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Montevideo, Uruguay

Silveira A.C.,Agronomy Faculty | Moreira G.C.,Sudan University of Science and Technology | Artes F.,Technical University of Cartagena | Aguayo E.,Technical University of Cartagena
Scientia Horticulturae | Year: 2015

The effect of natural antimicrobials such as vanillin (1 or 2g/L) or cinnamic acid (0.15 and 0.3gL-1) in an aqueous solution or the use of cinnamic vapors through a filter paper placed inside a container (active modified atmosphere packaging-MAP), on the quality of fresh-cut melon stored 10 days at 5°C was assayed. Immersion in water was used as the control treatment. All of these antimicrobial treatments had a good antimicrobial effect, mainly against the mesophilic bacteria (1.5logcfug-1), causing a reduction of Enterobactericeae (2.2logcfug-1). Total polyphenol contents (166mgkg-1 f.w.) decreased with time of storage although fresh-cut melon treated with vanillin (2g/L) and all cinnamon treatments had the highest polyphenol levels with a lower reduction with time of storage. All cinnamon treatments had a lower respiration rate and allowed for better vitamin C retention of melon pieces. The flavor of antimicrobial-treated melon was accepted by consumers, but a vanilla flavor was tasted in melon treated with this compound, although it did not lead to a rejection. A relationship between antimicrobial concentration and microbial population reduction was not found and from this point of view; the use of lower antimicrobial concentrations can be recommended. These natural antimicrobials had good antimicrobial effects and they can be an attractive green alternative for use as sanitizers. The use of cinnamon within active MAP can be helpful in the design of treatments in the packaging industry for fresh-cut products, creating a new opportunity to ensure a safe product. © 2015 Elsevier B.V. Source


Silveira A.C.,Agronomy Faculty | Aguayo E.,Technical University of Cartagena | Artes F.,Technical University of Cartagena
Food Control | Year: 2010

This study evaluated how traditional or new sanitizers, alone, or in combination with the use of a Clean Room (CR), affected the respiration rate, microbial, nutritional and sensorial quality of fresh-cut 'Galia' melon. Melon pieces were packed in polypropylene trays under passive modified atmosphere (7.4 kPa O2 + 7.4 kPa CO2) and stored up to 10 days at 5 °C. The following treatments were performed: 150 mg/l chlorine (control) for 1 min; 80 mg/l peracetic acid (PAA) for 1 min; ozonated water (0.4 mg/l) for 3 and 5 min. The combinations of: ozonated water and PAA; 150 mg/l chlorine and packaging in CR; ozonated water for 3 min and package in CR; ozonated water for 3 min + PAA and packaging in CR were also studied. Throughout the shelf-life psychrotrophic, mesophilic, Enterobactericeae, lactic acid bacteria, moulds and yeast growth were determined. The use of PAA provided the lowest microbial load, but this sanitizer decreased the total vitamin C and the antioxidant activity. Nevertheless, the combination of PAA with 0.4 mg/l of ozonated water (3 min) could be a good substitute of use of chlorine. This treatment was effective in reducing the microbial counts, maintaining the antioxidant compounds and respiration rate and maintained the sensorial quality of the product during the 10 days at 5 °C. Treated product packaged in a CR did not show increased treatment effect, probably due to air quality in the laboratory. The use of CR just for the packaging of the melon pieces did not offer any additional advantage. However, the utilization of CR in an industrial environment during all processing steps (from washing to packaging) should be investigated for potential benefits. © 2009 Elsevier Ltd. All rights reserved. Source


Silveira A.C.,Agronomy Faculty | Aguayo E.,Technical University of Cartagena | Escalona V.H.,University of Chile | Artes F.,Technical University of Cartagena
Innovative Food Science and Emerging Technologies | Year: 2011

The aim of the present study was to investigate if the use of hot water immersion dipping (HWD) alone or combined with other ecofriendly methods, could replace the use of chlorine in fresh-cut fruits such as melon. Melon pieces were subjected to hot (60 °C) or cold (5 °C) water dipping (60, 90, 120 s or 60 s, respectively) followed by immersion in 80 mg L - 1 peracetic acid (PAA) for 60 s at 5 °C or in water, packed in polypropylene trays under passive modified atmosphere (7.4 kPa O 2 and 7.4 kPa CO 2 at steady state), and stored up to 10 days at 5 °C. Respiration rate, ethylene emission, microbial load, flesh firmness, polyamine content and sensorial quality were determined. As main conclusions the longer HWD treatment times (90 and 120 s) followed by PAA dip, provided the lowest metabolic activity and helped to control microbial load without affecting the sensorial quality. In addition, both treatments increased the polyamine content helping to maintain the cell membranes integrity. Industrial relevance: Maintaining quality and microbial safety are the most important concerns of the fresh-cut fruit and vegetables industry. The present study focused on assessing the effect of HWD treatments alone or in combination with PAA, on the respiration rate, ethylene emission, microbial load, flesh firmness, polyamines content and quality retention of fresh-cut Galia melon. According to our results, the use of a heat treatment alone or combined with PAA could replace the use of chlorine, and could be a feasible alternative for fresh-cut industry as a sanitizing method, as or more effective as chlorine. © 2011 Elsevier Ltd. All rights reserved. Source


Silveira A.C.,Agronomy Faculty | Aguayo E.,Technical University of Cartagena | Chisari M.,University of Catania | Artes F.,Technical University of Cartagena
Postharvest Biology and Technology | Year: 2011

'Galia' melon is one of the most common cv produced in Spain destined for fresh consumption and/or for the fresh-cut processing industry. Nevertheless, fresh-cut melon is very susceptible to softening during storage, even under chilling and modified atmosphere packaging. This softening process is related to Ca levels in fruit tissue. After preparing trapezoidal shaped sections of 'Galia' melons, the pieces were dipped for 1min a 60°C in Ca chloride, citrate, lactate, ascorbate, tartrate, silicate, propionate or acetate using a Ca concentration equivalent to 0.4% (0.15gg-1) pure Ca chloride, combined with 50mgL-1 H2O2 for controlling microbial growth. Dipping in sterile distilled water (without Ca salt) at 60°C for 1min was used as a control treatment. Firmness, pectin methylesterase and polygalacturonase activity, Ca content, microbial growth, respiration rate, and sensory evaluation, were evaluated throughout 10 days of storage at 5°C under a passive modified atmosphere reaching 4.5kPa O2 and 14.7kPa CO2. At the end of shelf life, Ca ascorbate, chloride and lactate provided melon pieces with a lower respiration rate, increased tissue total Ca content, and maintained a good firmness. In addition, those Ca salts reduced microbial growth. Sensory parameters, such as flavor perception, were kept above the upper limits for marketability. A considerable loss of flavor was found in all treatments except with Ca chlorine, lactate and ascorbate, the only treatments found acceptable from the consumer point of view. © 2011 Elsevier B.V. Source


Mattiauda D.A.,Agronomy Faculty | Tamminga S.,Wageningen University | Gibb M.J.,Institute of Grassland And Environmental Research | Soca P.,Agronomy Faculty | And 2 more authors.
Livestock Science | Year: 2013

The objective of this study was to assess the effects of restricting access time to pasture and time of grazing allocation on grazing behaviour, daily dry matter intake (DMI), rumen fermentation, milk production and composition in dairy cows. Twenty-one autumn-calving Holstein cows were assigned to one of the following 3 treatments: providing access to a daily strip of pasture for either 8. h between 07:00 and 15:00. h (T7-15), 4. h between 07:00 and 11:00. h (T7-11), or 4. h between 11:00 and 15:00. h (T11-15). The experimental period consisted of 3 weeks of adaptation and 6 weeks of measurements. Cows were offered a daily herbage allowance of 18. kg DM/cow to ground level, 6.1. kg DM/day of a ground sorghum grain-based supplement and 5.2. kg DM/day of maize silage. Milk yield was greater for cows with 8. h access time to the pasture (25.4 vs. 24.1 for 8 and 4. h access time, respectively). Milk yield was not different between cows that access early (T7-11) or late (T11-15) to the grazing session. Milk protein yield was greater for cows with 8. h access time (0.75. kg/d) vs. 4. h access time treatments (0.72. kg/d). Cows with late access time to grazing in the morning produce more protein (0.74. kg/d) than cows with early access to the pasture (0.70. kg/d). Duration of access had a significant effect on herbage DMI (8.3 vs. 6.6. kg/d, for 8 and 4. h access, respectively), but there was no significant effect of time of grazing allocation. Intakes of concentrate and maize silage DM did not differ between treatments.Pasture depletion rate was significantly slower when cows had access to the pasture for 8. h compared with 4. h (0.04 vs. 0.09. cm/h), but was not affected by allocation time in the 4-h treatments.Cows grazed for significantly longer in treatment T7-11 than T11-15, achieved significantly more biting and non-biting grazing jaw movements. However, because herbage DMI did not differ between treatments T7-11 and T11-15, it appears that cows grazed more efficiency on treatment T11-15.The present study showed that reducing the period of access to pasture from 8 to 4. h decreases DMI and milk production. Cows that started their 4-h grazing session later in the morning (T11-15) produced more protein than cows that started earlier (T7-11), probably as a consequence of a larger bite mass and a tendency for higher intake rate. Rumen pH of cows grazing on treatment T11-15 declined faster than in cows on T7-11, which is in accordance with the higher VFA and ammonia rumen concentrations observed after the grazing session started. © 2012 Elsevier B.V. Source

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