obtain and characterize a hybrid dye and use it as a replacer for curing salt in the production of pink/red color in mortadella stored for 40 days. A layered zinc hydroxide salt (ZHN) was obtained by alkaline precipitation to immobilize and increase cochineal carmine stability, obtaining the hybrid dye (ZHN-carmine) by ion exchange in aqueous solution. The ZHN-carmine was subjected to ultrasound to increase color intensity and reduce the amount of application. ZHN, cochineal carmine and ZHN-carmine were characterized by X-Ray Diffraction, Fourier-Transform Infrared Spectroscopy, Thermogravimetric Analysis and Differential Scanning Calorimetry. The ZHN-carmine was used in the mortadella elaboration traditionally prepared with nitrite/nitrate and/or carmine. In the characterization it was observed that carmine dye was adsorbed on the lamellar compound surface and over the mortadella storage, it ensures a more stable pink/reddish color than the others product formulations. A more intense color with lower L* and higher a* values was observed for mortadella added of ZHN-carmine ultrasound-assisted. Therefore, the lamellar matrix adsorbed with cochineal carmine may a suitable and useful alternative to obtain the pink/reddish color characteristic of cooked meat products by applying a natural hybrid dye.

Ultrasound: a suitable technology to improve the extraction and techno-functional properties of vegetable food proteins.

Vegetable-based proteins may be extracted from different sources using different extraction methods, among them, ultrasound-assisted extraction stands out. This review presents the current knowledge on ultrasound-assisted extraction (UAE) and the functional properties of extracted vegetable proteins. Ultrasound generates cavitation in a liquid medium, defined as gas and vapor microbubbles collapse under pressure changes large enough to separate them in the medium. Cavitation facilitates the solvent and solid interaction, increasing yield and reducing extraction periods and temperature used. Moreover, ultrasound treatment changed extracted protein properties such as solubility, hydrophobicity, emulsifying and foam, water and oil absorption capacity, viscosity, and gelatinization. Ultrasound-assisted extraction is a promising technique for the food technology sector, presenting low environmental impact, lower energy and solvent consumption, and it is in accordance with green chemistry technology and sustainable concepts.

Application of statistical modelling of mixtures in the development of gluten-free bread with maca, potato, sweet and sour manioc / Aplicación de planificación de mezclar en el desarrollo de un pan sin gluten con maca, patata, yuca dulce y agria

ABSTRACT This study describes the development of mixed flour added of maca for gluten-free bread (GFB) employing a Simplex Centroid Design. Four pseudo-components were evaluated in order to improve the GFB specific volume and texture profile analysis: maca (MC; 0.25 to 0.75), potato starch (PS; 0.25 to 0.75), sweet manioc flour (SEM; 0 to 0.25), and sour manioc flour (SOM; 0 to 0.25). The best GFB formulation - by desirability results - was evaluated regarding physio-chemical, microbiological aspects, and sensory acceptance. The responses specific volume and hardness were adjusted with a special cubic model (R2= 0.973 and 0.913), while cohesiveness, springiness and chewiness was adjusted with a linear model. The significant contribution of maca into GFB dough was evident in the models, and the desirability results indicated an appropriate mixed flour composed by MC (0.25), PS (0.5), and SEM (0.25). The GFB elaborated with this mixed flour generated a product well accepted (acceptability index higher than 73.9%) for attributes of aroma, colour, texture, flavour, and overall acceptance. The values of physio-chemical parameters obtained in the present article was in the range described for GFB in the literature. In addition, the processing method applied allowed for obtaining a GFB that was microbiologically stable.

RESUMEN Este estudio describe el desarrollo de la harina mezclada (MF) agregada de maca para la elaboración de pan sin gluten (GFB) empleando un Diseño Centroide Simplex. Se evaluaron cuatro pseudo-componentes para mejorar el volumen específico y el perfil de textura de GFB: maca (MC; 0,25 a 0,75), almidón de patata (PS; 0,25 a 0,75), harina de yuca dulce (SEM; 0 a 0,25), y harina de yuca agrio (SOM; 0 a 0,25). La mejor formulación de GFB - por la deseabilidad - se evaluó en relación con los aspectos fisicoquímicos, microbiológicos, y sensoriales. El volumen específico y la dureza se ajustaron a un modelo cúbico especial (R2= 0,975 y 0,913). La cohesión, elasticidad y masticabilidad se ajustaron a un modelo lineal. La contribución de la maca a la masa de GFB fue evidente en los modelos, y los resultados indican una MF apropiada compuesta por MC (0,25), PS (0.5) y SEM (0,25). El GFB elaborado con esta MF genera un producto aceptado (índice de aceptabilidad mayor que 73,9%) para aroma, color, textura, sabor y aceptación general. Los parámetros físico-químicos obtenidos estaban en el rango descrito para GFB en la literatura y GFB se mostró microbiológicamente estable.

Soy protein: a food allergen frequently used in the preparation of meat products / Proteína de soya: un alergeno alimentario altamente utilizado en la preparación de productos cárnicos

The addition of soy proteins, currently classified as a food allergen, into meat products is a commonly used practice due to its functional properties and low cost. Its addition to meat products can cause health problems for individuals allergic to these proteins. Allergic individuals can be affected by the ingestion of low amounts of the allergen. In Brazil, limits are set for the addition of soy proteins in meat products in order to avoide fraud. Starting in 2015 reporting the name of the added component became mandatory for all food labelling. Some studies have reported that food processing can reduce the allergenicity, either by irreversible removal of allergens or by modifying the allergen structure. However, the technological approach to decrease allergenicity has largely been empirical. This review describes the use of soy protein in meat products and the health risk for allergic individuals and consumers of these products. Finally, appropriate methodologies for the detection and quantification of these proteins must be further explored and established to avoid fraud and to preserve consumer health.

La adición de proteínas de soya, actualmente clasificadas como alergeno alimentario, en los productos cárnicos es una práctica comúnmente utilizada debido a sus propiedades funcionales y bajo costo. Su adición en productos cárnicos puede causar problemas de salud en personas alérgicas a estas proteínas. Las personas alérgicas pueden verse afectadas por la ingestión de cantidades diminutas de alérgeno. En Brasil, se establecen límites para la adición de proteínas de soya en los productos cárnicos con el objetivo de evitar el fraude. Solo en 2015 se hizo obligatoria la declaración en la etiqueta de todos los alimentos que indicaban la presencia de sustancias alérgicas, así como el nombre del componente. Algunos estudios se refieren al procesamiento de alimentos para reducir la alergenicidad, ya sea mediante la eliminación irreversible de alergenos o modificando la estructura del alergeno; sin embargo, el enfoque tecnológico hasta ahora para disminuir la alergenicidad ha sido en gran medida empírico. Esta revisión describe el uso de proteína de soya en los productos cárnicos y el riesgo que puede causar para la salud de las personas alérgicas y a los consumidores de estos productos. Finalmente, las metodologías apropiadas para la detección y cuantificación de estas proteínas deben explorarse en profundidad y establecerse para evitar el fraude y preservar la salud de los consumidores.

A new and feasible analytical method using reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) for further determination of Nickel in hydrogenated vegetable fat.

A new and simple method for Ni determination in hydrogenated vegetable fat (HVF) has been developed using a RP-DLLME sample preparation procedure for further determination by flame atomic absorption spectrometry (FAAS) and graphite furnace atomic absorption spectrophotometry (GFAAS). The RP-DLLME procedure includes simultaneous microextraction and preconcentration of Ni in HVF, using 5.0 g of HVF preheated (75 °C) and diluted in 5.0 mL of xylene, with the addition of a dispersant/extractant mixture (n-propanol/dilute HNO3). The sample was manually stirred and centrifuged and the aqueous phase was collected for further Ni determination by FAAS and GFAAS. RP-DLLME was carried out using only 700 µL of n-propanol and 300 µL of 2.0 mol L-1 HNO3. The recovery varied from 93.3% to 101.5% for HVF. The LODs and LOQs were 40 and 90 ng g-1 for FAAS, and 0.41 and 1.36 ng g-1 for GFAAS. The proposed analytical method is viable and this is the first application of RP-DLLME to solid fat samples, with Ni determination as an example of application. This method consumes small amounts of reagents, with lower toxicity as compared to microwave decomposition. Furthermore, the key features of the RP-DLLME method include simplicity of operation, high sample mass, reduced reagent consumption, and use of diluted HNO3 as an extractant.

Feasibility of ultrasound-assisted optimized process of high purity rice bran protein extraction / Viabilidade do processo otimizado assistido por ultrassom para extração de proteína de farelo de arroz de alta pureza

ABSTRACT: Rice bran is a by-product of the rice milling process, found worldwide in abundance and highlighted due its protein content. This study optimized the conditions for ultrasonic-assisted extraction of protein from defatted rice bran (DRB) and characterized the rice bran protein concentrate (RBPC). A sequential strategy of experimental design was employed; the effect of pH, temperature, ultrasound exposure time, and amplitude were evaluated regarding the percentage of protein extraction by a Full factorial design (FFD) with a fixed frequencies (FFD-A: 37 kHz; FFD-B: 80 kHz). Subsequently, the percentage of protein extracted was optimized employing a Central composite rotatable design (variables: pH and ultrasound exposure time) and RBPC obtained was characterized regarding chemical and functional properties. The pH and ultrasound exposure time had positive effect (P ≤ 0.05) on percentage of protein extraction; moreover, 37 kHz frequency was more effective in protein extraction. The optimized condition (frequency: 37 kHz; temperature: 30 °C; pH: 10; ultrasound exposure time: 30 min; and amplitude: 100%) allowed 15.07% of protein recovery and the RBPC presented 84.76 g 100 g-1 of protein. Magnesium and copper were the main mineral in RBPC (34.4 and 25.5 µg g-1, respectively), while leucine was the limiting amino acid (0.42) and threonine presented the highest chemical score (1.0). The RBPC solubility was minimal at pH 4 and higher at pHs 6-10; the water and oil absorption capacity were higher than bovine serum albumin (BSA) and the emulsifying capacity was comparable to BSA, with a suitable stability. It was possible to obtain a higher purity RBPC than described in the literature, due to the optimization in the extraction process steps, with functional properties suitable for application in food products, especially emulsified ones.

RESUMO: O farelo de arroz é um subproduto do processo de moagem do arroz, encontrado em abundância em todo o mundo e destacado devido ao seu teor de proteínas. Este estudo otimizou as condições para a extração assistida por ultrassom da proteína do farelo de arroz desengordurado (DRB) e caracterizou o concentrado de proteína do farelo de arroz (RBPC). Uma estratégia sequencial de desenho experimental foi empregada; o efeito do pH, temperatura, tempo de exposição ao ultrassom e amplitude foram avaliados em relação à porcentagem de extração proteica por um Delineamento Fatorial Completo (FFD) com frequências fixas (FFD -A: 37 kHz; FFD-B: 80 kHz). Posteriormente, a porcentagem de proteína extraída foi otimizada empregando um Planejamento Composto Central (variáveis: pH e tempo de exposição ao ultrassom) e o RBPC obtido foi caracterizado quanto às propriedades químicas e funcionais. O pH e o tempo de exposição ao ultrassom tiveram efeito positivo (P ≤ 0,05) na porcentagem de extração proteica. Além disso, a frequência de 37 kHz foi mais eficaz na extração de proteínas. A condição otimizada (frequência: 37 kHz; temperatura: 30 °C; pH: 10; tempo de exposição ao ultrassom: 30 min; e amplitude: 100%) permitiu 15,07% de recuperação de proteínas e o RBPC apresentou 84,76 g 100 g-1 de proteína. Magnésio e cobre foram os principais minerais da RBPC (34,4 e 25,5 µg g-1, respectivamente), enquanto a leucina foi o aminoácido limitante (0,42) e a treonina apresentou o maior escore químico (1,0). A solubilidade do RBPC foi mínima em pH 4 e superior em pH 6-10; a capacidade de absorção de água e óleo foi maior que a albumina sérica bovina (BSA) e a capacidade de emulsificação foi comparável à BSA, com uma estabilidade adequada. Assim, foi possível obter um RBPC com elevada pureza, maior do que o descrito na literatura, devido à otimização nas etapas do processo de extração, com propriedades funcionais adequadas para aplicação em produtos alimentícios, principalmente emulsificados.

Sensory characterization and acceptance of coffee brews of C. arabica and C. canephora blended with steamed defective coffee.

Steam treatment has been reported as an alternative to improve the cup quality of coffee; in this research, it was applied to C. canephora defective coffee. The aim of the study was to evaluate the sensory perception of steamed defective C. canephora coffee (SDC) in roasted coffee blends, by Flash Profile and acceptance tests. SDC was produced by steam treatment (5 bar, 16 min) and a standardized roasting process was applied to all coffees. Four samples were prepared as follows: AB (100% C. arabica), CB (100% C. canephora), ASDB and CSDB, both blends with 50% of SDC and C. arabica or C. canephora, respectively. Coffee brews were prepared through percolation (50 g coffee/500 mL water at 92 °C). Coffee species were more relevant in sensory discrimination of the brews than SDC addition. AB and ASDB were characterized as having brown color, fruity/herbal/green bean aroma and coffee/residual coffee flavor. CB and CSDB were described as viscous, with foam, black color, bitter taste, and aroma/taste related to the roasting process. With SDC addition, typical sensory characteristics of each species were maintained, but the intensity of the attributes was reduced. Coffee brews blends with 50% SDC C. canephora are well accepted.

Steam pressure treatment of defective Coffea canephora beans improves the volatile profile and sensory acceptance of roasted coffee blends.

Between 15 and 20% of Brazilian coffee production corresponds to defective beans (PVA), which decreases the quality of the coffee brew. Steam treatment has been reported as an alternative to improve the volatile profile and cup quality of coffee. The aim of this study was to propose a steam treatment of defective Coffea canephora beans to improve the volatile profile of the roasted coffee. The sensory impacts of adding steamed coffee (SC) in Coffea arabica blends were evaluated. The steam treatments studied modified the volatile profile of roasted SCs, increasing the contents of acetoin, benzyl alcohol, maltol, 2,6-dimethylpyrazine, 2-furfurylthiol, and 5-methylfurfural and decreasing the contents of 4-ethylguaiacol, isovaleric acid, methional, 2,3-diethyl-5-methylpyrazine, and 3-methoxy-3-methylpyrazine. Among the evaluated parameters, the best condition to maximized the content of the volatiles with a potential positive impact and minimize those with a potential negative impact was 5bar/16min (SC 5). The thresholds of consumer rejection and of detection indicate that up to 30% SC 5 can be added to a high cup quality Coffea arabica coffee without perception or rejection of the coffee brew. A blend of 30% of SC 5 and 70% of Coffea arabica was well accepted.

Characterization of the spoilage lactic acid bacteria in "sliced vacuum-packed cooked ham".

The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples.

Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc/Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus, following by Lactobacillus sakei and Leuconostoc mesentereoides; the Enterococcus sp. was not present in the samples.

Growth inhibition of lactic acid bacteria in ham by nisin: a model approach.

Lactic acid bacteria (LAB) have been described as spoilage organisms in vacuum-packed cooked ham. A Fractional Factorial Design was performed to investigate the relative merits of sodium chloride, sodium lactate, sodium tripolyphosphate, sodium erythorbate, nisin and pediocin, in limiting the Lactobacillus sakei growth in broth culture. This allowed rejection of sodium chloride, sodium lactate and sodium erythorbate (no significant effects on growth), and a Central Composite Rotatable Design broth culture study was performed comparing the effects of nisin and pediocin. From this study, nisin was identified as a more important variable for inclusion into a cooked ham model (significant effects on growth parameters: logarithmic increase in the population, exponential microbial growth rate and lag phase extension). The validation of this outcome in a model formulation of vacuum-packed sliced cooked ham (0.001%, 0.007% and 0.013% of nisin) stored for 60days, confirmed the inhibitory effect of nisin on total LAB growth.