Grupo de Investigacion en Ingenieria de Alimentos

San Justo, Argentina

Grupo de Investigacion en Ingenieria de Alimentos

San Justo, Argentina
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Tomadoni B.,CONICET | Cassani L.,Grupo de Investigacion en Ingenieria de Alimentos | Viacava G.,CONICET | Moreira M.D.R.,CONICET | Ponce A.,CONICET
Journal of Food Process Engineering | Year: 2017

The aim of this study was to evaluate changes in quality attributes of non-clarified strawberry juice during storage at 5 °C after ultrasonication at 40 kHz for 10 and 30 min in comparison with thermally treated juice at 90 °C for 60 s. Ultrasound treatments maintained color parameters with no significant differences (p<.05) from untreated sample, while thermally treated juice showed lower L* values and higher hue angles than the control. No significant differences in °Brix and total acidity were found between treated and untreated samples, and both parameters remained unchanged throughout storage. Compared to the control, ultrasound treatments showed no significant reductions on day 0 in mesophilic and psychrophilic bacteria, and yeast and molds counts. However, the treatments showed significant decrease in the microbial growth rate through storage time, and significant increase in both polyphenol content and antioxidant activity, compared to control. Practical applications: With today's tendency towards the consumption of nutritious and fresh-like foods, non-thermal treatments are gaining popularity. Among them, ultrasound has become a feasible alternative against traditional thermal treatments. Strawberry products are considered of great nutritional value, because of their high content in antioxidant compounds and vitamin C. In this study, ultrasound was evaluated in strawberry juice through storage time, where significant reductions on microbial growth rate were achieved; meaning that shelf-life of the product was increased compared to control. Furthermore, physicochemical parameters were maintained through storage, and antioxidant capacity and polyphenol content showed a significant increment, which implies that nutritional value of the product was increased by ultrasound treatments. Therefore, sonication is a potential technology that can easily be applied at the fruit juice industry, replacing the traditional thermal treatment which compromises the organoleptical and nutritional quality of the final product. © 2016 Wiley Periodicals, Inc.


Goni M.G.,Grupo de Investigacion en Ingenieria de Alimentos | Goni M.G.,CONICET | Tomadoni B.,Grupo de Investigacion en Ingenieria de Alimentos | Tomadoni B.,CONICET | And 4 more authors.
Journal of Food Science and Technology | Year: 2017

Chitosan must be dissolved in acid solution to activate its antimicrobial properties. The objectives of present study were to determine whether acetic and lactic acids used to dissolve chitosan would influence its effectiveness to control the native microflora of Butterhead lettuce at harvest and during postharvest storage (7–8 °C, 5 days). Chitosan was applied as a SINGLE DOSE (14, 10, 7, 3 or 0 days previous to harvest) or in SUCCESSIVE DOSES (at 14 + 10 + 7+3 + 0 days prior to harvest). Although chitosan in acetic acid showed antimicrobial activity, treated plants showed dried brown stains which significantly reduced sensorial quality. Chitosan in lactic acid applied in a SINGLE DOSE at harvest or in SUCCESSIVE DOSES reduced microbial counts of all populations at harvest without affecting sensorial quality. After postharvest storage, lettuce treated with SUCCESSIVE APPLICATIONS of chitosan in lactic acid presented significant reductions in the microbial populations compared with untreated sample (−2.02 log in yeast and molds, −1.83 log in total coliforms, −1.4 log CFU g−1 in mesophilic bacteria and −1.1 log in psychrophilic bacteria). In conclusion, replacement of acetic by lactic acid did not affect the antimicrobial activity of chitosan, reducing microbial counts at harvest and after postharvest storage without affecting sensorial quality. © 2017 Association of Food Scientists & Technologists (India)


Tomadoni B.,Grupo de Investigacion en Ingenieria de Alimentos | Tomadoni B.,CONICET | Cassani L.,Grupo de Investigacion en Ingenieria de Alimentos | Ponce A.,Grupo de Investigacion en Ingenieria de Alimentos | And 5 more authors.
LWT - Food Science and Technology | Year: 2016

Optimum combination of ultrasound, vanillin and pomegranate extract to improve quality of strawberry juice was determined using response surface methodology. Samples were stored at 5 °C for 14 days. The optimal conditions to simultaneously minimize native microflora, maximize nutritional parameters and minimize the impact on sensory quality resulted in: 7.5 min of ultrasound treatment, pomegranate extract concentration of 360 μg/mL and vanillin concentration of 0.925 mg/mL. A new batch of strawberry juice was treated at these optimal conditions and stored for validation of the optimization and to evaluate the performance of the optimum treatment on quality parameters throughout storage. Furthermore, a second batch of juice was inoculated with Escherichia coli O157:H7 and processed at optimal conditions to evaluate the effectiveness of the treatment on the pathogen survival. The native microflora of the juice, as well as inoculated pathogen, decreased significantly using the proposed hurdle technologies, with no impact on sensory parameters. Ascorbic acid retention was slightly decreased by the optimum treatment; however, DPPH and polyphenolic compounds were significantly higher than those in untreated sample. Overall, a combination of ultrasound, vanillin and pomegranate extract showed interesting potential to enhance quality and safety of strawberry juice, extending the shelf-life of the product. © 2016 Elsevier Ltd.


Tomadoni B.,Grupo de Investigacion en Ingenieria de Alimentos | Tomadoni B.,CONICET | Cassani L.,Grupo de Investigacion en Ingenieria de Alimentos | Moreira M.R.,Grupo de Investigacion en Ingenieria de Alimentos | And 3 more authors.
LWT - Food Science and Technology | Year: 2015

In the present study, vanillin (Van) and geraniol (Ger) were studied as potential food biopreservatives. Minimal Inhibitory Concentration (MIC) was obtained in vitro using four different pathogens as indicators. Studies in vivo in strawberry juice inoculated with Escherichia coli O157:H7 were conducted to evaluate the pathogen survival. Biopreservatives were applied at 1 and 2 MIC concentration. Samples were stored at 5 °C during 14 days, in order to study the effects of the treatments against the inoculated pathogen. At day 0, untreated sample showed counts of 5.4 log CFU/mL. Samples treated with Van2MIC, Ger1MIC, Ger2MIC showed a significant control on E. coli population at day 0 (immediately before application of the compounds), with counts of 3.0-3.2 log. Furthermore, from day 3 until the end of storage, those samples showed E. coli counts below the detection limit. More studies should be made in order to investigate the impact of vanillin and geraniol application on sensory and nutritional characteristics of strawberry juice, and the effects on its native microflora and spoilage microorganisms. © 2015 Elsevier Ltd.


Ansorena M.R.,Grupo de Investigacion en Ingenieria de Alimentos | Ansorena M.R.,CONICET | Del Valle C.,Grupo de Investigacion en Ingenieria de Alimentos | Salvadori V.O.,CONICET | Salvadori V.O.,National University of La Plata
Food Science and Technology International | Year: 2010

Design and optimization of thermal processing of foods need accurate dynamic models to ensure safe and high quality food products. Transfer functions had been demonstrated to be a useful tool to predict thermal histories, especially under variable operating conditions. This work presents the development and experimental validation of a dynamic model (discrete transfer function) for the thermal processing of tuna fish in steam retorts. Transfer function coefficients were obtained numerically, using commercial software of finite elements (COMSOL Multiphysics) to solve the heat transfer balance. Dependence of transfer function coefficients on the characteristic dimensions of cylindrical containers (diameter and height) and on the sampling interval is reported. A simple equation, with two empirical parameters that depends on the container dimensions, represented the behavior of transfer function coefficients with very high accuracy. Experimental runs with different size containers and different external conditions (constant and variable retort temperature) were carried out to validate the developed methodology. Performance of the thermal process simulation was tested for predicting internal product temperature of the cold point and lethality and very satisfactory results were found. The developed methodology can play an important role in reducing the computational effort while guaranteeing accuracy by simplifying the calculus involved in the solution of heat balances with variable external conditions and emerges as a potential approach to the implementation of new food control strategies leading not only to more efficient processes but also to product quality and safety. © 2010 SAGE Publications.


Moreira M.D.R.,Grupo de Investigacion en Ingenieria de Alimentos | Moreira M.D.R.,CONICET | Ponce A.,CONICET | Ansorena R.,CONICET | And 2 more authors.
Journal of Food Science | Year: 2011

The use of edible coatings and mild heat shocks is proposed as postharvest treatments to prevent microbial deterioration of refrigerated broccoli. Minimally processed broccoli was coated with either chitosan or carboxymethyl-cellulose (CMC) combined or not with a previous application of a mild heat shock. The evolution of microbial populations (mesophilic, psycrotrophic, Enterobacteriaceae, molds and yeast, and lactic acid bacteria) was studied during 20 d of storage and fitted to Gompertz and logistic models. Results revealed that, at the end of the storage, chitosan coating significantly reduced all microbiological population counts, except lactic acid bacteria; while higher reduction was observed with chitosan coating combined with a heat shock treatment. A significant delay at the beginning of the exponential phase was observed for all the bacterial populations analyzed. On the other hand, CMC coating, with and without a previous thermal treatment, did not exert any antibacterial effect. Excellent agreement was found between experimental microbial counts and predicted values obtained from Gompertz and logistic models. Kinetic modeling was found to be valuable for prediction of microbiological shelf life of broccoli during storage. Results showed that the application of chitosan coating effectively maintained microbiological quality and extended shelf life of minimally processed broccoli. According to these results, the use of the edible chitosan coating alone or in combination with a heat mild shock appear to be a viable alternative for controlling microbiological growth and sensory attributes in minimally processed broccoli. © 2011 Institute of Food Technologists ®.


Tomadoni B.,Grupo de Investigacion en Ingenieria de Alimentos | Tomadoni B.,CONICET | Viacava G.,Grupo de Investigacion en Ingenieria de Alimentos | Viacava G.,CONICET | And 5 more authors.
Journal of Food Science and Technology | Year: 2016

Pomegranate extract, vanillin and geraniol were studied as natural antimicrobials on strawberry juice. Strawberry juice was treated with each agent at two concentrations: pomegranate extract at 180 and 360 μg/mL; vanillin at 2.5 and 5 mg/mL; and geraniol at 0.6 and 1.2 μL/mL. After being treated, juices were stored at 5 °C and microbiological, physicochemical and sensory studies were carried out. Also, a second batch of juice was inoculated with Escherichia coli O157:H7 (105 CFU/mL) before being treated, to safety study. Geraniol and vanillin, at both concentrations tested, were highly effective in reducing the native microflora on strawberry juice (more than 3 log cycles), extending the microbiological shelf-life of the product. Moreover, both antimicrobials improved the product safety by reducing inoculated E. coli O157:H7. Furthermore, vanillin showed a significant increase in polyphenol content compared to untreated juice. On the other hand, pomegranate extract applied at the highest concentration showed important reductions on mesophilic and psychrophilic bacteria, but no effect on yeast and molds and inoculated E. coli. Even though vanillin and geraniol incorporation on strawberry juice had a negative effect on its sensory quality, pomegranate extract had no impact on the sensory attributes evaluated. Combinations of the biopreservatives could be studied in order to decrease the concentration of the antimicrobials, reducing the effects on strawberry juice sensory characteristics. © 2015, Association of Food Scientists & Technologists (India).


Ansorena M.R.,Grupo de Investigacion en Ingenieria de Alimentos | Ansorena M.R.,CONICET | Marcovich N.E.,CONICET | Marcovich N.E.,University of the Sea | And 2 more authors.
Postharvest Biology and Technology | Year: 2011

The effects of edible coatings and mild heat shocks on quality aspects of refrigerated broccoli were studied. Minimally processed broccoli was coated with either chitosan or carboxymethyl-cellulose with or without a previous application of a mild heat shock of 1.5. min at 50°C. Product was packaged in multilayered polyolefin bags and stored at 5°C for 18. d. Quality parameters such as weight loss, texture, colour, ascorbic acid content, total chlorophyll content, oxygen concentration inside the bags, browning potential, mesophilic aerobic counts, and sensory quality, were evaluated during storage. Edible coatings exhibited a beneficial impact on broccoli quality. The weight loss in uncoated broccoli was found to be between 2 and 5 times higher compared to coated samples. During storage, coated florets from both thermally and non-thermally treated samples, presented higher retention of the (-aa*/ba*) ratio indicating better green colour retention and a reduced rate of floret yellowing. Chitosan coating always presented the lower ascorbic acid degradation rates (twofold lower compared with control samples). Broccoli texture for uncoated samples increased significantly during storage. However, for carboxymethyl-cellulose coated broccoli a slight increase in texture was observed while for chitosan coated broccoli no significant changes in texture were observed throughout the storage period. After the edible coating application the microbial broccoli load dropped by around 1.5 and 0.9. logarithmic units in chitosan and carboxymethyl-cellulose films, respectively. During storage, the application of chitosan coating significantly reduced total microbial counts in the thermally and non-thermally treated uncoated samples. Among the assayed edible coatings, chitosan effectively maintained quality attributes and extended shelf life of minimally processed broccoli. The single application of a mild heat shock had a measurable influence in reducing weight loss, enzymatic browning in broccoli stems, and in delaying yellowing of broccoli florets. Moreover, chitosan coating combined with a mild heat shock showed the best performance for long-term refrigerated storage of minimally processed broccoli. © 2010 Elsevier B.V.


PubMed | CONICET and Grupo de Investigacion en Ingenieria de Alimentos
Type: Journal Article | Journal: Journal of food science and technology | Year: 2016

Pomegranate extract, vanillin and geraniol were studied as natural antimicrobials on strawberry juice. Strawberry juice was treated with each agent at two concentrations: pomegranate extract at 180 and 360g/mL; vanillin at 2.5 and 5mg/mL; and geraniol at 0.6 and 1.2L/mL. After being treated, juices were stored at 5C and microbiological, physicochemical and sensory studies were carried out. Also, a second batch of juice was inoculated with Escherichia coli O157:H7 (10(5) CFU/mL) before being treated, to safety study. Geraniol and vanillin, at both concentrations tested, were highly effective in reducing the native microflora on strawberry juice (more than 3 log cycles), extending the microbiological shelf-life of the product. Moreover, both antimicrobials improved the product safety by reducing inoculated E. coli O157:H7. Furthermore, vanillin showed a significant increase in polyphenol content compared to untreated juice. On the other hand, pomegranate extract applied at the highest concentration showed important reductions on mesophilic and psychrophilic bacteria, but no effect on yeast and molds and inoculated E. coli. Even though vanillin and geraniol incorporation on strawberry juice had a negative effect on its sensory quality, pomegranate extract had no impact on the sensory attributes evaluated. Combinations of the biopreservatives could be studied in order to decrease the concentration of the antimicrobials, reducing the effects on strawberry juice sensory characteristics.

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