This study evaluated the antimicrobial properties of Piper carpunya extracts, which are traditionally used by Ecuadorian indigenous communities, and validated the in vitro findings in a real food matrix. Three different extracts (ethanolic, hydroethanolic, and aqueous-lyophilized) were evaluated by the agar well diffusion method against a panel of 20 microbial strains comprising both foodborne pathogens and spoilage microorganisms. The extracts with the highest yield and antimicrobial activity were then tested in a precooked risotto formulated under commercial conditions, in challenge tests with Clostridium perfringens. All extracts inhibited C. perfringens at a minimum inhibitory concentration below 80 mg/mL, the ethanol extract being the most effective. In the risotto model, the ethanol–water extract (8%, w/w) reduced C. perfringens counts by approximately 2 log CFU/g relative to the inoculated control and also lowered aerobic mesophilic and psychrophilic counts, whereas the freeze-dried extract was less effective and bacterial counts declined only until day 4 of storage. Both extracts slightly reduced pH and water activity and, rather than protecting the lipid fraction, exhibited a prooxidant effect; nevertheless, malondialdehyde remained below 0.35 mg/kg throughout the 30-day storage period, well below the thresholds associated with perceptible rancidity. P. carpunya extracts show potential as natural ingredients for improving the microbiological safety of ready-to-eat foods, and their chemical and sensory characterization is required before practical application.

Strawberry leaf extract (SLE) was used in dry fermented sausages, “Salchichón”, to enrich them with antioxidants. The effect of SLE on various characteristics was monitored during ripening and storage. SLE had a slight effect on microbiological characteristics; however, the pH after 3, 14, and 21 days was slightly lower (4.51–4.55) in the samples with higher SLE concentration (0.5% + 1% dextrose). Peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) values of sausages with SLE and with ascorbic acid (reference antioxidant), at the end of ripening, were similar. SLE acted as a pro-oxidant when the sausage was stored in the light; however, it showed antioxidant activity in the dark and at 50 °C storage conditions. Higher extract concentration reduced redness a* value and increased yellowness b* value in the CIELab colour system. Addition of SLE to dry fermented sausages has no negative effect on the ripening process; however, storage conditions of the final product should be carefully controlled. Sensory analysis of the final product showed that SLE imparts a recognisable herbal odour; however, it did not reduce the overall product acceptability. It may be concluded that SLE may be a promising ingredient for increasing the nutritional quality of fermented sausages.

Chicken breasts and burgers (88% breast and 12% backfat) were evaluated for physicochemical characteristics, thiobarbituric acid reactive substances (TBARS), and antioxidant capacity during storage in vacuum or atmosphere conditions for 18 days at 4 °C using the following two formulations: one without incorporating white pomace seasoning (WPS) and another with 3% WPS. The WPS was obtained from white grape skins, a byproduct resulting from the elaboration of white wine. The addition of the WSP decreased the L* values and increased the a* values, resulting in a significant turning toward brown tones in the chicken products. The addition of 3% of WSP led to higher values of ABTS and FRAP, regardless of the type of packaging. Both types of packaging significantly increased the levels of TBARS, although vacuum packaging proved more effective in protecting against lipid oxidation compared to modified atmosphere package (MAP). Additionally, the WSP improved the oxidative stability regarding the TBARS values. In conclusion, the WSP could be a viable alternative to chemical antioxidants and would lead to healthier and innovative chicken products.

Melanoidins isolated from bakery by-products are proposed as new sustainable ingredients for bakery products. The colour, odour profile, texture, water activity, and antioxidant capacity of two bakery food models, fat and fat-free, enriched with 2% and 4% soft bread and common bread melanoidins, were analysed. The colour of the bakery food models with melanoidins was darker than that of the respective control; the fat-free models with melanoidins showed higher values of hardness than the control, while no significant effect was observed in the fat models; the water activity did not change compared to the control; the odour profile was significantly modified with different effects depending on the type of melanoidin quantity added and the food model (fat or fat-free); and the antioxidant capacity increased proportionally to the quantity of melanoidin added. In general, melanoidins from soft bread exhibited a higher effect than the melanoidins from common bread. The melanoidins isolated from both fat and fat-free bakery food models did not show cytotoxicity nor did they modify the levels of reactive oxygen species in Caco-2 cells. Therefore, the results seem to indicate the favourable potential of bread melanoidins as new sustainable ingredients for bakery products.

White wine pomace products (wWPP) represent an innovative strategy as a functional food ingredient to be used as a seasoning both for their technological and functional properties. Nevertheless, the bioactive compounds of wWPP used as a seasoning could be modified during storage. The seasoning in the meat, regardless of the storage method used, modified its phenolic profile and in its bioaccessible fractions, while maintaining a high total antioxidant capacity and total polyphenol content. The contact of the seasoning with the meat can be considered safe as it does not show cytotoxicity in the Caco-2 cells. Additionally, the ability to modulate the cell oxidative stress of the bioaccessible fractions and the potential benefits on microbiota by the colonic fermentation fraction, suggest its potential use as a functional ingredient, without being affected by storage. These results are novel and may help to establish the value of this product as a functional ingredient.

It has been explored the potential utilisation of combined high-pressure processing (HPP) and chitosan edible films with or without clove essential oil (CEO) in order to improve quality (oxidative, sensorial) of rainbow trout fillets at 4 ºC over 22 days in comparison with untreated samples or cooked and HPP alone. The optimal CEO concentration was determined previously through total phenol and antioxidant capacity determination. Films up 20 gkg−1 of CEO did not show significantly higher phenolics compounds and antioxidant capacity. Both traditional cooking and HPP reduced the spoilage as reflected from TVBN results when compared to the control. HPP had less impact on lipid oxidation (TBARS, hexanal concentration and rancid odour) and produced lower colour changes (L* and a* parameters) than cooking. However, some significant changes occurred in pressurised samples. In this sense, application of chitosan films to pressurised samples reduced lipid oxidation and colour alteration. The use of 20 gKg−1 CEO-chitosan films showed a further improvement in oxidative parameters compared to that obtained with chitosan alone. Nevertheless, the remaining odour from the CEO can be a limitation in their application in fresh fish but it could be added to marinated seafood.

El pinole es una harina fina hecha con base en maíz reventado, tostado y es el alimento predominante en la dieta Rarámuri. Este trabajo tiene como objetivo avanzar en el mapeo sensorial del pinole de la Sierra Tarahumara de Chihuahua, México y evaluar su aroma. Se analizaron tres muestras del producto utilizando el Perfil Flash modificado, la cromatografía de gases-la espectrometría de masas con extracción dinámica en la fase sólida de espacio de cabeza (HS-SPDE) y la nariz electrónica (e-nose). En el análisis de la nariz electrónica hubo pocas diferencias significativas entre los pinoles. En los resultados del perfil sensorial las características descriptivas (diecisiete atributos en total)discriminaron cada muestra, como una consecuencia de las ligeras diferencias en los procesos tradicionales aplicados. Se identificaron cuarenta y nueve compuestos volátiles en las tres muestras, de los que veintidós se habían determinado previamente en las palomitas de maíz y en otros productos de maíz. El Análisis Factorial Múltiple mostró correlaciones de varios compuestos volátiles (p. ej., los compuestos heterocíclicos formados durante el tostado y el ahumado) y las respuestas de los sensores con dos tipos de atributos: de olores sensoriales como maní, maíz, tostado, dulce y pinole, y los de sabor como tostado, pinole, dulce y maíz.

A significant amount of bioactive compound-rich solid waste is released during the industrial phycocolloid-centric extraction of Gelidium sesquipedale. The impact of mild pressurized hot water extraction on repurposing this waste for the recovery of agar with an adjustable gel texture is investigated. A two-factor interaction response surface model assessed the influences of the operating temperatures (80 to 130 °C), times (45 and 150 min), pressures (1 to 70 bar), and algae concentrations (3 to 10% (w:v)). At a temperature of 100 °C, a pressure of 10.13 bar, a recovery time of 45 min, and a 10% algae concentration, the working parameters were considered ideal (w:v). Agar with a hardness of 431.6 g, an adhesiveness of −13.14 g.s−1, a springiness of 0.94, a cohesiveness of 0.63, and a gumminess of 274.46 g was produced under these conditions. A combined desirability of 0.78 was obtained for the exposed technology that retrieved gels with a minimum agar yield of 10% and thermal hysteresis between 39 ± 1 and 52 ± 0.5 °C. The fitted design can provide a high techno-commercial value to the agri-food industrial waste stream.

The objective of this work was to evaluate the antimicrobial potential of different extracts of Simira ecuadorensis, a characteristic plant of Ecuador, and to validate its potential as a food preservative. Four extracts referred to as ethanol, ethanol-water (50:50 v/v), spray-dried, and freeze-dried were obtained under different processes. Initially, their antimicrobial activities were evaluated against a wide group of microorganisms consisting of 20 pathogenic and spoilage microbial strains found in foods through the agar diffusion method. Then, the extracts with the best yields and antimicrobial properties against microorganisms of greatest interest were selected to determine their effect on model foods preserved under normal commercial conditions through challenge tests. Spray-dried and ethanol-water extracts were tested for their ability to inhibit C. jejuni in chicken model products, where is a common pathogen and Shew. putrefaciens in fish model products as it is a spoilage microorganism frequently found in fish. One solid and one liquid were chosen as model foods: burger and broth, respectively. Campylobacter jejuni and Shewanella putrefaciens were effectively inhibited by the four extracts with minimum inhibitory concentration (MIC) of 80 mg/mL. Bacillus cereus, Yersinia enterocolitica, Clostridium perfringens, and Leuconostoc mesenteroides were also inhibited by ethanolic extract. The ethanol-water extract showed greater antimicrobial activity in fish products, whereas spray-dried extract had low growth inhibition of C. jejuni in chicken burgers; however, it was quite effective on C. jejuni in broth. The spray-dried extract significantly decreased the pH of the chicken burgers, while the ethanolic extract had a slight impact on the pH of the fish burgers. The presence of antibacterial effects revealed that the S. ecuadorensis extracts could be potentially used in food preservation and as a natural antimicrobial.

Despite the commercial success of high pressure processing (HPP) in the juice industry, some regulatory agencies still require process validation. However, there is a lack of consensus on various aspects regarding validation protocols, including the selection of representative strains to be used in challenge tests. This study characterized the variable response of Escherichia coli O157:H7 (34 strains), Listeria monocytogenes (44 strains) and Salmonella enterica (45 strains) to HPP, and identified potential candidates to use in process validation. Stationary phase cells were submitted to 500 MPa for 1 min at 10 degrees C in model solutions consisting of tryptic soy broth + 0.6% yeast extract (TSBYE) adjusted to pH 4.5 and 6.0 with citric acid. At pH 6.0, pressure resistance widely varied between species and within strains of the same species. E. coli O157:H7 and L. monocytogenes were the most pressure resistant and showed high variability at strain level, as the total count range given by minimum and maximum counts spread between 2.0 and 6.5 log(10) CFU/ml. S. enterica was the least resistant pathogen with more than 82% of the isolates displaying non-detectable counts after HPP. Recovery through storage at 12 degrees C was also variable for all pathogens, but eventually most strains recovered with median counts on day 14 between 8.3 and 8.9 log(10) CFU/ml. For pH 4.5 solutions, 26 E. coli O157:H7 strains displayed survivors after HPP but did not adapt, registering non-detectable counts in the next sampling dates. None of the L. monocytogenes and S. enterica strains survived HPP or incubation at pH 4.5 (<2.0 log(10) CFU/ml), suggesting that citric acid at 4.16 g/l is a safe barrier for pathogen control under moderate HPP conditions. Principal component and cluster analyses served to propose strain cocktails for each species based on their pressure resistant and adaptation phenotypes. Additionally, S. enterica was identified as less pressure resistant and less prone to recover following HPP than E. coli O157:H7 and L. monocytogenes, so its relevance in process validation for juices should be questioned. Future work will validate the proposed strain cocktails on real food systems.

The aim of this study was to examine the possibilities of using chokeberry pomace extract for improving the stability of pork meat products. The extract was isolated with pressurized ethanol (EE) from defatted by su-percritical CO2 pomace and tested in raw pork burgers and cooked ham at 2% concentration. EE reduced burger pH, while its effect on ham pH was insignificant. EE containing anthocyanins remarkably decreased pork products lightness (L*) and yellowness (b*) and increased their redness (a*) coordinates; however, the differ-ences between control samples and the products with EE reduced during 16-days storage of burgers and 40-days storage of ham at refrigerated temperature. EE, as a strong antioxidant, significantly inhibited the formation of thiobarbituric acid reactive substances (TBARS): after 16 days it was 2.3 times lower in the burger with EE. EE did not have negative effect on the overall sensory quality of burgers and cooked ham, but had remarkable impact on product colour. These results indicated that chokeberry pomace EE has great potential as a natural antioxidant and additive to reduce oxidation, thereby extending meat products shelf-life. Chokeberry extract should be considered for use as an alternative to commercially available antioxidants that are currently used in meat products.

Bacterial spores survive high pressure processing (HPP). Group II Clostridium botulinum is an obligate anaerobe spore-forming pathogen that can produce the botulinum neurotoxin under refrigeration. This study assessed nontoxigenic type E C. botulinum and Group II Clostridium sp. growth in raw and HPP (550 MPa, 3 min, 10 degrees C) Thai coconut water (CCW; pH 5.2). No spore germination or growth occurred in HPP CCW inoculated with 10(5) CFU/ml after 61 days regardless of oxygen concentration (< 0.5 - 11 mg/l) or storage temperature (4 and 20 degrees C). Spore concentration decreased by 3.0 +/- 0.1 log CFU/ml in a worst-case scenario consisting of non-HPP filter-sterilized CCW (pH 7.0) under anoxic incubation at 30 degrees C during 61 days, suggesting spore germination followed by cellular death. Supplementing filter-sterilized CCW (pH 7.0) with selected germinants and free amino acids did not support spore development, but the addition of nutrient-rich laboratory media (TPGY broth) at low concentrations (6.25%) promoted growth, suggesting that a lack of nutrients prevents C. botulinum development in CCW. Further risk assessment will require evaluating other CCW varieties and toxin production.

Campylobacter spp. are the leading causes of bacterial human gastroenteritis worldwide; being poultry farms the main source of infections. In order to obtain information on prevalence and diversity of Campylobacter-infected flocks in the North of Spain, fourteen farms were studied between autumn and spring in 2014 and 2015, respectively. Moreover, virulence genes involved in pathogenicity and antimicrobial resistance were investigated. A survey about preventive hygiene practices at farms was performed to determine the risky practices that could contribute to the presence of Campylobacter in this step of the poultry food chain. Testing the presence of Campylobacter spp. showed 43 % of the farms were positive during autumn, whereas only 31 % were positive in spring. A very high prevalence within-flock was observed (43.1 % to 88.6 %) and C. jejuni was the most prevalent species in both periods. Genotyping by pulsed field gel electrophoresis (PFGE) showed a high heterogeneity among farms (309 isolates clustered into 21 pulsotypes). Virulence genes were present in all C. jejuni isolates while cdtA and cdtC were absent in C. coli. On the contrary, the latter showed higher antimicrobial resistance than C. jejuni. This study suggests that environment might be one of the main sources for Campylobacter transmission, as water supply seemed to be a clear cause of the contamination in a specific farm. However, in other farms other environmental factors contributed to the contamination, confirming the multifactorial origin of Campylobacter colonization in broilers. Therefore, biosecurity measures in farms are crucial to reduce Campylobacter contamination, which may have important implications for human and animal health.

The stress response of 11 strains of Listeria monocytogenes to oxidative stress was studied. The strains included ST1, ST5, ST7, ST6, ST9, ST87, ST199 and ST321 and were isolated from diverse food processing environments (a meat factory, a dairy plant and a seafood company) and sample types (floor, wall, drain, boxes, food products and water machine). Isolates were exposed to two oxidizing agents: 13.8 mM cumene hydroperoxide (CHP) and 100 mM hydrogen peroxide (H2O2) at 10 °C and 37 °C. Temperature affected the oxidative stress response as cells treated at 10 °C survived better than those treated at 37 °C. H2O2 at 37 °C was the condition tested resulting in poorest L. monocytogenes survival. Strains belonging to STs of Lineage I (ST5, ST6, ST87, ST1) were more resistant to oxidative stress than those of Lineage II (ST7, ST9, ST199 and ST321), with the exception of ST7 that showed tolerance to H2O2 at 10 °C. Isolates of each ST5 and ST9 from different food industry origins showed differences in oxidative stress response. The gene expression of two relevant virulence (hly) and stress (clpC) genes was studied in representative isolates in the stressful conditions. hly and clpC were upregulated during oxidative stress at low temperature. Our results indicate that conditions prevalent in food industries may allow L. monocytogenes to develop survival strategies: these include activating molecular mechanisms based on cross protection that can promote virulence, possibly increasing the risk of virulent strains persisting in food processing plants.

We report the characterization of 15 Listeria monocytogenes strains isolated from various food processing plants by multivirulence locus sequence typing to determine virulence types (VTs) and epidemic clones. Molecular mechanisms involved in adaptation to food processing environments and related to virulence were also studied. Phenotypic behaviors associated with various antimicrobials, biofilm formations, and invasiveness were assessed. There were 11 VTs among the 15 L. monocytogenes strains. Strains belonging to six VTs were stress survival islet 1 (SSI-1) and one strain of VT94 was SSI-2. Tn6188 was found in VT6 and VT94 strains, and bcrABC cassette genes were identified in VT21, VT60, and VT63 strains. Only one strain, in VT20, showed llxS, whereas a full-size inlA was detected in strains belonging to VT8, VT20, VT21, and VT63. VT10, VT20, VT21, VT60, and VT63 strains were the most tolerant to studied disinfectants. A VT6 strain showed the strongest biofilm formation ability in polyvinyl chloride, and strains belonging to VT10, VT11, VT20, and VT94 had moderate abilities. Antimicrobial sensitivity tests showed that all the L. monocytogenes strains were multidrug resistant. F tests revealed that only strains of VT10, VT60, and VT94 were significantly noninvasive (P < 0.05) in Caco-2 cells. Our findings illustrate how L. monocytogenes isolates exploit diverse mechanisms to adapt to adverse conditions. Consequently, detailed characterization of L. monocytogenes isolates is required for comprehensive elimination of this pathogenic bacterium in food processing environments.

This study shows the methodology in the application of a case study a teaching resource and results obtained in the optional course "Design and development of meat products" from the beginning in the Degree of Food Science and Technology in the University of Burgos (Spain). The main objective of this study is to show if the implementation of this innovative teaching resource allows to an improvement in this specific course. Although this study shows a specific contextualization of the application of this teaching resource, this case study could be adapted to other contexts taking into account the available facilities, equipment, and specific materials needed. It can be also concluded that this case study is a rewarding experience for the course, and it is also a challenge for the teacher that has to deal with different proposals from each team, keeps the teacher out of the comfort zone, and promotes their permanent knowledge update.

This work presents the experience on the students' perception of the system of distribution of marks proposed by Hortiguela [1] and Perez-Pueyo [2] in the framework of formative evaluation, and moreover, their proposals of improvement. This experience has been carried out for several years in 2 courses of the Faculty of Sciences in the University of Burgos. In both courses a number of procedures are applied based on the participation of the students in the evaluation process and in their own final mark. The main objective in this type of system is to try to solve the consequences of what is known as the "stowaway effect" in the working team that generates problems that avoid the harmonious development of the teamwork. In that sense, the system tries to eliminate also the initial rejection of students to the fact of having to accept that the score of the final work is identical for all the team regardless of the effort made by each member, which generates a sense of injustice. From the beginning of the course the procedure and the defined criteria regarding the distribution of marks are well established and explained. When the teaching and learning process ends, the assessment made by the students is that they have learnt the contents in a better way and, especially, the fairer qualification obtained by each member of the team. Although a priori, our experience is in general satisfactory regarding the students' perception of the system applied and, in the results, obtained, in our own evaluation surveys that are carried out to the students once these courses are finished, it has been observed that there is a room for improvement based on students' proposals and opinion.

The fastidious requirement of the zoonotic pathogen Campylobacter jejuni contrasts with its ability to overcome harsh conditions. Different strategies might be involved in the survival and persistence of C. jejuni through the poultry food chain. Therefore, the aims of this study were to get insights in the survival strategies in the poultry slaughterhouse environment by (i) characterizing factors such as biofilm formation, virulence and antimicrobial resistance in environmental isolates and (ii) understanding the possible link between the phenotypic and genetic characterization using whole genome sequencing (WGS). Results have shown that three STs: ST 443 (PFGE A), ST 904 (PFGE C) and ST 3769 (PFGE G), out of the six studied, formed biofilms with variable intensity according to different conditions (temperatures - 37 degrees C, 30 degrees C, 25 degrees C- and materials -stainless steel and plastic-). High levels of antimicrobial resistance were found in isolates to ciprofloxacin, nalidixic acid and tetracycline as well as to two common detergents used in the slaughterhouse. A combination of several changes in the genome of ST 904 (PFGE C) including mutations, insertions in antimicrobial resistance genes, the presence of T6SS and a set of genes related to virulence factors might explain its ability to form biofilm and persist longer in the environment. However, the complexity of the survival strategies adopted by the different strains of C. jejuni suggests that multiple mechanisms may exist that allow these organisms to persist and ultimately cause disease in humans.